Improving beam spectral and spatial quality by double-foil target in laser ion acceleration

Abstract

Mid-Z ion driven fast ignition inertial fusion requires ion beams of hundreds of MeV energy and <10% energy spread. The break-out afterburner (BOA) is one mechanism proposed to generate such beams; however, the late stages of the BOA tend to produce too large of an energy spread. Here we show how use of a second target foil placed behind a nm-scale foil can substantially reduce the temperature of the comoving electrons and improve the ion beam energy spread, leading to ion beams of energy hundreds of MeV and 6% energy spread.