Template for Final Paper - The Menlo Roundtable
Contents
1. 30 00 20 00 Coincidence frequency Hz 10 00 0 00 8 10 12 14 16 18 20 22 24 26 28 Hour 24 hour clock VI Conclusion Overall the project was a success though its solar muon results are not definitive The experimental results Table 1 amp Figure 5 support the idea of solar muon emission due to the correlation between the distance between the Sun and the Earth s surface and the observed muon coincidence rates with a noon peak of 62 64 Hz and a minimum value of only 32 46 Hz at 2AM the following morning with the Sun facing roughly the other side of the planet Error for the day night experiment was calculated using standard deviation of the coincidence frequencies as shown in Figure X s error bars Due to the magnitude of error involved approximately 10 on average our conclusions regarding noticeable solar muon activity are only probable not certain but the data does certainly seem to suggest that the solar muon effect does exist Error in this experiment could have been caused by irregularities aging of the scintillator material or PMTs QuarkNet hardware malfunction programming error in the Python script unexpected muon shower or other non solar fluctuation in natural muon emission unknown shielding effects of the experiment site or unknown unnatural sources of muon emission rates These could have caused the numbers to be biased or entirely incorrect though their coherency makes this2. def binary2int bin return int join reversed bin 2 utility function from itertools recipes def groupIn n iterable padvalue None grouper 3 abcdefg x gt a b c d e EE ge ge Se return list izip chain iterable repeat padvalue n 1 n def connect Connect to serial port QuarkBoard is connected to and output connection details Returns opened PySerial serial Serial object or exits on failure global PORT print Opening serial port try PORT serial Serial port 0 baudrate 19200 xonxoff True except serial SerialException e print failed print Error while connecting e message print Exiting on error exit 1 else print done print Connected on serial port s PORT port print Baud rate PORT baudrate print Xon Xoff enabled PORT xonxoff print Timeout PORT timeout if PORT timeout is not None print seconds lse print stopCounting VERIFICATION GREETING Quarknet Scintillator Card EXTRA GREETING LINES 3 RESET DELAY 1 def resetBoard Reset board to defaults Also confirms that board is connected if OUTPUT print Resetting board configuration to defaults writeln RE sleep RESET DELAY T if V RIFICATION GREETING not in readline
3. ignore r pair in pairs grab hex number sj convert hex to integer for i in 1 def readScalers Return ScalerData obj representing output from DS cmd if OUTPUT print Reading scaler values writeln DS atLine eat echoing of cmd pairs readline strip split 1 split spaces leading DS field hexVals pair split 1 fo from S1 846738 like fields scalers int val 16 for val in hexvVal scalers pop discard S5 the 1PPS signal GPS related if OUTPUT print done print Scaler values scalers return ScalerData scalers scalers 4 def prompt4chans Prompt user for coincidence and channel settings channels ask4bool Enable scintillator s i xrange 4 nFold ask4num Detection fold to be considered a coincidence 4 setupChannels nFold channels def prompt4period Prompt user for coincidence setTriggerPeriod ask4num Period d considered a coincidence in s ns ticks def prompt4width trigger period for triggers to be NS_PER TICK 2 Prompt user for gate width setGateWidth ask4num Gate width def terminal w TRIGGE R Gives user terminal like access to board connect print You n print Enter while True input if input p exit writeln sleep 1 while p rin rin def filename2log Generates return DATA def ma
