Repetitive Frequency Fitch Booster Using Coupled Magnetic Switches

In this paper, a novel repetitive frequency Fitch booster (named coupled magnetic switch (MS)-based Fitch booster or CMSFB) that is capable of both rise-time compression and amplitude multiplication is proposed. The operation principle is to charge capacitors in parallel via coupled MSs and reverse voltage polarity of every other capacitor to form voltage pulses across the load, with diodes blocking discharges from even stages to odd ones. Test stand shows that the four-stage CMSFB effectively boosts the input voltage from 8.5 kV in peak and 8.6 μs in rise time to 33.6 kV in peak and 1.6 μs in rise time. A following two-stage magnetic pulse compression network further compresses the voltage rise time to obtain the output voltage with a rise time of 84 ns, an amplitude of 31.2 kV, and a frequency of 1 kHz. Meanwhile, calculations show that the total core volume of a pulser with a CMSFB is much lower than one without it, and saved core volume increases with an increase in the number of the CMSFB stages. For the four-stage test stand, in particular, the total core volume is reduced to almost half, from 1540 to 775 cm³.