Enhanced spatial and spectral resolution in laser plasma spectroscopy using band-shaped implants on plane targets

Band-shaped aluminium implants on plane carbon targets were irradiated at 0.1-2*1015 W cm-2 by 600 ps laser pulses of 0.527 mu m wavelength. The resulting blow-off plasmas were diagnosed by X-ray spectroscopy using entrance slits of various dimensions, orientations and positions with respect to the target plane. The authors studied the longitudinal and radial variations of line intensities and Stark widths of He-like and H-like Rydberg series. The effect of time integration was also qualitatively studied by varying implant thickness. Results showed a tenfold decrease of instrumental broadening due to the small lateral expansion of the plasma eliminating radial spatial deconvolution and minimising opacity effects. Comparison with computer modelling showed that n>or=4 Al12+ Lyman series emissions peaked in a 20 mu m width region close to the target and that electron densities deduced from Stark broadening agree well with the simulations.