A scheme is considered and the parameters of a multipulse X-ray source for obtaining images of the compressed state of a primary laser thermonuclear target are determined. As an example of a source, we consider the characteristic radiation of an iron secondary target with focusing on it of several picosecond laser pulses of subrelativistic intensity. The proposed technique makes it possible to determine the relative large-scale inhomogeneity of the energy release of laser beams that irradiated the thermonuclear target, based on the results of X-ray diffraction of a compressed thermonuclear target, and to estimate the decrease in the neutron yield caused by the asymmetry of the compressed target. Keywords: picosecond laser plasma, characteristic X-ray radiation, target in laser thermonuclear fusion, iron secondary target, backlighter image.