ADAS308: Charge exchange spectroscopy
Contents
1. The data sets generally contain nl resolved cross section data but n resolved and nlm resolved are handled Resolution levels must not be mixed in datasets The ADFOI file nmaes distinguish different sources The first letter o or the code old has been used to indicate that the data has been produced from JET compilations which originally had parametrised distribution of cross sections The nl resolved data with such code has been reconstituted from them Data of code old is the preferred JET data Other sources codes include ory old Ryufuku ool old Olson ofr old Fritsch and omo old molecular orbital There are newer data such as kvi Additional codes are used for excited donors such as ex2 for hydrogen n 2 Click on a name to select it The selected name appears in the smaller selection window above the file display window Then the individual datafiles are presented for selection Datafiles all have the termination dat 4 Once a data file is selected the set of buttons at the bottom of the main window become active ADAS User manual Chap4 08 17 March 2003 Input Recombining Ion File Data Root m is coll u adas adas adfO1i User Data _ Edit Path Name gt 2 igcxth0 qcxth0 oldthe2 dat qcex h0_e2p h1 dat qcex h0_e2s h1 dat qcex h0_en2_kvi b5 dat qcex h0_en2_kvithbe4 dat qcex h0_en2_kvi c6 dat Data File qcxthO en2 kvithe2 dat qcex h0_en2_kvi 1i3 dat qcex h0_en2_kvi ne10 dat qcex h02. 02 0438D 11 2981 17 6 4 5 3 4 1148D 02 2 8450D 11 2981 37 6 5 5 4 5 5806D 02 5 7400D 11 2981 48 SUMS 1 3286D 03 1 0000D 12 MEAN WVL A 2981 39 EFF RATE COEFFT 1 9457D 08 ADAS User manual Chap4 08 17 March 2003 CM 2 PH CM 2 SEC 1 A 5 0 4 1 1 7194D 01 6 9357D 09 1619 35 N L N4 21 1COB10B0B1 QOD63BMIB89 AIR6GWVLNB2 5 1 4 0 1 7510D 01 8 0720D 09 1618 66 5 2 4 3 9 6686D 01 3 0518D 09 1619 48 5 2 4 1 9 6686D 01 8 9831D 10 1618 91 5 3 4 2 3 0982D 02 5 0070D 11 1619 22 5 4 4 3 6 7088D 02 1 7847D 12 1619 35 1 1121D 03 2 3953D 12 MEAN WVL A 1619 30 EFF RATE COEFFT 4 6607D 08 N L N L1 COL POP COL EMIS AIR WVLN CM 2 PH CM 2 SEC 1 A 4 0 3 alt 4 5713D 01 5 2466D 10 761 66 4 1 1 8361D 01 3 9904D 09 762 10 4 1 3 0 1 8361D 01 3 5193D 10 760 40 4 2 3 1 1 2747D 02 5 6097D 11 760 94 4 3 3 2 5 1345D 02 4 4270D 12 761 59 SUMS 7 0500D 02 5 0796D 12 MEAN WVL A 7061551 EFF RATE COEFFT 9 8836D 08 SUMMARY OF EMISSIVITIES N N1 COL POP COL EMIS AIR WVLN EFF COEFFT CM 2 PH CM 2 SEC 1 A CM3 SEC 1 6 5 1 3286D 03 1 0000D 12 2981 39 1 9457D 08 15 4 1 1121D 03 2 3953D 12 1619 30 4 6607D 08 4 3 7 0500D 02 5 0796D 12 1615351 9 8836D 08 Notes ADAS User manual Chap4 08 17 March 2003
3. 03eV ION DENS 2 50 113 5 ELECTRON DENS S5 00E 13cm EFFECTIVE Z 200 me 1 MAG INDUCTION 3 007 a ee fe BEAM PARAMETERS t lt lt 157 7 INDEX FRACTION ENERCY eV T m 1 0 830 8 00E 04 8 E 2 0 100 4 00E 04 amp 3r x 5 0 070 2 70E 04 o OBSERVED SPECTRUM LINES 2 80 J INDEX NU NL COL EMIS Ph cm s a 1 s 1 6 5 1 00E 12 2r d Cat oW 74 MODEL INFORMATION CHARGE EXCHANGE MODEL INPUT DATA SET EMISSION MEASURE MODEL CHARGE EXCHANGE 0 5 4 L L fi 0 0 li li 2970 2980 2990 3000 2970 2980 2990 3000 WAVELENGTH A WAVELENGTH A ADAS User manual Chap4 08 17 March 2003 The analysis of charge exchange emission by the code is shown in figure 4 8a and table 4 8a Emission following electron capture by B from neutral deuterium beam atoms in their ground state is illustrated A single observed line of sight emissivity in the transition BV n 6 gt n 5 is analysed Figure 4 8a shows the theoretical breakdown of emission in the above line into multiplets and the expected Doppler broadened profile of the feature Table 4 8a shows the tabular output A detailed tabulation of the component photon fluxes is allowed for three spectrum line In this case BV n 6 5 is the observed line For the other selected charge exchange lines the predicted photon fluxes are computed using the calculated emission measure The spectrum lines BV n 5 4 and BV n 4
