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SPIFI Operation Operation Manual 2004

1. 18 the power was out for more than 2 3 hours all of the He that condensed in the pot be fore the outage may now be evaporated Finish the rest of the cycle after step 21 as described in Step By Step Cycling of the ADR and 3He Fridge on page 45 Case III o If the power went out at any other time during cycling or if the system is warm for what ever reason then you will have to re cycle the ADR See Step By Step Cycling of the ADR and 3He Fridge on page 43 5 Plug in and reboot Fabry 50 You don t need to log on or anything since this can all be done re motely when you telnet Just push the power button 6 Power up the PZTs HOFPI Make sure the PZT cables are disconnected from the PI power supply 38 Make sure channels 1 2 amp 3 are turned all the way down to OV fully counterclockwise on the PI power supply Turn on the PI power supply Make sure all three channels 1 2 amp 3 still read OV Connect the PZT cables to the PI power supply Make sure you match the correct cable with the correct channel A 1 B 2 and C 3 Put the resistor caps which were on the cables on top of the PI power supply Parallelize the HOFPI Refer to the section below called Parallelizing the Fabry Perots page 53 LOFPI If applicable We did not need to use the LOFPI PZT s over the Antarctic summer Make sure the PZT cables are disconnected from the PI power supply
2. Assuming you refill according to the recommendations in column two Detailed instructions for maintenance filling follow in the subsections below Keep a record in the SPIFI note book for every fill Record the time of the fill the level of cryogens in the tank before and after the fill if this can be measured how long the fill took and estimate if you can the amount of cryogens that were used for the fill These notes will help you keep track of the maintenance filling schedule namely of what tanks need filled when They will also allow you to make estimates of SPIFI s boil off rate and help us make sure SPIFI is behaving well ADR Nitrogen The ADR 1 N tank must be filled approximately once every 22 hours Because the ADR is horizontal there is no way to check the level in the ADR I N tank although you can hold your thumb over the vent for a short while and then release to see if you see a plume if you do then there is still I N in the tank so it is important to fill on time The capacity of the tank is 5L so it should take about 6 7L of I N to fill 1 Attach the curved copper extension onto the 50L I N Dewar using a crescent wrench Next attach the yellow latex hose with the stainless steel stinger on the other end to the end of the copper extension using a hose clamp Note that if the yellow latex hose is too stiff in the Antarctic winter you may need to switch to Teflon The copper extension should
3. Kevlar Support Detector Array in Cu Housing Structure N Thermal Link N i T 280 mK N Pumping 4 KL gg Salt Pill T 60 mK MM Heat Switch Heat Switch 4 Tesla Solenoid Magnet Pumped He Bath T 1 5 K Heat Switch 3He Sorption Pump DAM gt e g KANA Heater Understanding the 3He Fridge The He fridge can achieve a temperature of 280mK for a hold time of approximately 40h It provides the nec essary thermal shield between our pumped 1 He tank and all the surfaces inside the ADR Dewar which are connected to it at 1 5K and the salt pill and detector array at 60mK The primary heat load seen by the He fridge is conduction from the 1 5K stage through the fiberglass G 10 which mechanically supports the fridge see Figure 14 above This load is 75mW and it vaporizes all of the 1 He from the pot in 40h The operation of the He fridge is much simpler than that of the ADR The key components of the He fridge the pump pot pumping tube and heat switches are shown in the right side of Figure 14 above The entire system is closed cycle it is a sealed system which contains a fixed amount of He at low pressure and ex changes no substances with the outside It has no moving parts other than the manually adjusted pump and pot heat switches 20 amp 19 The construction consists of the pumping chamber being connected to the pot chamber via the pumping tube That s
4. DONE Appendix A Table 7 Height vs Volume for SPIFI Cryo Tanks 64 SPIFI I He Tank Height in Volume L Height cm Volume L 0 25 1 9 0 5 1 5 0 50 3 8 1 0 3 0 0 75 5 7 1 5 4 5 1 00 7 5 2 0 5 9 1 25 9 4 2 5 7 4 1 50 11 3 3 0 8 9 1 75 13 1 3 5 10 3 2 00 14 9 4 0 11 8 2 25 16 8 4 5 13 3 2 50 18 6 5 0 14 7 2 75 20 4 5 5 16 2 3 00 22 2 6 0 17 6 3 25 24 0 6 5 19 0 3 50 25 8 7 0 20 4 3 75 27 5 7 5 21 9 4 00 29 3 8 0 23 3 4 25 31 0 8 5 24 7 4 50 32 7 9 0 26 1 4 75 34 4 9 5 27 4 5 00 36 0 10 0 28 8 5 25 37 7 10 5 30 2 5 50 39 3 11 0 31 5 5 75 40 9 11 5 32 9 6 00 42 5 12 0 34 2 6 25 44 0 12 5 35 5 6 50 45 5 13 0 36 8 6 75 47 0 13 5 38 1 7 00 48 5 14 0 39 4 7 25 49 9 14 5 40 6 7 50 51 3 15 0 41 9 7 75 52 7 15 5 43 1 8 00 54 0 16 0 44 3 8 25 55 3 16 5 45 5 8 50 56 5 17 0 46 7 8 75 57 7 17 5 47 9 9 00 58 9 18 0 49 0 9 25 60 0 18 5 50 1 9 50 61 0 19 0 51 2 9 75 62 0 19 5 52 3 10 00 62 9 20 0 53 3 10 25 63 8 20 5 54 4 10 50 64 6 21 0 55 4 10 75 65 3 21 5 56 4 11 00 65 8 22 0 57 3 22 5 58 2 23 0 59 1 23 5 60 0 24 0 60 8 24 5 61 6 25 0 62 4 25 5 63 1 26 0 63 7 26 5 64 4 27 0 64 9 2
5. Inside the right side door of the enclosure Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 Electronic control box for the calibration unit Resistance bridge for monitoring GRT temperatures HOFPI and LOFPI stepper motor box SPIFI motor box Fabry Turbo pump resistor leads for SPIFI temperature monitoring laser mirror mount screen for viewing fringes main SPIFI pump valve The blue box on the wall blue switch board or blue connector box Pressure gauge for monitoring pressure inside SPIFI displayed on front of turbo pump Catastrophic Mistakes To Avoid In no particular order here are catastrophic mistakes that must be avoided You should remind yourself of these caveats regularly to the point that they become part of your everyday thinking process while operating SPIFI This is not a troubleshooting guide if you have trouble with one of the things listed in this table then it is proba bly already too late Mistake Undesirable Result How To Avoid Where To Find More Info Loosing track of the e You could crash the e When starting a new SPIFI session make sure SPIFI Data HOFPI or LOFPI Fabry Perot plates to properly initialize the HOFPI and LOFPI to Acquisition position and incapacitate the last positions they were in Although the in Manual SPIFI dexer should remember if it wasn t turned off e You
6. Place the resistor caps which were on the cables on top of the PI power supply 6 Carefully watch the fringes that appear on the screen hanging from the external mirror on the ADR end of SPIFI Slowly turn up the three voltage knobs on the PI box one at a time and watch the fringes move When adjusting the voltage knobs never turn the voltage of one of the PZTs above 700V This can destroy or damage the PZT or greatly reduce its lifetime Keep an eye not only on the fringes but on the PI box s voltage LCD displays as well to make sure each channel is always less than 700V When you adjust the knob s in one direction the fringes should appear as straight lines and move in one direction like plane waves When you turn the knob s back the other way the fringes should move in the opposite direction At some point the fringes should rotate 90 degrees and move again in straight lines The point at which the HOFPI and LOFPI are parallel is the point where the fringes change their motion by 90 degrees In particular you should see two semi circular patterns of fringes moving towards each other and then disappearing in the middle This is the point at which the Fabry Perot is parallel 7 Make a record in the SPIFI notebook that you have parallelized the HOFPI and or LOFPD and record also the voltages of each channel 1 2 and 3 This helps us compare records of past parallelizations with the current attempt since each PZT may display individualized
7. Inside the Pillbox 10 11 12 13 14 15 16 17 ADR outer shell ADR 1 He neck connected to pump via KF end cap and clamp assembly ADR I N stickstoff neck Preamplifier box Data cables from pre amp to Fabry Pre amp power supply cable from bat tery box Vacuum hose for pumping on ADR l He tank ADR 1 He tank pump manifold Main pump valve for the ADR 1 He tank Pressure gauge for ADR 1 He tank 19 He pump heat switch 21 22 23 Persistent switch switch yes the switch 25 26 27 28 He Gas inlet or Backfill valve for 1 He tank He pot heat switch Salt pill heat switch Magnet control box Magnet power supply box has a switch Power supply for charcoal heater also called the He pump heater Ohmmeter for monitoring temperature of He pump Housekeeping cable Magnet leads Inside the left side door of the enclosure SPIFI outer shell SPIFI 1 N gt neck SPIFI 1 He neck SPIFI alignment table Dampers Enclosure heater Battery box Laser must be pronounced as by Dr Evil of Austin Powers Laser power HOFPI PZT power supply PI power supply LOFPI PZT power supply PI power supply Gas cell manifold Gas cell pump Gas lecture bottle Variac voltage regulator not currently in use Steve s special hand carved dipper stick Gas cell pump exhaust
8. 100L 1 He Dewar 9 Crack the main valve of the pump manifold slightly to create a suction Replace the KF end cap on the 1 He neck and make sure it is securely suctioned onto the flange The O ring of the KF cap should be clean and slightly greased with vacuum grease 10 Replace the KF clamp on this end cap Make sure it is oriented so that the red vacuum hose cap of the stickstoff is not blocked 11 Slowly reopen the main valve on the vacuum manifold Take at least five minutes to completely open this valve so as to minimize stress on the pump You won t be able to listen to the pump because it is downstairs so use your best judgement You should eventually see the pressure drop on the pressure gauge once it gets below 100 Torr The needle may oscillate wildly This is normal Sometimes you can dampen these oscillations by opening or closing the valve a bit The oscillations usually dampen out on their own once the pressure gets below about 30 Torr After some time about 1 2 hour or so the pressure should get below 10 Torr Eventually you want 3 Torr 12 Don t forget to shut off the He gas downstairs in the receiver room when you are finished SPIFI Helium SPIFI s 1 He tank can go a maximum of seven days between fills assuming that everything else stayed cold and the 1 N gt tank never ran out Therefore after an initial fill you should check the level of He in SPIFI s 1 He tank after about three days and then c
9. L meaning the left hand 5 3 2 6 switch is active To choose either 10 6 or 21mV you must have the R L switch up on R meaning that the right hand 21 10 6 switch is active For example if you want a 21mV bias on the detectors put the 12 10 6 switch up on 21 the R L switch up on R and the 5 3 2 6 switch doesn t matter because it is inactive this is the configuration pictured above All possible com binations are outlined in Table 4 above Using a higher bias voltage can in principle result in a stronger signal and a higher signal to noise ratio However one disadvantage of using a higher bias voltage is that you can heat up the detectors and shorten the hold time of the ADR So far 21mV has worked the best Any time you choose a new bias voltage setting for the pre amp make a note of the new setting in the SPIFI notebook 57 The Battery Box Understanding the Battery Box To maintain low levels of noise in our data it is necessary for the preamp 11 to be powered by an isolated and shielded set of batteries 35 We have constructed two identical battery boxes for this purpose with the idea that one could be used to power the preamp while the other charges so that there is never a delay in taking data while we wait for the battery box to charge Unfortunately shortly before leaving South Pole Station at the end of the summer we discovered that the second battery box labeled 2 is defective the military connecto
10. Locator Guide on page 5 34 to switch to Teflon The copper extension should be rotated so that it curves upwards See Figure 11 above 3 Lift the 50L Dewar up and set it into the enclosure on the battery box side of SPIFI or alternatively jack it up on the lift on the outside of the enclosure Do not pull or push on SPIFI or the SPIFI alignment table 32 while doing this or we could loose our alignment to the telescope Rotate the Dewar so that the copper extension is pointed upwards and towards the telescope wall of the enclosure front of SPIFD 4 Open the roof hatch above SPIFI s nitrogen neck 30 This is the larger hatch closest to the telescope side of the enclosure 5 Snake the yellow latex hose or Teflon hose if latex is too stiff in the winter through the roof hatch and insert the stinger into the I N neck If the hose does not reach then rotate the copper extension or the SOL Dewar until it does or else get a longer hose 6 Making sure there are no kinks in the yellow tubing or Teflon tubing open the 50L Dewar s main valve and fill SPIFI s 1 N gt tank When SPIFI is full close the main valve on the 50L Dewar Let the yellow hose or Teflon hose thaw and remove the stinger from SPIFI Remove the 50L Dewar from the enclosure or lower it from the lift 0 Make sure the enclosure side door and roof hatch are shut and latched 1 Record in the SPIFI notebook the time of the fill how long it took to f
11. Step By StepCyelingoftheADRand3HefFridee 1 43 Calibration Umt 2554 senlik li esl layla aile iken g a elan goal down ana 48 Basic description siri Bilek ayle gesi yel ea ban e ae i sali e i Blk ele 48 CHOppIN iseler ese he a lale dares Aba a ani dalla keli el ea aldilar di i lanma 49 Using the Gas Cell and Blackbody satisa sie eni demle eledi Slam sesle ilan asel e in Sani li de 49 Getting a Sync S1emal for Fabry secs celese geben cee iye sik salim EEEE A E elele alsa al ulasim Se 51 Parallelizing the Fabiy Perots sesi ei silelim iliielak Sela delki Sisal eli bellek a sl s 53 Ehe Pre Ainp e alm lll de il Pent egies dd pes densa da Made esd emis tes Peed a la asd 55 The Battery BOX ish elmas lalesi sa e ls atlanta eerie ed ot aetna 57 Understanding the B ttety B X sis ai yel reesei techie lal G dsi lala ini EA 57 UsingandChargingtheBatteyBw amp eee 59 PART DE WARM UP PROCEDURE Adsense anilar NS aVL ES oei IRE lisakan k aile 62 APPEL A me ere iler ie sellere Ma eli sekiler Melen Mile el sellem keci le ilik sleek 64 List of Tables Tablel TemperaturesforSPIFI sCarbonResistors 29 Table2 SummaryofC yogenTankMaintenanceFilling 32 Table 3 Persistent Switch S ttnes 0 2 101 el a an maal asan ne ai senay ven SOS 40 Table 4 Preamp S w
12. This livens the output to the pre amp 12V Battery Charger Normal Charging switch 1 amp 3 down switch 2 amp 4 up Normal charging refers to the situation where the battery box is not in use disconnected from the preamp and is being charged with the two independent blue 12V battery Lh chargers In this situation it is imperative to have mm EE vor c switch 3 down This disconnects the two 12V j AUTOMATIC batteries completely and allows them to be charged separately as normal 12V batteries would ATED gIASSOCIATED 1 On the battery box put switch 1 all the way down This will deaden the output to the preamp Put switch 3 all the way down This disconnects the two 12V batteries completely so that they can be charged independently If the battery box was in use switches 2 and 4 should already be down So at this point you should have all four switches on the front of the battery box all the way down 2 Disconnect the cable from the pre amp and carry the battery box downstairs to the AST RO annex where the two blue 12V battery chargers are pictured above right There should also be a DC power supply there as well which we used for charging the 4V battery Caution all of the chargers should be unplugged the two blue chargers don t have power buttons so as soon as they are plugged in they are live 3 Now set the chargers to the appropriate charge settings a On the blue 12V chargers e The SELECT SETTING s
13. at 20 2A we close a persistent switch 24 which was kept open up to this point The persistent switch is a supercon ducting switch that acts as a short between the two magnet leads 28 When the persistent switch is 39 depends on the maximum magnetic field closed it is superconducting The solenoid is of course also superconducting Therefore after closing the persistence switch we can take current out of the non superconducting leads at a fast rate 10A 5s but still leave 20 2A flowing around the superconducting solenoid and through the persistent switch short and around again and again The current path is supercon ducting and hence a 4T field is maintained with no dissipation We must leave the solenoid magnetized for about 30 minutes before continuing Next adiabatically isolate the salt from the cold tank and remove the magnetic field quasi statically this is the adiabatic demagnetization Because this is done adiabatically AQ 0 and quasi statically the entropy must remain constant dS dQ T In addition it can be calculated that the entropy of a paramagnetic salt is dependent on the independent variables B and T by a ratio of Bb 7 7 where b is the interaction field between the ions and is negligible except at very low temperatures Therefore during adiabatic demagneti zation with S constant one can see that B T B T So as B is decreased T must decreased But b pre vents T fr
14. but only if the brass valve is closed Attach the Teflon tube with the N gas supply to the brass valve on the nitrogen neck where the vacuum hose used to be attached via a yellow latex hose You will need to rig some adaptor here Let SPIFI suck on the N gas as it warms up This process can take a very very long time several hours The reason it takes so long is that the N gt in the tank is solid Therefore the N gas going in immediately becomes liquid and the pressure drops very low and everything stays cold At some point when all of the N is liquid SPIFI will stop sucking and you will get a sudden large boil off and an overpressure can quickly develop so be ready to remove the hose when SPIFI stops sucking Don t leave AST RO To check if SPIFI is still sucking use one of the following two methods a Pinch off the yellow latex hose and let N gas build up on one side of the pinch Then pinch the hose at a second position on the N gas side of your first pinch so that you have trapped N gas between your two pinches Then remove your first pinch and see if the hose collapses where you had trapped the N gt gas If it collapses SPIFI is still sucking If it doesn t collapse SPIFI is done b Another alternative way to check if SPIFI is still sucking is to reclamp or pinch the yellow la tex hose remove the Teflon tube with the N gas supply place your thumb over the end of the yellow latex hose and briefly open the
