Laser-driven high flux, high-repetition rate ion and neutron beams for radiography applications*

Laser-driven ion and neutron sources offer an attractive approach for the generation of short, intense bursts of ions and neutrons with MeV energies. Such beams are desirable to generate high energy density (HED) matter states of fusion-relevant materials and serve as probes for high-resolution static or in-situ HED radiography applications. Short pulse (few 10s fs) lasers offer advantages over conventional accelerators with shorter pulse duration, higher spatial resolution and the ability to scale to higher average fluxes. The next generation of high repetition rate (>1 Hz) petawatt-class short pulse lasers promises to deliver high flux particle beams capable of static radiography applications using accumulation in seconds-to-minute time scales while also achieving higher contrast on a single shot exposure.

 

Here we present results of reliable and controllable proton generation using high-repetition rate laser systems coupled to compatible target systems. Neutrons were generated in a pitcher-catcher setup through nuclear reactions between impinging protons and catcher target atoms. Experiments were conducted at the HAPLS laser at ELI (800 nm, 30fs, 8J, 0.2 Hz) and the ALEPH laser at Colorado State University (800 nm, 30 fs, 22 J, 0.5 Hz). We studied the effect of target thickness, laser energy and laser pulse shape on the ion acceleration and neutron production, which will inform the development of a flexible radiography setup for future facilities such as MEC-U.