Neutron production in ultraintense laser interactions with carbon-deuterated plasma at intensities of 1018 W cm-2

Wide-range neutron energy spectra that are produced when an ultraintense laser with an intensity of 3 x 10(18) W cm(-2) is focused on a CD2 target have been studied. The experimentally observed spectra and numerically calculated ones, by a three-dimensional Monte Carlo code, indicate that the energy range of the emitted neutrons is larger than that of the D(d,n)He-3 reaction. The reactions that can participate in neutron production and their relative importance have been analysed. An explanation for the measured spectra is introduced by taking into account the C-12(d,n)N-13 and D((12)c,n)N-13 reactions. These reactions strongly participate in neutron production due to their high cross sections. Moreover, the neutrons from these reactions will overlap the neutrons from the D(d,n)He-3 reaction, including the 2.45MeV neutrons, with increasing energy of the accelerated ions under higher irradiances.