High repetition-rate neutron beam generation using micron-scale converging heavy water jet targets *

Laser-driven neutron sources offer an attractive, alternative approach for generation of short, intense bursts of neutrons with narrow energy ranges. Such beams are desirable especially for damage cascade and pump-probe studies of fusion-relevant materials. In order to achieve necessary neutron beam fluxes, the utilization of petawatt lasers as drivers promises to surpass current recorded particle yields. This is due to the proportionality of laser-to-neutron conversion efficiency to the ion beam peak brightness. Together with recently available high-repetition rate laser systems, laser-driven neutron sources could outperform existing conventional sources.

Here, we present first results of reliable generation of deuteron beams using a converging heavy water sheet target at 0.5 Hz with the ALEPH laser at Colorado State University (400 nm, 45 fs, 10 J). Proof of principle measurements show efficient neutron generation through deuteron breakup and nuclear reactions.