Studies of the electrical properties of the LHD combline antenna

N. Takeuchi, T. Seki, K. Saito, T. Watari, R. Kumazawa, T. Mutoh, Y. Torii, G. Nomura, A. Kato, F. Shimpo, Y. Takase, H. Kasahara, T. Taniguchi, H. Wada, Naohiro Kasuya, K. Yamagishi, C. P. Moeller, M. Saigusa, Z. Yanping

Research output: Contribution to journalArticle

Abstract

A novel stacked combline antenna was fabricated for driving plasma current in order to control the rotational transform profile in the Large Helical Device. The antenna has ten elements facilitating excitation of fastwave traveling in the toroidal direction. Each antenna element has an electrical length of a half-wavelength and is supported at the midpoint from the back plate by a metallic block. Such an antenna has two modes: even and odd. A mixed excitation of these modes will reduce the current drive efficiency. The electrical properties of this antenna were studied in an attempt to find ways of exciting a traveling wave of pure even mode. A matching section was used in combination and proved to be a good measure to improve the directionality over that of a bare combline antenna. It is con firmed in this paper that the fabricated real antenna has fairly good even-mode purity keeping the odd-mode intensity at a tolerable level. An antenna with insulating supports instead of the metallic supports is also examined, and it is found that even-mode purity is further improved. For practical uses, an entire system including impedance matching and power circulation is proposed, and sensitivity to a change in plasma loading is analyzed. Finally, the power-handling capability is discussed including estimations of plasma loading and driven current reaching an assertion of consistency with the experimental goal.

Original languageEnglish
Pages (from-to)1267-1284
Number of pages18
JournalFusion Science and Technology
Volume48
Issue number3
DOIs
Publication statusPublished - Jan 1 2005

Fingerprint

Electric properties
antennas
electrical properties
Antennas
Plasmas
purity
impedance matching
plasma currents
traveling waves
excitation
Wavelength
sensitivity
profiles
wavelengths

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Takeuchi, N., Seki, T., Saito, K., Watari, T., Kumazawa, R., Mutoh, T., ... Yanping, Z. (2005). Studies of the electrical properties of the LHD combline antenna. Fusion Science and Technology, 48(3), 1267-1284. https://doi.org/10.13182/FST05-A1076

Studies of the electrical properties of the LHD combline antenna. / Takeuchi, N.; Seki, T.; Saito, K.; Watari, T.; Kumazawa, R.; Mutoh, T.; Torii, Y.; Nomura, G.; Kato, A.; Shimpo, F.; Takase, Y.; Kasahara, H.; Taniguchi, T.; Wada, H.; Kasuya, Naohiro; Yamagishi, K.; Moeller, C. P.; Saigusa, M.; Yanping, Z.

In: Fusion Science and Technology, Vol. 48, No. 3, 01.01.2005, p. 1267-1284.

Research output: Contribution to journalArticle

Takeuchi, N, Seki, T, Saito, K, Watari, T, Kumazawa, R, Mutoh, T, Torii, Y, Nomura, G, Kato, A, Shimpo, F, Takase, Y, Kasahara, H, Taniguchi, T, Wada, H, Kasuya, N, Yamagishi, K, Moeller, CP, Saigusa, M & Yanping, Z 2005, 'Studies of the electrical properties of the LHD combline antenna', Fusion Science and Technology, vol. 48, no. 3, pp. 1267-1284. https://doi.org/10.13182/FST05-A1076
Takeuchi N, Seki T, Saito K, Watari T, Kumazawa R, Mutoh T et al. Studies of the electrical properties of the LHD combline antenna. Fusion Science and Technology. 2005 Jan 1;48(3):1267-1284. https://doi.org/10.13182/FST05-A1076
Takeuchi, N. ; Seki, T. ; Saito, K. ; Watari, T. ; Kumazawa, R. ; Mutoh, T. ; Torii, Y. ; Nomura, G. ; Kato, A. ; Shimpo, F. ; Takase, Y. ; Kasahara, H. ; Taniguchi, T. ; Wada, H. ; Kasuya, Naohiro ; Yamagishi, K. ; Moeller, C. P. ; Saigusa, M. ; Yanping, Z. / Studies of the electrical properties of the LHD combline antenna. In: Fusion Science and Technology. 2005 ; Vol. 48, No. 3. pp. 1267-1284.
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