Nonuniform doping of the collector in avalanche transistors to improve the performance of Marx bank circuits

It is shown that the avalanche multiplication factor of transistors, which plays a key role in the functioning of the Marx bank circuit, can be considerably enhanced when the collector has a Gaussian doping profile, compared to uniform doping. The limiting of the maximum field in the collector, and the base push out are the events involved in the occurrence of the current mode second breakdown of avalanche transitors in the Marx circuit. Calculations show that the limiting of the maximum field, followed by the base push out, is the sequence conducive to the enhancement of the avalanche gain. Preliminary experimental assessment of the doping profiles of the same model of transistors from two different manufacturers supports the proposed idea.