Plasma and Fusion Research

Volume 14, 3402056 (2019)

Regular Articles

Capability Studies of the Heliotron J Soft X-Ray Tomographic Diagnostic
Shishir PUROHIT1), Yasuhiro SUZUKI1,2), Satoshi OHDACHI1,2) and Satoshi YAMAMOTO3)
1)
SOKENDAI, The Graduate University for Advanced Studies, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
2)
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
3)
Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
(Received 28 December 2018 / Accepted 11 February 2019 / Published 10 April 2019)

Abstract

Imaging diagnostics offers magnetic free information for the plasma emissions and able to define plasma shape and position, impurity distribution, and magnetohydrodynamics (MHD) instabilities. The tomographic reconstruction is one of the powerful tools to analyze imaging diagnostic data. Tomography is employed for a wide range of plasma studies prominently for the soft X-ray (SX). SX tomography allows access to spatiotemporal transient phenomena resulting from the magnetohydrodynamics (MHD) activities, which are important for plasma confinement. Heliotron J (H-J) is an L/M = 1/4 helical axis Heliotron with a low magnetic shear configuration and with a bumpy poloidal plasma shape. An attempt for qualitative evaluation of the tomographic reconstruction capabilities for the Heliotron-J device was made. The tomographic reconstructions were made via Phillips - Tikhonov regularizations from the experimental data set at different locations in the time-space. The results suggests that the diagnostic needs to be improved for a high quality of image reconstruction and possible realization of magnetic axis shift, Shafranov Shift.

Keywords

Heliotron J (H-J), soft X-ray, tomographic reconstruction, Phillips - Tikhonov regularizations and Shafranov shift

DOI: 10.1585/pfr.14.3402056

Full Text

PDF format (1.8Mbytes) PDF Download

References

  • [1] L.C. Ingesson, B. Alper, B.J. Peterson and J.C. Vallet, Fusion Sci. Technol. 53, 528 (2008).
  • [2] D. Lluveras Núñez, M.Á. Molero-Armenta, M.Á.G. Izquierdo, M.G. Hernández and J.J. Anaya Velayos, Sensors (Basel) 17, 1085 (2017).
  • [3] T. Ming, S. Ohdachi and Y. Suzuki, Plasma Sci. Technol. 15, 1178 (2013).
  • [4] N. Iwama and S. Takamura, Med. Imaging Technol. (In Japanese) 13, 132 (1995).
  • [5] R.S. Granetz and P. Smeulders, Nucl. Fusion 28, 457 (1988).
  • [6] A. Weller, J. Geiger, M. Zarnstorff, E. Sallander, S. Klose, A. Werner, J. Baldzuhn, R. Brakel, R. Burhenn, H. Ehmler, F. Gadelmeier, L. Giannone, D. Hartmann, R. Jaenicke, J. Knauer, H.P. Laqua, C. Nührenberg, E. Pasch, N. Rust et al., “Investigation of the β-Limit in the W7-AS Stellarator”, in: 19th Fusion Energy Conf. 14-19 October, Lyon, Fr. (2001), p.EX/S3-1.
  • [7] Y. Nagayama, J. Appl. Phys. 62, 2702 (1987).
  • [8] S. Murakami, M. Okamoto, N. Nakajima, M. Ohnishi and H. Okada, Nucl. Fusion 34, 913 (1994).
  • [9] T. Obiki, F. Sano, M.Wakatani, K. Kondo, T. Mizuuchi, K. Hanatani, Y. Nakamura, K. Nagasaki, H. Okada, M. Nakasuga, S. Besshou and M. Yokoyama, Plasma Phys. Control. Fusion 42, 1151 (2000).
  • [10] M. Wakatani, Y. Nakamura, K. Kondo, M. Nakasuga, S. Besshou, T. Obiki, F. Sano, K. Hanatani, T. Mizuuchi, H. Okada, K. Nagasaki, N. Inoue and M. Yokoyama, Nucl. Fusion 40, 569 (2000).
  • [11] V.D. Shafranov, Sov. At. Energy 13, 1149 (1963).
  • [12] S. Yamamoto, K. Nagasaki, S. Kobayashi, K. Nagaoka, A. Cappa, H. Okada, T. Minami, S. Kado, S. Ohshima, S. Konoshima, Y. Nakamura, A. Ishizawa, G.M. Weir, N. Kenmochi, Y. Ohtani, X. Lu, Y. Tawada, D. Kokubu and T. Mizuuchi, Nucl. Fusion 57, 126065 (2017).
  • [13] S. Yamamoto, K. Nagasaki, Y. Suzuki, T. Mizuuchi, H. Okada, S. Kobayashi, B. Blackwell, K. Kondo, G. Motojima, N. Nakajima, Y. Nakamura, C. Nührenberg, Y. Torii, S. Watanabe and F. Sano, Fusion Sci. Technol. 51, 92 (2007).
  • [14] K. Nishikawa, S. Yamamoto, T. Mizuuchi and K. Nagasaki, “Studies of Magnetohydrodynamics Equilibrium and Stability by Using Soft X-ray CT in High Density Plasmas of Heliotron J”, in: Plasma Conf. 18-21 November, Niigata, Japan (2014), p.19PA-027.
  • [15] M. Al-Frejat and M. HjoujBtoush, Int. J. Adv. Comput. Sci. Appl. 7, 476 (2016).
  • [16] M. Yang, X. Wang, Y. Liu, F. Men, X. Li, W. Liu and D. Wei, Chinese Phys. C 38, 046202 (2013).
  • [17] N. Iwama and S. Ohdachi, J. Plasma Fusion Res. 82, 399 (2006).
  • [18] G.H. Golub, M. Heath and G. Wahba, Technometrics 21, 215 (1979).
  • [19] N. Iwama, H. Yoshida, H. Takimoto, Y. Shen, S. Takamura and T. Tsukishima, Appl. Phys. Lett. 54, 502 (1989).
  • [20] S. Ohdachi, K. Toi, G. Fuchs, the TEXTOR Team and the LHD Experimental Group, Plasma Sci. Technol. 8, 45 (2006).
  • [21] S. Purohit, Y. Suzuki, S. Ohdachi and S. Yamamoto, Rev. Sci. Instrum, 89, 10 (2018).