Foil Acceleration of Double-Layer Target by Intense Pulsed Ion Beam Ablation

Abstract

A high-density, high-pressure ablation plasma produced by an intense pulsed ion beam was used to accelerate a thin foil target. A double layer target, where a thin layer of gold was coated on aluminum, was irradiated by a pulsed ion beam with an energy density of 120 J/cm2. A time-of-flight technique was used to measure the velocity of the accelerated foil. A maximum foil velocity of 2.1 km/s was observed, resulting in an energy transfer efficiency of 17.5% and a minimum acceleration pressure of 0.44 GPa. It was also found that the foil velocity depends on the thickness of the gold coating and that the maximum velocity appears at a gold thickness of 1.5 µm for a 50-µm-thick aluminum foil. In addition, one-dimensional hydrodynamic simulations were carried out for comparison of simulation results with experimental results. A reasonable agreement was obtained between the experimental and simulation velocities, which helps us to understand the basic characteristics of the ion-beam-generated ablation plasma produced by the pulsed ion beam.