NIST Research on Spectroscopy and Collisional-Radiative Modeling of Highly-Charged Ions of Tungsten Yuri Ralchenko National Institute of Standards and Technology Gaithersburg, USA Vienna, Austria, Dec 13, 2010 Supported in part by the OFES, U.S. DoE
NIST Team EBIT Experiments J.D. Gillaspy J. Reader J.N. Tan J.M Pomeroy I.N. Draganić (currently at ORNL) S.M. Brewer D. Osin Data Compilation and ASD A.E. Kramida Collisional-Radiative Modeling and ASD Yu. Ralchenko
Recent W publications Yu. Ralchenko et al. Accurate modeling of benchmark x-ray spectra from highlycharged ions of tungsten, Phys. Rev. A 74, 042514 (2006). A.E. Kramida and J. Reader. Ionization energies of tungsten ions: W 2+ through W 71+, At. Data Nucl. Data Tables 92, 457 (2006). A.E. Kramida and T. Shirai. Compilation of Wavelengths, Energy Levels, and Transition Probabilities for W I and W II, J. Phys. Chem. Ref. Data 45, 423 (2006). Yu. Ralchenko et al. Spectra of W 39+ W 47+ in the 12 20 nm region observed with an EBIT light source. J. Phys. B 40, 3861 (2007). Yu. Ralchenko. Density Dependence of the Forbidden Lines in Ni-Like Tungsten. J. Phys. B 40, F175 (2007). Yu. Ralchenko et al. EUV spectra of highly-charged ions W 54+ W 63+ relevant to ITER diagnostics, J. Phys. B 41, 021003 (2008). U. Feldman et al. Bright EUV lines emitted by highly ionized tungsten ions as diagnostic indicators of the tungsten transport in ITER core plasmas (Te > 7 kev), Nucl. Fusion 48, 045004 (2008). J.D. Gillaspy et al. Measurement of the D-line doublet in high-z highly charged sodiumlike ions, Phys. Rev. A 80, 010501 (2009). A.E. Kramida and T. Shirai. Energy levels and spectral lines of tungsten, W III through W LXXIV, At. Data Nucl. Data Tables 95, 305(2009); 95, 1051 (2009). Yu. Ralchenko et al. Multi-code Ab Initio Calculation of Ionization Distributions and Radiation Losses for Tungsten in Tokamak Plasmas, in: 16 th International Conference on Atomic Processes in Plasmas, AIP Conference Proceedings 1161, 242 (2009).
NIST EBIT Low electron density N e ~ 10 12 cm -3 Monoenergetic electrons E beam = 1-30 kev Width ~ 60 ev Localized volume Continuous operation X-ray microcalorimeter 1-10 kev Resolution ~5 ev at several kev EUV flat-field grazingincidence spectrometer 2-25 nm Resolution ~400
Collisional-Radiative Modeling of Tungsten Plasmas Universal non-maxwellian CR code NOMAD Yu. Ralchenko and Y. Maron, JQSRT 71, 609 (2001) Various options for atomic data input Account of plasma effects Used for diagnostics of various plasmas (laserproduced, astrophysical, fusion, EBIT) Atomic data from Flexible Atomic Code (FAC) M.F. Gu, Can. J. Phys. 86, 675 (2008) Relativistic model potential; Dirac equation; QED corrections Distorted wave approximation; Coulomb- Born Well suited for highlycharged high-z ions All relevant parameters
W from ASDEX Upgrade (4 kev) T. Pütterich, Ph.D. thesis (2005); R. Neu et al, Nuclear Fusion 45, 209 (2005) 7.93 Å in W 46+ 3d 10-3d 9 4s E2 line?
EBIT X-ray measurements (E b 4 kev) 3-4 3d 10-3d 9 4s 3d 9 4s E2 M3 M1 E2 M3 Phys. Rev. A 74, 042514 (2006)
CR population transfer M3 E2 Yu. Ralchenko, J Phys B 40, F175 (2007) E2 M3
E2/M3 ratio is sensitive to density E2+M3 E2/M3 Yu. Ralchenko, J Phys B 40, F175 (2007) E2 and M3 were recently resolved in Clementson et al, PRA 81, 012505 (2010)
EUV Spectra: E b =2.0-4.1 kev Zn Zn Cu Cu J.Phys. B 40, 3861 (2007)
EUV spectra from W 55+ -W 65+ (E = 8.8-25 kev) Motivation: U. Feldman et al, NF 48, 045004 (2009) Proposed multilayercoated segmented telescopes for ITER To study W transport and T e About 40 EUV lines from W 58+ to W 71+ J.Phys. B 41, 021003 (2008)
Experiment vs theory (W, E beam = 8.8 kev) EXP Ions included: [Ca]-[F] W 58+ W 55+ W 56+ W 57+ W 59+ W 60+ W 61+ THEO 6600 levels Charge exchange Included in CR W 62+ W 54+ transitions n=3-n=3 E1 and M1 J.Phys. B 41, 021003 (2008)
Isoelectronic spectra: identification test [Al]: 3s 2 3p 2 P 1/2 3s3p 2 4 P 1/2 [Mg]: 3s 2 1 S 0 3s3p 3 P 1 [Na]: 3s 2 S 1/2 3p 2 P 1/2 0.6 nm Δn=0: σ=a Z c +B J.Phys. B 41, 021003 (2008)
Na-like doublet in highly-charged ions 2 1 5890 Å D 2 D 1 5896 Å
D-doublet in Na-like W, Hf, Ta, and Au Phys. Rev. A 80, 010501 (2009)
Comparison of energies
EUV Spectra (10-25 nm) of 3d n Ions Co 3d 9 4180 ev Fe 3d 8 4309 ev Mn 3d 7 4445 ev Cr 3d 6 4578 ev V 3d 5 4709 ev Ti 3d 4 4927 ev Sc 3d 3 5062 ev Ca 3d 2 5209 ev K 3d 5347 ev Major issue in CR modeling: large number of excited states Solution: keep lower 3l states as atomic levels group higher n 4 levels into superterms Typical number of levels per ion: 1000-1500 (down from 10 4 fine-structure levels) Beam energies: 4.5-6 kev
(Only!) M1 Lines in 3d n Ions of W About 40 new lines were identified Yu.Ralchenko et al, to be published
Theory vs Experiment (E = 5.25 kev)
Density-Sensitive Line Ratios Example: W/Y in He-like ions Compare lines with differing transition probabilities A-values for measured M1 lines within 3d n configurations vary between 4 10 4 and 6 10 6 s -1
Density-Sensitive Ratios: Cr-like Ion
Density-Sensitive Ratios: V-like and Sclike Ions
W Spectroscopic Data Compilation A.E. Kramida and T. Shirai, energy levels and spectral lines, all ions of W A.E. Kramida and J. Reader, ionization potentials for all ions All data are in the NIST Atomic Spectra Database Bibliographic databases Energy levels and spectral lines: 528 refs Transition probabilities: 332 refs
NIST Atomic Spectra Database, December 2010 2067 energy levels 14406 spectral lines
Hf, Ta, Au spectra More than 100 new EUV lines IN Draganic et al, J Phys B, accepted
Conclusions NIST has an active program on production, analysis, and utilization of spectroscopic data for highly-ionized W (and other high-z elements) Experiments on the NIST EBIT supported by advanced CR modeling allowed to identify dozens of new spectral lines New diagnostics methods for fusion plasmas are proposed The spectroscopic data for W is disseminated via NIST Atomic Spectra Database
W at the NLTE Code Comparison Workshops to be continued