Evidence and consequences of cathode-spot substructure in vacuum arcs

Author

Juttner, Burkhard ; Förster, Andreas

Author_Institution

Sektion Phys., Humboldt-Univ., Berlin, Germany

Volume

1

fYear

1996

fDate

21-26 Jul 1996

Firstpage

118

Abstract

Time and spatial variations of vacuum arc spots have been studied by laser absorption and emission imaging techniques. It is shown experimentally that for t<10 ns there exist plasma structures with a size <5 μm. Experimental estimates of fragment size and lifetime are 1-2 μm and 1-2 ns, respectively. These estimates are supported by modelling the nonideal plasma state, based on the power input and the erosion rate. The model results in mean charge numbers of 2-3, electron temperatures of 8-9 eV, and plasma densities of about 10²⁷ m ^-3

Keywords

cathodes; electron field emission; electron microscopy; field emission electron microscopy; measurement by laser beam; plasma density; plasma temperature; vacuum arcs; 1 to 2 mum; 1 to 2 ns; cathode-spot substructure; electron temperatures; emission imaging technique; erosion rate; fragment lifetime; fragment size; laser absorption; mean charge numbers; nonideal plasma state modelling; plasma densities; plasma structures; power input; spatial variations; time variations; vacuum arc spots; vacuum arcs; Absorption; Electrons; Laser modes; Life estimation; Lifetime estimation; Plasma density; Plasma temperature; State estimation; Vacuum arcs; Vacuum technology;

fLanguage

English

Publisher

ieee

Conference_Titel

Discharges and Electrical Insulation in Vacuum, 1996. Proceedings. ISDEIV., XVIIth International Symposium on

Conference_Location

Berkeley, CA

Print_ISBN

0-7803-2906-6

Type

conf

DOI

10.1109/DEIV.1996.545332

Filename

545332