Title :
A model of cathode spot motion in a transverse magnetic field
Author_Institution :
Electr. Discharges & Plasma Lab., Tel Aviv Univ., Israel
Abstract :
A spot grouping and retrograde motion model based on previous study of the cathode thermal regime and the plasma flow in the near cathode region is proposed. The current per group spot is calculated by assuming that the plasma kinetic pressure is comparable to the self-magnetic pressure in the acceleration region of plasma jet. The results of the calculations indicate a linear increase of the current per spot group and retrograde spot velocity with the magnetic field and arc current, in agreement with previous experiments. The spot retrograde motion in a short gap and at atmospheric pressure arcs and the reversal motion in strong magnetic fields (>IT) observed by Robson and Engel are discussed.
Keywords :
arcs (electric); cathodes; magnetic fields; plasma flow; plasma jets; plasma simulation; atmospheric pressure arcs; cathode spot motion model; plasma flow; plasma kinetic pressure; plasmajet; retrograde motion model; self-magnetic pressure; spot grouping model; transverse magnetic field; Breakdown voltage; Cathodes; Magnetic confinement; Magnetic fields; Plasma accelerators; Plasma confinement; Plasma density; Plasma materials processing; Plasma sheaths; Plasma temperature;
Conference_Titel :
Discharges and Electrical Insulation in Vacuum, 2002. 20th International Symposium on
Print_ISBN :
0-7803-7394-4
DOI :
10.1109/ISDEIV.2002.1027330
