The physics of non-thermionic cathodes of electric arcs

Author

Lowke, J.J. ; Tanaka, M.

Author_Institution

CSIRO Mater. Sci. & Eng., Lindfield, NSW, Australia

fYear

2008

fDate

7-12 Sept. 2008

Firstpage

137

Lastpage

140

Abstract

It is proposed that the process of electron emission from non-thermionic cathodes of electric arcs in inert gases is by the impact at the cathode of excited neutral states, both metastable and radiative. Electron production at the cathode by other processes such as by ionization in the cathode sheath, field emission, impact by positive ions or photoelectric emission appear to be inconsistent with the low arc voltages that are observed for arcs with non-thermionic cathodes, for example the voltages of ~ 25V such as occur for the arcs used for Â¿Metal Inert GasÂ¿ welding.

Keywords

arc welding; arcs (electric); cathodes; electron emission; excited states; field emission; inert gases; ionisation; photoemission; plasma materials processing; cathode sheath; electric arcs; electron emission; electron production; excited neutral states; field emission; inert gases; ionization; metal inert gas welding; metastable states; nonthermionic cathodes; photoelectric emission; positive ions; Cathodes; Electron emission; Heat transfer; Ionization; Metastasis; Physics; Plasma sheaths; Production; Voltage; Welding;

fLanguage

English

Publisher

ieee

Conference_Titel

Gas Discharges and Their Applications, 2008. GD 2008. 17th International Conference on

Conference_Location

Cardiff

Print_ISBN

978-0-9558052-0-2

Type

conf

Filename

5379308