Amplification of soft-X-ray spontaneous emission in aluminium and magnesium plasmas

Abstract

Amplification of spontaneous emission at 105.7 and 127.9 AA is reported for Li-like aluminium and magnesium in recombining laser-produced plasmas. Evidence of gain is deduced from the variation of radiation intensity according to the length of a line-shaped plasma. Detailed calculations of rate equations with a suitable plasma model, associated with numerical simulations of plasma hydrodynamics, predict population inversions between 3d and 5f levels, in accordance with these experiments.