Energetic neutron beams generated from femtosecond laser plasma interactions

Abstract

Experiments at the HERCULES laser facility have produced directional neutron beams with energies up to 16.8 (± 0.3) MeV using d 1 2 (d, n) 2 3 He, Li 7 3 (p, n) 4 7 Be, and Li 3 7 (d, n) 4 8 Be reactions. Efficient Li 1 2 (d, n) 4 8 Be reactions required the selective acceleration of deuterons through the introduction of a deuterated plastic or cryogenically frozen D2O layer on the surface of a thin film target. The measured neutron yield was 1.0 (± 0.5) × 10 7 neutrons/sr with a flux 6.2 (± 3.7) times higher in the forward direction than at 90 °. This demonstrates that femtosecond lasers are capable of providing a time averaged neutron flux equivalent to commercial d 1 2 (d, n) 2 3 He generators with the advantage of a directional beam with picosecond bunch duration. © 2013 American Institute of Physics.