4. 3 are so tabulated Table 4 8a ADAS RELEASE ADAS93 V1 13 PROGRAM ADAS308 V1 6 DATE 16 04 98 TIME 13 10 TABULAR INPUT FROM L RESOLVED CHARGE EXCHANGE EMMISIVITY PROGRAM ADAS308 DATE 16 04 98 FILE home anderson adas adf01 qcx h0 qcex h0_old b5 dat RECEIVER NEUTRAL DONOR ELEMENT SYMBOL B H NUCLEAR CHARGE 5 RECOMBINING ION CHARGE 5 RECOMBINED ION CHARGE 4 ATOMIC MASS NUMBER 14 00 PLASMA PARAMETERS ION TEMPERATURE EV 5 00D 03 ELECTRON TEMPERATURE EV 5 00D 03 ION DENSITY CM 3 2 50D 13 ELECTRON DENSITY CM 3 5 00D 13 PLASMA EFFECTIVE Z 2 00 MAGNETIC INDUCTION T 3 00 BEAM PARAMETERS NUMBER OF BEAM COMPONENTS 3 INDEX FRACTION ENERGY EV 1 0 830 8 00D 04 2 0 100 4 00D 04 3 0 070 2 70D 04 OBSERVED SPECTRUM LINES NUMBER OF OBSERVED SPECTRUM LINES 1 INDEX NU NL COL EMIS PH CM 2 SEC 1 1 6 5 1 00D 12 CHARGE EXCHANGE MODEL INPUT DATA SET EMISSION MEASURE MODEL CHARGE EXCHANGE EMISSION MEASURE CM 5 5 1394D 19 N QEX N QTHEOR N CM3 SEC 1 CM3 SEC 1 6 3 7316D 08 3 7316D 08 nX PREDICTED EMISSIVITES N L COL POP COL EMIS AIR WVLN CM 2 PH CM 2 SEC 1 A 6 0 5 1 1 0898D 01 8275D 09 2981 51 6 1 5 2 2 3622D 01 4171D 09 2981 75 6 1 5 0 2 3622D 01 3 5889D 09 2980 26 6 2 5 3 9 3747D 01 2 2909D 09 2981 64 6 2 5 1 9 3747D 01 2 6350D 10 2980 65 6 3 5 4 2 3080D 02 6414D 09 2981 63 6 3 5 2 2 3080D
5. Tier bep Dev o iia 7 ieee eC predictions Tes deca 1 Ga lew dese ae 5 i 13 Required mmizrivity prediction Le i FOG B fam T me i Tu E eva H rd Delect charge srchange Ekesry Wss input data set gener siata HOG telect emission measure model Charge exchange Edit Tahle Ix coke table printing raqui rad Ue Hub ramum all srd A gme i allied M paml Erp d Uraphrcal amd abolar eet mam 22 E Tabular oobpet oly iram 5 oran blamk ote Blank s Zomeary mip Edit th pressing options data and press Tone be priced 7 Enter the plasma environment parameters These determine the collisional redistribution of the populations of the recombined plasma ion For ADAS308 B Magn has no effect but a value should be entered as a place holder 8 The final sub window allows model and theory choices Details are given in the ADAS Manual For each type clicking on the selection window drops down a short menu of choices Click on the appropriate choice The ADAS data base source numerical data of type ADFOI is the most usual that is the Use input data set choice button Note that the Select emission measure model choice includes Electron impact excitation as well as Charge exchange 9 Extended information on the rates used in the populaiton modelling may be printed 10 Clicking the Done button causes the next output options window to be displayed Remember that Ca
6. activates the predictive part of the code which becomes possible once the observed lines have been analysed in terms of emission measure Then any set of lines within the N shell limits may be predicted The standard output includes the mean wavelength and effective emisison coefficient but for up to five lines an extended tabulation of line component emissivities may be produced Graphs may be produced for two selected line Indicate these selections in the Key columnThe table may be edited by clicking on the Edit Table button ADAS User manual Chap4 08 17 March 2003 5 The Observed spectrum lines table allows introduction of a number of Observed intensities It is possible to enter values which do not allow a consistent solution The code advises of this but it is the responsibility of the user to check that the data is unblended etc It is also a usual practice to enter just one line possibly with a fictitious emissivity merely to obtain effective emission coefficients and line component details 6 The Beam parameter information button causes display of the third editable table in the sub window Note that no check is made that the various beam energy fractions sum to unity This is the responsibility of the user Fag RED imr Hls Birim Final Mic List En 3 8 H 8 Isput bam ard rpectrum lina information Input plasma parameter inforaabbca Beam parueetrr interaction Tem p dev derdh
7. in reconstructing precise n n line feature shapes The cases of hydrogen like ions and lithium like ions are treated separately Case i hydrogen like ions ADAS User manual Chap4 08 17 March 2003 E nl L Zeya 41 ZETA z 5 QED Zepa E nl L n RMC gS 4 8 18 11 ZETA Zopa where 2 j 4 1 1 3 l 0 RMC z cee eos C c Dd a z In n 1 3J4 120 ZETA 2 Intin KA 150 0 1 0 4 8 19 QED z Si z 3 v In V az J 29 L M with L7 2 984128 L7 4 811768 L3 2 767699 L 2 749859 and L 2 71632 0 02402 5 n gt 2 The effective charge prescription is Teffl Zeff2 lt 0 Case ii lithium like ions E 1s nl Lain HE te 2 ZETA Z5 E As nl Ln Zep AEC 1 ZETA Zea 4 820 where the E 4len are obtained from Ritz formulae for s and p orbitals and from polarisabilities for gt 1 due to Edlen 1979 The effective charge prescription is Zeff 20 Zeff2 20 2 Alternate driving processes Primary fundamental state selective charge exchange cross section data for the calculations are taken from ADAS compilations type in general For contrast a calculation may be carried out using state selective cross sections from analytic expressions in the high energy Eikonal approximation These analystic expressions are available for 1s 2sand 2p donor states of neutral hydrogen and for the 1s2 and 1s2s states o
