Influence of Magnetic Field on the Direction of Cathode Spot Plasma Jet Propagation

This paper presents the method for the simultaneous determination of locations of vacuum arc attachments to the cathode and to the anode by high-speed photography. The method provides a possibility to ascertain the propagation direction of a cathode spot jet subjected to the action of a magnetic field. This method is used to examine single-spot vacuum arcs between Cu electrodes. The arc length is $h=8~{\rm mm}$ , and the arc current is $I=65~{\rm A}$ . The magnetic field have two independently varied components (axial component $B_{z}\leq 0.2~$ and tangential one $B_{t}\leq 0.2~{\rm T}$ ). The accuracy of the jet angle determination is ${\pm}{\rm 3}^{\circ}$ . 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 the literature.