Gas switch studies for Linear Transformer Drivers

We are studying several competing gas switch geometries for Linear Transformer Drivers in an attempt to design an optimum switch for these applications as well as to increase our knowledge of the physics of the switching process. In addition to standard electrical diagnostics (V, I), we are studying the switches with a variety of optical diagnostics including fast photodiodes, a framing camera and a time-resolved spectroscopy system. In our test system, 20-nF capacitors on top and bottom of the switch are charged to voltages up to ±100 kV. Then the switch is triggered and current flows through the switch and a load resistor in a geometry that resembles the LTD ‘brick’ architecture. We will present results using the multistage gas switches designed at the High Current Electronics Institute [1] and compare them to results with a low inductance switch designed at Sandia that provides a 30% higher peak current through the LTD ‘brick’.