8. ADAS308 Charge exchange spectroscopy process effective coefficients l resolved The program analyses column line of sight integrated emissivity observations of charge exchange spectroscopy lines from hydrogenic impurities occuring through neutral beam plasma interaction in terms of emission measure It predicts the column intensities of spectral components of the charge exchange lines the Doppler broadened line shapes and effective emission coefficients for arbitrary lines in an l resolved picture Background theory Charge exchange spectroscopy is driven by of the form X D D 9 X nl Dj 4 8 1 in which an electron is captured from a donor atom in its ground or an excited state The principal application is usually to capture by the bare nuclei of impurity atoms in the plasma from the ground state of deuterium helium or lithium atoms in fast neutral beams Subsequently the hydrogen like impurity ion radiates as X n l XO Hn I hv 4 8 2 Composite spectral line features of the form n n are observed made up from unresolved n l n l multiplet components Charge exchange line features often involve high principal quantum shells and occur over wide spectral ranges including the visible range In general the populations of receiver levels are modified by redistributive collisions with plasma ions and electrons and by fields before radiation emission occurs The present programme includes redistribu
9. Relationship to direct coefficients With the effective emission coefficients calculated theoretically comparison with one observed charge exchange line intensity allows deduction of the emission measure Then all other line intensities are predictable If more than one line intensity is observed then a mean emission measure may be deduced and some comment may be made on the ratios of exeperimental to theoretical effective emission coefficients The organisation of the collisional radiative modelling in ADAS308 is specifically designed to allow such comparison The following points and assumptions are made i From the theoretical point of view the direct capture cross sections to levels are more fundamental quantities for comparison with experiment that the effective emission coefficients ii The dominant fundamental processes modifying the initial distribution of capture are redistribution within an n shell and radiative cascade in low and moderate density plasmas Limiting the collisional radiative theory to these dominant processes allows a compact invertable relationship to be established between column emissivities of charge exchange spectrum lines and direct capture cross sections 1 It is of most practical value to target experiment theory comparisons on the n shell distribution of capture including the n shell decrement in fusion studies This may be achieved by imposing theoretical information on the sub shell distribution of
10. _ex2 c6 dat qcex h0_ex3 c6 dat qcex h0_ex3 h1 dat qcex h0_ex4 c6 dat qcex h0_exk he2 dat qcex h0_exk hbe4 dat Browse Comments Cancel Done 6 Clicking on the Browse Comments button displays any information stored with the selected datafile It is important to use this facility to find out what has gone into the dataset and the attribution of the dataset The possibility of browsing the comments appears in the subsequent main window also 7 Clicking the Done button moves you forward to the next window Clicking the Cancel button takes you back to the previous window The processing options window has the appearance shown below 1 An arbitrary title may be given for the case being processed For information the full pathway to the dataset being analysed is also shown The button Browse Comments again allows display of the information field section at the foot of the selected dataset if it exists 2 Information is given on the fully ionised impurity receiver and the neutral beam donor The atomic mass of the receiver must be entered 3 The specification of beam parameters details of observed line of sight spectral emissivities to be analysed and emissivities to be predicted are required Input data of each of these three types may be addressed in turn by activation of the relevant button The window below the button list then presents the appropriate table 4 The Required emissivity predictions button is displayed This
