OSA's Digital Library

Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Editor: James C. Wyant
  • Vol. 47, Iss. 2 — Jan. 10, 2008
  • pp: 135–146

Characteristics of an absolutely calibrated flat-field extreme ultraviolet spectrometer in the 10–130 Å range for fusion plasma diagnostics

Malay Bikas Chowdhuri, Shigeru Morita, and Motoshi Goto  »View Author Affiliations


Applied Optics, Vol. 47, Issue 2, pp. 135-146 (2008)
http://dx.doi.org/10.1364/AO.47.000135


View Full Text Article

Enhanced HTML    Acrobat PDF (1794 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

A flat-field extreme ultraviolet (EUV) spectrometer with a nominal 2400 grooves / mm aberration-corrected ruled grating has been developed to analyze the emission spectrum in the wavelength range of 10 to 130   Å from large helical device (LHD) plasmas. Spectral properties such as resolution, sensitivity, contribution of higher-order light, and background stray light have been studied using emission spectra mainly from intrinsic impurities, e.g., C and Fe. It is found that the spectrometer well resolves closely existing spectral lines of highly ionized medium- and high-Z impurities even in a very short wavelength range such as 10 to 20   Å . As a result, it allows one to study the charge state distribution of elements in high-temperature fusion plasma. The ruled grating was then replaced by a laminar type holographic grating for the comparative study. The spectral resolution for the ruled grating ( Δ λ 0.08   Å at 33.73   Å ) is clearly better than the holographic grating ( Δ λ 0.13   Å at 33.73   Å ). Both gratings well suppress the higher-order light, e.g., the second-order light is only less than 11 % of the first-order light for C vi ( 33.73   Å ) . Relative sensitivity calibration with the wavelength has been done using bremsstrahlung continuum from the LHD plasmas. Absolute intensity calibration has been done by comparing the spectral intensities directly with the absolutely calibrated 1200 grooves / mm EUV spectrometer in the overlapping range of 90 120   Å due to the absence of a good branching pair in 10 130   Å . As a typical result on the present spectrometer well-resolved n = 2 3 full transition arrays from Ne- to Li-like ions are measured for Fe and Ti and wavelengths of the spectral array are tabulated for each charge state. Spectroscopic comparison is also made between the 1200 grooves / mm and 2400 grooves / mm gratings in a range of 50 130   Å .

© 2008 Optical Society of America

OCIS Codes
(050.2770) Diffraction and gratings : Gratings
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(300.6540) Spectroscopy : Spectroscopy, ultraviolet

ToC Category:
Spectroscopy

History
Original Manuscript: July 25, 2007
Revised Manuscript: November 8, 2007
Manuscript Accepted: November 26, 2007
Published: January 7, 2008

Citation
Malay Bikas Chowdhuri, Shigeru Morita, and Motoshi Goto, "Characteristics of an absolutely calibrated flat-field extreme ultraviolet spectrometer in the 10-130 Å range for fusion plasma diagnostics," Appl. Opt. 47, 135-146 (2008)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-47-2-135


