A new regime of short-pulse laser-particle acceleration: an overview of results from the NIF-ARC protons campaign

A high energy, high flux short-pulse driven proton source has been demonstrated and characterized on the NIF's Advanced Radiographic Capability (ARC) laser. The ARC laser resides in a unique parameter space: 4 separate beamlets, very high-energy (kJ), relatively long (multi-ps), large focal spot, quasi-relativistic (\textasciitilde 10\textasciicircum 18 W/cm\textasciicircum 2) intensities. The proton campaign at the NIF-ARC has focused on exploring proton acceleration via TNSA and investigating the underlying time-dependent physics of particle acceleration via an integrated experimental and simulation effort. A significant (\textasciitilde 5x) enhancement of maximum proton energy over that predicted by conventional scalings is observed at these laser intensities, definitively establishing a new superponderomotive acceleration regime. Furthermore, a high conversion efficiency of \textasciitilde 2.5-5{\%} laser energy into protons yields a record flux (\textasciitilde 50 J) of laser-accelerated protons. This opens exciting new applications such as proton isochoric heating of solids to several 100's of eV temperatures, and 3D tomography of evolving plasma conditions with \textless 10 ps temporal resolution. We will show results from proton heating and radiography and provide a prospective for future HED experiments with the NIF-ARC protons.