Numerical modelling of stability limit of diffuse discharge on thermionic cathodes
Abstract
Steady-state current transfer from arc plasmas to axially symmetric cathodes is treated. An approach is developed to calculation of the limit of stability of the diffuse mode (the current below which the diffuse mode becomes unstable). Effect produced on the stability limit by variations of control parameters (cathode dimensions, work function of the cathode material, plasma-producing gas and its pressure) is studied and found to conform to trends observed experimentally. The stability limit is found to be much more sensitive to variations of control parameters than characteristics of the diffuse mode are, the strongest effect being produced by variations of cathode dimensions and of the work function of the cathode material. This finding conforms to the fact that the diffuse-spot transition is difficult to reproduce in the experiment.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 2003
- Bibcode:
- 2003APS..GECWF2004B