Influence of angles of incidence of laser radiation on the generation of fast ions

It was established experimentally that the number and energy of fast ions i n laser plasma increased with increasing angle of focusing laser radiation onto a flat target. Numerical calculations showed that the increase in angl e of focusing brought the mean angle of incidence of laser radiation closer to the optimal angle corresponding to the maximal efficiency of the resona nce absorption mechanism and, as a result, increased the fraction of absorb ed laser energy in the energy of fast electrons and increased the number of fast electrons. In turn, the increase in the energy and number of fast ele ctrons resulted in an increase in the number of fast electrons involved in the formation of a self-consistent electric field at the target edge and le d to the growth of the field strength, which, eventually, was the reason fo r the increase in the number and energy of fast ions. (C) 2001 MAIK "Nauka/ Interperiodica".