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IAEA 2nd RCM on Atomic Data for Heavy Element Impurities in Fusion Reactors, 26 - 28 September, 2007EUV spectroscopy from LHD and Atomic Data T. Kato National Institute for Fusion Science
Introduction • Xe ion spectra and atomic data • Fe ion spectra and atomic data • Data needs for ITER modelling
Xe ion spectraT.Kato, G. O’Sullivan, N. Yamamoto, H. Tanuma et al • We have observed EUV spectra of Xenon ions from the Large Helical Device (LHD) at the National Institute for Fusion Science in Toki in the wavelength range of 10 – 17 nm using a high resolution SOXMOS spectrometer.A small quantity of xenon gas was injected into the Large Helical Device. In some cases, the plasma evolution was stable and a steady discharge was obtained for several seconds, but sometimes the plasma underwent radiation collapse and rapid cooling and in this situation the EUV yield was significantly increased. Investigation of the spectra showed that during the heating phase and in a stable plasma, the emission was dominated by ions with open 4s and 4p subshells, while during radiation collapse, the spectra were dominated by lines from species with open 4d subshells. From a comparison of these spectra with theoretical data from atomic structure calculations and also with charge state specific data generated in Tokyo Metropolitan University it was possible to make tentative assignments of the strongest lines arising from 4d-4f and 4p –4d transitions in Xe XVII and XVIII.
SOXMOS Spectrometer (TESPEL) LHD plasma 0 deg. SOXMOS -1 deg. 24 cm
Normal Discharge, stable sustained heating t = 400 ms Xe puff Xe puff
Normal Discharge (Te) Te(=0) ~ 1000 eV, Te(=0.5) ~ 700 eV
Discharge with Radiation Collapse t = 400 ms Xe puff Xe puff
Discharge with Radiation Collapse (Te) Te(=0) ~ 500 eV, Te(=0.5) < 200 eV @ t=1.4 s
Theory for Xe17+ • Cowan code Hatree Fock with Configuration Interaction (HFCI) by G. O’Sullivan (UCD) • GRASP2 Multiconfiguration Dirac Fock by D. Kato (NIFS) • Cascade model (for charge exchange spectra) by N. Yamamoto (Osaka Univ.) Grasp code for n = 4, Hullac code for other levels
Spectral lines during the heating are identified with 4p - 4d transitions of Xe17+ (4d) - Xe25+(4s) ions in 10 - 12 nm Xe11+,12+ Xe10+ Xe9+
Spectral lines during the heating are identified from ions with outer 4s or 4p electrons ( Xe23+(4s24p) - Xe25+(4s) ) in 12 - 16nm t = 400 ms 1. Xe23+ (4s24p) 3. Xe24+ (4s2) 5. Xe23+ 7. Xe24+ 8. Xe25+ (4s) 11. Xe23+ 13. Xe23+ 14. Xe24+ 1. Xe23+ 14. Xe24+ 3. Xe24+ 7. Xe24+ 5. Xe23+ 8. Xe25+ 11. Xe23+ 13. Xe23+
Spectra during radiation collapse indicate a recombining plasma 1. Xe23+ 2. Xe18+ 24+ 3. Xe24+ 5. Xe23+ 6. Xe10+ 7. Xe24+ 8. Xe25+ 11. Xe23+ 12. Xe8+ 13. Xe23+ 14. Xe24+ • Many new lines appear in the spectra during radiation collapse. • No.2 (131.709A, Xe18+ ?) and No.6 (135.34A, Xe10+?) increase. • The continuum emission increases. • No.12 is identified as Xe8+. Temperature is low.
Quasi continuous background 4p64dm - 4p54dm+1 + 4p64dm-14f Xe XII - XVI (m = 3 to 7)in 121 - 155A XVII-XVIII lines are not identified
Charge Exchange (CX) Spectroscopy of Xe and Sn ions by Hajime TANUMA, Hayato OHASHI, Shintaro SUDA Department of Physics Tokyo Metropolitan University
Xe ion spectra by Charge ExchangeXeq+ + He --> Xe(q-1)+ 4p1 Ground state Configuration of Incident ions 4p2 4p3 4p4 4p5 4p6 4p64d 4p64d2
Xe ion spectra by Charge ExchangeXeq+ + Rg --> Xe(q-1)+ Wavelength (nm)
Dominant capture levels - prediction with the classical over-barrier model - It : ionization energy of the target atom He : 24.588 eV Ar : 15.760 eV Xe : 12.130 eV
E(4s24p6)=430eV 5p 19 20 5p 5s 16 17 18 13 14 15 5d 11 12 6p 5d 10 n=6 9 8 7p n=7 4f n=6 4f n=5 n=5 4f 4f 4f n=5 4d 4f 4d 4d 4f 4d 4s24p44d4fnl 4s4p64fnl 4d 4s24p54fnl 4s4p54d2nl 4s24p54dnl 4s4p64dnl 4s24p6nl 4s24p44d2nl We make a cascade model for CX spectra Energy Levels Diagram in Radiative-cascade Model Xe18+ + Xe Xe17+ (nl) + Xe+ Xe17+ (n’l’) + hv total energy levels: 8831 Electron transfer energy band, dE~1eV l = 10-12A l = 12-15A
Xe17+ Line identification based on 4p64d - 4p54d2 4p64d 2DJ - 4p54d22FJ’2DJ’ (Ground state 4p64d 2D3/2 )Comparison with calculations by GRASP code and Cowan’s code • Wavelengths calculated fit well with the known three lines. • Broad feature of CX spectrum may be due to cascade transition.
