This article describes a Crossatron‐based modulator for driving 10–1000 &mgr;s duration plasma discharges. The modulator has demonstrated burst mode operation at pulse repetition rates of 50 kHz. Insulated gate bipolar transistors (IGBTs) are used to trigger the Crossatron. The pulse width of each individual pulse in a burst can be varied over a large range. A Jorway 221 timing and sequencing module command triggers the modulator, and a Labview‐based program is used to control the timing module via a GPIB bus. The modulator can output 25 kV pulses at 100 A. It can also operate at 10% duty cycle with peak currents of 10–20 A. ©1994 American Institute of Physics.