Experiments on a current-toggled plasma-opening switch

Abstract

Plasma‐opening switches have been used to improve pulsed‐power wave shapes for over a decade. These switches have used the inertia of the plasma to hold the switch closed. This results in conflicting requirements when long hold‐off time and fast opening are required, and also results in variation in opening current due to variation in initial plasma fill. The current‐toggled plasma‐opening switch attempts to overcome these problems by using external magnetic fields rather than inertia to control the plasma conductor. Data will be presented showing several features of the operation of this switch. These data will be compared to models used to design the switch. The comparisons indicate that the mass can be measured approximately from fast coil data and that the slow coil flux does set the opening level of the current. They also indicate that the opening current is somewhat dependent upon plasma mass, and that the design of the field coils that provide the control fields must be done more carefully to provide a switch that opens satisfactorily.