High rep-rate inductive-energy-storage pulsed power modulator using high voltage static induction thyristor

A high voltage static induction thyristor (SI Thy) has two significant features. One is that carriers can be quickly pulled out of gate region without applying a high voltage to the gate. The other is that its ON-state voltage is very low. These features make the SI Thy especially suitable for a switch of high rep-rate inductive-energy-storage pulsed power modulators, since the switch can interrupt a current rapidly and energy loss by the switch in a conduction phase can be remarkably reduced. In this research, a high rep-rate inductive-energy-storage pulsed power modulator, which uses a high voltage SI Thy as an opening switch, has been designed and constructed for application to an induction synchrotron. The maximum operating frequency of the modulator is expected to be 1 MHz. The induction synchrotron accelerates bunched charged particle beams using induced electric fields, which is proportional to the time derivative of magnetic flux in a toroidal core. In order to prevent a magnetic flux of the core from saturating, it is necessary to reset the toroidal core after each acceleration pulse. Therefore, a reset circuit independent of an acceleration circuit is needed in general. However, the proposed modulator can supply both the acceleration and the reset pulses without any additional circuit and is especially suitable for an induction synchrotron accelerator.