1991 Fiscal Year Final Research Report Summary
Research and Development of a High Current Deuterium Negative Ion Source
| Project/Area Number |
02452277
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
プラズマ理工学
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| Research Institution | Yamaguchi University |
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Principal Investigator |
FUKUMASA Osamu Yamaguchi University, Dept. of Electrical and Electronic Engineering, Professor, 工学部, 教授 (20026321)
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| Co-Investigator(Kenkyū-buntansha) |
SAKIYAMA Satoshi Yamaguchi University, Dept. of Electrical and Electronic Engineering, Research A, 工学部, 助手 (60162327)
NAITOU Hiroshi Yamaguchi University, Dept. of Electrical and Electronic Engineering, Associate, 工学部, 助教授 (10126881)
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| Project Period (FY) |
1990 – 1991
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| Keywords | NBI heating / volume production type negative ion source / double plasma type negative ion source / H^- / D^- production / vibrationally excited hydrogen molecules / dissociative attachment / magnetic filter / plasma grid |
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| Research Abstract |
High current hydrogen/deuterium negative ion sources are of interest to the fusion community for the preparation of neutral beams, namely NBI heating of fusion plasmas. To this end, basic processes for enhancement of H^- production and H^- extraction in volume sources have been studied experimentally, theoretically and computationally (i. e. particle simulation).
(1) The role of fast electrons e_f in H^- production processes is well clarified theoretically. Vibrational molecules H_2^*, are essential to H^- production. Among some production processes of H_2^*, the collisional excitation of H_2^* by e_f is most important to enhance the H^- yield.
(2) Relationship between extraction of H^- ions optimized by plasma grid potential and plasma parameters in a bucket source is clarified experimentally.
(3) A double plasma type negative ion source is newly designed. In this source, the energy distribution of e_f and its quantity are well controlled by changing the potential difference between two plasmas. Volume production of H^- ions caused by the so-called two step process is well confirmed experimentally.
(4) Two dimensional electrostatic particle simulation is implemented to study energy dependent electron transport across a magnetic filter, and to study extraction of H^- ions.
(5) Deuterium plasmas are well produced, and volume produced D^- ions are extracted. Isotope effects are now under study.
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Research Products
(12 results)
