Anomalously Hot Electrons due to Rescatter of Stimulated Raman Scattering in the Kinetic Regime

TL;DR

This study uses particle-in-cell simulations to investigate how stimulated Raman scattering and rescattering generate highly energetic electrons in plasma, relevant to high-energy laser experiments like NIF.

Contribution

It reveals the mechanism of anomalously hot electron production through plasma wave interactions in the kinetic regime with kλ_D > 0.3.

Findings

Energetic electrons produced via plasma wave interactions.

Energy bootstrapping of electrons into higher phase velocity waves.

Relevance to experimental conditions at NIF.

Abstract

Using particle-in-cell simulations, we examine hot electron generation from electron plasma waves excited by stimulated Raman scattering and rescattering in the kinetic regime where the wavenumber times the Debye length (k\lambda_D) is greater than 0.3 for backscatter. We find that for laser and plasma conditions of possible relevance to experiments at the National Ignition Facility (NIF), anomalously energetic electrons can be produced through the interaction of a discrete spectrum of plasma waves generated from SRS (back and forward scatter), rescatter, and the Langmuir decay of the rescatter-generated plasma waves. Electrons are bootstrapped in energy as they propagate into plasma waves with progressively higher phase velocities.