15. clamp or release your pinch and see if you feel a suc tion on your thumb If you do feel a suction quickly close off the hose again and reattach the N2 gas Don t let the I N tank suck on the atmosphere for very long while you are doing this test or you could get an ice plug in the I N neck Once SPIFI is done sucking you can remove the N gas supply and leave the I N tank open to the atmosphere The I N in the tank will boil off in time You may want to remove the special stinger assembly from the I N neck and check that the I N is still boiling off hold your thumb over the neck s vent for a little while release and see if you see a plume If there doesn t seem to be any boil off coming from SPIFI s 1 N neck drop a copper rod down the neck to make sure you don t have an ice plug It is very important to backfill the SPIFI I N gt tank and open it to the atmosphere or else you could get an overpressure in SPIFT s I N tank as the I N boils off Leave the main pump valve 55 on SPIFI closed You can leave SPIFI under vacuum and let it slowly rise in pressure on its own before summer 04 05 Le leave SPIFI hooked up to the turbo pump and leave everything alone 4 Turn off all the pumps if they aren t off already The turbo pump 51 can be turned off by pushing the button on the front once The gas cell pump 41 can be turned off by unplugging it The two pumpzillas in the receiver roo
16. could loose all refer to your written notes to make sure knowledge of what e After restarting Fabry 50 you will have to re order the HOFPI and initialize the HOFPI and LOFPI to the last posi LOFPI are in which tion they were in Although the indexer should will make the spectra remember refer to your written notes to be sure meaningless e After turning on the cryo motor box 48 from e Our summer calibra being off you will have to initialize the HOFPI tion efforts are and LOFPI to the last positions they were in wasted here the indexer will not remember the values but will use 0 You will have to use your writ ten notes to correct this e Keep careful notes of every scan done and of how many counts either the LOFPI or HOFPI were moved and in which direction e Before starting every scan make sure you have reset the LOFPI and or HOFPI to the desired starting values including backlash correction in the Matlab environment and make sure you have entered these starting values in the scan GUI e Double check both your written notes as well as the values you type into the computer to avoid typos and transcription errors Forgetting to discon You could destroy the e Always disconnect the PZT cables from chan Page 53 nect the PZT cables PZT s because of a large nels 1 2 amp 3 whenever you turn off the high before turning on the startup current voltage voltage power supplies high voltage PZT e Always turn the power to PZT
17. current ramp rate switch on the magnet control box is flipped to down Make sure the main power switches on the magnet control box and the magnet power supply are switched to their off positions Make sure the charcoal heater 25 is turned off Secure the PZT s HOFPI Turn the PZT voltage knobs all the way down fully counterclockwise on the PI power supply 38 Make sure channels 1 2 and 3 are all turned to OV Move the power switch of the PI power supply to the off position Disconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply LOFPI If applicable We did not need to use the LOFPI PZT s over the Antarctic summer Turn the PZT voltages all the way down fully counterclockwise on the PI power supply 39 Make sure channels 1 2 and 3 are all turned to OV Move the power switch of the PI power supply to the off position Disconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply Unplug Fabry 50 This will prevent Fabry from booting up automatically when the power comes back on Pressing the power switch of Fabry when the power is out does not turn the machine off probably because the switch is on a relay which needs electrica
18. filling and working in the enclosure to preserve heat gt While you are standing inside the enclosure pull the door shut as far as possible behind you gt Always latch the doors when going back downstairs even if you will be returning in a short time Mechanical Make sure the enclosure can clear all objects on the roof of AST RO before rotating the telescope such as Nitrogen tanks etc Do not overload the pillbox 2 the weight limit is approximately 401lbs Do not push or pull on SPIFI when working in the enclosure or when climbing in and out of the enclosure or we could loose our alignment to the telescope Figure 2 Steve stands triumphantly on top of the SPIFI enclosure Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 20 PART 1 PREPARATION Pumping on SPIFI Pumping SPIFI Down from a Partial Vacuum State We left SPIFI under vacuum when we left the South Pole at the end of the 03 04 summer season Therefore the winterovers you shouldn t have to pump down SPIFI from atmospheric pressure in winter 2004 although this full procedure is described in the next section below entitled Pumping SPIFI Down from Atmospheric Pressure for reference and just in case Nevertheless SPIFI will have inevitably lost some pressure by June or July and will be in a partial vacuum state Use the steps below to reinitiate pumping on SPIFI from a partial vacuum state 1 The main pump valve on SP
19. future pump downs For your reference after filling cryogens the final pressure in SPIFI at the pumped 1 He temperature of 1 5K should get to between 5x10 and 1x10 Torr This is discussed below on page 26 Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 22 Cooling SPIFI Down from 293K Once the pressure in SPIFI reaches about 5x10 8x10 Torr the cool down process can be started The entire cool down takes about two days Our best estimates for the total cryogens used for a complete cool down from room temperature are 170L I N and 150L 1 He So make sure you have this much cryogens on hand before you start The SPIFI system has four cryogen tanks SPIFI 1 N tank capacity 25L SPIFI 1 He tank capacity 65L ADR l N tank capacity 5L ADR 1 He tank capacity 5L The SPIFI tank necks are accessed through the roof hatches in the enclosure The larger hatch 6 which is closer to the telescope is for the SPIFI I N gt tank neck 30 The smaller hatch 7 is for the SPIFI 1 He tank neck 31 The ADR tank necks are accessed by opening the back double doors of the pillbox 2 on the enclo sure The ADR I He tank neck 9 is labeled Helium and the ADR I N tank neck 10 is labeled Stickstoff which means Nitrogen auf Deutsch Because the necks of the ADR s cryogen tanks are horizontal it is not possible to directly measure the level of cryogens in
20. initial cool down which could open up leaks the fill necks from room tempera or cause an explosion ture Closing the main You may get an overpres If you must keep the main pump valve closed for an Pages 34 14 brass pump valve on sure inside SPIFI s I N extended period of time more than 2 3 hours for amp 16 and 62 the SPIFI 1 N neck tank which could open up instance in the case of an extended power outage 30 while I Ng isin leaks or cause an explo you should backfill with N gas and open the tank to SPIFI s tank sion the atmosphere see step 2 on page 62 Closing the main You may get an overpres e Monitor the pressure gauge 17 on the ADR 1 Page 35 14 pump valve on the sure inside the ADR s l He manifold to make sure that the pressure amp 16 ADR 1 He pump He tank which could does not start climbing If the pressure climbs manifold 16 while open up leaks or cause an steadily up to 100 Torr which is the maximum l He is in the explosion value on the gauge and beyond there is most ADR s tank likely significant boil off and you should ei ther start pumping again or backfill with He gas and open the ADR s 1 He tank to the at mosphere e There is a pressure release valve on the ADR l He pump manifold which might be able to handle the job e However if you must keep the main pump valve closed for an extended period of time more than 2 3 hours for instance in the case of an ex
21. is at room temperature and not being used It should be closed during cool down when you start pumping on the ADR 1 He tank and left closed as long as everything is cold The second further back Swagelok valve opens the stor age tank to the atmosphere Never touch this valve or you will release all our He to the atmosphere 43 Step By Step Cycling of the ADR and 3He Fridge Below is a step by step procedure for cycling the ADR and He Fridge Notice that the cycling of the two sys tems is an intermixed process To help you understand the reasoning behind each step below a right hand col umn with Explanations has been included You may also wish to consult Figure 13 Figure 14 and Table 3 above while going through the cycling to get a better picture of what s going on inside the ADR Step Action Explanation 1 Put the battery box on the charger while you cycle See The Battery Box on page 57 below for charging instructions We only have one working batter box and it will need to be charged everyday while observing Since observ ing can t take place during cycling this is an ideal time to charge the battery box Top off the ADR 1 He 9 and ADR 1 N 10 tanks see Maintenance Filling on page 32 above This is to make sure you don t boil off all your liquid cryogens since the boil off rate will increase during cycling due to the He pump heater the persistent switch heater the heat of
22. long it took to fill and estimate if you can how many liters of cryogens were used 3 Then slowly 1 1 5 psi in the fill Dewar fill 1 N into the SPIFI 1 N tank until its full use the proce dure described in the section SPIFI Nitrogen with no pump attached on page 33 below If the vac uum hose and special stinger assembly are still attached to the SPIFI I N gt tank you will have to remove them first See Figure 12 page 34 for a detailed diagram of the special stinger and pumping assem bly While cooling down SPIFI the pressure should decrease as indicated on the LCD display on the front of the turbo pump 51 We once measured that to get about 7 inches of I N in this tank from room temperature takes about 11 2 hours maximum fill height is 11 inches The 50L I N Dewar won t last for both the ADR 1 N tank fill and the SPIFI 1 N tank fill and you will have to refill the Dewar once before you can top off the SPIFI I N gt tank Record in the SPIFI notebook the time of the SPIFT l N tank fill how long it took to fill the level of cryogens in the tank and estimate if you can how many liters of cryogens were used 4 Next fill EN slowly 1 1 5 psi in the fill Dewar into the ADR 1 He tank use the procedure described in the section ADR Nitrogen on page 32 below Since SPIFI cannot be tilted when it s in the enclosure it is difficult to get the I N gt out of the 1 He tank once the tank reaches 77 K In this case what
23. magnetization the latent heat of condensation of He and various other sources of waste heat from electrical currents and from work being done on the system Open the pump heat switch 20 and close the pot heat switch 19 We close the pot switch so that the pot cools down to 1 5K We open the pump switch because we will soon start heating the pump to a temperature higher than 2 2 5K in order to evaporate all the 1 He which is soaked into the charcoal in the pump Then the gaseous He will flow from the pump to the pot and condense out in the pot which is at 1 5K Close the pill heat switch 21 Makes sure the pill stays at 1 5K during the cycling process This is necessary because the ADR cooling process requires that we magnetize the salt pill isother mally Connect the housekeeping cable 27 to the ADR Connects the electrical inputs for the He pump heater the persistent switch and the GRT read outs Put the ADR 1 He back on the pump Gets your 1 He surface cold It must eventually drop below the boiling point of I He in the He fridge sys tem This point depends on the pressure inside the He fridge system but is probably around 2 2 5K which is easily achieved by the ADR 1 He tank when it gets down below to 5 10 Torr Note that all three heat switches pill pot and pump thermally connect to this surface when closed Turn on the He pump heater 25 and set it to 5 volts This
24. negative terminal on the first power supply is outputting 12V relative to conductor running between the two power supplies and that the positive terminal of the second power supply is outputting 12V relative to the conductor running be tween the two power supplies See Figure 25 below You can now proceed to connect the power supplies to the battery box connect the first power supply to the female banana sockets at the top center of the battery box labeled Charge 12V Battery 1 Make sure you connect red to red and black to black or to and to Next connect the second power supply to the OV relative to the ground wire e 10 11 12 13 61 female banana sockets on the battery box labeled Charge 12V Battery 2 Again connect red to red and black to black or to and to Make sure that the negative black terminal of 12V battery 1 is receiving 12V relative to the conductor running between the two power supplies the positive termi nal of 12V battery 2 is receiving 12V relative to the conductor running between the two power supplies and that the other two terminals are receiving common ground relative to the conductor running between the two power supplies Refer to Figure 25 below Figure 25 Charging the Battery Box While its in Use 4V Charging Not Shown 12V relative to lt lt J ON the ground wire Chargel2V Abs EN Battery 2 a Cx OV relative to the ground w
25. persistent switch short because of the potential difference created by the magnet controller between its leads Here we can just take the current out of the leads by ramping down Note that because the solenoid coil and the persistent switch short are superconducting a current of 20 2 amps will be left flowing around the solenoid This creates a stable central magnetic field of approximately 4T which will magnetize the salt pill isothermally since the pill heat switch is closed the 45 salt pill will be held at 1 5K To completely magnetize the salt pill we must wait for the paramagnetic ions within the salt to align with the 4T field This takes about 30 minutes 19 Once the magnet controller reads 0 00 amps or 0 01 amps turn off both the magnet controller and mag net power supply at the same time The superconducting solenoid magnet is activated and we don t need a current source anymore 20 Check again that the pump heater has stabilized around 2kQ You are done with the first half of the cycle Go have a coffee Everyone needs a cup of Joe 21 Wait 4 hours for He to condense in pot When heating the pump at 2kQ it will take approxi mately 4hrs for all of the He to completely evaporate from the charcoal in the pump and to condense out in the pot Note that the salt pill will be completely mag netized after only a half hour Don t worry about this You can leave the s
26. still lit it means that circuit has failed to stop the blade out of the beam path If the LEDs continue to flash the circuit has failed to stop the blade at all If this is the case the blade can be stopped by simply turning off the main power to the control box see step 5 below The blade must then be moved out of the beam path by reaching into the cali bration box from the telescope hatch door and moving the blade physically with a pen for instance Be careful not to touch the window on SPIFI Always stop the chopping blade when you are leaving AST RO or when you won t be using it for a while You can leave the control box and all its components turned on to help heat the enclosure However if you need to turn off the control box for whatever reason first make sure that the temperature control the driver and indexer have been turned off in that order and then turn off the main power It is okay to leave the temperature controller set at a high temperature when you turn it off Using the Gas Cell and Blackbody 1 The control box should already be turned on all the electronics should have been turned on to help heat the enclosure after SPIFI was first cooled down from room temperature provided that the temperature in the enclosure was above 0 C to begin with If the control box isn t turned on then in the following order turn on the main power then turn on the indexer then the driver and finally the Omega tempera ture contro
27. these tanks However keeping careful records of times and amounts of fills in the SPIFI notebook will help you to make close estimates of the cryogen levels and stay on top of the ADR s tanks Although we never want to let the cryogens in SPIFI or the ADR run out once SPIFI has been cooled down to 1 He tempera ture if you do suspect that you have accidentally run out of cryogens in either of the ADR s horizontal tanks you can use the trick of holding your thumb over the neck vent for a minute or so and then letting go If a plume of gas comes out afterwards then you still have cryogens left In SPIFI it will be necessary for you to monitor the levels of cryogens in the two SPIFI tanks while you fill You can check the level of SPIFI s I N2 tank using Steve s hand carved wooden dipper stick which we usually store on the SPIFI alignment table 32 inside the enclosure on the battery box side of SPIFI Figure 4 Steve s Hand Carved Wooden Dipper Stick a To measure the I N level in SPIFI put the blue end of the stick all the way down into SPIFI s I N neck until it touches the bottom of the tank and hold it there for 10 20 seconds Remove the stick and blow on the end of it several times to create a frost line Use a tape measure to measure the height of the frost line and record it in the SPIFI notebook The height of cryogens in the 1 He tank can be measured by traditional means such as by us ing a thumper Also record this height
28. we usu ally do is fill 1 2 liters of 1l N and watch the temperature by temporarily closing the pill heat switch and watching the GRT for instance See Temperature Monitoring below on page 29 Once the tempera ture stabilizes or starts to increase fill another liter or so of 1 N into the l He tank Continue this proc ess until the temperature stabilizes close to 77 K To be conservative stop filling I N when the tempera ture reaches about 85 90 K The last time we filled we found that two full fills of the ADR 1 He tank was too much One full fill takes about 15 minutes Record info about the fill in the SPIFI notebook Top off the ADR I N tank again with I N Record in the notebook 6 Lastly fill the SPIFI 1 He tank slowly 1 1 5 psi in the fill Dewar with 1 N use the procedure de scribed in the section SPIFI Nitrogen with no pump attached on page 33 below This fill will take a long time 1 2 hours Check the level after filling for 1 1 hours to make sure you don t get more than 3 inches of I N in the tank or you may have trouble blowing it out later and you will waste it One to two inches of I N gt in this tank should be enough You may need to refill the 50L 1 N Dewar during this fill Record in the SPIFI notebook the time of the fill how long it took to fill the level of cryogens in the tank and estimate if you can how many liters of cryogens were used 7 Top off the ADR I N tank once more wit
