Influence of magnetic field on direction of cathode spot plasma jet propagation

The paper presents the method for simultaneous determination of locations of vacuum arc attachments to the cathode and to the anode by high-speed photography. The method provides possibility to ascertain propagation direction of a cathode spot jet subjected to action of magnetic field. This method was used to examine single-spot vacuum arcs between Cu electrodes. The arc length was L = 8 mm, and the arc current was I = 65 A. The magnetic field had two independently varied components (axial component B_z ≤ 0.2 T and tangential one B_t ≤ 0.2 T). The accuracy of the jet angle determination was ±3 degrees. The measurement data show that the jet, which is normal to the cathode in the immediate vicinity of its surface, is turned parallel to the magnetic field at some distance Z_B, which depends on magnetic field induction B and its inclination to the cathode surface. The experimental results are compared with calculation results found in literature.