Detailed hydrodynamic and X-ray spectroscopic analysis of a laser-producedrapidly-expanding aluminium plasma

We present a detailed analysis of K-shell emission from laser-produced rapi dly-expanding At plasmas. This work forms part of a series of experiments p erformed at the Vulcan laser facility of the Rutherford Appleton Laboratory , UK. 1-D planar expansion was obtained by over-illuminating Al-microdot ta rgets supported on CH plastic foils. The small size of the At-plasma ensure d high spatial and frequency resolution of the spectra, obtained with a sin gle crystal spectrometer, two vertical dispersion variant double crystal sp ectrometers, and a vertical dispersion variant Johann Spectrometer. The hyd rodynamic properties of the plasma were measured independently by spatially and temporally resolved Thomson scattering, utilizing a 4 omega probe beam . This enabled sub- and super-critical densities to be probed relative to t he 1 omega heater beams. The deduced plasma hydrodynamic conditions are com pared with those generated from the 1-D hydro-code Medusa, and the signific ant differences found in the electron temperature discussed. Synthetic spec tra generated from the detailed term collisional radiative non-LTE atomic p hysics code Fly are compared with the experimental spectra for the measured hydrodynamic parameters, and for those taken from Medusa. Excellent agreem ent is only found for both the H- and He-like At series when careful accoun t is taken of the temporal evolution of the electron temperature. (C) 2001 Published by Elsevier Science Ltd.