X-ray spectroscopic investigation of the spatial distribution of the parameters of a laser plasma heated by 10–10 sec pulses

A laser plasma was generated by pulses of ~5×10¹⁵ W/cm² intensity and τ~10^–10 sec duration. The x-ray emission spectra of this plasma were recorded in the spectral range 3–18 Å. The apparatus employed made it possible to record the spectrum produced by a single laser flash and its resolving power was high (λ/Δλ~5000). The relative intensities of the lines due to helium-like and hydrogen-like ions were used in the determination of the electron temperature T_e and electron density N_e in the plasma. The spatial distribution of the x-ray emission of a magnesium plasma was determined with a resolution of 25 μ. The laser radiation was focused on a plane target and in a recess. In both cases the values of T_e, N_e, and of the Stark and Doppler broadenings of several lines (T_e was found from the relative intensities of the lines and N_e from the relative intensities and Stark broadening) were determined as a function of the distance to the target.