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Laser produced directed neutron beams

The new generation of ultrashort pulse lasers offers a novel way of producing high-energy (1–100 MeV) neutrons from table-top devices. Ultrashort lasers of sufficiently high intensity (1018–1021 W/cm2) are capable of producing fast ions with energies in the megaelectronvolt (MeV) range from thin (∼1–10 µm) planar foils, which drive nuclear fusion reactions and generate a copious amount of neutrons. The Naval Research Laboratory (NRL) in collaboration with the Center for Ultrafast Optical Science (CUOS) at the University of Michigan have been performing basic and applied research on the development of laser-based non-thermal neutron sources. The program's focus is on production of collimated neutron beams with energy in the 10's of MeV at moderate peak fluence (∼106–109 neutrons/ster per shot). We study the neutron production from protons/deuterons impinging on low-Z material and compare the neutron yield with that from traditional sources such as d-d and d-t. Recent simulation results and experimental data on both light ion acceleration and ion-induced nuclear fusion reactions driven by high-intensity lasers will be presented [1,2]. The mechanism of the neutron production process will be discussed with emphasis on the underlying fundamental physics and numerical implementation, as well as technological issues and challenges associated with the neutron production. An introduction to the current state of the art will be given and possible applications will be discussed.