Efficient fusion neutron generation from heteronuclear clusters in intense femtosecond laser fields

We demonstrate experimentally the efficient fusion neutron generation from Coulomb explosion (CE) of laser irradiated large-size heteronuclear deuterated methane clusters. A conversion efficiency of 2.1×10⁶ neutrons/J of incident laser energy is obtained with a 120 mJ, 70 fs laser pulse. It is 50 times higher than that of homonuclear deuterium clusters of similar size. This enhancement is attributed to the significant increase in the deuteron kinetic energies by fourfold due to energetic boosting and overrun effects during CE of heteronuclear clusters. The yield of 5.5×10⁶ neutrons per pulse is obtained with a 100 TW, 50 fs driving laser pulse at an intensity of 1.5×10¹⁹ W/cm². This work may facilitate the development of a high-flux table-top neutron source.