Directional Neutron Beams Using High-Intensity Ultrashort Laser Pulses

Neutron production using high energy protons or deuterons from p-Li or d-Li reactions are superior in terms of the number and directionality to that from d-d reactions [1]. These schemes require a pitcher-catcher target method instead of using laser-driven fusion neutron production d(d,n)$^{3}$He from bulk deuterated plastic targets. The experiments performed with 400 fs T-cubed laser focused to maximum intensities of up to 3.10$^{19}$ Wcm$^{2}$ onto the bulk deuterated plastic targets produced neutrons beamed preferentially in the laser propagation direction with a flux of 2.10$^{4}$ neutrons/J/steradian [2]. In recent experiments at the Hercules facility with 30 fs laser pulses focused to intensity of 2.10$^{21}$ Wcm$^{2 }$on thin CH plastic targets very high neutron yield of $\sim $10$^{8}$ neutrons/J/steradian was produced from (p,n) reactions in the LiF catcher target. Neutron energies peaked at 4 MeV were determined through TOF using fast PMT with a large area plastic scintillator. This work was supported by DTRA and the NRL. \\[4pt] [1] J. Davis et al., PPCF 52, 045015 (2010). \\[0pt] [2] L Willingale et al., POP (2011) (submitted).