Formation of Plasma potential by means of ECH at divertor and peripheral region of plasma
| Project/Area Number |
08458108
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
プラズマ理工学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MAEKAWA Takashi Kyoto University, Graduate School of Energy Science, Professor, エネルギー科学研究科, 教授 (20127137)
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| Co-Investigator(Kenkyū-buntansha) |
ASAKAWA Makoto Kyoto University, Graduate School of Science, Instructor, 理学部研究科, 助手 (30280704)
TERUMICHI Yasushi Kyoto University, Graduate School of Science, Professor, 理学研究科, 教授 (50025384)
TANAKA Hitoshi Kyoto University, Graduate School of Energy Science, Associate Professor, エネルギー科学研究科, 助教授 (90183863)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1997: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1996: ¥5,300,000 (Direct Cost: ¥5,300,000)
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| Keywords | ECH / divertor plasma / plasma potential / LHCD / ダイバータ / ECH / プラズマ周辺電位 / 電子バーンスタイン波 / 双方向LHCD / 周辺プラズマ / セパラトリックス |
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| Research Abstract |
Stabilization of plasma has been attained via formation of plasma electric potential or control of pressure profile by means of electron cyclotron heating (ECH). ECH experiments on (1) inner region of plasma, (2) peripheral region and (3) divertor region were planned and done. The results are summarized as follows.
(1) In the case of strong magnetic field and/or relatively low electron density, lower hybrid wave (LHW) can propagate into the inner side of plasma, where the tearing instability is suppressed by LH current drive (LHCD) and then a new MIHD instability is destabilized, The experimental results show that this instability is a pressure driven mode and pressure profile control by ECH is quite effective for suppression of the mode.
(2) In the case of high electron density, toroidal rotation of plasma is slowed down by LHCD and the tearing mode is mode-locked to the vacuum vessel, and finally plasma disruption takes place. The slowdown of plasma rotation suggests the decrease of plasma potential, which may be ascribed to the loss of LHCD driven fast electrons at the plasma periphery. ECH is quite effective for unlocking of the mode lock and recovery of the plasma toroidal rotation. As a result, the plasma disruption can be avoided. These results suggests that ECH is effective for recovering of potential.
(3) Since ECH by using Electron Bernstein waves is assumed to be quite effective for low electron temperature plasma near the divertor region, we have prepared a heating mm wave power source and designed the transmission line and injection antenna for the Bernstein wave heating. In this scheme, trapped electrons in toroidal ripple may be heated and injected into the main plasma via toroidal drift, and plasma potential may be formed at the j3lasma peripheral region.
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Report
(3 results)
Research Products
(6 results)