29. 39 Make sure channels 1 2 amp 3 are turned all the way down to OV fully counterclockwise on the PI power supply Turn on the PI power supply Make sure all three channels 1 2 amp 3 still read OV Connect the PZT cables to the PI power supply Make sure you match the correct cable with the correct channel A 1 B 2 and C 3 Put the resistor caps which were on the cables on top of the PI power supply Parallelize the LOFPI Refer to the section below called Parallelizing the Fabry Perots page 53 O 7 Turn on everything else Calibration control box 46 in the following order and from left to right turn on the main power switch turn on the indexer turn on the driver and turn on the temperature control unit Cryo motor box 48 in the following order turn on the main power switch turn on the indexers power and then turn on the HOFPI and LOFPI driver power You may need to turn this box off and turn it back on again after logging into Fabry due to some initialization problem with the in dexer that we don t fully understand Make sure you always turn on the indexer before the driver however SPIFI motor box 49 in the following order turn on the main power then turn on switch 5 Turn on the battery box 35 by flipping Switch 1 on the battery box up Make sure all the other switches on the battery box are also in the correct po
30. 7 5 65 4 28 0 65 9 SPIFI I N2 Tank Height in Volume L Height cm Volume L 0 25 0 7 0 5 0 6 0 50 1 5 1 0 1 2 0 75 2 2 1 5 1 7 1 00 2 9 2 0 2 3 1 25 3 6 2 5 2 9 1 50 4 4 3 0 3 4 1 75 5 1 3 5 4 0 2 00 5 8 4 0 4 6 2 25 6 5 4 5 5 1 2 50 7 2 5 0 5 7 2 75 7 9 5 5 6 3 3 00 8 6 6 0 6 8 3 25 9 3 6 5 7 4 3 50 10 0 7 0 7 9 3 75 10 7 7 5 8 5 4 00 11 4 8 0 9 0 4 25 12 0 8 5 9 6 4 50 12 7 9 0 10 1 4 75 13 3 9 5 10 7 5 00 14 0 10 0 11 2 5 25 14 6 10 5 11 7 2 50 15 3 11 0 12 2 2 75 15 9 11 5 12 8 6 00 16 5 12 0 13 3 6 25 17 1 12 5 13 8 6 50 17 7 13 0 14 3 6 75 18 3 13 5 14 8 7 00 18 8 14 0 15 3 7 25 19 4 14 5 15 8 7 50 19 9 15 0 16 3 7 75 20 5 15 5 16 7 8 00 21 0 16 0 17 2 8 25 21 5 16 5 17 7 8 50 22 0 17 0 18 1 8 75 22 4 17 5 18 6 9 00 22 9 18 0 19 0 9 25 23 3 18 5 19 5 9 50 23 7 19 0 19 9 9 75 24 1 19 5 20 3 10 00 24 4 20 0 20 7 10 25 24 8 20 5 21 1 10 50 25 1 21 0 21 5 10 75 25 3 21 5 21 9 11 00 25 6 22 0 22 3 22 5 22 6 23 0 23 0 23 5 23 3 24 0 23 6 24 5 23 9 25 0 24 2 25 5 24 5 26 0 24 8 26 5 25 0 27 0 25 2 27 5 25 4 28 0 25 6 Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 65
31. IFI 55 which is the big yellow handled valve located above and to the left of the ADR SPIFI interface should be closed see Figure 3 below You shouldn t need to adjust it be cause we left it closed at the end of the summer Never open this valve if SPIFI is under vacuum and you suspect that the hose is not pumped down or you could blow out the Fabry Perots Make sure that both the turbo pump 51 and the pressure gauge for SPIFI 57 are plugged in to 120VAC 60Hz The turbo pump has a grey power cord and the pressure gauge has a black power cord Turn on the turbo pump station by pressing the main power button on the front of the pump once Listen to hear if the turbo pump is running smoothly If it is not let it run for a few minutes Do not move on to the next step until the pump is running smoothly Pump out the vacuum hose between the turbo pump and the main SPIFI pump valve Ideally we want to have the same pressure inside SPIFI and inside the vacuum hose before opening the main pump valve equal pressure on both sides of the valve To achieve this a If SPIFI is in the Torr range gt 1 Torr run the turbo pump for about 1 minute before opening the main pump valve b If SPIFI is in the the sub Torr range lt 1 Torr run the turbo pump for 5 10 minutes before opening the main pump valve Note that these times are not written in stone You should use your best judgment to try to achieve an equal pressure on both sides of the main p
32. PIFI and e Remember to close the valve if there will be a the turbo pump if power outage and you are still pumping on SPIFI is under vac SPIFT uum and or the pump e Never open the valve to the atmosphere if SPIFI is turned off is still under vacuum Opening SPIFI to the The Fabry Perots will e Be extremely careful when working near any Page 20 atmosphere in any blow out windows on SPIFI Do not puncture these win way while at low dows pressures se Don t let the enclosure freeze as this will freeze the o rings and cause them to fail e Never open the yellow valve 55 if the other side is at atmospheric pressure Moving SPIFI within We loose our alignment e Don t use the SPIFI alignment table 32 to pull the enclosure to the telescope and our yourself up into the enclosure offset calculations e Try not to bump or push SPIFI or the ADR Over pressurizing the e You will blow out e Fill the gas cell very slowly and monitor the Page 49 calibration gas cell the windows to the gas cell e You will have to jury rig some type of new blackbody and calibration source since gas cell and blackbody are inac cessible for mainte nance pressure meter carefully while doing so e Keep the bleeder valve near the lecture bottle closed and open the main valve for only a sec ond or two we call this one shot Close the main valve and then very carefully open the bleeder valve to fill the gas cell Monitor the pressure gaug
33. SPIFI Operation Manual 2004 for AST RO Winterovers BY THOMAS OBERST STEPHEN PARSHLEY THOMAS NIKOLA amp GORDON STACEY Table of Contents INTRODUCTION MPORTANTBASICS een 4 C ntact ntormatl ne sesiaisiesee se eri iesileiie iresleke iila yebai EEEE EEESC REEE SEE ATEAC STEERER isa 4 SPIFE Quick Locator Guide serorei NE L DA NEES NE eke 5 The SPIPI encl s rer 11101 se seli eE ees E EE ETE gida Bl iel SE teed as 5 Inside th PuUlbOX vec ra eka tee e i e ya E Shel ial A E EER 6 Insidetheleftsidedooroftheenclosure eee 7 Insidetherightsidedooroftheenclosure 8 Catastrophic Mistakes To A Void Petrisor teis eee kaslar E AEE EEE aminn sake eee alk AEE 9 Emergency Shutdown Checklists isle iieekizeseni ei EAEE E EEE el 13 Case 1 You have been notified that there will be a power outage and the power is currently still on A EE A EEE EEN E E E E E E E A E T E EE E AEE E O 13 Case 2 Thepowerwentoutunexpected y eee 15 Power Up Checklist AfteranEmergencyShutdown 17 The SPIPTENClOSUre 154461 lde ilereliri seslerine iletir eslelileekinise silici sebhasbeaesleeeblatseenss saddens eoeesbbessceee 19 Temperature ekil e mel Gitede its dir Sin il dl la li ded Sami gele eee te 19 Mech
34. about it The pump is not a mechanical pump but rather a piece of char coal sealed inside the pumping chamber When the charcoal is cooled to low temperatures 1 5K its enormous surface area adsorbs He gas In this way it pumps on the atmosphere inside the closed system Furthermore the pressure inside the fridge is such that He goes through the liquid gas phase transition at 2 2 5K This al lows the entire fridge to be cycled simply by heating and cooling the pot and pump they can both be cooled down to 1 5K by thermally connecting them to the pumped I He tank via the pot and pump heat switches and the pump can be heated up to 50K via a resistive heater which is thermally strapped to it The process for cooling to 280mK is as follows 42 e First the pump heat switch is closed the pot heat switch can be either open or closed it doesn t matter This cools the charcoal in the pump to 1 5K causing it to adsorb most of the He in the system I don t know for sure how long this process takes but this is the state that is achieved at the end of the hold time of a cycle Therefore when you are ready to re cycle the He is already all adsorbed in the char coal e Next the pot heat switch is closed and the pump heat switch is opened e The pump is then heated to about 50K This causes all the He to evaporate out of the charcoal Be cause the pot heat switch is closed the pot is at 1 5K Therefore the evaporated He will c
35. ainly help Case 1 You have been notified that there will be a power outage and the power is currently still on O 1 Secure the ADR 8 including the magnet power supply 23 and magnet control box 22 Case I If time allows you should always try to have the ADR completely cycled and cold i e 60mK before the power outage In this case you don t need to do anything The magnet control box 22 and the magnet power supply 23 should already be turned off in this case If they aren t turn them off Case II o If the ADR needs to be cycled and there is not time to complete a full cycle before the power outage then you have two options a Wait until the power comes back on to start the cycle or b If you have 45 minutes to an hour until the power outage get the first half of the cycle done up to step 21 of Step By Step Cycling of the ADR and 3He Fridge on page 45 be low Make sure you turn off the charcoal heater 25 right before the power goes out this is not part of the cycling procedure The magnet control box 22 and the mag net power supply 23 should be turned off by the time of the outage Case III If the ADR is in the process of being cycled and you don t have time to finish the cycle be fore the power outage then a If you are in the first stages of cycling and you have enough time get the first half of the cycle done up to step 21 of Step By Step Cycling of the ADR and 3He Fridge on page 45
36. ally by rection to down taking current out of the leads at a very slow rate 0 1 amps sec 30 Wait about hour Wait for the current to ramp down 31 Once the magnet controller reads 0 00 amps or 0 01 We don t need them anymore The magnetic field has amps turn off the persistence switch heater Then now been removed from the salt pill Within a half turn off both the magnet controller and magnet hour the paramagnetic ions in the salt will start to loose power supply at the same time Remove the magnet their alignment Because the salt pill is thermally iso leads from the ADR lated the pill heat switch is open this demagnetization will occur adiabatically and hence the pill will be forced to very low temperatures 60mK 32 Top off the ADR 1 He and ADR I N j tanks Gotta keep the cryo tanks happy 33 After about 1 2 hour the pill GRT should be in the By now most of the paramagnetic ions in the salt have 700Q 5kQ range and the pot GRT should be around lost their alignment Through this adiabatic demagneti 120Q see Temperature Monitoring on page 29 zation the salt will equilibrate at 60mK after about one P g pag half hour above You are now cold enough to observe 34 Don t forget to take the housekeeping cable out of This cable adds noise and heat and is no longer neces the ADR sary except when you want to check the GRTs DONE 47 Persistent keyed switch is
37. anical asm Hes la lay ama slim lala Hasim la ya anes ilik d seeks 19 PART PREPARA TION a rE Doses kiss daralmalar ln Sa ik aa ETA 20 Pumping On SPIED zeinera mandi nde sie ii iel lisan emeyi Sanaya laaan ala masa 20 Pumping SPIFI Down from a Partial Vacuum State 20 Pumping SPIFI Down from Atmospheric Pressure 21 Cooling SPIPL Down from 293K sci cei alay pe Sanel se eal eda Ji Blk 22 PART OPERA TION o a e lak Baal lana alaka ll alada ein ikea nin 29 Temperature M nttorin e resm sekel kelam azyasli bali el asena sale kel ise ana Ee 29 SPIPE Temperature Check ismek ecinic ienee aee se ili nice ili lala i le acele ke likeme lal 29 ADR Temperature Check ermesine lem i len ll lim ek ellisi 30 Manten nce kilin amp 5m A akk asl ease de ls etle damn elli ayal T 32 ADR NITO eDi Meis seri dala ai lense i si simay ska aim allam jeli medi 32 SPIFINitrogen withnopumpattached eee 33 SPIFINitrogen withpumpattached eee 34 ADR Helitm s1 in saa eee eerie ere erste re aml a ilan Gala i l eer ie peers N 35 SPY Dee Laurin sia Hanak Balaman Barla ke dele e E a a a laa ik ln dai 36 CYCIING fei eae ii as aa kay ll S eae 38 UnderstandingMagneticCooling eee 38 Understandingthe3HefFridge ea AS Te AEE a a e tE eTR E NE 41
38. atmosphere until the oil heats up The pump should be able to pump down the manifold gas cell and all the con necting lines to about 1 2 Torr if you let it run for several minutes 8 When all the manifold valves are open and the manifold gas cell and connecting lines have been pumped down to 1 2 Torr close the valve at the bottom of the manifold to close off the pump 9 Close the bleeder valve on the gas lecture bottle 10 Unplug the pump it creates vibrations which heat up the detectors 11 Put a small shot of gas from the lecture bottle into the gas cell You must be extremely careful not to put too much gas in or you could blow out the fragile plastic windows of the gas cell We sug gest the following method for doing this ll e Figure 19 Gas cell manifold setup bd Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 51 a Make sure the bleeder valve on the gas lecture bottle is closed The main valve on the lecture bottle should also be closed b Crack open the main valve on the gas lecture bottle for 1 or 2 seconds and then close it immedi ately This allows a shot of pressurized gas to fill the small cavity between the lecture bottle s main valve and the lecture bottle s bleeder valve This is our definition of a shot c Now slowly crack open the lecture bottle s bleeder valve and let the shot fill the manifold and the gas cell Carefully watch the pre
39. be rotated so that it curves upwards See Figure 11 below 2 Position the 50L Dewar midway between the end of the pillbox and the baby buggy cover pi 7 8 9 1 33 Remove the red vacuum hose cap from the ADR s I N Stickstoff neck 30 Before opening the I N valve on the Dewar make sure the yellow latex hose or Teflon hose is not kinked near the end of the copper extension Also make sure the stainless steel stinger is held at the height of the Stickstoff neck and is parallel to the ground Slowly open the 1 N valve on the Dewar Just when the hose starts to get stiff insert the stinger in the Stickstoff neck and move the entire Dewar towards the pillbox until the stinger is inserted all the way into the Stickstoff neck The stinger should be inserted as far as possible until it hits the bottom of the ADR s 1 N tank and then should be backed off a half inch or so to allow the I N gt to flow freely from the end of the stinger When the ADR s I N gt tank is full shut off the main valve on the Dewar Move the Dewar back towards the baby buggy cover to remove the stinger from the Stickstoff neck Replace the red vacuum hose cap on the Stickstoff neck 0 Make sure the pillbox doors are closed and latched Yellow latex hose in Top of stainless steel stinger Curved copper extension 50L Dewar Figure 11 Filling SPIFI s I Nz Tank from the 50L Dewar SPIFI Nitrogen with no pump attache
40. behavior The Laser this must be pronounced as by Dr Evil of Austin Powers Screen with fringe pattern Figure 22 Parallelizing the Fabry Perots Observing Fringes Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 55 The Pre Amp The signals coming from our 25 pixel bolometer array our detectors must be filtered and amplified before we import them into Fabry This is the job of the pre amp box 11 which is mounted directly to the lower left side of the ADR as viewed when looking in the pillbox doors Figure 23 Preamp switches O off bat e 2 PODO m 26 10 e a 10 6 Switch configuration for having the preamp turned on and a 21mV bias across the detectors The two grey cables with D style connectors with all the embarrassing packing tape wrapped around them are our main data cables 12 These are perhaps the most important cables in the whole enclosure don t laugh Try not to move or bump these cables too much since they may become sensitive to noise if moved The mili tary style cable 13 on the right brings in the power supply to the pre amp from the battery box see The Battery Box on page 57 below for information on the battery box Table 4 Preamp Switch Positions Desired Function of Position of Position of Position of Position of R L Position of Pre amp leftmost bat int switch 5 3 2 6 switch switch
41. below Make sure you turn off the charcoal heater 25 right before the power goes out this is not part of the cycling procedure The magnet control box 22 and the magnet power supply 23 should be turned off by the time of the outage If you don t have much time the most important thing to do is make sure there is no current in the magnet leads when the power goes out If there is any current in the leads power may be dumped into the solenoid when the power goes out and the whole system will heat up and boil off cryogens Set the current ramp rate on the magnet controller 22 If you are demagnetizing the solenoid i e if the persistent switch heater 24 is turned on then 0 1 amps sec is ideal but this takes 2 hour or so If you don t have 2 hour then 1 amp sec is better than nothing If you are not demagnetizing the solenoid i e if the persistent switch heater is turned off then you can ramp down at 10 amps sec Flip the current ramp direction on the magnet controller to the down position Wait until the magnet controller reads 0 00 amps or 0 01 amps Turn off the persistent switch heater 24 if it was ever on Turn off the magnet control box 22 and the magnet power supply 23 at the same time b wm O 4 Also make sure the charcoal heater 25 is turned off Secure the PZT s HOFPI Turn the PZT voltages all the way down fully countercloc
42. channels 1 2 power supplies 38 and 3 down all the way before turning on the amp 39 power supply and before hooking up the PZT leads Turning up the volt You could destroy the e Always adjust the PZT voltages slowly and keep Page 53 age on any of the PZT s an eye on the nominal values don t just stare at PZT s to more than the fringes Never exceed 700V in any of the 700V channels 1 2 or 3 e Always turn the power in channels 1 2 and 3 to zero before turning on the PZT power supply 10 Mistake Undesirable Result How To Avoid Where To Find More Info Allowing the SPIFI e Fabry won t function e Check the temperature by feel or by thermome Page 19 enclosure to freeze properly ter of the enclosure at the beginning and end of inside go below e Fans may be de every day 0 C stroyed inside Fabry e Make sure both heaters are working If one the magnet control fails replace it immediately boxes and other e Try not to open the enclosure doors for very electronics boxes long e Other electronic e Keep the doors shut as far as possible behind components may fail you when working in the enclosure e The O rings in SPIFI e Always shut the doors and latch them whenever may fail and we ll you are done loose our vacuum Opening the main SPIFI may loose pressure e Remember to close the valve when you have Page 20 yellow valve 55 through the turbo pump finished pumping SPIFI down between S
