EUV Spectroscopy of Tungsten Observed
in SH-Htsc EBIT and related Calculations
Yang Yang
Report
4/8/2015
Shanghai EBIT Laboratory
Institute of Modern Physics, Fudan University, Shanghai, China
YY
@ADAS Workshop 2014, Warsaw, Poland, 30th Sep. 2014
Outline:
1. Much Attentions to Tungsten Spectroscopy
2. Devices well fit the measurements of EVU
Spectroscopy of Tungsten
3. Experimental Results (Preliminary)
4. Calculation methods and results
5. Comparisons between experiments and calculations
6. Identification of Ground state of W13+
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
1. Much Attentions to Tungsten Spectroscopy
•
•
•
A strong candidate for plasma facing material for
future fusion devices, such as ITER
High radiation power which may degrade the
plasma performance
Great need of tungsten spectroscopy for ITER
diagnostics was pointed out by Skinner in 2006.
From a talk given by Charles Skinner
at the “20 Years of EBIT Spectroscopy”
held in Berkeley in 2006
• Little spectroscopic data for tungsten in EUV
ITER
W
(20nm-40nm)
Only 5 lines from
WXII-WXVII
Divertor
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
2. Devices well fit the measurements of EVU Spectroscopy of Tungsten
•
Shanghai High Temperature Super-Conductor EBIT(SH-Htsc EBIT)
•
High resolution extreme ultraviolet (EUV) and soft x-ray spectrometer
SH-Htsc EBIT
Flat-Field Grating
Spectrometer
Vacuum
1.0×10-9 Torr
Wavelength
Range
1-50 nm
Resolving
Power (λ/Δλ)
>1000
Ee
30-4000 eV
Ie
10 mA
re
~120 μm
Vacuum
<1.0e-9 Torr
Magnetic
field
0-0.25 T
Z. Shi, et al., Rev. Sci. Instrum. 85, 063110 (2014)
J. Xiao, et al., Proceedings of IPAC2013 MOPFI066 (2013)
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
3. Experimental Results
- Calibration first
Operation Parameters
Ee
200-400 eV
Ie
8.1 mA
Gas Injection
W(CO)6
Injection
Pressure
6.0×10-8
Vacumm
< 1.0×10-9
Fig. Spectrum for Calibration taken at a beam energy of 120 eV
and a current of 8.1mA. Oxygen and Nitrogen are from the
residual gas in the SH-Htsc EBIT
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
3. Experimental Results
The ionization potential of W10+ to W15+ *
* A.E. Kramida and T. Shirai, Atomic Data and Nuclear
Data Tables 95, 305C474 (2009)
Spectra taken at beam energies from 200 to 410 eV
Most spectral lines were seen in the region between 170-260 Å
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
4. Calculation methods and results
 Flexible Atomic Code(FAC)*
- Relativistic Configuration-Interaction(RCI)
- Collisional-Radiative Modeling (CRM)
* M. F. Gu, Canadian Journal of Physics 86, 675 (2008)
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
4. Calculation methods and results
Configurations used in the RCI model of W11+ ~ W15+
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
4. Calculation methods and results
Results after CRM calculation and
line broading:
Ee=230,270,310,350,390eV
Ne=5.0×10-10 cm-3
Resolving Power = 850 (for simulation)
Most distinct lines lay on wavelengths
between 160Å ~ 270Å, that is
coincident with experimental results
The synthetic spectra of W10+ to W15+ with CR model
ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
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4. Calculation methods and results
Summary about the transitions contributing to the spectra
The synthetic spectra of W10+ to W15+ with CR model
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
5. Comparisons between experiments and calculations
• Slight shift in wavelength
• packages of peaks are
wider.
•Δn = 0
160-190Å 5d → 5p
210-260Å 5p → 5s
Experimental spectra of W10+ to W15+
The synthetic spectra of W10+ to W15+ with CR model
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
5. Comparisons between experiments and calculations
Comparison with
LHD spectra
Quasi-continuum spectra around 30nm observed in LHD
Many Thanks to Suzuki san.
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
6. Identification of Ground state of W13+
1/2
4f135s2
no
yes
resonance
doublet lines
4f145s
spectrum was recorded on Berlin EBIT at beam energy of
300eV
C. L and E. D. Alkalilike, Physical Review Letters 45(26), 2099 (1980)
T. C. E and R. V., Physical review. A, General physics 28(2), 1186C1188 (1983)
A. K. a and T. Shirai, Atomic Data and Nuclear Data Tables 95, 305C474 (2009)
R. Hutton, Y. Zou, Nuclear Instruments and Methods in Physics Research Section B: Beam
Interactions with Materials and Atoms 205, 114 (2003)
ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
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6. Identification of Ground state of W13+
1/2
Experimental spectra at 320eV
the level structure of W13+ from RCI method
4f135s2
Visible transitions: Z. Z. Zhao, submitted (2014)
Synthetic spectra at 310eV
ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
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Summary
• EUV Spectra of W11+ ~ W15+ ions have been
studied both experimentally and
theoretically. Preliminary comparison
between them have been done.
• Identification of the ground-state
configuration of W13+ has been done, which
shows 4f135s2 should be the lowest
configuration.
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014
Thank you for your attention !
Members in Shanghai EBIT Laboratory
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ADAS Workshop 2014 - Warsaw, Poland 30th Sep. 2014