Abstract:
In this work, the dependence of the cathode erosion
rate on vacuum arc spot velocities and cathode pore size
are investigated for four types of graphite under an external
variable magnetic field. Different graphite cathode properties
show varying erosion rates, indicating that each graphite type
should be treated as a different material. Increasing the spot
velocity through an increase of the magnetic field intensity on
a given cathode material decreases the erosion rate. At given
magnetic field values, cathodes having higher arc velocities show
an increase in the erosion rate. Other studies indicating that
the increase in the arc spot velocity leads to a reduction in
macroparticles emission indicate a possibility of increasing the
emission of the carbon ions component. A decrease in the pore
size of the cathode also shows am increase in the cathode erosion
rate.