11. capture CX Consider the monoenergetic direct capture rate coefficients to n sub levels q from the initial neutral donor state DO by the fully stripped impurity ion with number density N denoted more compactly by N qi E v 0 v 4 8 7 nl where E is the relative collision energy per atomic mass unit so that y JJ 2E m is the relative collision speed with 71 the proton mass and O the capture cross section It is supposed that Cx heor CX qu nes don on E 4 8 8 Since no collisional excitation from lower to higher n shells is allowed the populations of the j sublevels of the principal quantum shell n gt n 1 may be written as CX Nus N N Wor 4 8 9 Then the equations determining the populations of the sub shells of the principal quantum shell n are zr p theor CX Y N ue x foy Fn Y Au wp N uy 4 8 10 n 2n 1 so that ADAS User manual Chap4 08 17 March 2003 Ny NoN Wynd O NUN YW gh 4811 nlj ni n 2nl with Wy n CM ouf Uj J quU Iq 4 8 12 and W n Moy wj W ey ni 4 8 13 ry The solution can proceed recursively downwards in n with compact vector and array storage Tabulations of experimental or theoretical state selective e exchange cross section data span a range of principal quantum shells ot v ny n n Cascade from levels n gt ri may contribute significantly to the populations of l
12. f neutral helium It is of interest to compare the analysis with that which would occur with two alternative driving mechanisms These are free electron capture and collisional excitation by electron impact from the ground state of the hydrogen like impurity ion The previous formulation remains the same but with the emission measure and capture rate coefficients redefined as N N ds and g 4 821 J i or N NUvP 1sds and qi 4 822 J i respectively Source data The program operates on collections of fundamental state selective charge exchange cross section data The allowed content organisation and formatting of these files are specified in ADAS data format ADFOI Centrally supported data collections are stored in directories such as adas adas adf0 1 qcx h0 where the A0 identifies neutral hydrogen is the donor The individual data set names take the form qcx h0O_ lt code gt lt ion gt dat where lt code gt is a three character identifier of the source and lt ion gt is the receiving fully ionised ion for example c6 More detail is given below ADAS User manual Chap4 08 17 March 2003 Program steps These are summarised in the figure below Figure 4 8 read and verify begin select charge file establish enter user prepare all exchange data n shell ranges data atomic data in file and fractions Iooksupxables repeat repeat i com
13. ncel takes you back to the previous window The Output options window is shown below Note that two plots are produced if required The Plot A is the stick diagram of component line of sight emissivities The Plot B is of the Doppler broadened profile of the line at the plasma ion temperature ADAS User manual Chap4 08 17 March 2003 l Asin the previous window the full pathway to the file being analysed is shown for information Also the Browse comments button is available 2 Graphical display is activated by the Graphical Output button This will cause a graph to be displayed following completion of this window When graphical display is active an arbitrary title may be entered which appears on the top line of the displayed graph By default graph scaling is adjusted to match the required outputs 3 Press the Explicit Scaling button to allow explicit minima and maxima for the graph axes to be inserted Activating this button makes the minimum and maximum boxes editable Plot A axes limits refer to the stick diagram and Plot B axes limits to the Doppler broadened profile 4 Hard copy is activated by the Enable Hard Copy button The File name box then becomes editable A choice of output graph plotting devices is given in the Device list window Clicking on the required device selects it It appears in the selection window above the Device list window 5 The Text Output button activates writing to a text output file The file name ma
