X-ray emission spectrum of a magnesium plasma heated by picosecond ruby laser pulses

An investigation was made of the x-ray emission spectrum of a magnesium plasma heated by ruby laser pulses of 10–20 psec duration and 1014 W/cm2 power density on the target surface. The relative intensities of the spectral lines were used to determine the electron temperature (200 eV), density [(1–1.15) × 1020 cm–3], and ionization state ([Li]/[He] ≈ 1) of the luminous part of the plasma. The relative intensities of the resonance lines of the H- and He-like ions yielded an estimate of the electron temperature in the vicinity of the critical point (Tcr550–700 keV).