43. d The tank should be filled approximately every two days The maximum hold time for this tank is three days but check the level every day to make sure you don t run out sooner use Steve s hand carved wooden dipper stick see Figure 4 and instructions for use on page 22 above If you fill every day SPIFI will drink about 10L of l N If you wait two days it will drink about 20L The capacity of the tank is 25L One other note the method described below of putting the 50L I N Dewar inside the enclosure with the door partly open behind it worked well in the summer However in wintertime if this causes too much heat loss in side the enclosure which it very well may you might try putting the 5 0L Dewar on the lift jacking it up and just filling through the roof hatch from the outside This is especially true if Fabry and other electronics are running if it drops below 0 C inside the enclosure Fabry and fans inside electronics boxes may be destroyed 1 2 Check the level of 1 N gt in the tank before filling and record this value and the time in the SPIFI note book Attach the curved copper extension onto the 50L I N Dewar using a crescent wrench Next attach the yellow latex hose with the stainless steel stinger on the other end to the end of the copper extension using a hose clamp Note that if the yellow latex hose is too stiff in the Antarctic winter you may need Bold numbers in parenthesis refer to the SPIFI Quick
44. d on first turn on the main power switch and then turn on the power switch lo cated above port 5 But only turn it on if the enclosure temperature is above 0 C Move the flip mirror into the laser beam by typing the command flip_home in the Matlab interface on Fabry via a computer downstairs which is logged onto Fabry To move the flip mirror out of the beam path type flip_clear If the motor box or Fabry was not already turned on you will need to type flip_home first in order to initialize the indexer and driver so that they know where the flip mirror is at Next you will need to go up to the enclosure and turn on the laser power This is the Melles Griot box 37 located in the middle of the shelf under SPIFI on the battery box side Turn the key to power on the laser If you stand up inside the battery box side of the enclosure you should be able to see a la ser pattern on the screen 54 hanging opposite the laser 36 on the ADR end of SPIFI see Figure 22 below If you don t then either the flip mirror is not in the beam path the laser is not turned on or the external laser mirror needs adjusted Or maybe you just need to turn the lights out Otherwise it means that something catastrophic happened i e the Fabry Perot meshes are blown out Locate the two PI boxes 38 amp 39 on the shelf on either side of the Melles Griot box These are the high voltage power supplies that powe
45. ds and use the persistent switch in order to demagnetize the salt pill 26 Put current on the leads by flipping the current direc tion to up Set the rate to 10 amps sec There are 20 2A of current flowing around the super conducting solenoid but no current in the leads There fore if we were to open the persistent switch without putting current into the leads first then the 20 2A would be quickly forced out of the solenoid through the leads and to ground in the magnet controller This would cause the power stored in the 4T magnetic field to be dumped into the pill and the ADR in the form of heat energy thus causing the temperature of the whole system to rise drastically We would then have to refill the ADR s liquid cryogen tanks and re cycle How ever if we first put 20 2A of current in the leads and then open the persistent switch we can quasi statically 46 demagnetize the solenoid by ramping down the current very slowly 27 Once the system is current limited 20 2 amps turn The leads now have the same current as is flowing on the persistence switch heater around the superconducting solenoid 20 2A and there will be no current jump and hence no power dump when we open the persistent switch 28 Wait 2 minutes Wait for the persistent switch to go normal open 29 Set current rate to 0 1 amps sec and flip current di We now demagnetize the solenoid quasi static
46. dy for use See Normal Use above Using and Charging at the Same Time All four switches up amp special charging configuration The reason the battery box is so complicated is to allow the possibility of charging and observing at the same time If both battery boxes were working then we would probably never need to do this However with only one battery box it is highly likely that we will need to observe when the battery box is in need of charging 1 Put switch 1 all the way down and disconnect the cable to the pre amp from the battery box Keep switch 1 down and the cable to the pre amp disconnected while you set up the chargers as a precaution against damaging the pre amp Make sure switches 2 and 4 are all the way down Put switch 3 all the way up This is very important since we will now be charging with power supplies at 12V and 12V Carry three power supplies up to the enclosure You will only need two power supplies if the 4V battery is okay The 4V battery usually doesn t need charged nearly as often as the 12V batteries Take two of the power supplies and connect the positive output of the first power supply to the negative output of the second power supply via a banana plug cable this is the ground cable shown in Figure 25 below Plug in the two power supplies and turn on the power Set both power supplies to 12V Use a voltmeter to check the outputs of the two power supplies You should observe that the
47. e atmosphere You can also start pumping on SPIFI s I N tank at the time that you start pumping on the ADR 1 He First reconnect the vacuum hose and special stinger assembly to the SPIFI I N neck We left the vac uum hose and special stinger assembly for pumping on SPIFI s 1 N tank connected to SPIFI s I N gt neck at the end of the 03 04 summer season at Pole However you had to remove this assembly in step 3 above in order to fill I N See Figure 12 page 34 for a detailed diagram of the special stinger and pumping assembly a Make sure the brass valve connecting SPIFI s I N neck to the vacuum hose is closed b Make sure the yellow latex hose is securely clamped off near the end which connects to the stainless steel stinger c Start the appropriate pumpzilla in the receiver room by flipping the switch on the breaker box on the wall d Slowly open the brass valve on SPIFI s I N neck Don t open the valve too fast or you will over load the pump It will be difficult to gauge this since the pump is downstairs and you can t hear it although Steve claims he can hear the change in the pump through its exhaust But because we use the same type of pump on SPIFI s 1 N as we do to pump on the ADR s 1 He the pump down rate should be similar Record the time that your pump down started in the SPIFI notebook Check the ambient temperature inside the SPIFI enclosure after filling to make sure its still warm By war
48. e carefully We typically use about 50 150 Torr e Ifyou hear any popping noises shut off the gas flow immediately This is the sound of the gas cell windows bulging 11 Mistake Undesirable Result How To Avoid Where To Find More Info Charging the battery You could ruin the batter Read all the labels and warnings on the front of Page 57 box 35 incorrectly iesin Box 1 Box 2 the battery box before hooking it up to the already has at least one chargers bad battery Therefore e The normal charging configuration is to have there is no immediate the two left hand switches on the battery box all backup if Box 1 is dam the way down they are 3 position switches aged However in an and the two right hand switches all the way up emergency you could use You then connect one blue 12V charger to 12V whichever batteries are battery 1 red to red black to black and the still good from Box 2 other blue 12V charger to 12V battery 2 red and you could also take to red black to black batteries from the old Make sure you connect the charging cables to battery box which is in the the battery box before plugging in the chargers SPIFI crate labeled A2 to avoid the risk of electrical shock The in the AST RO Annex chargers have no on off button and the charg ing leads become live as soon as the charger is plugged in Also by the same token when charging is complete unplug the chargers be fore re
49. e most important by far is switch 3 While the negative terminal of 12V battery 2 and the negative terminal of the 4V bat tery are always connected when switch 3 is closed these two negative terminals are both connected with the positive terminal of 12V battery 1 This is what provides the necessary 12V power source to the preamp Table 5 Source of Voltage for the Preamp Voltage Out to Pre amp Source 12V positive terminal 12V battery 2 12V negative terminal 12V battery 1 4V positive terminal 4V battery floating ground negative terminal of 12V battery 2 negative terminal of 4V bat tery and positive terminal of 12V battery 1 all tied together when switch 3 is up The result of the positive terminal of 12V battery 1 being connected to the negative terminals of the other two batteries is that you must take extra caution when charging and make sure the chargers and the switches of the battery box are properly configured The other three switches are not as important they simply make the out puts of the battery box live or dead on off switches Switch 3 changes the electrical nature of the outputs Table 6 Functions of Battery Box Switches Switch What it controls 3 connects disconnects positive terminal of 12V battery 1 to the negative terminals of the other two batteries in the box 1 livens deadens the output to the pre amp livens deadens the banana plugs for 12V charging i
50. e way up on the battery box Once everything is set up okay connect the pre amp cable to the battery box and flip switch 1 to the up position all the way You should now have all four switches on the battery box up all the way Now turn on the pre amp see The Pre Amp on page 55 and take a scan to see if you get a signal refer to the SPIFI Data Acquistion manual Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 62 PART 3 WARM UP PROCEDURE Whenever SPIFI operations are complete use the procedure outlined here to safely warm SPIFI up to room temperature and shut everything down 1 Backfill the ADR s 1 He tank with He gas and open it to the atmosphere use steps 1 6 in the ADR He lium subsection under Maintenance Filling on page 35 above It is very important to do this or else you could get an overpressure in the ADR s I He tank as the l He boils off Backfill SPIFI s 1 N2 tank with N gt gas and open the tank to the atmosphere you may want to refer to Figure 12 on page 34 above In the receiver room open the N gas cylinder make sure you don t accidentally hook up the He gas and adjust the regulator so that about 2 psi are going to the roof through the clear Teflon tube Close the main brass vacuum valve on the SPIFI nitrogen neck 30 Disconnect the pumpzilla vacuum hose from the brass valve on the SPIFI nitrogen neck
51. elf The heat load to our salt pill is dominated by two sources which each contribute about 20 30nW con duction from 300mK through array wiring and 1 5K radiation Therefore we have a total heat load of about 50nW which limits the hold time of 60mK in the salt pill to 100 hours However our whole system is lim ited by the He 300mK stage which acts as a thermal conduction shield between the 1 5K stage and the 60mK stage The hold time of the He system is only about 40 hours See Understanding the 3He Fridge below Figure 13 Electrical Schematic for Magnetizing and Demagnetizing the Solenoid rape oes ed b N oe ir nnd CR ADR Ee Red Magnet lead gt 1 5K mot superconducting I I 1 ee Superconducting Solenoid 1 5K Persistent Switch Normal Superconducting 21 5K Magnet Control Box 293K Table 3 Persistent Switch Settings il Black Magnet lead gt 1 5K not superconducting 40 Persistent Switch Settings Key Position Nominal Temperature Status State Switch po Position sition key vertical 90 counter clockwise OFF Switch at 1 5K not being heated superconducting closed key horizontal 90 clockwise ON Switch being heated gt 1 5K Normal open Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 41 Figure 14 Mechanical and Thermal Schematic of the ADR and 3He Fridge
52. ely open this valve so that you don t put too much stress on the pump You probably won t be able to hear the pump because it is downstairs so use your best judgment ADR Helium The ADR s 1 He tank needs to filled once every day The capacity of the tank is 5L but the transfer usually takes between 8 10L depending on the transfer tube used The level of I He in the tank cannot be measured be cause the neck of the tank is horizontal 1 In the receiver room open the He gas cylinder make sure you don t accidentally hook up the N gas and adjust the regulator so that about 5 to 10 psi are going to the roof through the clear Teflon tube 2 Close the main pump valve 16 on the pump manifold on the right hand wall of the pillbox This is the large black handled valve 36 3 Attach the He gas line clear Teflon tube which comes up from the receiver room to the gas inlet nip ple 18 on the manifold You will need to use the small brass yellow tubing adaptor piece Make sure that you feel gas coming out of the Teflon tube The pressure should be 5 10 psi 4 Slowly crack the gas inlet valve on this nipple to start backfilling the ADR s 1 He tank with He gas You should see the pressure in the pressure gauge 17 start to rise However this gauge only goes up to 100 Torr so you won t be able to monitor the pressure beyond this value Make sure you do this slowly so that you don t get an overpressure above 760 To
53. er outage lasts more than 2 3 hours then you should backfill with Nz gas and then open the tank to the atmosphere see step 2 on page 62 If you have been using the gas cell make sure the gas cell pump 41 is unplugged there is no on off button on this pump Shut down all other electronic devices Calibration control box 46 in the following order and from right to left turn off the tempera ture control unit turn off the driver turn off the indexer turn off the main power switch Turn off the resistance bridge box 47 Cryo motor box 48 in the following order turn off both the HOFPI and LOFPI driver power turn off the indexers power and turn off the main power SPIFI motor box 49 in the following order turn off switch 5 and then turn off the main power Make sure the laser power is turned off 37 Turn off the battery box 35 by pushing Switch 1 on the battery box down Turn off the preamp 11 by moving the two left most switches to off and bat both switches up Don t let the cryogen tanks run dry during the power outage Case 2 The power went out unexpectedly O 1 Secure the ADR 8 including the magnet power supply 23 and magnet control box 22 Make sure the persistence switch heater 24 on the magnet control box 22 is turned to the off position key should be vertical Make sure the
54. erface before opening it There is no pres sure gauge on the vacuum hoses between the main pump valve and the turbo pump so use your best estimate of how long to let the turbo pump run to achieve an equilibrium between the pres sure in SPIFI and the pressure in the vacuum hose The pressure in SPIFI is always the pressure shown on the front of the turbo pump Open the main pump valve It is spring loaded and can only be turned to either open or closed 2 Assuming that you didn t let the cryogen tanks run dry and they don t need filled then you can re commence pumping on the ADR 1 fHe tank and the SPIFI 1 N tanks Turn on the two pumpzillas in the receiver room and wait several minutes for the vacuum hoses to get pumped out Slowly open the main pump valve on the ADR 1 He pump manifold 16 to start pumping on the ADR 1 He tank You should spend at least 5 minutes cracking this valve to minimize stress on the pump Slowly open the brass valve on the SPIFI 1 N neck to start pumping on the SPIFI I N tank You should spend at least 5 minutes cracking this valve to minimize stress on the pump 3 Check the temperature of the ADR refer to ADR Temperature Check on page 30 below if you don t know how to do this 0 4 Cycle the ADR Casel o If cycling of the ADR was already complete when the power went out and you are still within the limits of the h
55. gt tank will suck I N gt out of the handheld Dewar until the tank is full When the tank is full SPIFI will simply stop drinking because the vacuum in SPIFI will have been replaced by I N Make sure the end of the stainless steel stinger is all the way at the bottom of the handheld Dewar while SPIFI drinks Never let SPIFI suck on the atmosphere as this will cause an ice plug to form If you happen to run out of I N in the handheld Dewar while SPIFI is drinking quickly remove the Dewar and place a rubber stopper size 0 in the end of the stainless steel stinger to plug the vacuum some of these stoppers should already be in the enclosure or else in the SPIFI crates in the AST RO Annex Refill the handheld Dewar while the yellow latex hose thaws Once the hose is flexible re clamp it near the end with the stainless steel stinger Remove the rubber stopper and follow steps 1 4 again Once SPIFI stops drinking you will see the flow stop through the translucent yellow latex hose af ter rubbing the frost off the outside leave the end of the stainless steel stinger immersed in the I N of the handheld Dewar while the yellow latex hose thaws When the hose has thawed enough the clamp should seal off the hose again Remove the handheld Dewar and make sure the clamp is secured near the end of the yellow latex hose near the stainless steel stinger Slowly open the main vacuum valve on the SPIFI nitrogen neck Take at least five minutes to complet
56. h I N gt Record in the notebook 8 After everything reaches 77K SPIFI should achieve a pressure of 10 Torr indicated on the turbo pump 51 Record the pressure and the time of the reading in the SPIFI notebook A Wait about a day before filling helium Before filling I He into SPIFI or the ADR check if the HOFPI is parallel at l N temperatures See Parallelizing the Fabry Perots on page 53 below If the HOFPI is way out of parallel SPIFI will not work properly and it would be a waist of 1 He trying to operate SPIFI Record the state of the parallelism in the notebook Also it is important to get all of the I N out of the 1 He tanks before filling 1 He 9 Parallelize the HOFPI See Parallelizing the Fabry Perots on page 53 below 10 If there is still 1 N in the ADR 1 He tank blow it out using the special ADR blow out invention see Figure 8 on page 28 below which we stored in the SPIFI crate labeled A2 in the AST RO Annex Record how much I N needed to be blown out in the notebook 11 Hopefully at this point there is no I N still left in the ADR 1 He tank Just in case there is heat the tank with the pump heater 25 and the persistent switch heater 24 a connect the housekeeping cable 27 to the ADR b Make sure the pump heat switch 20 is closed 12 13 14 15 16 24 c Turn on the pump heater 25 the small green power supply in the bottom left corner inside the pillbox door
