Intense, directed neutron beams from a laser-driven neutron source at PHELIX

Laser-driven neutrons are generated by the conversion of laser-accelerated ions via nuclear reactions inside a converter material. Here, we present results from an experimental campaign at the PHELIX laser at GSI in Darmstadt where protons and deuterons were accelerated from thin deuterated plastic foils with thicknesses in the μm and sub-μm range. The neutrons were generated inside a sandwich-type beryllium converter, leading to reproducible neutron numbers around 10¹¹ neutrons per shot. The angular distribution was measured with a high level of detail using up to 30 bubble detectors simultaneously. It shows a laser forward directed component of up to 1.42 × 10¹⁰ neutrons per steradian, corresponding to a dose of 43 mrem scaled to a distance of 1 m from the converter.