14. ower levels especially at high collision energies when the decrease of the direct charge exchange cross sections with n is slow O n and 2 However redistribution amongst j sub levels of the higher n shells is high approaching statistical in most circumstances Therefore the cascade solution is initiated at some Da C20 typically for complete n shell populations only matrices wer with subshells implicitly statistically populated down to 7t whereupon the j resolved low solution matrices W is commenced In general observable spectrum lines are associated with upper principal quantum shells n If M lines are identified each with a distinct upper n shells rep irep 1 M then a condensation may be imposed such that ny rep M ep CX _ CX q nirep In for Ny n En 4 8 14 irep 1 and X X qo n m for n gt n 4 8 15 giving after integration along the line of sight a matrix relation CX Izor eges Tee PRAE 4 NpN ds 5 CX y a PAM rep ay rep ay rep M rep yu 4 8 16 The coefficients of the matrix are theoretically calculated quantities The equations may be solved for the the d C and the emission measure subject to 5 the constant M 4817 e Energy levels Precise energy levels are required in calculating collisional redistribution between the degenerate and nearly degenerate states This is also required
15. putesoln Output tables prepare display selecte lt accoding to ae us ely emission end tabulations emissivities measure type Interactive parameter comments ADAS308 which make use of data from archived ADAS datasets initiates an interactive dialogue with the user in three parts namely input file selection entry of user data and disposition of output The file selection window is shown below 1 Data root shows the full pathway to the appropriate data subdirectories Click the Central Data button to insert the default central ADAS pathway to the correct data type ADFOI in this case Note that each type of data 15 stored according to its ADAS data format adf number Click the User Data button to insert the pathway to your own data Note that your data must be held in a similar file structure to central ADAS but with your identifier replacing the first adas to use this facility 2 The Data root can be edited directly Click the Edit Path Name button first to permit editing 3 Available sub directories are shown in the large file display window Scroll bars appear if the number of entries exceed the file display window size There are a large number of these They are stored in sub directories by donor which is usually neutral but not necessarily so eg qcxZh0 The individual members are identified by the subdirectory name a code and then fully ionised receiver eg qcx hO oldZc dat
16. tive collisions of the form e 1 e X n estu ys 4 8 3 Z Z where Z denotes a bare nucleus of charge Z and field induced redistribution of the form X nl nl not fully implemented 4 8 4 mag The line of sight integrated photon emissivity of a charge exchange driven line may be written as JE PD 0 7 I 2 D wr E SINE Ni ds Lu B Ay ra ENSNX INSN 4 8 5 E ema IN N ds sfa N N ds x qi Pr d where S is the path m through the neutral beam plasma intersection along a spectrometer line of sight is the neutral donor number density and N 50 is the number density of fully ionised impurity atoms g is the effective emission ADAS User manual Chap4 08 17 March 2003 coefficient for the whole 7 n principal quantum shell transition and Np N Co ds is the emission measure The mean transition energy is 5 os eff eff AE w EE y AE ers wr row 4 8 6 LU eff where AE yr is the line component transition energy and q y is the component eff effective emission coefficient The effective emission coefficient q may be calculated theoretically If it is approximately constant over the emitting volume 25 0 non allows deduction of the then measurement of a charge exchange line intensity I emission measure Np N ods If neutral beam attenuation to the observed 5 volume is known or calculable then local impurity density may be inferred
17. y be entered in the editable File name box when Text Output is on The default file name paper txt may be set by pressing the button Default file name ADAS308 OUTPUT OPTIONS Graphical Output Select Device Graph Title Post Script Post Script Explicit Scaling yin 1 Seman f HP GL _ Enable Hard Copy J Repiace File Name _ Text Output _ Hepilace Dofault File Nane File Name Done 8 Cancel ADAS User manual Chap4 08 17 March 2003 The Graphical output window is shown below 1 Printing of the currently displayed graph is activated by the Print button DAS T DEAPHKCRL OUTPUT Illustration Figure 4 8a L RESOLVED CHARGE EXCHANGE EMISSIVITIES ADAS ADAS RELEASE ADAS93 V1 13 PROGRAM ADAS308 V1 6 DATE 16 04 98 TIME 13 10 FILE home anderson adas adf01 gqcx hO gex hO_oldfb5 dat 5000000000 m USER INPUT DATA TRANSITION N 6 2 N98 8 000 DONOR INFORMATION E EFF RATE COEFF cm s 1 9457E 08 ELEMENT SYMBOL H NUCLEAR CHARGE 1 6 25r RECEIVER INFORMATION ELEMENT SYMBOL NUCLEAR CHARGE INITIAL CHARGE FINAL CHARGE x10 x10 ATOMIC MASS NO T PLASMA PARAMETERS 20r ION TEMP 5 00E 03eV ELECTRON TEMP 5 00E
Download Pdf Manuals
Related Search