TY - JOUR
T1 - High harmonic ECH experiment for extension of heating parameter regime in LHD
AU - Shimozuma, Takashi
AU - Takahashi, Hiromi
AU - Kubo, Shin
AU - Yoshimura, Yasuo
AU - Igami, Hiroe
AU - Nishiura, Masaki
AU - Ogasawara, Shinya
AU - Makino, Ryohei
AU - Idei, Hiroshi
AU - Marushchenko, Nikolai B.
AU - Turkin, Yuri
AU - Mutoh, Takashi
N1 - Funding Information:
The authors gratefully acknowledge the LHD experiment group for their operation of LHD, and the heating and diagnostic devices. They also thank Doctors R. Minami, T. Kariya and T. Imai at the University of Tsukuba for the development of the powerful gyrotrons. This work was supported by NIFS under ULRR701, 801, and 804. This work was also supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (24560066)
PY - 2013
Y1 - 2013
N2 - High harmonic electron cyclotron resonance heating (ECH) can extend the plasma heating region to higher density and higher β compared to the normal heating scenario. In this study, the heating characteristics of the second-harmonic ordinary (O2) and third-harmonic extraordinary (X3) modes and the possible extension of heating regime are experimentally confirmed. At the same time, a comparative study using ray-tracing calculation was performed in the realistic three-dimensional configuration of the Large Helical Device. The O2 mode heating showed a 40% absorption rate even above the X2 mode cut-off density. The X3 mode heating using powerful 77 GHz gyrotrons demonstrated an increase of about 40% in the central electron temperature in the plasmas at β-value of about 1%. These results were quantitatively explained to some extent by ray-tracing calculations.
AB - High harmonic electron cyclotron resonance heating (ECH) can extend the plasma heating region to higher density and higher β compared to the normal heating scenario. In this study, the heating characteristics of the second-harmonic ordinary (O2) and third-harmonic extraordinary (X3) modes and the possible extension of heating regime are experimentally confirmed. At the same time, a comparative study using ray-tracing calculation was performed in the realistic three-dimensional configuration of the Large Helical Device. The O2 mode heating showed a 40% absorption rate even above the X2 mode cut-off density. The X3 mode heating using powerful 77 GHz gyrotrons demonstrated an increase of about 40% in the central electron temperature in the plasmas at β-value of about 1%. These results were quantitatively explained to some extent by ray-tracing calculations.
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U2 - 10.1585/pfr.8.2402073
DO - 10.1585/pfr.8.2402073
M3 - Article
AN - SCOPUS:84961633631
SN - 1880-6821
VL - 8
JO - Plasma and Fusion Research
JF - Plasma and Fusion Research
M1 - 2402073
ER -