Laser-plasma interactions for fast ignition

TL;DR

This paper reviews recent advances in understanding laser-plasma interactions relevant to fast ignition in inertial confinement fusion, emphasizing simulation techniques, physics insights, and experimental comparisons.

Contribution

It provides a comprehensive overview of modeling approaches, physics phenomena, and the relevance of experiments for fast ignition laser-plasma interactions.

Findings

Enhanced multi-dimensional PIC simulation capabilities

Insights into laser absorption and electron spectra

Comparison of simulations with experimental data

Abstract

In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale fast ignition problem.