57. h the vacuum hose from the turbo pump to the yellow main pump valve for SPIFI 55 via a 90 pipe Make sure the o rings and o ring surfaces are clean and make sure that the o rings are slightly greased with vacuum grease Don t touch the yellow valve if SPIFI is under vacuum or you could blow out the Fabry Perots 2 If you are sure SPIFI is at atmospheric pressure open the main yellow pump valve The valve is spring loaded and can only be turned to either open or closed 3 Once the yellow valve is opened then start the turbo pump station 51 by pressing the power button on the front of the pump once This will start the diaphragm pump and the turbo pump simultaneously The turbo pump is supposed to handle the torture of pumping at atmospheric pressure for a while The pump down time to about 5x10 Torr is approximately 8 hours However this depends strongly on how long the SPIFI dewar was open to the atmosphere If the turbo pump station can pump SPIFI down to the few Torr range within about 30 to 40 minutes then that is a good indication that everything is okay The pressure should be in the mid upper 10 Torr range within 2 3 hours Once the pressure in SPIFI reaches about 5x10 8x10 Torr the cool down process can be started Create a small table of pressure versus time in the SPIFI notebook while you are pumping down This will allow you to properly gauge SPIFI s progress and to compare with records of past and
58. he pumps SPIFI ADR interface It is spring loaded and can only be turned to either open or closed When the screen indicates that everything has been halted go ahead and push the power buttons If SPIFI is on the pump you will need to first close the main pump valve 55 and then turn off the turbo pump 51 The main pump valve is the big yellow valve to the top left of the If the ADR 1 He tank is on the pump close the main pump valve 16 on the ADR pump mani fold 15 and turn off the corresponding pumpzilla in the receiver room by flipping the switch on the breaker box on the wall Warning After closing the pump valve the ADR 1 He tank will be a closed system and boil off could create an over pressure If the pressure gauge 17 maxes out i e the pressure rises over 100 Torr then you should backfill with He gas and then open the tank to the atmosphere see steps 1 6 of ADR Helium on page 35 You probably also need to refill at this point since a high pressure indicates lots of boil off the corresponding pumpzilla in the receiver room by flipping the switch on the breaker box the wall If SPIFT s I N tank is on the pump close the brass valve on the SPIFI I N neck 29 and turn off on O 5 0 6 15 Warning After closing the pump valve the SPIFI I N tank will be a closed system and boil off could create an over pressure If the pow
59. heck it just about everyday thereafter Basically you should develop a sense of the rate at which the 1 He is boiling off in the tank and check the level when you think it is getting low Use a thumper to check the level and use the chart in Appendix A on page 64 Table 7 to convert the height of 1 He in the tank to the volume Each time you check the level in the tank record the level and the time at which you checked it in the SPIFI notebook The capacity of the tank is 65L but it always takes about 100L to fill Therefore to minimize loss of 1 He you should always start with a full 100L Dewar of 1 He before filling SPIFI s l He tank The reason for this is that if you run out of 1 He in the 100L Dewar while filling you may not realize it immediately and you will be injecting warm air into SPIFI s 1 He tank thereby blowing out all the 1 He that was in the tank to begin with and any you may have just filled If you must begin the fill with a partially full 100L capacity Dewar keep a 37 close eye on the pressure in the Dewar When it starts to get low remove the stinger from the SPIFI 1 He tank frequently to make sure it is still blowing out liquid 1 Check the level of 1 He in the tank before filling and record this value and the time in the SPIFI note book 2 Place a full 100L 1 He Dewar on the hand crank lift dolly Crank the dolly up to a height which allows the transfer tube to reach the hatch to SPIFI
60. ia a Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 52 female female BNC adaptor mate the two cables which are labeled in Figure 20 Also you need to make sure the white sync signal cable is actually connected to the AST RO chopper control electronics in the AST RO re ceiver room Figure 21 shows where the white sync signal cable needs to be plugged in The black banana style connector is for grounding purposes SPIFI AST RO sync signal cable white Sync signal banana style connector ground Figure 21 ATS RO chopper electronics located in reciever room Note that the phases also need to be adjusted depending on what kind of observation is carried out See the SPI FI Data Acquistion manual for details Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 53 Parallelizing the Fabry Perots In order for our Fabry Perot interferometers to work the two plates on each Fabry Perot must be parallel This is accomplished by adjusting three ceramic piezoelectric actuators PZT s which are positioned equidistantly around the moveable plate of each Fabry Perot The PZT s expand by a small precise amount when a high volt age is applied across them The high voltage is supplied by the two PI power supply boxes 38 amp 39 under neath the SPIFI alignment table inside the battery box side of the enclosure This should be done during an initial cool down after a
61. ill the level of I N gt in the tank and estimate if you can how many liters of 1 N gt were used e goal SPIFI Nitrogen with pump attached When we pump on the SPIFI I N gt tank there is no way to measure the level of I N gt in the tank not even with ingenious hand carved tools made by Steve Therefore we must fill this tank every day to make sure it doesn t run dry When filling every day SPIFI s 1 N tank will drink about 10L of I N per fill Make sure that you have at least 10L available If the I N tank starts sucking on air you ll get an ice plug Special filling stinger placed as close to the top of the I N gt in the handheld Dewar as possible Stainless steel stinger p Red rubber vacuum hose must reach the bottom l of the handheld Dewar SPIFI nitrogen neck SPIFI outer shell cross Handheld Dewar gt 10L sectional view from end 1 N in handheld Dewar is sucked into SPIFI s I N tank by vacuum for when I N tank is on pump Yellow latex hose near telescope SPIFI I N gt tank Figure 12 Special Pump and Stinger Assembly for Pumping on SPIFI s I N Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 35 If SPIFI s I N tank is being pumped on the vacuum hose and special stinger assembly should already be connected to SPIFI s nitrogen neck and the main vacuum valve on the neck should be open Also the yel low latex ho
62. in the SPIFI notebook Once you have measured the height in either SPIFI s 1 N or l He tank you can use Table 7 in Appendix A to convert your measurement to a volume We will begin the cool down process by filling all four cryogen tanks with I N gt Be careful not to fill too much 1 N into the two 1 He tanks or else you will have the problem of getting this I N out when it comes time to fill 1 He and you may loose time and waste cryogens Also it is important to initially fill very slowly with a low N pressure 1 1 5 psi in the fill Dewar If you fill quickly with high pressure the boil off in the tanks may create a dangerous over pressure inside the reservois Keep a record in the SPIFI notebook while you are cooling down of what times you filled which tanks how full they are how long it took to fill them and how much cryogens where used in the process This will help you keep track and gauge the progress of the cool down process and will allow us to compare the present cool down with records of past and future cool downs 23 1 Close all the heat switches on the ADR pot 19 pump 20 and pill 21 to make sure everything will get cold 2 First slowly 1 1 5 psi in the fill Dewar fill I N into the ADR I N Stickstoff tank until it s full use the procedure described in the section ADR Nitrogen on page 32 below This normally takes about 15 minutes Record in the SPIFI notebook the time of the fill how
63. inear approximation for high tempera tures say above 10K We do not have good calibration measurements of these GRT s for tempera tures below 4K However after cycling the He fridge and the ADR and when the system is cold enough for observing the pot GRT should read something on the order of 120Q which means the pot is around 275mK and the pill GRT should read something between 700Q up to 5kQ which means the pill and detectors are around 60mK The wide range of 700 5000Q is because the resistance temperature curve of the GRT for very low temperatures is very steep Therefore a large increase in re sistance only corresponds to a small decrease in temperature Also you should know that the pill GRT doesn t always appear to be stable and can jump around a bit When finished unplug the housekeeping cable If the housekeeping cable is left in it can add consid erable noise to the signal while taking scans It can also cause a heating of the detectors due to micro phonics and the bias current for the GRTs You can leave the Resistor Bridge Box turned on however to help with enclosure heating Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 31 a Linear GRT Temperature vs Resistance Approximation 1800 Ow sdue sisoy Temperature K Figure 10 GRT Temperature vs Resistance Plot 32 Maintenance Filling Table 2 below summarizes the most important facts
64. inger Assembly for Pumping on SPIF S N 34 Electrical Schematic for Magnetizing andDemagnetizingtheSolenoid 40 Mechanical and Thermal Schematic of the ADRand3HerFridee 41 Magnet Controller top and Magnet Power Supply bottom 47 Magnet leads plugged into the ADR 47 A view of the end of SPIFI opposite the ADR before SPIFI went into the enclosure 48 The electronic control box for the SPIFI calibrationunit 48 Figure 19 Gas cell manifold Setup cierren Makas bes sansi da a alakam pa yn deyi el s 50 Figure 20 Sync signal cables on the electroniccontrolboxforthecalibrationunit 51 Figure 21 ATS RO chopperelectronicslocatedinrecieverroom 52 Figure 22 Parallelizing the Fabry Perots Observing Fringes 54 Fisure 23 Preamp Switches seen chests mke le esasy ike Seul pas asi salla maki caves a Bel e 55 Figure 24 Battery box wiringschematic forasinglebatterybox 57 Figure 25 Charging the Battery Box While itsinUse 4VChargingNotShowm 61 INTRODUCTION IMPORTANT BASICS Contact Information You will be able to find a good deal of the information you will need for day t
65. ire 12V relative to the ground wire 7 Turn the current output on both power supplies to OA Put switch 2 up all the way on the battery box This will liven the female banana plug sockets to which the power supplies have been connected Slowly turn up the output current on the two power supplies used to charge the 12V batteries This will be gin the charging process You may notice that the output voltage on the power supplies is a function of the output current For instance when the power supply output current is set to the usual 2A used for peak charging the output voltage may read lower than 12V You may want to check the output voltages of the battery box at the military style connector which connects to the prep amp and see if it reads 12V 12V and 4V on the top left top center and top right pins relative to ground which is the bottom center pin You may find that you need to turn up the amperage a bit higher to get closer to 12V This seems to be okay for a while but when the batteries become partially charged you may want to turn down the amps If you also need to charge the 4V battery which doesn t need done as often hook up a third power supply and connect it to the battery box as described in steps 5 and 7 under Normal Charging on page 60 above Depending on how depleted the 4V battery is you may need to turn up the current a little to keep the output voltage just above 4V Also you will need to put switch 4 all th
66. is the small green power supply located in the bottom left corner of the pillbox under the ADR Heats the charcoal in the pump to a temperature above 2 2 5K and up as high as 50K This causes the He to boil out of the charcoal since its boiling point at the pressures inside the fridge is 2 2 5K The He then flows to the pot which is at 1 5K because the pot heat switch is closed and condenses out there Check that the resistance of the He pump is going down on the multi meter 26 which is connected to the He pump heater via the blue switch board 56 This is to make sure the pump is heating up properly Once the resistance is equal to 2kQ which takes about 30 40 minutes turn the He pump heater 2kQ is the desired temperature or corresponding resis tance if you like at which we would like to heat the 44 down to 2 volts pump for the next 4 hours We start with 5V just to speed up the process of getting the pump warmed up to 2kQ However if you leave the heater on 5V too long and let the resistance drop much below 2kQ then you will have to wait longer than 4 hours in step 21 below This is because you will start overheating the He gas which flows to the pot and it will take longer to con dense in the pot Your l He boil off will also increase 10 Plug the magnet leads 28 into the ADR Match red to red tape on ADR and black to black paint on ADR See Figure 16 belo
67. istors 1 Record in the SPIFI notebook the resistance across the red pair of banana sockets and the white pair of banana sockets 2 Use the calibration chart below to interpret the temperature of the red resistor based on your measured resistance The red resistor is tied to the LOFPI stage 4 2K stage in SPIFI s main Dewar 3 Use the calibration chart below to interpret the temperature of the white resistor based on your measured resistance The white resistor is tied to the HOFPI stage 77K stage in SPIFI s main Dewar White Resistor kQ Red Resistor kO Temperature Temperature HOFPI 77K stage LOFPI 4 2K stage C K 9 31 10 8 22 6 295 6 9 32 10 8 21 0 294 0 9 36 10 8 15 0 288 0 9 40 10 8 10 0 283 0 9 48 10 9 0 0 273 0 9 57 10 9 10 0 263 0 9 66 10 9 20 0 253 0 9 75 11 0 30 0 243 0 9 86 11 1 40 0 233 0 9 97 11 1 50 0 223 0 10 08 11 2 60 0 213 0 10 21 11 4 70 0 203 0 10 34 11 5 80 0 193 0 10 49 11 7 90 0 183 0 10 65 11 9 100 0 173 0 10 84 12 1 110 0 163 0 11 04 12 4 120 0 153 0 11 27 12 7 130 0 143 0 11 53 13 1 140 0 133 0 11 82 13 6 150 0 123 0 13 16 15 4 180 0 93 0 13 31 16 0 183 5 89 5 13 34 16 2 184 5 88 5 13 36 16 3 185 8 87 2 13 39 16 4 187 1 85 9 13 41 16 5 187 9 85 1 13 43 16 6 189 4 83 6 Table 1 Temperatures for SPIFI s Carbon Resistors 30 ADR Temperature Check The temperature i
68. itch POSilOnS neme elan anma dan da islamla a alan aslen salla 55 Table5 SourceofVoltageforthePreamp ee 58 Table6 FunctionsofBatteryBoxSwitches ee 58 Table7 Heightvs VolumeforSPIFIC yo Tanks 64 List of Figures Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 TheGang attheCeremonialPolk eis ne 4 SPIFI Pump M nifold eeii eni Ayi ak alel go Me nasa n Bana E A a EEN 21 Steve sHand CarverJWoodenbDipperStiek 22 Swagelok Valve to ADR He tank 2700 2 a adele kali le ia ele sna en Dan 26 Blowing N Out of the SPIFI1 HeTank eee 27 Pouring I N blown out of SPIFI s 1 He tank into SPIFI s N gt tank eeeececeeeeeeeerererenereees 27 Blowing 1 N gt Out of the ADR 1 He Tank cccssssssssessssssesscssssssesscsssssscsscsssssscescensssscenesssssscenes 28 Selecting Pill amp Pot GRT sontheSmallBlueBox 56 30 GRT Temperature vs ResistancePlot Ra Era 31 Filling SPIFI sI NzTankfromthe50LDewar 33 Special Pump and St
69. kwise on the PI power supply 38 Make sure channels 1 2 and 3 are all at OV Diconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply Turn off the PI power supply LOFPI If applicable We did not need to use the LOFPI PZT s over the Antarctic summer Turn the PZT voltages all the way down fully counterclockwise on the PI power supply 39 Make sure channels 1 2 and 3 are all at OV Diconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply Turn off the PI power supply Properly shutdown Fabry 50 Turn on the monitor inside the right side door of the enclosure At the prompt type the following sequence of commands gt means type at the prompt means hit the space bar once and means strike the enter key ee 99 va e gt root 4 e gt whoami 14 This last command whoami will tell you what kind of user you are If you are the root user continue If you are not root type gt su and enter the password gt r fin ord to become the super user Then continue e gt cd_ e gt shutdown h _ now Wait for Fabry to go through its shutdown procedure on the Fabry PC and on the monitor Secure t
70. l lows Fabry to read the chopping frequency Finally the two serial cables on the left side of the control box are part of a serial cable daisy chain which allows Fabry to communicate with the stepper motor Note if there is ever a need to use the remote while on the roof of AST RO there is an additional remote control cable located on the floor of the Fabry side of the enclosure to the left of the electronics rack and you can simply disconnect the remote in the telescope control room and take it up on the roof and use the extra cable up there External Stepper Motor for flip mirror Calibration Unit which is now enclosed in the AST RO beam tube Figure 18 The electronic control box for the SPIFI calibration unit Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 49 Chopping 1 The control box should already be turned on all the electronics should have been turned on to help heat the enclosure after SPIFI was first cooled down from room temperature provided that the temperature in the enclosure was above 0 C to begin with If the control box isn t turned on then in the following order turn on the main power then turn on the indexer then the driver and finally the Omega tempera ture control unit these switches should run from left to right across the box Only turn it on if the en closure temperature is above 0 C Using The Remote located in the telescope control room turn the ch
71. l at OV Diconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply Turn off the PI power supply 7 Shut down all other electronic devices Calibration control box 46 in the following order and from right to left turn off the tem perature control unit turn off the driver turn off the indexer turn off the main power switch Turn off the resistance bridge box 47 Cryo motor box 48 in the following order turn off both the HOFPI and LOFPI driver power turn off the indexers power and turn off the main power SPIFI motor box 49 in the following order turn off switch 5 and then turn off the main power Make sure the laser power is turned off 37 Turn off the battery box 35 by pushing Switch 1 on the battery box down Turn off the preamp 11 by moving the two left most switches to off and bat both switches up Make sure the magnet control box and magnet power supply are turned off 22 amp 23 Make sure the the charcoal heater small green power supply is turned off 25 8 Check around the enclosure one last time to make sure everything is turned off 9 Leave the heaters in the enclosure running and make sure all the doors and hatches in the enclo sure are shut and latched
