A Hydrodynamic Model of the Interaction of Picosecond Laser Pulses with Condensed Targets

We consider a physical model of the interaction of highpower laser pulses with plasma created upon irradiation of condensed targets. The model is based on the equations of singlefluid, twotemperature hydrodynamics taking into account the ponderomotive force, and the Maxwell equations for laser radiation at oblique incidence in the cases of s and ppolarizations. The model takes into account the generation of fast electrons in the conditions of plasma resonance at the critical surface, and their transport with consideration for the friction force, caused by the ionization losses. Heating of ions in the plasma due to beats of the ponderomotive potential is considered. The results of numerical modeling of the interaction of a picosecond laser pulse, containing a prepulse, with a deuterium target at power densities of 10¹⁶–10¹⁷ W/cm² are presented. It is shown that the neutron yield of the DDreaction decreases with increase in prepulse energy, because the plasma created inhibits heating of the dense region of the target where a high rate of the reactions can be realized. It is also shown that the laser radiation losses caused by the stimulated scattering increase with increase in prepulse energy.