Investigation of switch designs for the dynamic load current multiplier scheme on the SPHINX microsecond linear transformer driver

SPHINX is a microsecond linear transformer driver (LTD), used essentially for implosion of Z-pinch loads in direct drive mode. It can deliver a 6MA current pulse within 800ns into a Z-pinch load. The Dynamic Load Current Multiplier (DLCM) concept enables the current pulse to be modified by increasing its amplitude while reducing its rise time before being delivered to the load. This compact system is made up of concentric electrodes (autotransformer), a dynamic flux extruder (cylindrical wire array), a vacuum convolute (8 postholes) and a vacuum closing switch, which is the key component of the system. Several different schemes are investigated for designing a vacuum switch suitable for operating the DLCM on the SPHINX generator for various applications, including Isentropic Compression Experiments (ICE) and Z pinch radiation effects studies. In particular, the design of a compact vacuum surface switch and a multichannel vacuum switch, located upstream of the load are studied. Electrostatic simulations supporting the switch designs are presented along with test bed experiments. Initial results from shots on the SPHINX driver are also presented.