72. l power to change its position O 4 m5 6 16 Secure the pumps If SPIFI is on the pump you will need to close the main pump valve 55 and also push the power button on the Turbo pump 51 once so that it is in the off setting and does not start up auto matically when the power comes back on The main pump valve is the big yellow valve to the top left of the SPIFI ADR interface It is spring loaded and can only be turned to either open or closed If the ADR 1 He tank is on the pump close the main pump valve 16 on the ADR pump mani fold 15 and turn off the corresponding pumpzilla in the receiver room by throwing the switch on the breaker box on the wall Warning After closing the pump valve the ADR l He tank will be a closed system and boil off could create an over pressure If the pressure gauge 17 maxes out i e the pressure rises over 100 Torr then you should backfill with He gas and then open the tank to the atmosphere see steps 1 6 of ADR Helium on page 35 You probably also need to refill at this point since a high pressure indicates lots of boil off If SPIFT s I N gt tank is on the pump close the brass valve on the SPIFI 1 N neck 29 and turn off the corresponding pumpzilla in the receiver room by throwing the switch on the breaker box on the wall Warning After c
73. l unit these switches should run from left to right across the box Only turn it on if the en closure temperature is above 0 C The temperature of the blackbody can be set to a constant Celsius temperature by adjusting the up down small arrow buttons on the Omega temperature control face We usually leave it set at 80 C The bot tom of the digital display screen indicates the desired temperature of the blackbody in green The top of the digital display screen indicates the actual temperature of the blackbody in red Upon turning on the temperature control unit you should see the red numbers climb as the blackbody warms up When the red value finally reaches the green value the blackbody may continue to heat and the red value may overshoot the green a little However the red value should eventually equilibrate about the green value To momentarily check the ambient temperature near the chopping blade depress the red check ambient temperature button to the left of the temperature controller 50 3 The blackbody and gas cell together can be moved into or out of the beam path by typing a command in the Matlab interface on Fabry via a computer downstairs which is logged on to Fabry To move the gas cell into the beam path type Gas_Cell_in It takes about a minute to complete this command To move the gas cell out type Gas_Cell_out If the gas cell is already out of or in the beam path and you type the wrong command the program will tell
74. ll four cryogen tanks have been filled with the appropriate amount of l N and SPIFI is at approximately 77K see Cooling SPIFI Down from 293K page 22 above after an initial cool down is complete and the temperature and pressure are stable any time you move the HOFPI or LOFPI a large distance such as when changing orders or wave lengths otherwise about once a day How to adjust manually This usually only needs to be done for the HOFPI but the same procedure also applies to the LOFPI 1 First you must move the flip mirror into the laser must be pronounced as by Dr Evil in Austin Pow ers beam path The flip mirror which is located inside the main SPIFI Dewar is controlled by a step per motor which is attached to SPIFI just above the calibration box see Figure 17 on page 48 above The electronics box that controls this motor is located at the very bottom of the electronics rack in the enclosure on the Fabry side of SPIFI We call this the SPIFI Motor Box 49 The motor box can op erate up to four motors serial addresses 2 5 but the flip mirror s stepper motor is the only thing con nected at the moment its connected to port 5 The motor box should already be turned on all the electronics should have been turned on to help heat the enclosure after SPIFI was first cooled down from room temperature provided that the temperature in the enclosure was above 0 C to begin with If it is not already turne
75. losing the pump valve the SPIFI l N tank will be a closed system and boil off could create an over pressure If the power outage lasts more than 2 3 hours then you should backfill with N gas and then open the tank to the atmosphere see step 2 on page 62 If you have been using the gas cell make sure the gas cell pump 41 is unplugged there is no on off button on this pump Flip off the power switches on all other electronic devices Calibration control box 46 turn off the temperature control unit turn off the driver turn off the indexer and turn off the main power switch Turn off the resistance bridge box 47 Cryo motor box 48 turn off both the HOFPI and LOFPI driver power turn off the indexers power and turn off the main power SPIFI motor box 49 turn off switch 5 and turn off the main power Make sure the laser power is turned off 37 Turn off the battery box 35 by pushing Switch 1 on the battery box down Turn off the preamp 11 by moving the two left most switches to off and bat both switches up Don t let the cryogen tanks run dry during the power outage 17 Power Up Checklist After an Emergency Shutdown O 1 If SPIFI was on the turbo pump 51 before the power went out then Restart the turbo pump Ideally you want to have the same pressure on both sides of the main pump valve 55 This is the big yellow valve to the top left of the SPIFI ADR int
76. m we mean above 0 C we never want the enclosure to get much colder than this If the enclo sure is below 0 C take measures to warm it up This may involve simply keeping the doors of the en closure closed for a while and letting the heaters in there do their jobs I could also involve adding an other heater or more weather stripping and insulation if needed Only if the enclosure is above 0 C turn on all the electronics in the enclosure to help with heating a Calibration control box 46 in the following order and from left to right turn on the main power switch turn on the indexer turn on the driver and turn on the temperature control unit b Turn on the resistance bridge box 47 c Cryo motor box 48 in the following order turn on the main power switch turn on the indexers power and then turn on the HOFPI and LOFPI driver power You may need to turn this box off and turn it back on again after logging into Fabry due to some initialization problem with the in dexer that we don t fully understand Make sure you always turn on the indexer before the driver however d SPIFI motor box 49 in the following order turn on the main power then turn on switch 5 Boot up Fabry 50 You don t need to log on or anything since this can all be done remotely when you telnet Just push the power button But only turn on Fabry if the temperature is above 0 C Parallelize the HOFPI again See Parallelizing the Fab
77. m can be turned off by flipping off the switches on the breaker boxes on the wall 5 Properly shutdown Fabry 50 63 Turn on the monitor inside the right side door of the enclosure At the prompt type the following sequence of commands gt means type at the prompt means hit the space bar once and means strike the enter key e gt root 4 e gt whoami This last command whoami will tell you what kind of user you are If you are the root user continue If you are not root type gt su and enter the password gt r fin ord to become the super user Then continue e gt cd_ e gt shutdown h_ now 4 Wait for Fabry to go through its shutdown procedure When the screen indicates that everything has been halted go ahead and push the power buttons on the Fabry PC and on the monitor 6 Shutdown the PZT s HOFPI Turn the PZT voltages all the way down fully counterclockwise on the PI power supply 38 Make sure channels 1 2 and 3 are all at OV Diconnect all three PZT cables A B amp C from the PI power supply and cap them with the re sistor caps which should be on top of the PI power supply Turn off the PI power supply LOFPI If applicable We did not need to use the LOFPI PZT s over the Antarctic summer Turn the PZT voltages all the way down fully counterclockwise on the PI power supply 39 Make sure channels 1 2 and 3 are al
78. moving the charging cables e The switches on the blue power supplies should be at Normal Automotive Charge and 2A 12V Auto There is no power button you start the charging by plugging the charger into 120AC e Switch 3 is very important If switch 3 is up then the terminal of one of the 12V batteries is connected to the terminal of the second 12V battery This is a special situation that allows you to charge while observing at the same time The charging and switch configuration in this case is non trivial Refer to the circuit diagram of the battery box the instructions in this man ual or contact us if you need to Overfilling 1 Nz into e You might not be able Follow the cool down filling instructions carefully Page 22 the SPIFI and ADR 1 He tanks during an initial cool down to get the 1 N gt out of the tanks e If you are able to get the I N out using the special blow out de vices you will unnec essarily waste some l Ng in the process and keep an eye on the temperature 12 Mistake Undesirable Result How To Avoid Where To Find More Info Filling 1 N or He You may get an overpres Fill the cryogen tanks on SPIFI and the ADR slowly Page 23 too fast at too high sure inside SPIFI s and the 1 1 5 psi in the fill Dewar during an initial cool of a pressure during ADR s cryogen tanks down to allow time for boil off gas to escape out of an
79. mputs livens deadens the banana plugs for 4V charging inputs Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 59 One other note the switches we used for the battery box are 3 position switches However only the very top and very bottom positions have meaning we were just trying to use up old switches in the lab Therefore when you throw a switch push it all the way up two clicks or all the way down two clicks The middle position isn t connected to anything Using and Charging the Battery Box Because we are down to only one battery box it will need to be charged everyday while observing Therefore you will need to get in the habit of putting the battery box on the chargers every time you will be leaving AST RO for a while and whenever you are cycling the ADR Normal Use switch 1 amp 3 up switch 2 amp 4 down Normal use is when the battery box is being used to power the pre amp and is not being charged and not con nected to any chargers 1 Put switch 3 all the way up This connects the positive terminal of 12V battery 1 to the negative terminals of the other two batteries and thus provides the necessary 12V to the pre amp 2 Put switches 2 and 4 all the way down This is just deadens the female banana sockets used for charging inputs a safety measure 3 With switch 1 in the down position connect the cable to the pre amp 4 Put switch 1 all the way up
80. n the ADR is monitored through two GRT s One is located on the salt pill and the other on the He pot 1 Plug the housekeeping cable 27 into the ADR This is the large black braided cable with the military style connector It plugs into the bottom right underside of the end of the ADR near the double pillbox doors The connector is not a bayonet style or screw on Rather just push it straight in snuggly Next locate the small blue box 56 on the inner right hand wall of the enclosure on the Fabry side of SPIFI A knob to select which GRT you wish to read is located on the box Select either position 3 Pill or position 2 Pot See Figure 9 below er i X or hi Knob for select ing Pot or Pill GRT Figure 9 Selecting Pill amp Pot GRT s on the Small Blue Box 56 After selecting which GRT you want to use on the small blue box locate at the Resistor Bridge Box 47 in the electronics rack second box from the top of the electronics rack on the Fabry side of SPIFI in the enclosure If the Resistance Bridge is not already on tum it on Wait several minutes for the resistance to climb and stabilize at its actual value Once the resistance has become stable or is bouncing around some mean value record the resistance in the SPIFI notebook Compare your recorded value with the graph below Figure 10 to get the temperature and record this temperature in the SPIFI notebook Figure 10 is a very rough l
81. o day operations of SPIFI in this manual However when questions arise don t hesitate to contact one of the members of the SPIFI team Thomas Nikola Cornell University 224 Space Sciences Bldg Ithaca NY 14853 Email tn46 cornell edu Office Phone 607 255 3140 Thomas Oberst Cornell University 226 Space Sciences Bldg Ithaca NY 14853 Email teo4 cornell edu Office Phone 607 255 4806 Cell Phone 607 731 0577 Steve Parshley Cornell University 226 Space Sciences Bldg Ithaca NY 14853 Email scp8 cornell edu Office Phone 607 255 4806 Cell Phone 413 219 6305 Gordon Stacey Cornell University 212 Space Sciences Bldg Ithaca NY 14853 Email stacey astro cornell edu Office Phone 607 255 5900 Home Phone 607 273 9380 Figure 1 The Gang at the Ceremonial Pole SPIFI Quick Locator Guide Images of SPIFI and of most of our operating equipment are shown below with labels indicating what s what This is intended as a quick guide for understanding the SPIFI setup and for locating equipment dis cussed in this operation manual Throughout the rest of this manual bold numbers in parenthesis will refer to numbered pictures in this Quick Locator Guide The SPIFI enclosure 1 The SPIFI enclosure 5 Roof of enclosure 2 The pillbox 6 Hatch for SPIFI 1 N neck 3 Right side or Fabry side of enclosure 7 Hatch for SPIFI 1 He neck 4 Left side or battery box side of en closure
82. old time 40 hours normally then you might still be cold Keep in mind however that the remainder of the hold time will be shortened if the pumps where turned off since the temperature in the ADR s 1 He tank and in SPIFT s I N 2 tank will have risen Case II o If you are powering back up from the four hour waiting period of the cycling process step 21 of Step By Step Cycling of the ADR and 3He Fridge on page 45 below then you can pick up the waiting process where you left off Make sure that the He fridge is still set up properly the pump heat switch 20 should be open the pot heat switch 19 should be closed the pill heat switch 21 should be closed and the housekeeping cable 27 should be plugged into the ADR Turn on the charcoal heater 25 and set it to 5 volts Check that the resistance of the He pump is going down on the multimeter 26 which is connected to the He pump heater Once the resistance is equal to 2kQ which may take up to 40 minutes turn the He pump heater down to 2 volts Now wait up to four hours for the He to condense in the pot i e pick up with step 21 of Step By Step Cycling of the ADR and 3He Fridge on page 45 below If you were already waiting for an hour or two before the power went out then you shouldn t need to wait the full four hours since some the He will have already condensed in the pot before the power outage However this depends on how long the power was out If
83. olenoid magnetized for the entire 4hrs without any negative effects while you wait for the He to condense Note that the limiting process in the time it takes to cycle is the condensation of He in the pot 4hrs 22 Turn off the He pump heater small green power supply At this point all of the He should have boiled off from the charcoal in the pump and condensed in the pot 23 Open the pot heat switch and close the pump heat switch you might try to do this at the same time Opening the pot switch will disconnect the pot from the 1 5K surface and thermally isolate the pot Closing the pump head switch will connect the charcoal in the pump to the 1 5K surface As the charcoal cools its large surface area will begin to adsorb He gas and it will therefore act as a pump on the atmosphere above the 1 He in the pot Pumping on the I He in the pot will lower the temperature of the pot to about 280mK 24 Open the pill heat switch We have isothermally magnetized the salt pill and it is now time to begin an adiabatic demagnetization of the pill Opening the pill heat switch will thermally adia batically isolate the pill 25 Make sure the current direction on the magnet con troller is set to down and turn on the magnet power supply and the magnet controller at the same time Wait a minute or so until the fans in the boxes start up and are running smoothly We will need to put current in the lea
84. om reaching OK Open the pill heat switch to thermally decouple the salt pill from the pumped 1 He tank Put 20 2A of current back in the magnet leads quickly at 10A s The pur pose of this is to eliminate any current jump between the leads and the solenoid so that no power is dumped in the ADR when we pull the 20 2A of current out of the solenoid through the magnet leads Open the per sistent switch This causes the closed circuit through the persistent switch and around the solenoid to be interrupted The new current path flows in from the magnet controller through the positive magnet lead around the solenoid and out to the magnet controller ground through the negative magnet lead Take the current out of the leads very slowly 0 1A s to de magnetize the solenoid quasi statically It takes about 30 minutes until the current on the magnet power sup ply is at OA Turn off the persistent switch heater and then turn off the magnet control box and the magnet power supply at the same time Then disconnect the magnet leads from the ADR With another 1 2 hour the salt pill will be near 60mK As the salt absorbs heat from its surroundings the temperature and entropy rise iso magnetically I don t know if that s a word but I mean with B constant 0 until the salt has reached its initial temperature somewhere between 1 2K The time constant de pends on the heat load on the salt and on the physical properties of the salt its
85. on the computer you are using to operate SPIFI refer to the SPIFI Data Acquisition manual for more info If the Lockin Tool is not already up select sync present in the Data Acquisition Tool GUI When carrying out the wavelength calibration observing the blackbody through the gas cell the sync signal for lockin detection is provided by the electronic control box 46 for the SPIFI calibration unit In this case a BNC cable must be connected from the data acquisition board in the back of Fabry 50 to the sync signal BNC con nector on the front of the electronic control box this connector is labeled check chopping frequency and it can be seen in Figure 20 below Sync Signal Ca ble white from Receiver Room m Sync Signal BNC Cable black to Fabry E J 100 FOUR WIRE AC RESISTA RIDGE gi Figure 20 Sync signal cables on the electronic control box for the calibration unit On the other hand when doing observations of a celestial source in which case the AST RO tertiary mirror is used as a chopper the sync signal is provided by the AST RO chopper electronics In this case the white BNC cable shown in Figure 20 above will carry this signal This cable must now be connected to Fabry The easiest and by far most convenient way to do this is by unplugging the black BNC cable from the check chopping fre guency connector on the front of the electronic control box and mating it with the white sync signal cable v
