Interaction of nuclear and laser radiation with Si

Full text: The influence of properties gamma and neutron-irradiated of Si target on laser heating, evaporation and ionization is investigated. As the kinetics, dynamics of processes of evaporation and escape of laser plasma investigated. The installation that carried out experiments described in the paper. The irradiation (nuclear radiation) of Si target created by a flow of reactor radiation 1015-1019 neutrons/cm2, and by gamma radiation up to doses 109 R. The power intensity of laser radiation (λ=1.06 μm, τ=60 ns, E=3 J), focused on a surface of a target, varied in an interval q=108-1011 W/cm2. Investigations of charge and energy characteristics of multiply charged plasma ions formed at action of laser radiation on a surface gamma and neutron-irradiated target (Si) has shown, that increases of an output and charge of ions, expansion of a range of their energy allocation in this case are observed. For example, if at action of laser radiation with q=1010 W/cm2 on a surface unirradiated and irradiated by a fluence 2·1018 neutrons/cm2 of Si Target , in the formed plasma the maximum charge number (Zmax) of ions did not exceed 5 and 14 accordingly. Thus, there was increase of ions intensity of all multiplicities of charge filed in plasma, and waist of their spatial distribution. The investigation of energy spectra of plasma ions has shown, that in case of similar processing of targets with increase of a dose gamma and neutron irradiation for ions with any charge number, is peculiar increase of range of energy allocation at the expense of expansion in the party of high energies. The analysis of all obtained results allows making a conclusion that in the result og charge properties of the irradiated target, the transpiration and ionization of substance of a target, and kinetics, and as dynamics of processes of transpiration and escape of plasma in vacuum varies as a balance of energy of laser radiation spent on a heating. The obtained result can be used by development of effective injectors of ions and nuclei, plasma lasers, radiation-proof materials for an internal thermonuclear reactor