Scaling Laws of Ion Acceleration in Ultrathin Foils Driven by Laser Radiation Pressure

TL;DR

This paper develops and verifies scaling laws for ion acceleration in ultrathin foils driven by intense laser radiation pressure, accounting for instabilities and hot electron effects through theoretical modeling and simulations.

Contribution

It introduces a comprehensive theoretical model that explains ion energy scaling laws considering instabilities and hot electron effects, validated by simulations and experiments.

Findings

Maximum ion energy has contributions from bulk and sheath acceleration.

Scaling laws match experimental data across various parameters.

Energy spread and cutoff energies are larger than simple models predict.

Abstract

Scaling laws of ion acceleration in ultrathin foils driven by radiation pressure of intense laser pulses are investigated by theoretical analysis and two-dimensional particle-in-cell simulations. Considering the instabilities are inevitable during laser plasma interaction, the maximum energy of ions should have two contributions: the bulk acceleration driven by radiation pressure and the sheath acceleration in the moving foil reference induced by hot electrons. A theoretical model is proposed to quantitatively explain the results that the cutoff energy and energy spread are larger than the predictions of "light sail" model, observed in simulations and experiments for a large range of laser and target parameters. Scaling laws derived from this model and supported by the simulation results are verified by the previous experiments.