86. ondense out into the pot It takes about four hours for the He to be forced out of the charcoal and for the heat of va porization to be removed from the pot through the heat switch to the I He tank e Once most of the He has condensed in the pot stop heating the pump Now the heat switches are re versed once again close the pump and open the pot This causes the charcoal to once again cool to 1 5K and start pumping on the He atmosphere above the 1 He in the pot As the pressure in the pot decreases so does the temperature It takes about 1 2 hour from this point for the pot to reach 280mK e After 40h the pot will warm back up to 1 5K and you will have to start the process over again When the instrument is at room temperature the He gas inside the fridge collects in an external storage tank with a volume of 2L At room temperature the gas is stored there under a pressure of about three atmospheres This storage tank is the long cylindrical chrome plated structure attached to the ADR s outer shell When SPIFI is mounted in the enclosure on AST RO this is found on the upper right side of the ADR see Figure 5 on page 26 above There are two green colored Swagelok valves connected to this tank The first valve the valve closest to the end of the ADR with the 1 He and I N filling necks closest to the pillbox doors connects the storage tank to the rest of the closed fridge system This valve should be opened when the ADR
87. ontact with a cold reservoir around 1 2K and an external magnetic field is slowly applied then the paramag netic ions in the salt will align themselves with the external field Because this is done isothermally at some specific temperature in the range of 1 2K the temperature of the salt cannot increase Instead the heat of magnetization AQ is dumped into the cold reservoir Therefore the entropy S of the salt de creases recall dS dQ T by definition Our cold reservoir is the pumped 1 He tank which is 1 5 1 8K The salt pill is kept in contact with this tank during magnetization by closing the pill heat switch 21 and in practice the pill does actually show some increase in temperature as can be monitored on its GRT The magnetic field is supplied by a super conducting solenoid coil also at pumped 1 He tank temperature which coaxially surrounds the salt pill We use the magnet power supply 23 and the magnet control box 22 to supply 20 2A of current to the so lenoid via the magnet leads 28 at the moderate ramp up rate of 1A s At 20 2A the solenoid has an internal magnetic field of 4T Once the external magnet field has been increased to its maximum value it should be left at that value until all but a very small percentage of the paramagnetic ions in the salt are aligned with the field The entropy continues to decrease to some limiting value which When the solenoid achieves a field of 4T
88. opping blade on off switch to on The red and green LEDs to the right of this switch should start flashing indicating that the blade is ro tating The red and green LEDs on the remote are directly connected to two photo sensors which are located on different sides of the beam path in the calibration box itself Each LED on the remote lights precisely when the blade passes through its corresponding photo sensor in the calibration box If the LEDs do not immediately start flashing this means that the speed of the blade is set too low for the blade to have sufficient start up inertia If this is the case the blade can be started by simply turning up the blade speed using the pot in the middle of the remote Once the blade is running adjust the pot on the remote to achieve the desired chopping frequency We usually use 8 2 Hz which corresponds to a setting of 9 5 on the remote s pot A chart for comparing chopping frequencies to pot settings is located on the back of the remote If needed one can check the chopping frequency directly by connecting a BNC cable to the top of the remote To stop the chopping blade simply move the switch on the remote to the off position There is a logic circuit in the control box which should stop the blade only when the blade is completely out of the beam path When the blade has been stopped out of the beam path both the red and green LEDs on the re mote should be off If either or both of these two LEDs are
89. own out I N3 SPIFI 1 N gt Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 28 Figure 8 Blowing I N Out of the ADR I He Tank N gas input 5 10 psi Rubber Stopper with small hole Teflon capillary tube for sucking out I N On the inner side of the stopper there is approximately 22 of Teflon tubing which reaches into the 1 He neck and bends down wards so that it is immersed in the 1 N near the bottom of the 1 He tank On the outside as you can see there needs to be enough tub Handheld Dewar for j ing to direct the blown out 1 N collecting the blown out into a dewar 1 N gt ADR He Neck Rubber Vacuum Hose Makeshift manifold N gas input 5 10 psi Makeshift manifold Rubber Stopper with small hole Rubber Vacuum Hose Teflon Capillary tube Blown out I N 22 of Teflon capillary tube on this side of stop per Make sure tube bends down into I N upon insertion N gt gas pressure 29 PART 2 OPERATION Temperature Monitoring SPIFI Temperature Check SPIFI has four carbon resistors inside The leads of these carbon resistors 52 are hanging over the edge of the SPIFI alignment table 32 on the Fabry side of SPIFI The leads are female banana sockets colored red green white and black with two sockets of each color To determine SPIFI s temperature we usually only use the red and white res
90. p the current direction to the up position on the magnet controller The controller and power supply should show in creasing current on their displays Start ramping up the magnet by putting current into the leads at a rate of 1 amp sec Because the persistent switch is open the current will flow from the positive lead through the solenoid coil and back out through the negative lead to ground in the magnet controller 16 Once the current has peaked at 20 2 amps about 1 2 minutes turn the persistent switch heater off The green indicator light should go off and the current limit LED should light up The maximum current we want to leave in the solenoid is 20 2 amps By turning the persistent switch heater off the switch will go superconducting and close This will provide a short between the magnet leads How ever because the solenoid and the persistent switch are superconducting and the warm leads are not all of the 20 2 amps of current will take the path of least resis tance and will flow in a continuous loop around the solenoid 17 Wait 2 minutes Give the persistent switch time to go superconducting 18 Take the current out of the leads by flipping the cur rent direction to down If the system is behaving well i e the current is dropping at the ramp down rate of 1 amp sec you can increase the rate to 10 amps sec There is still current in the leads as well as the solenoid and
91. r on the outside of the box has all the correct voltages but when we hook it up to the preamp we get no signal indicating that one of the batteries in the box must be incapable of putting out any power This is not an immediate problem since only one battery box is needed to operate the preamp However it means that you winterovers will have to be diligent about putting the only battery box we have on the charger whenever you leave AST RO for a while or whenever cycling the ADR You will also have to be very careful to use the correct charging method and to make sure the switches are in the correct positions when charging so that you don t damage box 1 It should be noted that the old SPIFI battery box is lo cated in the SPIFI crate labeled A2 in the AST RO Annex and it should still have good batteries which can be used in an emergency The preamp requires a power source with DC voltages of 4V 12V and 12V as well as a ground The wir ing schematic for our battery box Figure 24 below reveals how we accomplish this using two 12V batteries and one 4V battery Charge 12V 1 12V Switch 1 Out to Preamp Charge 4V Switch 3 Switch 4 Figure 24 Battery box wiring schematic for a single battery box 58 Female banana nan sockets for charging 6 pin military style connector out to pre amp There are some important things to take note of in the wiring schematic for the battery box Th
92. r the PZTs Do not turn the power of the PI boxes until you have checked the following three things se Do not turn on the PI power supply unless you are either at atmospheric pressure or below 1x10 Torr At pressures in between you may get arcing in the PZTs which can ruin them and other components of the Fabry Perot and SPIFI 54 se Do not turn on the PI power supply unless you have turned the voltages down to OV on chan nels 1 2 and 3 knobs turned fully counterclockwise A large start up current voltage could damage the PZTs which should never receive any voltage over 700V e Do not turn on the PI power supply unless the PZT cables are unplugged from the PI power supply This is necessary because when the PI boxes are first turned on they can output a very high voltage spike even if all the knobs are turned to OV Any voltage over 700V can damage the PZTs If the cables are unplugged the knobs are turned to OV and SPIFI is below 1x10 Torr turn on the PI box you wish to use We usually use the PI box on the left for the HOFPI and the box on the right for the LOFPI Usually the LOFPI is stable and we only need to make regular adjustments to the HOFPI Therefore in most cases you will only need to use the PI box on the left 5 If channels 1 2 and 3 are outputting OV connect the PZT cables to the PI box you have turned on Connect the correct cable to the correct channel The cables should be labeled A 1 B 2 and Ce 3
93. rightmost off on switch 21 10 6 switch OFF off up bat up doesn t matter doesn t matter doesn t matter switch is inactive switch is inactive switch is inactive ON amp 2 6mV bias on down int down 2 6 down L down doesn t matter switch is inactive ON amp 5 3mV bias on down int down 5 3 up L down doesn t matter switch is inactive ON amp 10 6mV bias on down int down doesn t matter R up 10 6 down switch is inactive ON amp 21mV bias on down int down doesn t matter R up 21 up switch is inactive On the top left hand side of the pre amp are five switches pictured above The first two the two switches on the left hand side furthest in from the pillbox doors power the preamp on and off To turn the preamp OFF move these two switches to the off and bat positions both switches up To turn the preamp ON move these two switches to the on and int positions both switches down 56 The last three switches on the pre amp the three switches on the right hand side closest to the pillbox doors labeled 5 3 2 6 R L and 21 10 6 are used to select the bias voltage across the detectors The four bias voltages you can choose from are 2 6mV 5 3mV 10 6mV and 21mV To choose either 2 6 or 5 3mV you must have the R L switch down on
94. rr in the ADR s He tank See step 5 5 At the same time you are letting He gas seep into the 1 He tank loosen and remove the KF clamp on the ADR s I He neck 9 but don t take off the end cap Just the clamp This will allow the KF end cap to pop off of the neck in the case of an overpressure since you can t monitor pressure above 100 Torr 6 Once the I He tank has reached near atmospheric pressure or the KF end cap has popped off remove the end cap and shut off the gas inlet nipple valve 7 You can now start filling with 1 He using a standard 1 He transfer tube Make sure that liquid is flow ing from the end of the transfer tube s stinger before inserting it into the ADR or the warm He gas could blow all of the 1 He out of the I He tank Insert the stinger all the way into the neck until it touches the bottom of the ADR s I He tank and then back it off a half inch so that the l He can flow freely Ideally to minimize l He waste you will have already set up the I He Dewar and transfer tube by the time the KF end cap pops off the neck so that there is already liguid flowing from the end of the transfer tube s stinger and you can immediately begin filling However this involves good timing and reguires a bit of practice especially with only one person 8 Once the I He tank is full remove the stinger and transfer tube from the 1 He neck and from the 1 He Dewar Shut off and secure the
95. ry Perots on page 53 below 26 Green Swagelok valve to He tank close before cycling ADR Don t touch this valve the other green Swagelok valve further back on the ADR or you ll release all our He to the atmosphere Don t touch this guy or he ll release a can of whoop ass on you Figure 5 Swagelok Valve to ADR He tank Good job you re done with the initial cool down SPIFI should be getting very cold by now Watch the pres sure on the turbo pump and see if it gets between 5x10 and 1x10 Torr and record the pressure in the SPIFI notebook Also check the GRT s and SPIFI s carbon resistors to monitor the temperature see Temperature Monitoring on page 29 Keep a record in the SPIFI notebook every time you check the temperatures Now your only worry is to make sure the tanks never run out of cryogens Refer to Maintenance Filling on page 32 below for regular filling methods and schedules Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 27 Figure 6 Blowing I N Out of the SPIFI l He Tank SPIFI l He Neck Access Hatch Enclosure Roof Ng gas input 5 10 psi Special stinger de vice for blowing l N out of SPIFI l He tank 1 N blown out of SPIFI comes through this tube SPIFI 1 He Neck Funnel for pouring blown out I N into SPIFI s 1 N gt Tank Handheld De war for collect ing bl
96. s and set it to 5V d To use the persistent switch heater you will have to turn on the power of both magnet control boxes simultaneously 22 amp 23 and wait a half minute or so until you hear the fans in these boxes have started up and are running smoothly the fans in these boxes don t like the cold e Next turn the keyed persistent switch 24 on by rotating the key 90 clockwise see Figure 15 on page 47 Turning on these two heaters will heat up the He tank and the remaining 1 N will hopefully evaporate But don t heat it up too much Le try to keep the ADR below 90K you can monitor the temperature by closing the pill heat switch and watching the GRT for instance see Temperature Monitoring on page 29 below Once the ADR 1 He tank has no 1 N in it fill it completely with 1 He Make sure you use a low pres sure when filling with 1 He for the first time 1 1 5 psi in the fill Dewar If you fill too quickly with too high of a pressure then the tank may become over pressured and leaks in the I He neck could de velop This fill takes about 30 minutes Record in the SPIFI notebook the time of the fill how long it took to fill and estimate if you can how many liters of cryogens were used Blow all of the I N out of the SPIFI 1 He tank using the special SPIFI blow out device see Figure 6 on page 27 below which is stored in the SPIFI crate labeled in the AST RO Annex Record how much I N gt you blew ou
97. s helium neck but not so high up that you can t get the transfer tube in under the baby buggy cover 3 Once the stinger of the transfer tube is squirting out liquid only or else you may blow all the 1 He out of the SPIFI 1 He tank with warm helium gas fill SPIFI s 1 He tank as you would in any normal l He fill i e 4 5 psi in the 100L Dewar 4 Record in the SPIFI notebook the time of the fill how long it took to fill the level of He in the tank before and after filling and estimate if you can how many liters of l He were used 38 Cycling The ADR 8 or adiabatic demagnetization refrigerator is used to cool our bolometer detectors to approxi mately 60mK which is necessary in order to achieve high sensitivity in the detectors However the ADR alone cannot support the heat load which comes in from the 1 5K pumped 1 He surfaces which surround it and so we use a 300mK He fridge system as a thermal guard between the 1 5K and 60mK stages Because the ADR needs the He guard you must cycle the two systems ADR and He fridge at the same time in a synergistic manner The hold time of the ADR is limited by the hold time of the He fridge which is approximately 40 hours During and between this 40 hour hold time you will have to keep all the cryogenic tanks filled see Maintenance Filling on page 32 above Below you will find explanations of how the ADR and He systems work followed by step by step instruc
98. se should be clamped off near the end before the stainless steel stinger of course otherwise the vacuum would be sucking on the atmosphere 1 Fill a handheld Dewar with more than 10L of I N gt A wide top Dewar is preferred If the Dewar has a narrow neck be sure to arrange things so that the yellow latex hose and stainless steel stinger can be removed from the Dewar quickly while still frozen in case the handheld Dewar runs out of l N gt Close the main brass vacuum valve on the SPIFI nitrogen neck Place the stainless steel stinger at the end of the yellow latex hose into the I N in the handheld De war The end of the stinger must be at the bottom of the Dewar Also if the Dewar has a narrow neck make sure the yellow hose and stinger are inserted straight down into the Dewar without kinks so that you can get the Dewar out from under them quickly if the I N gt runs out Open the clamp on the latex hose and hold it open until the yellow latex hose is frozen stiff and then release the clamp and replace it on the hose this way when the hose thaws again the clamp will automatically seal it off We aren t sure if there are any of these types of clamps at the South Pole so you may have to find or invent something that will work here It needs to be strong enough to clamp off the hose tightly but not so tight that it causes damage At this point SPIFI will simply drink till she s full meaning that the vacuum in SPIFI s 1 N
