Simulation of hydrodynamic phenomena caused by prepulse in picosecond laser-plasma interaction

We consider a physical model of the interaction of high-power laser pulses with plasma created upon irradiation of condensed targets. The model is based on the equations of single-fluid, two-temperature hydrodynamics taking into account the ponderomotive force and the Maxwell equations for laser radiation at oblique incidence in the cases of s- and p-polarizations. 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. For a number of experiments we have performed the numerical modeling of the laser picosecond pulse interaction with targets. We present the interpretation of the experiment on the basic harmonic shift depending on the pre-pulse energy. It has been shown that, if under the irradiation of a deuterated target the pre-pulse energy grows, the neutron yield of DD-reactions diminishes, since the produced plasma prevents the heating of the dense part of the target. It has been also shown that the growth of the pre-pulse energy can provoke, due to the induced scattering, the losses in the main pulse radiation. We give interpretation of the experimental data on the picosecond pulse absorption by plasma at the flux density of 1016-1019 W/cm2.