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FFS at JET/Ameigs

FFS model. Model D10-2 to D13-2 as Voigts. Absence of working continuum model use flat baseline and restrict highest balmer in fit to 13-2. Coupling Lorentzian widths to the Griem Stark broadening formula. Coupling Balmer positions to D10-2 thru Rydberg formula. Fixed Gaussian width.

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FFS at JET/Ameigs

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  1. FFS model Model D10-2 to D13-2 as Voigts Absence of working continuum model use flat baseline and restrict highest balmer in fit to 13-2 Coupling Lorentzian widths to the Griem Stark broadening formula Coupling Balmer positions to D10-2 thru Rydberg formula Fixed Gaussian width FFS at JET(Spectral fitting using FFS) A. Meigs FFS at JET/Ameigs 02-09-13

  2. FFS at JET: Outline of talk • What is FFS? • Balmer series D10-2 to D13-2 Fitting • Single Balmer D7-2 with W I and N II • Work needed/planned FFS at JET/Ameigs 02-09-13

  3. What is FFS? • Framework for Feature Synthesis (FFS) • Created by Chris Nicholas (see 2010 ADAS PhD) with A. Meigs and Allan Whiteford from an earlier start called glvoop by A. Meigs • ADAS Workshop presentations by C. Nicholas in 2008, 2009 A. Meigs in 2007 • Object oriented system in IDL for modular modelling, and fitting • Uses a Model Definition Language (MDL), Lisp-like scripting language, • for creating complex models (command line for simple models also available*): • Handles complex combination of elements that comprise a model • Loads initial parameter values, limits for fitting, fixed parameters • MDL also handles coupling of parameters • System comprised of a Model/Element/Parameter-Property hierarchy linked with a parser/executor for the MDL scripts. • Easily links with the ADAS AFG system to import ADAS special feature models (Zeeman, Motional Stark multiplet, Heavy species envelopes) See C. Nicholas thesis for a wide range of examples • Currently, limited to 1D models (extension to 2D should not be hard, just not investigated yet) FFS at JET/Ameigs 02-09-13

  4. FFS at JET: Class Diagram Available elements Line shapes: Dirac-Delta approx (sticks) GaussianLorentzian Voigt(ian) Broadeners: GaussianLorentz Maths: Add (+) Scale factor AFG: ZeemanHigh-z envelopeStark emission… *C. Nicholas, Thesis 2010 FFS at JET/Ameigs 02-09-13

  5. Density Limit Discharge (81469) fitting Balmer spectra FFS at JET/Ameigs 02-09-13

  6. KT3 Diagnostic Three spectrometers with “common” LOS Mirror Link view of the outer divertor:No fibers  largest wavelength coverageof any diagnostic on JET (200nm-1200nm) LOS cover just inside tile-5 to vertical tile-8 (tile-7 is shadowed) ADAS/Ameigs 02-09-13

  7. Model of High-n Balmer Spectra Value from fitting impurity line pre-recombining phase Left out in this model the extra impurity linesas they get swamped out by the Balmerlines for this pulse (have included them inless dense/recombining plasmas) FFS at JET/Ameigs 02-09-13

  8. Fits to High-n Balmer Spectra: 81469 Density Limit Pulse Highish density spectra fit FFS at JET/Ameigs 02-09-13

  9. Fits to High-n Balmer Spectra: 81469 Density Limit Pulse Lowish density spectral fit FFS at JET/Ameigs 02-09-13

  10. R outer strike point R X-point Electron density results for 81469 from Stark Broadening Can follow for the first time the density limit from strike point to MARFE formation at the X-point FFS at JET/Ameigs 02-09-13

  11. Simple model of W I/D 7-2/N II spectra (model kt3b_wv4020_simple2 (+ (+ (voigtian d72) (gaussian w1a) (gaussian n2f) (gaussian n2j) (gaussian u0) (gaussian u1) (gaussian u2) (gaussian u3) ) (background-linear bkg) ) ) (dummy d ) (setval bkg.m 0.0) (setval bkg.c 8.0e18) (setlimits bkg.c 1.0e12 1.0e21) (setval d.dens 5.0e19) (fixed bkg.m) (log d.dens) (setlimits d.dens 5.0e18 1.0d21) (setval d72.pos 396.899) 7->2 396.899 nist (setval w1a.pos 400.87506) (setval n2f.pos 399.5) (setval n2j.pos 395.585) (couple d72.fwhml (* (/ (* 0.00139 (^ (* d72.pos 1e-9) 2) (^ d.dens (/ 2.0 3.0)) (- (^ 7.0 2)(^ 2.0 2))) 1.8836516e09) 1e9)) FFS at JET/Ameigs 02-09-13

