[en] A vertical dispersion variant of the Johann spectrometer has been used to record the high-resolution X-ray spectra of the chlorine He-like resonance line group emitted from low-radiance plasma. The emission profiles were measured at two observation angles and decomposed into single spectral lines by using a fit based on the Levenberg-Marquardt algorithm. The results of computerized analysis of the one-dimensional (1-D) spatially resolved spectra were used to evaluate the distribution of the main plasma parameters. The electron temperature gradient 7.5.10⁴) eV cm^-1 was computed by modeling the measured spectra with the collisional-radiative package RATION. The blowoff maximum velocities 4.2-6.1.10⁷ cm s^-1 and the velocity gradients 0.9-1.6.10⁹ s^-1 were determined from the Doppler shifts of individual spectral lines within their different spatial extent. (author)