The temporal development of hollow cathode discharges

Author

Ngo, Mai T. ; Schoenbach, Karl H. ; Gerdin, Glenn A. ; Lee, Ja H.

Author_Institution

Dept. of Electr. & Comput. Eng., Old Dominion Univ., Norfolk, VA, USA

Volume

18

Issue

3

fYear

1990

fDate

6/1/1990 12:00:00 AM

Firstpage

669

Lastpage

676

Abstract

The temporal development of hollow cathode discharges was studied by means of electrical and optical diagnostic techniques. The results indicate that the discharge develops in two stages. The initial breakdown occurs along the longest straight path of the system, i.e. from the anode to the bottom of the cathode hole. This predischarge is confined to a narrow filament along the axis and carries a current of up to hundreds of milliamperes. The resulting distortion of the electric field in the cathode hole is assumed to cause a radial breakdown from the filamentary plasma on the axis to the edge of the cathode hole. After this second breakdown, an increase in current by more than three orders of magnitude is observed. Measurements with axial magnetic fields support the two-stage model

Keywords

cathodes; electric breakdown of gases; high-frequency discharges; plasma diagnostics; 100 A; He; axial magnetic fields; cathode hole; distortion; electric field; electrical diagnostics; filamentary plasma; hollow cathode discharges; narrow filament; optical diagnostic; plasma diagnostics; predischarge; radial breakdown; temporal development; two-stage model; Cathodes; Discharges; Electric breakdown; Electrodes; Fault location; Magnetic field measurement; Plasma confinement; Plasma measurements; Switches; Voltage;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.55942

Filename

55942