Theoretical Study of Ion Acceleration by Double-Layer Formation in Multicharged Laser-Produced Plasmas

A theoretical study about the ion acceleration in low-energy (10¹⁰ W/cm²) laser-produced plasma is presented. Calculations have been implemented following a 1-D particle-in cell method. We describe the plasma-vacuum expansion dynamics and the ion acceleration due to the so-called double-layer formation. Observed results show that, regardless of the initial temperature and density of the plasma, postheating is needed to obtain average values of final ion kinetic energy distributions similar to the experimental results. This confirms that, with nanosecond pulsed lasers, the plasma is strongly heated by the laser pulse tail.