Experimental Test Of Whether Electrostatically Charged Micro-organisms And Their Spores Contribute To The Onset Of Arcs Across Vacuum Gaps

[摘要] Recently it was proposed [L.R. Grisham, A. vonHalle, A.F. Carpe, Guy Rossi, K.R. Gilton, E.D. McBride, E.P. Gilson, A. Stepanov, T.N. Stevenson, Physics of Plasma 19 023107 (2012)] that one of the initiators of vacuum voltage breakdown between condu cting electrodes might be micro-organisms and their spores, previously deposited during exposure to air, which tnen become electrostatically charged when an electric potential is applied across the vacuum gap. The note describes a simple experiment to compare the number of voltage-conditioning pulses required to reach the nominal maxium operating voltage across a gap between two metallic conductors in a vacuum, comparing cases in which biological cleaning was done just prior to pump-down with cases where this was not done, with each preceded by exposure to ambient air for three days. Based upon these results, it does not appear that air-deposited microbes and their spores constitute a major pathway for arc initiation, at least for exposure periods of a few days, and for vacuum gaps of a few millimeters, in the regime where voltage holding is usually observed to vary linearly with gap distance

[发布日期] 2014-02-24

[学科分类] 原子、分子光学和等离子物理

[关键词] Micro-organisms