Background pressure effects on MeV protons accelerated via relativistically intense laser-plasma interactions.

ABSTRACT: We present how chamber background pressure affects energetic proton acceleration from an ultra-intense laser incident on a thin liquid target. A high-repetition-rate (100 Hz), 3.5 mJ laser with peak intensity of [Formula: see text] impinged on a 450 nm sheet of flowing liquid ethylene glycol. For these parameters, we experimentally demonstrate a threshold in laser-to-proton conversion efficiency at background pressures [Formula: see text], wherein the overall energy in ions [Formula: see text] increases by an order of magnitude. Proton acceleration becomes increasingly efficient at lower background pressures and laser-to-proton conversion efficiency approaches a constant as the vacuum pressure decreases. We present two-dimensional particle-in-cell simulations and a charge neutralization mo

SUBMITTER: Snyder J 

PROVIDER: S-EPMC7588495 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature