Laser-to-proton conversion efficiency studies for proton fast ignition

Abstract

We assess the conversion efficiency from intense picosecond laser pulses to multi-MeV ion beams for a wide range of laser and target parameters, using 2D kinetic particle-in-cell simulations. Scalings are addressed in a quasi-one-dimensional geometry, leaving out beam divergence. Then, we study the conversion efficiency into a narrow spatial band along the laser axis for flat and hemispherical targets in large-scale 2D simulations. Combining these findings allows us to calculate the energy requirements for ignition of a compressed ICF target with an intense proton beam in a fast-ignition scenario.