Efficient Fusion Neutron Generation Using a 10-TW High-Repetition Rate Diode-Pumped Laser

Abstract

The first use of a high-repetition-rate laser-diode (LD)-pumped laser in a fusion target experiment is demonstrated. An LD-pumped Nd-solid state laser's output is coupled to a Ti:sapphire laser, enabling the resulting HAMA laser to generate 2-J, 815-nm-wavelength output with a pulse width of 150 fs and a repetition rate of 10 Hz. A photon-to-photon efficiency of 1.25% (electric-to-photonic 0.7%) is achieved, which is an order of magnitude higher than that of current flash-lamp lasers. Irradiation of a 500-µm-thick deuterated polystyrene film by a 0.6-J pulse yielded 105 DD fusion neutrons. The efficiency from the electric input to the neutron yield is 10 times higher than the flash-lamp-pumped table-top lasers.