Production of a high-density and high-temperature plasma with an intense high-contrast subpicosecond laser

Abstract

We report on the observation of high-electron-density (ne ≈ 15nc where nc is the critical density, 4 × 1021 cm−3 for λ = 0.53 μm) and high-temperature (Te ≈ 400 eV) plasma obtained when an intense high-contrast 400-fs laser pulse interacts with a solid Al target. After the laser intensity is increased from 1016 to 5 × 1017 W/cm2, the kiloelectron-volt x-ray emission is brighter by approximately an order of magnitude and is still produced from very dense plasma (6 × 1022 cm−3).