4. f OUTPUT print failed raise IOError Card not connected properly QUESTION add SA 1 or SA 2 here try both ways eatLine EXTRA_GREETING LINES if OUTPUT print done H Ef T def disableCounters Disable coincidence counters print Disabling coincidence counters writeln CD atLine print done def enableCounters Re enable coincidence counters and start displaying data lines if OUTPUT print Enabling coincidence counters writeln CE eatLine 2 if OUTPUT print done def setupChannels fold channels bit twiddling has been checked to be theoretically correct Sets coincidence level and enables desired channels fold int indicating coincidence level required channels list of bools specifying which channels on off if len channels 4 raise ValueError On off state not specified for all channels if fold lt 1 or fold gt 4 raise ValueError Invalid of channels specified if OUTPUT print Enabling channels amp setting coincidence level leftChar hexSans0x fold 1 channels reverse convert channels from bools to ints 0 or 1 then combine into binary string and convert that to hex rightChar hexSansOx int join str int chan for chan in channels 2 writeln WC 00 leftChart rightChar eatLine 2 if OUTPUT
5. 7 2006 4 Sanuki et al Atmospheric neutrino and muon fluxes 29th International Cosmic Ray Conference Pune 00 p101 104 2005 5 Ochanov Calculation of the atmospheric muon flux motivated by the ATIC 2 experiment 30th International Cosmic Ray Conference 6 2007 6 Wikipedia The Free Encyclopedia Muon Wikimedia Foundation Inc http en wikipedia org wiki Muon last modified 5 08 2008 3 14PM UTC 7 Wikipedia The Free Encyclopedia Pions Wikimedia Foundation Inc http en wikipedia org wiki Pions last modified 3 23 2008 1 06PM UTC 8 Wikipedia The Free Encyclopedia Scintillator Wikimedia Foundation Inc http en wikipedia org wiki Scintillator last modified 3 22 2008 10 13AM UTC 9 Jeff Tyson How Night Vision Works Howstuffworks http electronics howstuffworks com nightvision htm 10 Rylander et al QuarkNet Walta CROP Cosmic Ray Detectors User s Manual 08 2004 11 Python programming language version 2 5 Guido van Rossum et al Python Software Foundation http python org 4 2008 12 Dr James Dann Applied Science Research class Menlo School Atherton CA 2007 2008 Acknowledgments The author experimenter would like to take this opportunity to thank e Dr James Dann for coming up with the idea for this project and helping explain some of the physics and electronics behind the experiment to me e Jeff Rylander Tom Jordan R J Wilkes Hans Gerd Berns Richard Gran Fermilab and the University
6. ER TICK None log file DIR fF writel tt Wri PORT w se d Ww Pp P fe ull w in the manual 24 tick 24 nanoseconds C Documen logs in csv extension of log files rue ts and Settings MenloTech Desktop None folder WW n s te line of text to board with proper newline char rite s NEWLINE _ debug __ rite writeln te s rint rin RRR ld write s S writeln new write def BOAR def readline Reada 1l line PORT if re turn line ELAY 1 tLine n 1 D DI at vy fo Retrieve roi in xr sleep BOARD D readlin _ debug __ ine of ou creadline tput from the board strip pass print GOT line in seconds yes and discard next output line from the board ange n FLAY wait for board to catch up e def hexSans0x n Returns string representing integer n in base 16 without leading Ox return hex n 2 upper def int2bin n bits 8 Returns int n represented in binary as a string using count number of digits return join str n gt gt y amp 1 for y in range count 1 1 1 def hex2binDigits hexNum convert from hex to string of binary digits then reverse string so digits n is nth bit n starts 0 digits join reversed _int2bin int hexNum 16 return digits
7. ext filepath Write line LOG write line def parseEventLin to Tlog tile tt fields line log join f triggerCount riseFalls groupIn 2 fields n line split 9 chop off GPS fields ields int fields 0 16 parseRise rise parseFall fall for rise fall 1 def parseRise hexVal bits hex2bin ticks binary valid bool i newTrigger b def parseFall hexVal bits hex2bin ticks binary Digits hexVal 2int bits 5 nt bits 5 ool int bits 7 Digits hexVal 2int bits 5 valid bool int bits 5 DEFAULT D 6 DEFAULT W 10 def calibrationExpmt f file ask4aLog Filename to log incidents to csv whb w writer DATA f print Connect scintillator to QuarkBoard port 0 wait4user w writerow Scintillator ask4str Scintillator s designation w writerow trigger period d ticks DEFAULT D w writerow gate window w ticks DEFAULT W fieldNames voltage time s scaler scal freq Hz w writerow fieldNames DURATION ask4num Duration of each run sec kind int print Connect scintillator to be calibrated to port 0 wait4user try while True connect v ask4num Sc
