An investigation of the secondary-electron emission of carbon samples exposed to a hydrogen plasma
An investigation of the secondary-electron emission of carbon samples exposed to a hydrogen plasma
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DOI：
10.1088/0022-3727/20/9/008
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发表时间：
1987-09
期刊：
影响因子：
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通讯作者：
M. E. Woods;B. Hopkins;G. Matthews;G. Mccracken;P. Sewell;H. Fahrang
中科院分区：
文献类型：
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作者：
M. E. Woods;B. Hopkins;G. Matthews;G. Mccracken;P. Sewell;H. Fahrang
本文报道了在JET托卡马克装置上对5890 PT石墨样品和暴露几个月的相同材料样品的二次电子发射（SEE）产额的测量结果。暴露在JET托卡马克中的样品给出的值比干净样品高得多。对照实验表明，注入H2+离子和沉积薄金属膜增加SEE产量。实验数据已被集成在一个3D麦克斯韦分布，以获得有效的SEE产量预期从等离子体作为电子温度的函数的值。从这些单粒子电动势产额，鞘层电位和鞘层能量传输因子的理论值已被计算。离子溅射和功率损耗的影响进行了讨论。
Measurements of secondary-electron-emission (SEE) yield are reported for samples of clean 5890 PT graphite and for the same material exposed for some months in the JET Tokamak. The samples exposed in the JET Tokamak give substantially higher values than the clean samples. Controlled experiments show that both implantation with H2+ ions and deposition of thin metal films increase the SEE yield. The experimental data have been integrated over a 3D Maxwellian distribution to obtain the values of effective SEE yield expected from a plasma as a function of electron temperature. From these SEE yields, theoretical values of sheath potential and sheath energy transmission factor have been calculated. The implications for ion sputtering and power loss are discussed.