Target expansion modelling for problems of laser ion acceleration optimization

At present, a significant part of experiments on the interaction of high-power short laser pulses with solid targets is faced with the problem of target modification under the action of a nanosecond prepulse. In this paper, a series of hydrodynamic calculations of target irradiation with a nanosecond laser pulse is performed, which describes the plasma density profiles arising during the target expansion as a function of the parameters of the laser prepulse/additional pulse. The results obtained can make it possible to improve the efficiency of ion acceleration in the interaction of short laser pulses with a profiled plasma target.