Series plasma opening switch experiment on Hawk

Summary form only given, as follows. A vacuum power amplification concept using Plasma Opening Switches (POS) in series to increase the voltage was proposed by Mason (1995). We have implemented a series POS on Hawk to test its effectiveness for increasing the bremsstrahlung production from high-power generators. The series POS consists of three coaxial cylindrical conductors in vacuum. The inner conductor is connected to the negative-voltage Hawk center conductor, the outer conductor is connected to the grounded outer conductor of Hawk. The intermediate cylinder is isolated from the other two by suspending it using resistors or inductors. Cable guns inject plasma radially inward between the outer and intermediate conductors, and an inside-out flashboard on axis injects plasma from inside the center conductor between the inner and intermediate conductors. The generator current flows through both plasma switches as they are electrically in series. Preliminary experiments used inductive loads to test the simultaneity of opening and to find promising configurations for future work with electron-beam diode loads. By adjusting the time delay of the inside-out and outside-in plasma sources, the two POSs could be made to open at nearly the same time and their voltages added constructively. Two diode load configurations are envisioned, either two diodes in series to effectively use the current twice, or one diode to operate at the sum of the POS voltages. Experimental results with diode loads will be presented and the technique will be evaluated as a way to decrease the x-ray pulse width and increase the dose and dose-rate from high-power electron-beam generators.