8. of Washington for writing the user s manual for QuarkNet e the myriad of people who developed the QuarkNet data acquisition unit e the Menlo School Technology Department for finding and letting me use their serial cable and gender changer e Chris Liechti developer of the PySerial library which made writing my program infinitely easier e the Applied Science Research class of 2008 for providing me encouragement and entertainment while I agonizingly waited for my program to gather data Appendix A Python scripts Please note that line wrapping by the word processor may have slightly altered the sources whitespace quarknet py user friendly console interface to the QuarkNet DAQ board us Prog Copy rom mpor rO rO rO rO rO rO rO Fy FH h h hhh Fh m m m m m m m EWLINE F ORT None serial r bin env python ram righ _ future _ t se time menu sys import exit itertools time impo csv import writer os path import to facilitate interaction with QuarkBoard t 2008 Christopher V Rebert import division rial import sleep lib import time strftime import izip rt time sleep chain repeat exists INTA Line char connection to QuarkBoard Quarkboard s new F RIGG R P ERIOD d in the manual MC_DE S_P DATA DATA tO STO DAT TA OUTPUT au de if Fal ol def new wri re EXT AY
9. turn val s s lstrip 0 print val gt maxi validator Non r errMsg raw_input question if validator and not validator input else re wait4user Does not raw_input P turn ress return unt Ente input r to continue Or r a string for which val is not None else lid input Not within valid kind int r Invalid input Must be a valid mini is not None and Ww o range s 6 rng rrMsg Try again Lidator returns True print error til user acknowledges the program print print def valida Chec Allowed spaces for cha at return teFilename name k that proposed filename contains only valid characters chars are letters digits underscores dashes and r in name char not in ACC return False True EPTABL BAD FILENA M underscores def ask4fil lasks v the given def val return def ask4cho Asks prompt while T E MSG Filename must contain only letters digits dashes or spaces and must not already be in use prompt validator the user for a filename validator idater s return _ ask4str prompt val 1 E that passes _validateFilename and and validator s E MSG validateFilename s idater _BAD_ FILENAM ice prompt titleValPairs the u
10. voltage setting 0 917V which gave reading of 40 18Hz Scintillator A count rate thresh 0 3V 200 180 160 140 120 100 incidence frequency Hz 0 85 0 9 0 95 1 1 05 1 1 1 15 PMT voltage V Figure 2 Graph of scintillator B raw count data Optimal voltage setting 0 983V which gave reading of 39 83Hz Scintillator B count rate thresh 0 3V 120 100 80 60 40 20 incidence frequency Hz 0 0 85 0 90 0 95 1 00 1 05 1 10 1 15 PMT voltage V Figure 3 Graph of scintillator C raw count data Optimal voltage setting 1 019V which gave a reading of 39 62Hz scintillator C count rate thresh 0 3V 80 70 60 50 40 30 20 10 0 0 850 0 900 0 950 1 000 1 050 1 100 1 150 PMT voltage V incidence frequency Hz Figure 4 Graph of scintillator D raw count data Optimal voltage 0 910V which gave a reading of 38 31Hz Scintillator D count rate thresh 0 3V 300 250 200 150 100 50 0 0 850 0 900 0 950 1 000 1 050 1 100 1 150 PMT voltage V incidence frequency Hz Data Table 1 Plateauing results for scintillator A Voltage V Frequency ratio 0 729 0 00314 0 835 0 0192 0 947 0 860 0 951 0 928 0 957 1 0
11. 2 0 970 1 13 1 106 1 42 1 120 987 1 140 7260 Data Table 2 Plateauing results for scintillator B Voltage V Frequency ratio 0 737 0 00528 0 886 0 0344 0 976 0 941 0 982 0 973 1 003 0 986 1 062 1 108 1 119 1 242 1 360 769 1 429 8416 Data Table 3 Plateauing results for scintillator C Voltage V Frequency ratio 0 754 0 00259 0 861 0 0385 0 972 0 969 0 989 0 981 1 089 1 09 1 154 1 26 1 189 1 48 1 359 747 1 412 4392 Unfortunately I was unable to figure out how to create an Excel graph with a logarithmic scale as is required for graphs of the plateauing data to be intelligible but exponential trends are clearly visible in the data and based on 10 