X-ray spectroscopic investigation of the spatial structure of a laser plasma with electron densities in the range 1018–1021 cm–3

Measurements were made of the spatial distributions (with a resolution of 65 μ) of the intensities of spectral lines of heliumlike multiply charged ions emitting in the range λ = 4–10 Å. These measurements made it possible to determine for the first time the electron density profile in the 10¹⁸–10²¹ cm^–3 range near the point of reflection of a plasma-heating laser beam from a target as well as the profile of the electron temperature T_e at distances up to r~0.8 mm from the target surface. The maximum electron temperature measured in this way was 0.8 keV. The characteristic size of plasma inhomogeneities was estimated to be ~9×10^–3 cm. A comparison was made of the capabilities of interferometric and spectroscopic methods in measurements of plasma parameters.