Circuit techniques for a cold-cathode electron beam modulator with compensation for drooping load impedance

A cold-cathode electron-beam modulator for the pumping of gas lasers presents a drooping load impedance which must be accommodated in the modulator design. A set of performance requirements is described which characterize a typical application. A circuit approach is chosen that uses a Marx generator as part of a type-A PFN (pulse forming network) circuit. The antiresonant sections of the PFN circuit involve inductance values so low as to be physically unrealizable with practical components. A Foster transformation is used to realize a modified form of the prototype network with reasonable inductance values. A simple method for compensating the drooping impedance of the load is described, and a circuit implementation is given. A physical arrangement of the modulator is described. The results of a detailed computer simulation are given, showing that the basic goals are met.<>