Initiation of the (γ, n) and (p, n) nuclear reactions in the picosecond laser plasma at a laser intensity of 2 × 10~(18) W/cm~2

摘要

The experimental results on the initiation of various (γ, n) and (p, n) nuclear reactions in the picosecond laser plasma are presented. It is demonstrated that the following (γ, n) and (p, n) nuclear reactions can be initiated at a laser intensity of 2 × 10~(18) W/cm~2 with the threshold energies of γ-quanta ranging from 1.67 to 7.56 MeV and the threshold energies of protons ranging from 1.88 to 5 MeV: ~9Be(γ, n)2α, ~(181)Ta(γ, n) ~(180)Ta, ~7Li(p, n)~7Be, ~(63)Cu(p, n) ~(63)Zn, ~(48)Ti(p, n)~(48)V. The method based on the detection of fast neutrons using the 3He counters is employed for the measurement of the number of the initiated (γ, n) and (p, n) nuclear reactions. The measured yield of the (γ, n) and (p, n) nuclear reactions ranges from 5 × 10~1 to 10~5 reactions per laser pulse.