PIC simulations of ion acceleration in laser irradiated submicron droplets

摘要

The interaction of femtosecond laser pulses with submicron water clusters is studied by two-dimensional particle-in-cell simulations. We search for optimum laser and cluster parameters to obtain quasimonoenergetic beam of protons accelerated from the cluster. For the laser amplitude a0 = 3, the optimum cluster size is about 150 nm for the generation of pronounced peak in proton energy distribution function at maximum energy and the optimum laser pulse duration is about 40 - 80 fs. Various initial density profiles of cluster plasma, formed due to insufficient laser pulse contrast and prepulses, are involved in this study, including underdense clusters.