Title :
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
fDate :
12/1/2001 12:00:00 AM
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, ICR ~ 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;
Journal_Title :
Plasma Science, IEEE Transactions on
