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Current issue   Ukr. J. Phys. 2016, Vol. 61, N 9, p.806-811
https://doi.org/10.15407/ujpe61.09.0806    Paper

Dreval M.B.1, Turianska O.V.2

1 National Science Center “Kharkov Institute of Physics and Technology”,
Nat. Acad. of Sci. of Ukraine
(1, Akademichna Str., Kahrkiv 61108, Ukraine)
2 V.N. Karazin Kharkiv National University
(4, Svobody Sq., Kharkiv 61022, Ukraine)

Concerning Space Distribution of the Soft X-Ray Emissivity in the U-3M Torsatron

Section: Plasmas and Gases
Original Author's Text: English

Abstract: A miniature pinhole camera array has been installed on the U-3M torsatron for spatially re-solved measurements of soft X-ray plasma emission along 20 lines of sights. The recent line-integrated SXR emission data provide important information about the U-3M plasma confine-ment. The local SXR emissivity distribution in the poloidal cross-section “A-A” is calculated numerically on the base of experimental data. The U-3M magnetic surfaces have been approx-imated as a set of normalized plasma radius data in the grid covering this cross-section. The local SXR emissivity is determined as a function of the normalized radius. The line-integrated SXR emission is calculated for every viewing area of each SXR channel on the base of this local emissivity in the real geometry of the SXR diagnostics. A fitting of the calculated line-integrated SXR emission profiles to the experimental profiles shows that the radial profiles of local SXR emissivity are quite narrow, with strong gradient in the central plasma part. The SXR emissivity profiles are quite different from the parabolic form.

Key words: U-3M, SXR, tomography.

References:

  1. M.B. Dreval, Design and initial operation of multichord soft X-ray detection array on the U-3M torsatron, Probl. Atom. Sci. Technol. 6(20), 250 (2014); available at  PDF
  2. M.B. Dreval, Design of multichord soft X-ray detection arrays for the Uragan-2M stellarator, Probl. Atom. Sci. Tech-nol. 6, 11 (2010); available at  PDF
  3. M.B. Dreval, First results of multichord soft X-ray detection array on the U-3M torsatron, Probl. Atom. Sci. Technol. 1(95), 8 (2015); available at  PDF
  4. V.V. Chechkin, I.M. Pankratov, L.I. Grigor’eva et al., RF discharge dynamics with passing over L-and H-like mode states in the Uragan-3М torsatron, Probl. Atom. Sci. Technol. 6(82), 3 (2012); available at  PDF
  5. I.M. Pankratov, A.A. Beletskii, V.L. Berezhnyj et al., Behavior of RF discharge plasmas in the Uragan-3M and Uragan-2M torsatrons, Contrib. Plasma Phys. 50, 520 (2010).   https://doi.org/10.1002/ctpp.200900012
  6. R.O. Pavlichenko, Influence of suprathermal electrons on ECE measurements in the Uragan-3M torsatron, Probl. Atom. Sci. Technol. 1(95), 293 (2015); available at  PDF
  7. V. Pickalov and N. Preobrazhenski, Reconstructive Tomography in Gas Dymanics and Plasma Physics (Nauka, Novosibirsk, 1987) (in Russian).
  8. L.C. Ingesson, B. Alper, B.J. Peterson, and J.-C. Vallet, Chapter 7: Tomography diagnostics: bolometry and soft-X-ray detection, Fusion Science and Technology, 53, 528 (2008).
  9. M. Anton, H. Weisen, M.J. Dutch et al., X-ray tomography on the TCV tokamak, Plasma Phys. Control. Fusion, 38, 1849 (1996).   https://doi.org/10.1088/0741-3335/38/11/001
  10. K. Ertl, W. von der Linden, V. Dose, and A. Weller, Maximum entropy based reconstruction of soft X-ray emissivity profiles in W7-AS, Nucl. Fusion 36, 1477 (1996).   CrossRef
  11. A.P. Navarro, M.A. Ochando, and A. Weller, Equilibrium-based iterative tomography technique for soft X-ray in stellarators, IEEE Transactions on Plasma Science 19, 569 (1991).   https://doi.org/10.1109/27.90321
  12. A.P. Navarro, V.K. Par’e, and J.L. Dunlap, Two-dimensional spatial distribution of volume emission from line integral data, Rev. Sci. Instrum. 52, 1634 (1981).   https://doi.org/10.1063/1.1136510
  13. S. Ohdachi, K. Toi, G. Fuchs, S. von Goeler, and S. Yamamoto, High-speed tangentially viewing soft X-ray camera to study magnetohydrodynamic fluctuations in toroidally confined plasmas, Rev. Sci. Instrum. 74, 2136 (2003).   https://doi.org/10.1063/1.1537449
  14. R. Sano, B.J. Peterson, M. Kobayashi et al., Reconstruction of 3-D radiation profile from 2-D images viewed by IR imaging video bolometers with SVD, IEEE Trans. on Plasma Sci. 42, 2860 (2014).   https://doi.org/10.1109/TPS.2014.2330605
  15. D. Zhang, M. Glaubitz, H.P. Laqua et al., Determination of electron thermal diffusivity at the WEGA stellarator, Nucl. Fusion 52, 043002 (2012).   https://doi.org/10.1088/0029-5515/52/4/043002
  16. S. Ma, J. Howard, B.D. Blackwell, and N. Thapar, Measurements of electron density and temperature in the H-1 heliac plasma by helium line intensity ratios, Rev. Sci. Instrum. 83, 033102 (2012).   https://doi.org/10.1063/1.3692756
  17. D. Mazon, D. Vezinet, D. Pacella et al., Soft X-ray tomography for real-time applications: present status at Tore Supra and possible future developments, Rev. Sci. Instrum. 83, 063505 (2012).   https://doi.org/10.1063/1.4730044
  18. M. Odstr˘cil, J. Mlyn’aˇr, V. Weinzettl et al., Plasma tomographic reconstruction from tangentially viewing camera with background subtraction, Rev. Sci. Instrum. 85, 013509 (2014).  
  19. C. Nardone, Multichannel fluctuation data analysis by the singular value decomposition method. Application to MHD modes in JET, Plasma Phys. Control. Fusion, 34, 1447 (1992).   https://doi.org/10.1088/0741-3335/34/9/001
  20. V.N. Kalyuzhnyj and V.V. Nemov, Calculations of 1/ Transport in an = 3 stellarator magnetic field in the presence of magnetic islands caused by magnetic system errors, Fusion Sci. Technol. 46, 248 (2004); available at  LINK
  21. V.N. Bondarenko, V.G. Konovalov, S.A. Tsybenko, V.S. Voitsenya, and E.D. Volkov, Investigation of radial distributions of spectral line radiation emissivities in torsatron "Uragan-3M", Probl. Atom. Sci. Technol. 1(9), 23 (2003); available at  PDF
  22. M. Fujiwara, K. Kawahata, N. Ohyabu et al., Overview of LHD experiments, Nucl. Fusion 41, 1355 (2001).   https://doi.org/10.1088/0029-5515/41/10/305
  23. A. Fujisawa, H. Iguchi, T. Minami et al., Experimental study of the bifurcation nature of the electrostatic potential of a toroidal helical plasma, Phys. Plasmas 7, 4152 (2000).   https://doi.org/10.1063/1.1290483
  24. J. S’anchez, D. Alegre, A. Alonso et al., Transport, stability and plasma control studies in the TJ-II stellarator, Nucl. Fusion 55, 104014 (2015).   https://doi.org/10.1088/0029-5515/55/10/104014