High-Energy Ion Expansion in Laser-Plasma Interactions

Measurements of energetic-ion energy distributions produced from CD₂ and CH₂ targets are compared with a numerical model. The model describes the ambipolar expansion of hot electrons and two relatively cold ion species from an electron pressure gradient. For CD₂ the plasma expansion is adequately represented by a single ion species, whereas for CH₂ two-ion fluids are required to account for the energy and the relative behavior of the high-energy ion species.