Anomalous secondary electron emission of metallic surfaces exposed to a Glow Discharge plasma
Anomalous secondary electron emission of metallic surfaces exposed to a Glow Discharge plasma
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DOI：
10.1016/j.jnucmat.2013.01.170
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发表时间：
2013-07
影响因子：
3.1
通讯作者：
E. Oyarzabal;A. B. Mart́ın-Rojo;J. Ferreira;D. Tafalla;F. Tabarés
中科院分区：
文献类型：
--
作者：
E. Oyarzabal;A. B. Mart́ın-Rojo;J. Ferreira;D. Tafalla;F. Tabarés
利用实验I-V曲线计算了Li、不锈钢和W表面在He直流辉光放电（dc-GD）等离子体中的二次电子发射（SEE）产率γ与电子平均能量的关系。所得数据表明，γLi>γSS>γW。激发He和Langmuir探针测量的线发射比728/706提供了一个明确的证据，证明存在一个负责观察到的SEE的超热电子尾。结果表明，SEE与在I-V曲线中发现的异常额外电流分量有很好的相关性。所得的γ - li值明显高于理论值，表明离子轰击可能在锂的SEE中产生协同效应。Li表面氧化的影响也得到了解决，导致高氧含量Li的溅射产率和SEE产率大幅下降。
Secondary electron emission (SEE) yields, γ, of Li, stainless steel (SS) and W surfaces immersed in a He Direct Current Glow Discharge (dc-GD) Plasma have been calculated from the experimental I–V curves as a function of electron mean energy. The data obtained showed that γLi>γSS>γW. Line emission ratios 728/706 of excited He and Langmuir probe measurements provide a clear evidence of the presence of a suprathermal electron tail responsible for the observed SEE. The results show that SEE is well correlated with the anomalous extra current component found in the I–V curves. The resulting value of γLiis significantly higher than its theoretical value suggesting a possible synergetic effect of the ion bombardment in the SEE of lithium. The effect of Li surface oxidation has also been addressed, leading to a substantial decrease of both, sputtering yield and SEE yield of Li with higher oxygen content.