Time dependence of vacuum arc parameters

Author

Anders, André ; Anders, Simone ; Jüttner, Burkhard ; Brown, Ian G.

Author_Institution

Lawrence Berkeley Lab., California Univ., CA, USA

Volume

21

Issue

3

fYear

1993

fDate

6/1/1993 12:00:00 AM

Firstpage

305

Lastpage

311

Abstract

Time-resolved investigations of the expanded plasma of vacuum arc cathode spots are described, including the study of the ion charge state distribution, the random cathode spot motion, and the crater formation. It was found that the ion charge state distribution changes over a timescale on the order of hundreds of microseconds. For the random spot motion two timescales were observed: a very short spot residence time of tens of nanoseconds which gives, combined with the step width, the diffusion parameter of the random motion, and a longer timescale on the order of 100 μs during which the diffusion parameter changes. Crater formation studies by scanning electron microscopy indicate the occurrence of larger craters at the end of crater chains. The existence of a timescale much longer than the elementary times for crater formation and spot residence can be explained by local heat accumulation

Keywords

arcs (electric); cathodes; plasma diagnostics; plasma transport processes; scanning electron microscope examination of materials; 100 mus; cathode spots; crater formation; diffusion parameter; expanded plasma; ion charge state distribution; local heat accumulation; random cathode spot motion; residence time; scanning electron microscopy; time resolved spectra; vacuum arc parameters; Cathodes; Electric breakdown; Ionization; Plasma devices; Plasma sources; Scanning electron microscopy; Spectroscopy; Titanium; Vacuum arcs; Voltage;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.277556

Filename

277556