Enhancements Using Compound Parabolic Concentrators For Hot-Electron and Proton Acceleration *

The peak on-target laser intensity is a key parameter for applications such as laser driven particle acceleration and x-ray sources. We have tested Compound Parabolic Concentrator [1] (CPC) targets which act as a non-imaging focusing optic. We demonstrate experimental measurements [2] collected at Texas Petawatt laser facility that show a hot-electron temperature enhancement of approximately a factor of 9 from the CPC target when compared to planar target. Using PIC simulations, we describe this hot-electron enhancement from a purely geometric intensity enhancement and existing temperature-intensity scaling laws. Using the CPC geometry, enhancements in proton acceleration and maximum proton acceleration are predicted due to the increase in electron temperature and reduction in electron source size.

[1] MacPhee et al., “Enhanced laser-plasma interactions using non-imaging optical concentrator targets,” Optica, vol. 7 issue 1 (2020).

[2] Rusby et al., “Enhancements in laser-generated hot-electron production via focusing cone targets at short pulse and high contrast,” PRE 103, 053207 (2021)