Optimization of the driving circuit for material processing with a pulsed-glow discharge

The effect of including an inductance in the circuit of a glow-discharge-pulsed electron gun for materials processing is analyzed. Due to the particular nonlinear behavior of the current vs. 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. A critical damping value for the inductance is obtained and within the range of practical interest, analytical expressions are derived for the required inductance, capacitance and source voltage for a given peak power, pulse duration, gas pressure, and pulse shape. The efficiency increase with the improved design is also discussed.