Sort:  Year  |  Journal  |  Reset  

References

  1. C. De Michelis and M. Mattioli, "Spectroscopy and impurity behavior in fusion plasmas," Rep. Prog. Phys. 47, 1233-1346 (1984). [CrossRef]
  2. H. Nozato, S. Morita, M. Goto, A. Ejiri, and Y. Takase, "Acceleration characteristics of spherical and nonspherical pellets by the LHD impurity pellet injector," Rev. Sci. Instrum. 74, 2032-2035 (2003). [CrossRef]
  3. R. Katai, S. Morita, M. Goto, H. Nishimura, K. Nagai, and S. Fujioka, "Development of double-structure heavy-elements impurity pellet for active spectroscopy of high-temperature plasmas," Jpn. J. Appl. Phys. , Part 1 46, 3667-3669 (2007). [CrossRef]
  4. S. Morita, M. Goto, S. Masuzaki, H. Suzuki, K. Tanaka, H. Nozato, Y. Takeiri, J. Miyazawa, and LHD experimental group, "Effect of Ne glow discharge on ion density control in LHD," Plasma Sci. Tech. 6, 2440-2444 (2004). [CrossRef]
  5. S. Morita, M. Goto, Y. Takeiri, J. Miyazawa, S. Murakami, K. Narihara, M. Osakabe, K. Yamazaki, T. Akiyama, N. Ashikawa, M. Emoto, M. Fujiwara, H. Funaba, P. Goncharov, Y. Hamada, K. Ida, H. Idei, T. Ido, K. Ikeda, S. Inagaki, M. Isobe, K. Itoh, O. Kaneko, K. Kawahata, H. Kawazome, K. Khlopenkov, T. Kobuchi, A. Komori, A. Kostrioukov, S. Kubo, R. Kumazawa, Y. Liang, S. Masuzaki, K. Matsuoka, T. Minami, T. Morisaki, O. Motojima, S. Muto, T. Mutoh, Y. Nagayama, Y. Nakamura, H. Nakanishi, Y. Narushima, K. Nishimura, A. Nishizawa, N. Noda, T. Notake, H. Nozato, S. Ohdachi, K. Ohkubo, N. Ohyabu, Y. Oka, T. Ozaki, B. J. Peterson, A. Sagara, T. Saida, K. Saito, S. Sakakibara, R. Sakamoto, M. Sasao, K. Sato, M. Sato, T. Satow, T. Seki, T. Shimozuma, M. Shoji, S. Sudo, H. Suzuki, N. Takeuchi, N. Tamura, K. Tanaka, K. Toi, T. Tokuzawa, Y. Torii, K. Tsumori, T. Uda, K. Y. Watanabe, T. Watari, Y. Xu, H. Yamada, I. Yamada, S. Yamamoto, T. Yamamoto, M. Yokoyama, Y. Yoshimura, and M. Yoshinuma, "Experimental study on ion temperature behaviors in ECH, ICRF and NBI H2, He and Ne discharges of the large helical device," Nucl. Fusion 43, 899-909 (2003). [CrossRef]
  6. R. Katai, S. Morita, and M. Goto, "Identification and intensity analysis on forbidden magnetic dipole emission lines of highly charged Al, Ar, Ti and Fe ions in LHD," J. Quant. Spectrosc. Radiat. Transfer 107, 120-140 (2007). [CrossRef]
  7. R. Katai, S. Morita, and M. Goto, "Observation of visible and near-UV M1 transitions from highly charged Kr, Mo and Xe ions in LHD and its prospect to impurity spectroscopy for D-T burning plasmas," Plasma Fusion Res. 2, 1-4 (2007). [CrossRef]
  8. M. B. Chowdhuri, S. Morita, M. Goto, H. Nishimura, K. Nagai, and S. Fujioka, "Line analysis of EUV spectra from molybdenum and tungsten injected with impurity pellets in LHD," Plasma Fusion Res. 2, S1060 (2007). [CrossRef]
  9. M. Koike, T. Yamazaki, and Y. Harada, "Design of holographic gratings recorded with aspheric wave-front recording optics for soft x-ray flat-field spectrographs," J. Electron Spectrosc. Relat. Phenom. 101-103, 913-918 (1999). [CrossRef]
  10. N. Nakano, H. Kurada, T. Kita, and T. Harada, "Development of a flat-field grazing-incidence XUV spectrometer and its application in picosecond XUV spectroscopy," Appl. Opt. 23, 2386-2392 (1984). [CrossRef] [PubMed]
  11. M. B. Chowdhuri, S. Morita, M. Goto, H. Nishimura, K. Nagai, and S. Fujioka, "Spectroscopic comparison between 1200 grooves/mm ruled and holographic gratings of a flat-field spectrometer and its absolute sensitivity calibration using bremsstrahlung continuum," Rev. Sci. Instrum. 78, 023501 (2007). [CrossRef] [PubMed]
  12. M. Koike, K. Sano, E. Gullikson, Y. Harada, and H. Kumata, "Performance of laminar-type holographic grating for a soft x-ray flat-field spectrograph in the 0.7-6 nm region," Rev. Sci. Instrum. 74, 1156-1158 (2003). [CrossRef]
  13. W. L. Hodge, B. C. Stratton, and H. W. Moos, "Grazing incidence time-resolved spectrograph for magnetic fusion plasma diagnostics," Rev. Sci , Instrum. 55, 16-24 (1984). [CrossRef]
  14. M. May, J. Lepson, P. Beiersdorfer, D. Thorn, H. Chen, D. Hey, and A. Smith, "Photometric calibration of an EUV flat field spectrometer at the advanced light source," Rev. Sci. Instrum. 74, 2011-2013 (2003). [CrossRef]
  15. A. M. Daltrini and M. Machida, "Modified branching ratio method for absolute intensity calibration in VUV spectroscopy," IEEE Trans. Plasma Sci. 33, 1961-1967 (2005). [CrossRef]
  16. J. H. Parkinson, "New observations of Fe xvii in the solar x-ray spectrum," Astron. Astrophys. 24, 215-218 (1973).
  17. K. J. H. Phillips, R. Mewe, L. K. Harra-Murnion, J. S. Kaastra, P. Beiersdorfer, G. V. Brown, and D. A. Liedahl, "Benchmarking the MEKAL spectral code with solar x-ray spectra," Astron. Astrophys. , Suppl. Ser. 138, 381-393 (1999).
  18. G. V. Brown, P. Beiersdorfer, D. A. Liedahl, K. Widmann, and S. M. Kahn, "Laboratory measurements and modeling of the Fe xvii x-ray spectrum," Astrophys. J. 502, 1015-1026 (1998). [CrossRef]
  19. G. V. Brown, P. Beiersdorfer, D. A. Liedahl, K. Widmann, S. M. Kahn, and E. J. Clothiaux, "Laboratory measurements and identification of the Fe xviii-xxivL-shell x-ray line emission," Astrophys. J. , Suppl. Ser. 140, 589-607 (2002). [CrossRef]
  20. P. Beiersdorfer, S. von Goeler, M. Bitter, and D. B. Thorn, "Measurements of the 3d --> 2p resonance to intercombination line-intensity ratio in neon-like Fe xvii, Ge xxiii, and Se xxv," Phys. Rev. A 64, 032705 (2001). [CrossRef]
  21. K. J. H. Phillips, C. J. Greer, A. K. Bhatia, I. H. Coffey, R. Barnsley, and F. P. Keenan, "Fe xvii x-ray lines in solar coronal and laboratory plasmas," Astron Astrophys. 324, 381-394 (1997).
  22. S. B. Utter, G. B. Brown, P. Beiersdorfer, E. J. Clothiaux, and N. K. Podder, "Grazing-incidence measurements of L-shell line emission from highly charged Fe in the soft x-ray region," Rev. Sci. Instrum. 70, 284-287 (1999). [CrossRef]
  23. Yu. Ralchenko, F.-C. Jou, D. E. Kelleher, A. E. Kramida, A. Musgrove, J. Reader, W. L. Wiese, and K. Olsen, "NIST atomic spectra database," version 3.1.1 (2007), http://physics.nist.gov/PhysRefData/ASD/lineslowbarform.html.
  24. R. L. Kelly, "Atomic and ionic spectrum lines below 2000 angstroms: hydrogen through krypton," J. Phys. Chem. Ref. Data 16, 1-1678 (1987).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited