Eight triaxial Blumlein circuits have been stacked in series at one end while being synchronously commuted at the other end with a single hydrogen thyratron. Having no other switching elements, operation has been possible at repetition rates up to 100 Hz. Improvement in matching an X-ray diode to this pulse power source has been realized, making possible the emission of an average bremsstrahlung exposure rate of 15 R/s from a sequence of 20 ns pulses. Recent advances in the development of this device resulting in open-circuit voltage gains approaching six times the charging voltage are described.