Pulse shaping for optimal energy deposition with a cold cathode electron gun for surface treatment

摘要

A pulse-forming network is added in the discharge circuit of a cold-cathode electron gun that gives rise to an improved shape of the pulse, making it closer to the ideal square pulse needed for optimal energy deposition in material surface treatments. It is shown that the circuit can be very accurately designed by means of simulations using empirical equations for the nonlinear response of the gun. Due to the particular nonlinear behavior of the current-voltage in these guns, and the strong nonlinear self-focusing of the beam, the adequate shaping of the temporal profile of the discharge becomes relevant to the efficiency of the system. The effect of using a new discharge circuit for a glow-discharge pulsed electron gun for materials processing is analyzed, showing an almost two-fold improvement in the efficiency of the system regarding the fraction of the energy not wasted in long pulse tails.