Refurbishment of a low jitter trigger system for a Marx generator

This paper details the refurbishment and testing of a generic trigger unit design for installation on several Marx generators; this system was designed and built in 1990. The purpose of the refurbishment is to remove all obsolete components, update the design to meet modern wiring standards and safety practices. The design is to be installed on several different Marx generators. The basic structure of the design is that a High Voltage supply charges a capacitor to 15kV, then a 300V pulse triggers a thyristor to break the spark gap to discharge the capacitor into a pulse autotransformer (which has an output up to 500kV). This design is compact, has low jitter (~2ns), is invulnerable to self triggering and the majority of the system operates in air (except for the oil-filled pulse autotransformer). Safety features that will be introduced to the design will be two voltage monitoring lines (local and at control point), a dedicated bleed resistor chain (for the 112.5J stored energy) and will be inside an earthed container that can be accessed by key only. When power is removed, the two monitor resistor chains and bleed resistor chain will give a RC discharge of 20-30 seconds.