Thin foil acceleration by intense pulsed ion beam ablation

Abstract

Thin foil acceleration by ablation plasma pressure produced by irradiation of an intense pulsed ion beam has been studied. The acceleration process including expansion of the ablation plasma was simulated based on a fluid model. The interaction between the incident pulsed ion beam and a thin foil target was considered. In experiments, we used the ETIGO-II intense pulsed ion beam generator with two kinds of diodes; 1) magnetically insulated diode (MID, power densities of <100 J/cm/sup 2/) and a 2) spherical-focused plasma focus diode (SPFD, power densities of up to 4.3 kJ/cm/sup 2/). Numerical results of accelerated foil velocity agreed well with measured one over wide range of incident ion beam energy density. A foil velocity of 5.6 km/s and ablation plasma pressure of 15 GPa was demonstrated by the present experiments. Acceleration of a double-layer target consisting of gold/aluminum and other combinations were studied. For adequate layer thickness, such a flyer target accelerated more than a single layer. The effect of waveform of the ion beam was also examined. A parabolic waveform could accelerate more efficiently than a rectangular waveform.