The PHELIX pulsed power project: Bringing portable magnetic drive to proton radiography

Abstract

The PHELIX pulsed power project will introduce magnetically driven hydrodynamics experiments to the Los Alamos National Laboratory's proton radiography facility (pRad). The Precision High Energy-density Liner Implosion eXperiment (PHELIX) has been commissioned at Los Alamos. A small footprint capacitor bank consisting of four parallel, air-insulated, single-stage, marx units (U ~ 300 kJ) is cable coupled to a toroidal, current step-up transformer to deliver multi-megampere current pulses (t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pulse</sub> ~10 μs) to cm size cylindrical loads. In a sequence of tests the performance of each component (capacitor bank and transformer) was evaluated and compared to a computer model. The transformer coupling was observed to be k ~ 0.93. A series of liner implosion experiments has been performed in which an aluminum liner (R ~3 cm, r = 0.8 mm, L = 3 cm) was accelerated to a velocity of ~ 1 km/s. The suite of machine diagnostics included linear Rogowski coils and Faraday rotation for current measurements. The experimental diagnostics include B-dot probes, multi-channel photon Doppler velocimetry (PDV), and single-frame, flash X-radiography to evaluate the performance of the high precision liner implosion. Currently, work is focused on integrating PHELIX into normal operations with the 800 MeV proton radiography facility at the Los Alamos Neutron Science Center (LANSCE), to enable high-resolution, high-frame-rate imaging of hydrodynamic experiments.