An experimental study of the dependence on the current intensity of the erosion of thoriated tungsten cathodes in plasma arcs

Author

Casado, Eduardo ; Colomer, Vicente ; Sicilia, Rafael ; Muñoz-Serrano, Encarnación

Author_Institution

Dept. of Phys., Cordoba Univ., Spain

Volume

29

Issue

6

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

888

Lastpage

894

Abstract

The erosion occurring in thoriated tungsten cathodes used in transferred plasma torches operating with current intensities ranging from 30 to 210 A has been experimentally investigated. The cathode erosion rate was determined by measuring the cathode´s weight loss after arcing, and the eroded cathode surface was explored by a scanning electron microscope and an energy dispersive X-ray spectrometer. It has been discovered that a critical current intensity, I_CR ~ 50 A, exists for which the cathode erosion rate becomes maximum

Keywords

X-ray chemical analysis; arcs (electric); cathodes; plasma torches; plasma-wall interactions; scanning electron microscopy; thorium compounds; tungsten; wear; work function; 30 to 210 A; 50 A; W; W-ThO₂; W-ThO₂ cathode; arcing; cathode erosion rate; critical current intensity; current intensities; current intensity; energy dispersive X-ray spectrometer; eroded cathode surface; erosion; plasma arcs; scanning electron microscope; thoriated W cathodes; transferred plasma torches; tungsten cathodes; weight loss; Cathodes; Dispersion; Energy measurement; Loss measurement; Plasma measurements; Plasma x-ray sources; Scanning electron microscopy; Spectroscopy; Tungsten; Weight measurement;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.974975

Filename

974975