Numerical Simulations of the Acceleration of Fast Protons and of the Excitation of Nuclear Reactions 11B(p,3a) and 11B(p, n)11C at the Intensities of Picosecond Laser Radiation in the Range of 1018-1019 W/cm2

Results of numerical simulations for acceleration of proton beams at the irradiation of Al target by a superintense laser pulse are presented. There is a good agreement with the experimental data in a broad range of laser intensities from I = 10(18) W/cm(2) to I = 10(19) W/cm(2) at the fixed laser pulse duration. The obtained parameters of proton beams were used for calculation of the total yield of a particles and neutrons for the nuclear reactions B-11(p, 3a) and B-11(p, n)C-11 at the collisions of proton beams with boron targets. It is shown that the number of a particles escaping boron target and arriving at track detectors is less than 5% of the total amount of a particles, because the majority of these particles remain inside the target owing to ionization losses. The derived values of the yield of a particles' which arrive at detectors are in good agreement with the experimental data. We also calculate the total yield of neutrons in the reaction B-11(p, n)C-11. It is found that, at the intensity I = 10(19) W/cm(2) of the picosecond laser pulse, the yield is equal to N-n = 1.4 x 10(8), this value is approximately of 3% of the total yield of a particles.