Basic study on lithium coating and plasma-surface processes
| Project/Area Number |
05680391
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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 |
プラズマ理工学
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| Research Institution | Nagoya University |
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Principal Investigator |
TOYODA Hirotaka Nagoya University, Department of Electrical Engineering, Assistant Professor, 工学部, 講師 (70207653)
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| Co-Investigator(Kenkyū-buntansha) |
SUGAI Hideo Nagoya University, Department of Electrical Engineering, Pro Professor, 工学部, 教授 (40005517)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Nuclear fusion / Lithium coating / Hydrogen recycling / oxygen gettering |
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| Research Abstract |
1. Establishment of Lithium Coating Technique
Lithium coating with evaporation method is investigated. It was found that the evaporation speed can be easily controlled by the oven temperature around 400 C.To suppress impurity from heated oven, RF inductive heating is used, which effectively heat the lithium itself without heating other materials.
2. Chemical reaction of lithium with various gases
Chemical reactivity of lithium film with various gases such as O_2, H_2, CH_4 or CO was investigated. It is found that the lithium is highly reactive with the oxygen gas, and the coated lithium film is completely oxidized when the oxygen gas is fed into the vessel. CO and CH_4 are also reactive with lithium, but reaction is limited up to a few monolayrs of lithium film surface. Hydrogen does not react with lithium film.
3. Interaction of lithium film with hydrogen plasma
Interaction of lithium film with hydrogen DC glow plasma is investigated. Lithium film absorbs large amount of hydrogen. Hydrogen absorption is almost comparable to the coated lithium, which implies that the one lithium atom reacts with one hydrogen atom, and that the hydrogen penetrates into bulk of lithium film irrespective to the ion implantation range of hydrogen ion into the lithium film (less than a few hundred nano-meters).
4. Lithium coating of JIPPT-IIU fusion experiment device.
Lithium coating is successfully applied to the JIPPT-IIU fusion experiment device at National Institute for Fusion Science. Lithium (0.5g) is evaporated on the vessel wall of JIPPT-IIU,with coating area of about Im^2. It was found that the hydrogen recycling is reduced in the initial stage of tokamak discharge, and that the oxygen and carbon impurities is reduced.
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Report
(3 results)
Research Products
(3 results)