LHD spectra (yellow) with Cowan (blue) and GRASP (red) code calculations for Xe XVIII for 120 – 150 A. CX spectrum (green) of Xe XVIII
Cascade Model spectra for charge transfer spectraXe18+ + Xe --> Xe17+ (nl ) --> Xe17+ (n’l’) + hv (by N. Yamamoto) Strong by cascade GRASP calc. Red: w.o. cascade Blue: with cascade The wavelengths by GRASP code are shifted by 2.8A.
Assignments of Rb I like lines in Xe XVIII based on 4p64d-4p54d2 transitions (unless otherwise stated) New (Kato & O’Sullivan)
CX spectra show4p54d2 levelsare made through Charge Transfer from 4p6(Inner shell excitation) • Xe 18+ (4p6) + Xe (or He) ---> Xe 17+ (4p54dnl) or Xe 17+ (4p44d2nl) ---> Xe17+ (4p54d2) + hv (4p - nl) ---> Xe17+ (4p64d) + hv (4p - 4d)
LHD spectrum with Xe XVII spectrum CX (green), Cowan code calculations for 120 – 160 A. gA (s-1) (red)
Assignments of SrI like lines in Xe XVII 4p64d2 - 4p54d3(Only lines with gA>3x1010 s-1 are included) New Kato & O’Sullivan (2007)
規格化小半径 (H. Kubo (JAEA), J. Nucl. Mater., 2007) In some tokamaks, Xe has been injected to study high-Z impurity behavior or to enhance radiation losses for reduction of heat load to the walls. Study of highly ionized Xe spectra in JT-60U reversed shear plasmas Xe spectra (3s-3p & 3p-3d) observed in JT-60U *The red indicate the lines observed for the first time. Internal transport barrier Intensity (arb.) Xe37+ (1s)2(2s)2(2p)6(3s)2(3p)5 Xez+ density (arb.) Calculation Wavelength (nm) HULLAC and Desclaux’s code were used for the analysis. r/a Normalized minor radius In the reversed shear plasma, we can simply calculate spectral lines from the highly ionized Xe atoms inside the internal transport barrier using a coronal equilibrium model and a collisional radiative model with the electron temperature and density at the plasma center. 軟X線強度分布(arb) 軟X線の測定視野（ch)
Summary • EUV Xe ion spectra in 10 ~ 16nm from LHD were measured. • Spectra during heating phase are identified to be lines from Xe 23+ (4p, 762.4 eV) to Xe 25+ (4s, 857.0eV). (outer 4s or 4p electrons) • They are strong at 25 cm from the center. • The spectra from radiation collapse phase are considered to be emitted from Xe8+ (4d10,179.9 eV) to Xe17+ (4d,452.2 eV). (open 4d shell) • We have made line identifications for Xe17+ and Xe16+ spectral lines in the wavelength range of 12 - 16 nm. • Unidentified lines of highly charged Xe ions are measured in JT60 in the wavelength range of 4 - 16 nm. • We will make a theoretical model for Xe ion emissions for LHD and charge exchange spectroscopy by ECR source.