ratios closest to 1 0 indicate optimal voltage These voltages are summarized in Table 4 Data Table 4 Optimum voltages for scintillators based on plateauing Scintillator Optimum voltage V A 0 957 B 1 003 C 1 089 The following experimental results Table 5 amp Figure 5 from the day night muon detection experiment support the idea of solar muon emission because the muon coincidence rates increased to a noon peak of 62 64 Hz when the Sun is approximately overhead and closest to the Earth s surface and then decreased all the way down to 32 46 Hz at 2AM the following morning with the Sun shining all the way on the opposite side of the E
12. 753 48 03 0 983 39 83 1913 48 03 0 984 42 39 2036 48 03 0 985 41 94 2015 48 05 0 993 46 43 2230 48 03 1 003 48 28 2319 48 03 1 105 100 39 4822 48 03 Data Table 4 Raw count calibration data for scintillator C Voltage V incidence frequency Hz lincidence count _ time s 0 910 16 76 805 48 03 0 921 17 30 831 48 03 0 935 19 86 954 48 03 0 945 19 92 957 48 05 0 950 21 57 1036 48 03 0 963 23 26 1117 48 03 0 973 25 09 1205 48 03 0 982 27 79 1335 48 03 0 995 30 42 1461 48 03 1 019 39 62 1903 48 03 1 110 73 18 3515 48 03 Data Table 5 Raw count calibration data for scintillator D Voltage V incidence frequency Hz lincidence count _ time s 0 892 33 85 1627 48 06 0 902 36 02 1734 48 14 0 910 38 31 1840 48 03 0 914 42 22 2030 48 08 0 925 45 37 2179 48 03 0 942 53 19 2559 48 11 0 953 56 78 2730 48 08 0 964 63 79 3071 48 14 0 975 76 75 3691 48 09 1 100 252 96 12150 48 03
13. Applied Science Research Dann Christopher Rebert 5 10 08 Final Project Paper Muon lifetimes I Abstract In this project the number of atmospheric muons was measured at day and night using provided scintillators and a QuarkNet DAQ board This entailed raw count calibration counter plateauing and the creation of a Python program to more easily interact with the QuarkNet board Experimental results support the idea of solar muon emission with coincidence rates increasing until a noon peak of 62 64 Hz when the Sun is approximately overhead and closest to the Earth s surface and then decreasing all the way down to 32 46 Hz at 2AM the following morning with the Sun shining on the opposite side of the Earth II Motivation and History Originally I had intended to do an experiment proving relativity by showing a discrepancy in the lifetimes of cosmic ray muons which sounded particularly intriguing to me 1 It would also involve writing a program to communicate with the DAQ unit and being a programmer this piqued my interest However once Dr Dann had located the exact paper outlining the experiment we both concluded that it would not be feasible for a high school student considering the limited time remaining in the course However having already made significant progress on my computer program and finished initial calibration I decided to proceed with an alternate muon related experiment After consulting further with Dr Dann it was de
14. another in a sandwich configuration with some wood blocks used to space and stabilize them Scintillator D was not used due to time constraints and only 3 scintillators being required for plateauing For ease of explanation in the plateauing experiment let e 1 be the top scintillator e 2 be the middle scintillator e 3 be the bottom scintillator In the plateauing experiment 2 fold coincidences between 1 amp 2 were counted for 120s and then 2 fold coincidences between 1 amp 3 were counter for 120s The ratio of the frequency of the former over the frequency of the latter term is then calculated This process is then repeated for several PMT voltage values and the frequency ratio vs PMT voltage is then plotted The voltage where the graph is flattest is then the optimal value The scintillators are then repositioned appropriately and the entire process conducted again to plateau the next scintillator until all of them have been plateaued In the day night experiment 2 fold coincidences between the scintillators were counted and polled periodically throughout consecutive 1 hour periods with the starting and ending times of each period noted Simple division yields average muon rates for each 1 hour period which can then be plotted V Results The results of the initial scintillator calibration may be found in Tables 2 5 in Appendix B and Figures 1 4 which follow Figure 1 Graph of scintillator A raw count data Optimal
