| Project/Area Number |
04680019
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Morphological basic dentistry
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| Research Institution | NATIONAL INSTITUE FOR FUSION SCIENCE (NIFS) |
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Principal Investigator |
KAWAMURA Takaichi NIFS,PROFESSOR, 研究・企画情報センター, 教授 (70023710)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Takako NIFS,ASSOCIATE PROFESSOR, 研究・企画情報センター, 助教授 (20115546)
TAWARA Hiroyuki NIFS,ASSOCIATE PROFESSOR, 研究・企画情報センター, 助教授 (90037797)
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| Project Period (FY) |
1992 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | BOUNDARY PLASMA / ATOMIC AND MOLECULAR PROCESSES / PLASMA-WALL INTERACTIONS / プラズマ・壁相互作用 / スパッタリング率 / データのフィッティング / シース |
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| Research Abstract |
The boundary plasma includes recycling hydrogen neutrals and impurities, and many kinds of atomic/molecular (AM) reactions and plasma wall interactions take place therein. Radiative power loss arising from collisions of plasma electrons with neutrals and impurities reduces the boundary plasma temperature and realizes cool and dense plasma in front of the first wall such as divertor plate. Then the analysis of the boundary plasma is much important in studies on fusion reactor development.
In this research we reviewed and evaluated the semi-empirical farmulas of cross sections sigma (E) for many AM processes, because the rate coefficient <sigmaupsiron> of these processes are needed for analysis of results from boundary plasma diagnostics or for simulation calculation of boundary plasma. We also evaluated the reflection coefficients and sputtering yields of graphite by right particles. In these fields almost all experimental data are relevant to monoenergetic and normal incidence of primary particles, however, the maximum value of yields is placed at nealy grancing angle incidence. Then we obtained the calculated data using the sputtering simulation code ACAT which is developed by Prof.Y.Yamamura. In order to have a precise erosion rate of graphite irradiated by boundary plasma, we obtained it by averaging sputtering yields for primary particles with velocity distribution corresponding to the boundary plasma temperature T.And we introduced a new fitting formula Y (T) for an arrangement of the numerical data of sputtering yields, in which six fitting parameters Q_1・・・Q_6 are determinded from numerical results. These results provide a way to estimate of carbon materials by boundary plasma.
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