  12. Rest of the Simple model of W I/D 7-2/N II spectra (setlimits d72.pos 396.6 397.3) (setlimits w1a.pos 400.7 400.9) (setlimits n2f.pos 399.4 399.6) (setlimits n2j.pos 395.3 395.7) (s etlimits he1a.pos 402.4 402.8) (setval n2f.fwhm 0.1) (setlimits n2f.fwhm 0.01 0.4) (s etval w1a.fwhm 0.1) (s etlimits w1a.fwhm 0.01 0.4) (couple d72.fwhmg = n2f.fwhm) (couple n2j.fwhm = n2f.fwhm) (couple w1a.fwhm = n2f.fwhm) (c ouple he1a.fwhm = n2f.fwhm) (setval d72.area 3.e18) (setval w1a.area 8.e15) (setval n2f.area 4.e16) (setval n2j.area 1.e16) (setlimits d72.area 0.01 9.0e23) (setlimits w1a.area 0.01 5.0e20) (setlimits n2f.area 0.01 5.0e21) (setlimits n2j.area 0.01 5.0e19) (setval u0.pos 397.326) (setval u1.pos 398.291) (setval u2.pos 395.437) (setval u3.pos 401.389) (setlimits u0.pos 397.0 397.6) (setlimits u1.pos 398.1 398.4) (setlimits u2.pos 395.2 395.6) (setlimits u3.pos 401.2 401.5) (setval u0.area 1.0e16) (setval u1.area 9.0e15) (setval u2.area 6.0e15) (setval u3.area 3.0e15) (setlimits u0.area 0.01 5.0e17) (setlimits u1.area 0.01 5.0e17) (setlimits u2.area 0.01 5.0e17) (setlimits u3.area 0.01 5.0e17) (couple u0.fwhm = n2f.fwhm) (couple u1.fwhm = n2f.fwhm) (couple u2.fwhm = n2f.fwhm) (couple u3.fwhm = n2f.fwhm) FFS at JET/Ameigs 02-09-13

  13. Low electron density pulse (81474) example fit n2f (N II) D7-2 u1 w1a (W I) u0 u2 n2j u3 FFS at JET/Ameigs 02-09-13

  14. Higher electron density pulse (81478) example fit D7-2 u1 w1a (W I) u0 u2 n2j n2f (N II) u3 FFS at JET/Ameigs 02-09-13

  15. Comparison High vs D7-2 electron densities High-n balmer fit (81476) D7-2 fit (81478) Able to fit D7-2 early (hence expanded time range) Shapes very similarMagnitudes another matter FFS at JET/Ameigs 02-09-13

  16. 2D comparison for two times Pre-detachment (t=8.94s) Post-detachment (t=15.7s) High-n ne (81476) High-n ne (81476) D7-2 ne (81478) D7-2 ne (81478) • Caveats/Problems: • Two different pulses (even though 81478 meant to be a repeat of 81476) • N II reference may not be good for higher densities (see next page) • Really need measurement in same pulse (pretty sure I have it at some point) FFS at JET/Ameigs 02-09-13

  17. Simple model of W I/D 7-2/N II spectra Problems with this fit (preliminary): 1) Using the N II 399.5nm line as fwhm reference for high density plasmas can be problem as it’s intensity decreases as the plasma gets colder and denser(same holds true for tungsten) Will need to fit the reference early and use that width (as I did for the High-n Balmer series reference) FFS at JET/Ameigs 02-09-13

  18. Work to be done in FFS • Additional elements coded: • Multiply element (Gaussian x Gaussian) • Bremsstrahlung model (ffs/afg) • Re-implement interface to PPP (revive collaboration with Marseille) • Implement Model containing another model • FFS (probably ffs_model) handling blind areas (areas of independent axis where you want no weighting so that it does not affect chi^2, i.e. allow removal of nuissance lines) • Revive tree-view of models (ffs_model_browser__define and ffs_tree__define, presented by C. Nicholas in 2008-09): • Aim to get usable model editor • Needs limits display • Needs coupling tab/display • Write back to a model file • Needs ability to move elements up/down tree... • Enforce unique element names! • Enforce non-zero values/limits... • Gui to model file and gui to model changes (improve model to parser communication) • Finally(1), a tutorial on using FFS/AFG to be given at the ADAS-EU workshop at JET end of September/Early October • Finally(2), we need new users and developers! FFS at JET/Ameigs 02-09-13

  19. Simple model of W I/D 7-2/N II spectra FFS at JET/Ameigs 02-09-13

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