15. arth This correlation of Sun exposure and muon coincidences suggest that the Sun is outputting muons which are then detected when the Sun is visible thus increasing the observed muon counts However as discussed in the Conclusion s error section these data do not prove definitively that the Sun is emitting muons Data Table 5 Data from day night muon flux experiment Time period Coincidence frequency Hz Time elapsed s Coincidences 10 02 12AM 11 00 07AM 54 71 3475 190128 11 00 15AM 12 00 24PM 59 22 3609 213731 12 00 33PM 01 00 38PM 62 64 3605 225815 01 00 47PM 02 00 03PM 60 42 3556 214867 02 00 18PM 03 00 23PM 57 36 3605 206781 03 00 40PM 04 00 01PM 53 28 3561 189733 04 00 52PM 05 00 29PM 48 16 3577 172257 05 00 37PM 06 00 08PM 49 83 3571 177949 06 00 42PM 07 00 31PM 48 25 3589 173156 07 00 56PM 08 00 11PM 43 56 3555 154839 08 00 38PM 09 00 21PM 41 32 3583 148041 09 00 32PM 10 00 03PM 38 07 3571 135934 10 00 06PM 11 00 55PM 39 79 3649 145194 11 01 09PM 12 00 48AM 35 89 3579 128468 12 00 53AM 01 00 40AM 34 56 3587 123982 01 01 13AM 02 00 10AM 32 46 3537 114813 02 00 34AM 03 00 36AM 33 91 3602 122142 Figure 5 Graph of day night experiment data with error bars Error calculated using standard deviation Hour values greater than 24 indicate times in the following day 70 00 60 00 50 00 40 00
16. at freq _lplateauDatum top plateaued bot log writerow v freq DATA flush if ask4bool Done plateauing break DATA close def dayNight setupParameters nPeriods ask4num Number of periods duration ask4num Duration of periods min delay ask4num Time to wait before beginning w writer DATA w writerow start end elapsed s frequency Hz DATA flush base time doneInit time delay doneInit base sleep delay for i in xrange nPeriods togo duration oldcount 0 total start time while togo gt 0 count coincidenceCount if count lt oldcount 0 total oldcount oldcount count sleep 60 togo 60 end time x plateaued PLATEAU DURATION mini 2 60 xperiment sec coincidences total count elapsed end start w writerow strftime start strftime end elapsed total total elapsed DATA flush DATA close def prompt4DataDir global DATA DIR DATA DIR ask4dir Log amp data directory def setupParameters connect prompt4log prompt 4period prompt 4width prompt4chans ACTIVITIES Calibrate scintillator calibrationExpmt Terminal interface to Quarkboard terminal Plateau scintillator plateauExpmt Perform day night solar muon experiment dayNight try prompt4logDir prompt4log ask4choice C
17. calers coins offset PORT clos end time OUTPUT print e oldoOutput Done gathering datum elapsed end start freq co ins elapsed return freg ALL OFF False 4 def lplateauDatum top mid bot PLATEAU DURATION print Gathering datapoint first ALL OFF first top first mid True second ALL OFF second top second bot True numer _runCoinExpmt first PLATEAU DURATION print Power cycle the QuarkBoard wait4user denom _runCoinExpmt second PLATEAU DURATION ratio numer denom print Datapoint calculated print Coincidence frequency ratio ratio return ratio def plateauExpmt PLATEAU DURATION ask4num Duration of one plateauing experiment run sec mini 0 kind float plateaued 1 top 0 bot 2 print Connect 3 scintillators in a sandwich configuration as follows print Top scintillator connected to port s top print Middle scintillator to be plateaued connected to port s plateaued print Bottom scintillator connected to port s bot wait4user f file ask4aLog Log file to output plateauing data to CCST a Swit log writer DATA log writerow Scintillator voltage V Coincidence frequency ratio while True v ask4num Scintillator s voltage V kind flo
