Pulse Switching Characteristics of MAGTs for Pulsed Power Applications

Abstract

For pulsed power systems such as lasers and accelerators, semiconductor switches with their longer service life have been actively developed as replacements for thyratrons. The MOS-driven thyristors are suitable for pulsed power applications because they have the high-power handling and fast turn-on capabilities. The MOS Assisted Gate-triggered Thyristor (MAGT), especially designed for pulsed power, is a promising candidate in this field.
This paper presents the results of an investigation into the performance of MAGTs. Using a pulse forming network (PFN), the pulse switching characteristics and the dynamic resistance characteristics during the current flow were investigated. A maximum current density of 21.8kA/cm² and di/dt of 106kA/ μs/cm² with 1, 550 V anode voltage on a single shot basis were obtained. Furthermore, a life test with 10⁹ shots at a high repetition rate showed no degradation in the observed characteristics. Based on these experimental results, a carrier flow model of MAGT during turn-on process was proposed and the turn-on mechanism was considered.