Basic study on lithium coating and plasma-surface processes

锂涂层和等离子体表面工艺的基础研究

• 批准号: 05680391
• 负责人: TOYODA Hirotaka
• 金额: $ 1.28万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680391/
• 关键词: Nuclear fusion; Lithium coating; Hydrogen recycling; oxygen gettering

1. Establishment of Lithium Coating TechniqueLithium 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 gasesChemical 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 plasmaInteraction 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.

1.镀锂工艺的建立研究了蒸发法镀锂。发现蒸发速度可以通过烘箱温度容易地控制在400 C左右。为了抑制来自加热烘箱的杂质，使用RF感应加热，其有效地加热锂本身而不加热其他材料。锂与各种气体的化学反应研究了锂膜与O_2、H_2、CH_4、CO等气体的化学反应性。发现锂与氧气具有高反应性，并且当氧气被供给到容器中时，涂覆的锂膜被完全氧化。CO和CH_4也与锂反应，但反应限于锂膜表面的几个单层。氢气不与锂膜反应。锂膜与氢等离子体的相互作用研究了锂膜与氢直流辉光等离子体的相互作用。锂膜吸收大量的氢。氢吸收几乎与涂覆的锂相当，这意味着一个锂原子与一个氢原子反应，并且氢渗透到锂膜的本体中，而与氢离子注入到锂膜中的离子注入范围（小于几百纳米）无关。JIPPT-IIU聚变实验装置的锂涂层。锂涂层成功应用于国立聚变科学研究所的JIPPT-IIU聚变实验装置。锂（0.5g）蒸发在JIPPT-IIU的容器壁上，涂层面积约为1m^2。研究发现，在托克马克放电初期，氢的循环减少，氧和碳杂质减少。

项目成果

H.Sugai: "Wall Conditioning by Lithium Evaporation" J.Nucl.Mater.(in press).

H.Sugai：“通过锂蒸发进行壁调节”J.Nucl.Mater.（​​正在印刷中）。

H.Sugai, H.Toyoda, K.Nakamura, K.Furuta, M.Ohori, K.Toi, S.Hirokura and K.Sato: "Wall Conditioning by Lithium Evaporation" J.Nucl.Mater. (in press). (1995)

H.Sugai、H.Toyoda、K.Nakamura、K.Furuta、M.Ohori、K.Toi、S.Hirokura 和 K.Sato：“锂蒸发的墙壁调节”J.Nucl.Mater。