18. cided that I would do a day night comparison experiment wherein I would count the number of muons per hour during day and night and see if there was an appreciable difference between the night and day numbers There have been a few fairly recent studies about atmospheric muon detection In 2 the experimenters used an underwater neutrino telescope and evaluated its performance as well as that of their DAQ system They also measured muon flux as a function of zenith angle and found their data to be in line with previous measurements and predictions 3 was a similar experiment measuring muon flux at the South Pole at 5 different zenith angles using a unique scintillator compound 4 examines muon flux at several altitudes and uses the data to calculate the error in neutrino flux generated by a certain neutrino interaction model which they then go on to refine themselves 5 uses cosmic ray energy spectrum data from a balloon experiment to calculate cosmic ray muon flux at ground level and finds the results to be in keeping with those of similar experiments III Theory of operation To begin with according to the Standard Model of particle physics the muon symbol u is an elementary particle with electric charge le and spin 4 It was discovered by Carl D Anderson winner of the 1936 Nobel Prize in Physics in 1936 at Caltech 6 When cosmic rays high energy particles from space hit atoms in the atmosphere they react producing among oth
19. djusts the PMT voltage so that the data acquired contains a minimum of electronic noise and a maximum of real muon interactions If the voltage is set too high then electronic noise will be heavily amplified and give false positives If the voltage is set too low then the amount of data acquired will be significantly decreased only high energy muons will be detected while low or medium energy muons will be ignored resulting in the loss of legitimate data In the multi counter plateauing step the flat part of the graph is chosen as this indicates that one is detecting most of the muons present with only minimum electronic noise and increasing the voltage slightly is finding no additional muons The edges of the graph go up and down exponentially due to the cascading effect used by the PMTs For the raw count calibration PMT voltage was varied and incidence counts were taken at each voltage setting for 45s From this the incidence rate was calculated The scintillators were laid flat on a countertop with nothing on top of them so as to avoid any extra muon shielding and expose maximum surface area to skyward muon detection As a muon incidence rate of 40Hz at ground level had been established as the accepted value 12 the PMT voltage was set to the voltage setting which gave a reading closest to 40Hz until after counter plateauing was done For the plateauing experiment and the day night experiment the scintillators were placed one on top of
20. er things pions non elementary particles that quickly decay into muons and neutrinos via the following reaction T gt u tv These muons then continue traveling along almost exactly the same path as their progenitor pions It is also theorized that the Sun could be producing muons as a result of its nuclear reactions 7 When a muon hits a scintillator the scintillator then absorbs the radiation and in response fluoresces 8 The light produced is then directed into a Photomultiplier Tube PMT In the PMT after being focused by a lens the photons are converted into electrons by a photocathode These electrons go through a MicroChannel Plate MCP a plastic disc with metal electrodes on each side and millions of microscopic holes in it High voltage bursts that are constantly sent through the electrode pair accelerate the electrons through the microchannels in the plate causing cascaded secondary emission drastically increasing the number of electrons 9 These electrical impulses are then conveyed via Lemo signal cables to ports on the QuarkNet DAQ board for processing After being amplified by 10x the signal is sent through discriminators The discriminators check whether the signal meets a specified threshold level set by potentiometer If it does then this constitutes an incident and the incident counter for that scintillator is incremented And if at least a specified number of incidents occur within a specified time interval this const