2. Fe Spectra and Atomic Data • Fe is an iｎｔｒｉｎｓｉｃ iｍｐｕｒｉｔｙ in Laboratory Plasmas • Important also in Astrophysics and the Sun • We are developing a non-equilibrium model for Fe ion emissions. • We studied EUV spectra from Fe XIII ions for plasma diagnostics • We evaluate Atomic Data for Fe ions Ionization, Excitation
FeXIII FeXII FeXI Sum EUV Spectra measured from LHD ~ FeXIII lines region 196-210A ~ Te=136.6eV, Ne>1013cm-3, N(FeXI)=1.0, N(FeXII)=3.0, N(FeXIII)=0.4
(5) (1) Ip=361eV (4) (3) (7) (6) (2) 3P 3F 1P 1F 3S 3D 1S 5S 1D 3s23p3d (2,3) (6) (1) 3s3p3 (4,7) (5) 3s23p2 Energy levels for Fe XIII lines #66810-4.3s@LHD 3p-3d transition (3s23p2-3s23p3d) （1） 196.525A: 1D2-1F3 (with FeXII) （2） 200.021A: 3P1-3D2 （3） 201.121A: 3P1-3D1 (with FeXII) （4） 202.044A: 3P0-3P1 （5） 203.793A+203.826A: 3P2-3D2,3D3 （6） 208.679A: 1S0-1P1 （7） 209.617A: 3P1-3P2
Hullac -DW Aggarwal, 2005 –R-matrix CHIANTI (Landi,1999) -DW Ne=106cm-3 Ne=1015cm-3 Ne=1010cm-3 Hullac v.s. Aggarwal v.s. CHIANTI by N. Yamamoto Te=136eV (=logT[K]=6.2)
Hullac / Aggarwal – Cij- excitation I. Murakami Aggarwal Hullac Hullac Aggarwal
Hullac / Aggarwal – Cij- excitation I. Murakami Aggarwal Aggarwal Hullac Hullac
3s23p23P0 – 3P1 Fe XIII 3s23p23P0 – 3P2 3s23p23P0 – 1D2 3s23p23P0 – 1S0 Effective collision strength 0 105 3x105 5x105 Te (K) Tayal S. S., ApJ, 544, 575 (2000)Aggarwal, K. M. & Keenan, F. P., A&A, 429, 1117 (2005) by I. Skobelev and I. Murakami
3s23p23P1 – 3s23p3d 3D1 Fe XIII W 2 Collision strength and effective collision strength 1 G 10 20 30 40 Energy (Ryd) by I. Skobelev and I. Murakami Gupta G.P. & Tayal S. S.,ApJ, 506, 464 (1998)Aggarwal, K. M. & Keenan, F. P., A&A, 429, 1117 (2005)
Line intensity ratios of FeXIII-1 N. Yamamoto
Line intensity ratio of Fe XIII-2 by N. Yamamoto by CHIANTI Atomic Data are important for Plasma Density Diagnostics by Line Ratios
Atomic data for Ionization of Fe ions Experimental data are still not sufficient by D. Kato
Fe+15 Ion storage ring measurement Gregory (1987) Linkemann by D. Kato Linkemann, PRL 74, 4173 (1995)
Fe+14 Theoretical calculations only EA is dominant. Direct cross section is factor three smaller. Younger’s calculations (1983) include the direct cross section only. by D. Kato Pindzola et al., Nuclear Fusion special suppl. (1987) “Recommended data on atomic collision processes involving iron and its ions”
Summary for Fe ions EUV spectral line intensities for Fe XIII are studied Line ratios with different atomic data are compared Excitation rate coefficients for Fe XIII are evaluated Ionization data are surveyed
Atomic, Molecular and Surface DataNeeds for ITER Modelling A.S. Kukushkin1, D. Reiter2 1 ITER Organization, Cadarache, France 2 FZ Jülich, Jülich, Germany Prepared for DCN meeting, October 2007, Vienna
Introduction • ITER: modelling is the way of extrapolation from present experiments • A&M&S data necessary to model the plasma and wall interaction • data on surface interactions equally important! • Composition of the plasma: • fusion reactions D, T, He • mixed materials on PFCs Be, C, W • impurity seeding for core control Ne, Ar diagnostics Li, … off-normal events O, Fe, Cu, … Plasma conditions Core: fully ionized (but NBI, pellets?), T ~ 0.2 – 20 keV, n ~ 1020 m-3 Edge: a lot of neutrals, T ~ 0.1 – 200 eV, n ~ 1019 – 1021 m-3 This presentation: mostly edge modelling
Surface Materials: W • Physical sputtering: rates known (?) • No molecules no chemical erosion (despite carbides?) • Ionization, recombination: no full data set; accuracy? • Excitation, multi-step ionization? • Elastic collisions with D, T ions? • – probably unimportant, atomic mass too large • Too many charge states, usual multi-fluid approach inefficient • “bundling” certain charge states together for transport • raw cross-section data + technology for effective rates are needed Surface properties: hydrogen uptake, interaction with Be, C? Limited experience in ITER modelling yet (DIVIMP – test particle approximation)
Seeded Impurities: Ne, Ar(, Kr, Xe) • Atomic species, no chemistry • Ne, Ar very probable candidates for the plasma control; • Kr, Xe might cause problems with transmutations, although radiate better • Ne: ionisation, recombination data exist for all charge states; accuracy? • charge exchange? • detailed excitation data? multi-step ionization? • elastic collisions with D, T ions – some data exist; accuracy? • Ar: the same state as for Ne, probably less reliable? • Data for the core conditions equally important
Conclusions for ITER data needs • Edge modelling is now an essential part of the ITER project • design analysis • development of the operation strategy • It relies strongly on the A&M&S data supplied by the community • the results depend on the completeness and accuracy of the data • Most important groups of species: • Fuel (D, T): data for the edge (A&M) and beam (A, up to 1 MeV). Isotope effects in molecules! • Ash (He): data for the edge • Wall produced, light (Be, C): data for the edge. Hydrocarbons! • Wall produced, heavy (W): data for the edge & core. Bundling! • Seeded (Ne, Ar): data for the edge and core • Structural materials (Fe, Cu, …): data for the edge and core to analyze severity of possible off-normal events • Data on surface interactions equally important for all groups