HIGH-PRECISION MEASUREMENT OF VELOCITY PROFILES IN LASER-CREATED CHLORINE PLASMA

A vertical dispersion variant of the Johann spectrometer has been used to record the high-resolution X-ray spectra of the chlorine He-like r esonance line group emitted from low-radiance plasma. The emission pro files were measured at two observation angles and decomposed into sing le spectral lines by using a fit based on the Levenberg-Marquardt algo rithm. The results of computerized analysis of the one-dimensional (1- D) spatially resolved spectra were used to evaluate the distribution o f the main plasma parameters. The electron temperature gradient 7.5 . 10(4) eV cm(-1) was computed by modeling the measured spectra with the collisional-radiative package RATION. The blowoff maximum velocities 4.2-6.1 . 10(7) cm s(-1) and the velocity gradients 0.9-1.6 . 10(9) s( -1) were determined from the Doppler shifts of individual spectral lin es within their different spatial extent.