21. hoose activity ACTIVITIES finally print Goodbye print Closing port try PORT close except pass print done print Closing log file try LOG close except pass print done menulib py simple console based menu driven user interface library from os path import isdir from string import ascii letters as LETTERS digits as DIGITS _ACCEPTABLE set LETTERS DIGITS del LETTERS DIGITS def ask4bool question Asks the user a yes no question Returns a bool indicating their response question while True input raw_input question lower if input in yes y return True elif input in no n return False print Invalid input Must b ither y es or n o def ask4num question Asks the user for an integer within the given range str maxi decimal numbe maxi is not None and val def def rng WoW mid UVesyouns A if maxi is not None else rng mini None maxi None if mini ae Y rJe str mini if mini is None and maxi is None n mid prompt while True try s al val except S al lt mini print else re Valuel question mid raw input prompt 0t kind s Error ask4str quest Asks the user fo question Invalid input error while True input tion Inval
22. intillator voltage V kind float setTriggerPeriod DEFAULT D setGateWidth DEFAULT W init _ask4boardValue print Gathering data This will take str DURATION seconds xxx prevOutput OUTPUT OUTPUT False start time setupChannels 1 True 3 False sleep DURATION s readScalers end time print Data gathered OUTPUT True scal s scalers 0 init c s coins duration end start being cal def def def seconds finally DATA exit 0 OTH tM S O KH EH req scal duration v duration scal freq rint Incidence frequency freq Hz writerow row ORT close f ask4bool Done with this scintillator break rini O Power cycle the QuarkBoard Also change the voltage setting on the scintillator rint librated wait4user DATA flush close _ask4counter prompt Asks the user for a number corresponding to a port return ask4num prompt mini 0 maxi 3 kind int coincidenceCount return readScalers coins _runCoinExpmt chans PLATEAU DURATION global OUTPUT connect setTriggerPeriod 6 setGateWidth 10 offset coincidenceCount print Gathering datum Please wait str PLATEAU_ DURATION kkk oldOutput OUTPUT OUTPUT False start time setupChannels 2 chans sleep PLATEAU DURATION coins readS
23. itutes a coincidence and the coincidence counter is incremented There are also 2 parameters d and w The incidence and coincidence counts can then be read by computer over a serial cable connection 10 The interactive console based Python 11 script communicates using the simple ASCII based commands defined in the user manual 10 while presenting a friendlier menu driven interface to users and not requiring them to know anything about the DAQ board s command language Note that the script should work on both Windows and unix including Mac systems but only Windows was used in this project due to the difficulty of locating a Mac with a serial port or a serial port adapter For further information on how the script operates see the heavily commented source in Appendix A IV Design Due to uncertainty as to their effect d and w were left at their default values d 6 144ns w 10 240ns 10 throughout the experiment 0 3V was used as the threshold voltage value throughout this experiment on the advice of Dr Dann All experiments took place in the first floor ASR classroom at Menlo School approximately at ground level Before performing the day night experiment it is necessary to plateau the scintillators This is done in 2 steps raw count calibration and multiple counter plateauing Plateauing is needed to compensate for differing PMT gain and aging degredation of the scintillator material in order to get accurate data Plateauing a
24. keValidato def validat ERIOD 1 ow have terminal access to the Quarkboard end to terminate the session raw input QuarkNet gt get cmd from user lower end t Exiting 0 input PORT inWaiting gt O display output t readline Path filename ext full path to log fil DIR filename xt r ext or name le based on given filename Checks whether a filename has already b directory path return n rn vali retu def as k4aLog pro iP file retu log def prompt4log Prompt us create def create tt LE lobal OUT yi Log fi DATA PUT P ct HQ Hooh DATA f except Envir print Bt E E E Sy print print raise else if OUTPU prin prin prin def log line Er ot exists path dator mpt ext er for lepath rint Creating log file w err ile filepath onmentError stemExit Les 4 done filename2logPath name rn filename2logPath ask4file prompt ror opening log file iting on error ext rompt user for log file name and return full makeVa file to log to and open the Log ask4aLog Filename to log data to reate log file or die on error o SS str e n used in the log DAT pa lida th of desired tor ext TA
