1/15/2015 report yy euv spectroscopy of tungsten observed in sh-htsc ebit and related calculations...

04/11/23ReportYY

EUV Spectroscopy of Tungsten Observed EUV Spectroscopy of Tungsten Observed in SH-Htsc EBIT and related Calculationsin SH-Htsc EBIT and related Calculations

Yang YangYang YangShanghai EBIT LaboratoryInstitute of Modern Physics, Fudan University, Shanghai, China@ADAS Workshop 2014, Warsaw, Poland, 30th Sep. 2014

ADAS Workshop 2014 - Warsaw, Poland 30ADAS Workshop 2014 - Warsaw, Poland 30 thth Sep. 2014 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+

2


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.

• Little spectroscopic data Little spectroscopic data for tungsten in EUV

3

ITERITER

WW

From a talk given by Charles Skinner at the “20 Years of EBIT Spectroscopy” held in Berkeley in 2006

DivertorDivertor

(20nm-40nm)

Only Only 55 lines from lines from WXII-WXVIIWXII-WXVII


2. DevicesDevices 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

4

SH-Htsc EBITSH-Htsc EBITEe 30-4000 eV

Ie 10 mA

re ~120 μm

Vacuum <1.0e-9 Torr

Magnetic field

0-0.25 T

Flat-Field Grating Flat-Field Grating SpectrometerSpectrometerVacuum 1.0×10-9 Torr

Wavelength Range

1-50 nm

Resolving Power (λ/Δλ)

>1000Z. Shi, et al., Rev. Sci. Instrum. 85, 063110 (2014)

J. Xiao, et al., Proceedings of IPAC2013 MOPFI066 (2013)


5

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

3. Experimental Results

Operation ParametersOperation 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

- Calibration first


6

Spectra taken at beam energies from 200 to 410 eV

The ionization potential of W10+ to W15+ *

* A.E. Kramida and T. Shirai, Atomic Data and Nuclear Data Tables 95, 305C474 (2009)

3. Experimental Results

Most spectral lines were seen in the region between 170-260 ÅMost spectral lines were seen in the region between 170-260 Å



Flexible Atomic Code(FAC)*

- Relativistic Configuration-Interaction(RCI)

- Collisional-Radiative Modeling (CRM)

7

* M. F. Gu, Canadian Journal of Physics 86, 675 (2008)


8


Configurations used in the RCI model of W11+ ~ W15+


9


The synthetic spectra of W10+ to W15+ with CR model

Results after CRM calculation and line broading:

Ee=230,270,310,350,390eVNe=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


10

4. Calculation methods and resultsSummary about the transitions contributing to the spectra

The synthetic spectra of W10+ to W15+ with CR model



11

The synthetic spectra of W10+ to W15+ with CR modelExperimental spectra of W10+ to W15+

• Slight shift in wavelength

• packages of peaks are wider.

•Δn = 0160-190Å 5d → 5p210-260Å 5p → 5s


12


Quasi-continuum spectra around 30nm observed in LHDMany Thanks to Suzuki san.

Comparison with LHD spectra


13


spectrum was recorded on Berlin EBIT at beam energy of 300eV

4f135s2 4f145s

resonance doublet lines

no yes

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)

1/2


14


the level structure of W13+ from RCI method

Experimental spectra at 320eV

Synthetic spectra at 310eV

4f135s2

Visible transitions: Z. Z. Zhao, submitted (2014)

1/2


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.

15


16

Thank you for your attention !

Members in Shanghai EBIT Laboratory

1/15/2015 report yy euv spectroscopy of tungsten observed in sh-htsc ebit and related calculations...

Documents