Development of Novel Solid State MARX Generator

Solid State Marx Generators (SSMGs) are increasingly used in pulsed power applications requiring high repetition rates. However, when thyristors are employed as primary switches, their inherent turn-on delay limits the output pulse rise time. In this work, a solid state Marx generator is developed in which saturable magnetic cores are integrated in series with thyristor stages as magnetically assisted elements, improving the pulse rise time characteristics. The magnetic cores delay current conduction until saturation, thereby sharpening the rising edge and mitigating the effect of thyristor turn-on delay. The novelty lies in this integration, which enables inherent core reset through the Marx charging and discharging cycle without additional circuitry. A governing equation is developed to describe the interaction between thyristor turn-on dynamics, the magnetic core saturation process, and the circuit current, providing a physical explanation of the observed volt-sec product driven switching behavior. The system produces negative pulses up to 13 kV with a rise time of 224 ns and pulse width of 1.1 μs (FWHM) at 25 Hz of repetition rate using a 100 Ω load. This paper further describes the design considerations of the thyristor gate drive circuits and discussed the operation of the magnetic core with respect to its placement in the SSMG's structure. Based on experimental results, the proposed configuration is a practical method for improving pulse rise time in thyristor based SSMGs.