25. less likely Over the course of the project much was learned about interfacing with scientific hardware as well as the particle physics involved in the experiments Unfortunately much time was taken up by learning and trying to understand the somewhat arcane operation of QuarkNet board which left less time in which to perform the actual experiments Future work could include re doing of the experiments for longer time periods to further minimize error calibration and plateauing of scintillator D and enhancement of the program produced including proper handling of the integer overflow of the QuarkNet incidence and coincidence counters and parsing of the live data words stream the board makes available but was not utilized by this project Unfinished code for the data words processing is included in the quarknet py source Hopefully future classes or projects can build on the experience and tools gleaned from this experiment to do more interesting or complex experiments VII Bibliography 1 Nichols A Romero amp Mukund T Vengalattore Speed and Decay of Cosmic Ray Muons Junior Physics Laboratory Massachusetts Institute of Technology 1998 2 The NESTOR Collaboration Aggouraset al A measurement of the cosmic ray muon flux with a module of the NESTOR neutrino telescope Astroparticle Physics 23 p377 392 2005 3 Bai et al Muon flux at the geographical South Pole Astroparticle Physics Volume 25 Issue 6 p361 367
26. print done def stopCounting Stop incidence and coincidence counters global OUTPUT if OUTPUT print Stopping counters oldOutput OUTPUT OUTPUT False setupChannels 4 False 4 OUTPUT oldOutput if OUTPUT print done def setTriggerPeriod ticks Set in ticks how close time pulses must be to cause a trigger global TRIGGER PERIOD period is difference between memory cells 01 and 02 so set cell 01 to 0 d as ote to given value in timeOvertThresh TRIGGER PERIOD ticks if OUTPUT print Setting trigger period writeln WT 01 00 eatLine 2 writeln WT 02 s hexSansOx ticks zfill 2 eatLine 2 if OUTPUT print done def setGateWidth ticks Set gate width w in the board manual treks trI if OUTPUT print Setting gate width w TMC_DELAY ticks bits hexSans0x ticks zfill 4 4 hex digit number split across 2 memory cells writeln WC 02 s bits 2 eatLine 2 writeln WC 03 s bits 2 eatLine 2 if OUTPUT print done class ScalerData object Represents output of DS command def init self scalers coins self scalers scalers self coins coins coincidence count self timeOver timeOverThresh
27. ser to choose an option from a list 2 rue print prompt print len prompt 2 for i titleVal in enumerate titleValPairs title titleVal 0 print s i 1 title print try choice int raw_input Enter the number of your choice ie Ue a if choice gt i or choice lt 0 raise ValueError except print Invalid input Try again wait4user continue else break print print return titleValPairs choice 1 def ask4dir prompt Asks the user for an existing directory prompt while True path raw input prompt if isdir path return path print Directory does not exist Try again wait4user Appendix B Raw count data Data Table 2 Raw count calibration data for scintillator A Voltage V incidence frequency Hz incidence count _ time s 0 867 26 19 1258 48 03 0 878 30 40 1460 48 03 0 889 32 69 1570 48 03 0 902 36 62 1759 48 03 0 917 40 18 1930 48 03 0 921 42 24 2029 48 03 0 931 50 86 2443 48 03 0 940 51 13 2456 48 03 0 951 55 86 2683 48 03 1 109 187 02 8983 48 03 Data Table 3 Raw count calibration data for scintillator B Voltage V incidence frequency Hz lincidence count _ time s 0 908 20 51 985 48 03 0 920 22 90 1100 48 03 0 931 24 48 1176 48 03 0 940 27 32 1312 48 03 0 952 31 98 1536 48 03 0 960 31 92 1533 48 03 0 970 36 50 1
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