THE DISTRIBUTION OF TRANSIT TIMES IN A MAGNETICALLY STEERED CATHODIC ARC

An electromagnetic system of coils capable of steering the cathode spo t of a vacuum are has been implemented. The radius of the are track, a nd the velocity and confinement of the spot are controllable by suitab le choice of coil currents. Measurements have been made on a range of cathode materials of the statistical distribution of the transit times of the orbiting spot. The measured distributions have been compared w ith predictions made from a stochastic model of steered are motion. Re sults are consistent with the model and with random are measurements o f other authors.