99. shown here in the on position Turn on the power to both boxes simul taneously and wait a half minute or so until you hear the fans running smoothly Current ramp rate Current ramp direction Current limit LED Figure 15 Magnet Controller top and Magnet Power Supply bottom Figure 16 Magnet leads plugged into the ADR Bold numbers in parenthesis refer to the SPIFI Quick Locator Guide on page 5 48 Calibration Unit Basic description The calibration unit is the aluminum box mounted to the front of SPIFI on the telescope side where the beam first enters SPIFI from the telescope see Figure 17 below It includes the chopping blade a DC motor for run ning the chopping blade a blackbody a gas cell a stepper motor for moving the gas cell and blackbody into and out of the beam path and various photometric and thermometric sensors The electronics control box 46 for the calibration unit is located at the top of the electronics rack on the Fabry side of SPIFI in the enclosure There is a single grey cable which connects the control box with the calibration box There is also a grey cable which runs from the control box through the cable wrap down into the telescope control room and which con nects to The Remote The Remote is a remote control device which allows one to operate the chopper mo tor without going outside Additionally there is a BNC cable running from the control box to Fabry which a
100. sitions See page 58 for more details Turn on the preamp 11 by moving the two left most switches to on and int both switches down 19 The SPIFI Enclosure Temperature Check periodically to make sure the enclosure is still heated The enclosure should not drop below 0 C gt If the enclosure does drop below 0 C lots of bad things can happen Fabry will not operate properly and may be damaged fans inside Fabry and inside other electronics boxes may be destroyed other elec tronic components may malfunction and the o rings in SPIFI and the ADR can fail in which case we would loose our vacuum If one of the heaters in the enclosure fails replace it immediately Add more insulation or weather stripping to the enclosure if needed Realize that the enclosure has never been tested under Antarctic winter conditions until now and the winterovers may be called upon to make adaptations and improvements Perhaps the lights could be left on to add some additional heat When you are observing and all the elec tronics boxes are running these should add some heat as well However you should not leave the elec tronics running during months when SPIFI is not being used since this will cause them to wear out faster and could also cause extensive damage if the enclosure freezes while the fans and other electrical compo nents are powered Try to keep the doors closed as much as possible while
101. ssure meter to make sure you don t over pressurize the gas cell One shot should fill the manifold and gas cell with about 50 Torr of gas d Add another shot if you need to The optimal pressure of gas to put in the gas cell depends on the spectral line which you are observing and typically falls between 50 150 Torr 12 When you have the desired pressure of gas in the gas cell close the bleeder valve on the lecture bottle 13 Close the right hand bleeder valve to the gas cell on the pump manifold 14 Now the gas cell should be filled with the desired pressure of gas the blackbody should be heated to the desired temperature the gas cell and blackbody should be moved into the beam path and the chopper blade should be running at the desired frequency If this is the case then you are ready to take calibra tion scans Refer to SPIFI Data Acquisition manual 15 You can leave the control box and all its components turned on to help heat the enclosure However if you need to turn off the control box for whatever reason first make sure that the temperature control the driver and the indexer have been turned off in that order and then turn off the main power It is okay to leave the temperature controller set at a high temperature when you turn it off Getting a Sync Signal for Fabry In Lockin observing mode which is the only mode we will be using the Lockin Tool has to be enabled Le the Lockin Tool GUI should be displayed
102. t in the manual You can use a funnel to pour the blown out I N gt into the SPIFI I N tank so it does not go to waste Fill the SPIFI 1 He tank completely with 1 He use the procedure described in SPIFI Helium on page 36 below Make sure you use a low pressure when filling with 1 He for the first time 1 1 5 psi in the fill Dewar If you fill too quickly with too high of a pressure then the tank may become over pressured and leaks in the 1 He neck could develop This fill takes a while and it might be necessary to stop and top off the ADR 1 He tank again before the SPIFI 1 He tank is full We have estimated that within about one hour you Will get approximately 1 5 inches of 1 He in the SPIFI 1 He tank A complete fill takes about 2 3 hours You will run out of l He in the 100L Dewar before you can complete the fills of both SPIFI s and the ADR s l He tanks Therefore make sure you have enough I He 150L on hand before you start Record in the SPIFI notebook the time of the fill how long it took to fill the level of cryogens in the tank and estimate if you can how many liters of cryogens were used After completely filling the 1 He tanks steps 12 and 14 above SPIFI should optimally be able to achieve a pressure between 5x107 and 1x10 Torr The first cool down uses a lot of cryogens Since the ADR s cryo tanks are small they will run out of cryogens quickly and it will be necessary to fill the ADR cryo tanks again af
103. tended power outage you should backfill with He gas and open the tank to the atmosphere see steps 1 6 of ADR Helium on page 35 Opening the second e All of our precious He Don t touch this valve ever Pages 25 amp green Swagelok gas will be released from 26 valve further back on the top of the ADR see Figure 5 on page 26 below the He fridge into the atmosphere e A couple thousand dol lars will float away e The instrument will be useless 13 Emergency Shutdown Checklists Outlined below are checklists for shutting down SPIFI in the case of an announced case 1 or unannounced case 2 power outage The information in these lists has been kept as brief as possible so that they can be used quickly in the case of an emergency Much more detailed information about all of the procedures involved in shutting SPIFI down and powering SPIFI back up is provided in other parts of this manual We covered everything we could think of here but in practice new situations always arise which have not been dealt with before It is there fore very important to think about what you are actually doing to SPIFI while going through these checklists and there may be times when you will have to deviate from the lists below to handle whatever circumstances or obsta cles arise Understanding how SPIFI works comes with time and experience but having read through this manual ahead of time before an emergency outage occurs will cert
104. ter about 6 8 hours Remember a good way to check if the ADR s tanks still have cryogens is to hold your thumb over the neck vents for a minute or so and then release If you see a plume of cold gas then there are still cryogens in the tank After 6 8 hours top off the ADR s cryo tanks Record in the SPIFI notebook the time of the fill how long it took to fill and estimate if you can how many liters of cryogens were used About one day after the cool down from 293K was started you can start pumping on the ADR 1 He tank a First make sure that the main valve on the ADR 1 He pump manifold is closed 16 b Make sure the gas inlet valve 18 on the manifold is open to allow boil off to escape to atmos phere so you don t get an overpressure c Insert and secure the KF end cap and clamp assembly 9 with the red vacuum hose 14 attached into the ADR 1 He neck The o ring of the KF cap should be clean and slightly greased with vac uum grease so that you get a good seal When you attach the red vacuum hose the hose should come off the of the top left of the neck higher than horizontal see the picture in the Inside the Pill box section of the SPIFI Quick Locator Guide on page 6 above Also make sure the KF end cap and clamp assembly is oriented so that the red vacuum hose cap of the Stickstoff neck is not blocked 17 18 19 20 21 22 25 d Start the appropriate pumpzilla in the receiver room b
105. tions to guide you through the cycling process Understanding Magnetic Cooling The functioning of the ADR is explained below in the following manner in the left hand column is a description of the general theory of magnetic cooling in the right hand column is an explanation of the specifics of our sys tem which correspond to the general theory Refer to Figure 13 Figure 14 and Table 3 on page 40 below while reading over the explanations General Magnetic Cooling Theory Correspondence in Our System ADR s are able to achieve low temperatures by adia batically demagnetizing a paramagnetic salt In a paramagnetic solid such as a crystalline salt lattice the basic atomic unit has unpaired electrons and thus contains what are referred to as paramagnetic ions Around 1 2K and in the absence of an externally ap plied magnetic field the interaction energy of these ions with their crystalline environment the salt lattice is much less than the average thermal energy kT Therefore each ion is relatively free and a randomly oriented system of dipoles results with negligible net magnetism of the salt Our salt pill is a 230g cylindrical pill of FeNH4 SOx 12H 0 or ferric ammonium aluminum or FAA Gold wires are threaded through the pill and thermally cou ple the pill to the detector array FAA can reach tem peratures down to 50mK through adiabatic demagneti zation If the salt is kept at a constant temperature in c
106. ump valve There is no way to know for sure that the pres sures are equal since there is no pressure gauge between the turbo pump and the main pump valve Once you have pumped out the vacuum hose open the main SPIFI pump valve The valve is spring loaded and can only be turned to either open or closed Never open this valve if SPIFI is under vacuum and you suspect that the hose is not pumped down or you could blow out the Fabry Pe rots Once the pressure in SPIFI reaches about 5x10 8x10 Torr the cool down process can be started We would like you to keep records of pump downs in the SPIFI notebook by creating a small table of pressure versus time This will allow both us to properly gauge SPIFI s progress and to compare with records of past and future pump downs 21 Pressure gauge for monitoring pressure inside SPIFI dis play on front of turbo pump Yellow Vac uum Valve Main SPIFI Valve 90 Elbow Pipe Figure 3 SPIFI Pump Manifold Pumping SPIFI Down from Atmospheric Pressure The basic procedure for pumping down SPIFI from atmospheric pressure is described here briefly for reference Note that the AST RO winterovers should not have to pump down SPIFI from atmospheric pressure during the 2004 winter season since we left SPIFI under vacuum when we left the South Pole at the end of the 03 04 summer season see the section above Pumping SPIFI Down from a Partial Vacuum State 1 Attac
107. utput of the power supply to the black female banana socket at the bottom of the battery box Note you only need to do this if the 4V battery needs charged it usually lasts much much longer than the 12V batteries Check to make sure all your connections make sense If everything looks okay plug in the two blue 12V chargers and the small power supply Turn on the power of the small power supply and set the output voltage and current to slightly above 4V say 4 25V and to 0 5A respectively Now put switches 2 and 4 on the battery box to the up position all the way up This will liven all the female banana sockets on the battery box and begin the charging process When the 12V batteries are fully charged the amperage on the blue chargers will drop down close to 0A and the charge complete indicator should light up although I think the charge complete indicator is burned out on one of the two chargers When the 4V battery is fully charged the amperage on the power supply will drop close to OA When the batteries are fully charged put switches 2 and 4 on the battery box to the down position all the way down This will deaden the female banana sockets on the battery box Turn the power button of the small power supply off and unplug the power supply and both blue chargers Disconnect all of the charging leads from the battery box make sure the chargers are all unplugged first or these leads will be live The box is now rea
108. w Make sure the magnet leads don t make a short Connects the magnet leads from the magnet control box 22 to the ADR We will use these leads to get current into and out of the solenoid coil which surrounds the salt pill And hence magnetize and demagnetize the salt pill See Figure 13 above 11 Check that the current direction on the magnet con troller 22 is set to the down position see Figure 15 below Therefore when you turn on the controller the magnet won t start ramping up automatically It is important that you don t ramp up until the persistent switch is opened step 13 below 12 Turn on both the magnet controller 22 and magnet power supply 23 at the same time see Figure 15 below Wait a minute or so until you can hear the fans in both boxes start up and running smoothly The magnet controller and power supply will be used to activate the persistent switch and to magnetize and de magnetize the salt pill 13 Turn the persistent switch heater 24 on the magnet controller to on by turning the key 90 clockwise see Figure 15 and below and Table 3 above The green indicator light should come on The persistent switch will open when heated i e it will go normal and develop a resistance This will block the short between the magnet leads 14 Wait 2 minutes Give the persistent switch time to heat up and open 15 Set the current rate to 1 amp sec and fli
109. witch should be set to 2A 12V AUTO e The SELECT FUNCTION switch should be set to CHARGE e The SELECT BATTERY switch should be set to NORMAL AUTOMOTIVE b For now turn the voltage and amperage on the small power supply all the way down to 0 You can ad just these to the appropriate values after everything is hooked up and you plug the power supply in 4 Make sure all of the switches on the battery box are down and all of the chargers are unplugged Each of the two blue 12V battery chargers has two male banana plug leads one red and one black Connect these leads Bold numbers in parenthesis refer to the S Locator Guide on hade 5 Locator Guide on page 9 10 11 12 13 60 to the female banana sockets on the battery box labeled Charge 12V Battery 1 top center on the battery box Make sure you connect black to black and red to red Do the same with the second battery charger and the second set of female banana sockets on the battery box located just below the top ones and labeled Charge 12V Battery 2 At the bottom center of the battery box you will see one more pair of red and black female banana sockets labeled Charge 4V Battery Connect these to the positive and negative outputs of the small power supply via red and black banana plug cables Make sure you connect the positive output of the power supply to the red female banana socket at the bottom of the battery box and the negative o
110. y flipping the switch on the breaker box on the wall e Close the gas inlet valve 18 on the manifold and go immediately to the next step f Slowly reopen the main valve 16 on the vacuum manifold Take at least 5 minutes to completely open this valve to minimize stress on the pump You won t be able to listen to the pump because it is downstairs so use your best judgement although Steve claims he can hear the change in the pump through its exhaust You should eventually see the pressure drop on the pressure gauge once it gets below 100 Torr the gauge has a range of 0 100 Torr The needle may oscillate wildly This is normal Sometimes you can dampen these oscillations by opening or closing the valve a bit The oscillations usually dampen out on their own once the pressure gets below about 30 Torr After some time 42 hour or so after fully opening the main valve the pressure should get below 10 Torr Make a record of this in the SPIFI notebook Eventually you will want 3 Torr Either during or after you have pumped down the ADR I He tank you will need to close the green Swagelok valve on the side of the ADR to seal off the He tank This is the first green colored valve handle on the top right of the ADR as viewed when looking in through the pillbox doors see Figure 5 below This must be closed before cycling the ADR Don t touch the other green Swagelok valve further back on the ADR or you will release all our He to th
111. you need to know about maintenance filling for the four cryogen tanks in the SPIFI system see page 22 for an introduction to SPIFI s four cryo tanks When check ing the level of cryogens in SPIFI s 1 N and I He tanks you may also need to refer to the height versus volume chart for SPIFT s tanks which is found in Appendix A on page 64 Table 7 Keep records in the SPIFI notebook every time you check the levels in these tanks Note that from the values shown in Table 2 one can assume an average usage of about 17L of I N per day and about 25L of 1 He per day Table 2 Summary of Cryogen Tank Maintenance Filling Tank Recommended Recommended to check Cryogens needed per Maximum Capacity of to refill every level every fill hold time tank L ADR l N2 22 hours or not possible 6 7L I Ne 22 hours 5 more often when cycling SPIFI I No 2 days 1 day use Steve s hand 20L I N gt 3 days 25 no pump carved wooden dipper before and after fills SPIFI I N gt 1 day not possible 10L I N2 minimum make same as same as with pump sure it doesn t suck air above above ADRI 4He 1 day or more not possible 8 10L He 1 day 5 often when cy cling SPIFII He 5 7 days check 3 days after a fill 100L He never start 7 days 65 then check more often as filling with a partially full needed use thumper 100L Dewar Also check immediately before and after any fill
112. you that the gas cell is already out of or in the beam path You can easily check if the gas cell is in or out of the beam path by typing the wrong command into the computer and noting the output or by looking at the yellow and green LEDs at the bottom of the remote The yellow LED should light if the gas cell is in the beam path and the green one should light if the gas cell is out of the beam path gas cell shown here left while removed from bleeder right line to calibration unit valve bleeder gas cell to valve lecture to gas bottle cell digital pressure gauge lecture bottle bleeder valve lecture bottle main valve gas cell pump manifold bottom bleeder valve to pump line to lecture bottle pump exhaust line to atmosphere 4 Tofill the gas cell with a gas of choice first make sure that all three green colored bleeder valves on the gas cell pump manifold 40 located in the enclosure under SPIFI on the battery box side are open Close the main valve on the gas lecture bottle 42 as it should already be See Figure 19 above 6 Ifthe main valve on the gas lecture bottle is closed open the green colored bleeder valve on the gas lec ture bottle 7 Turn on the orange pump 41 under SPIFI by plugging it in If the pump is very cold then you may need to physically disconnect the pump from the gas cell manifold and let it pump on the

SPIFI Operation Operation Manual 2004

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