X-ray fluorescence analysis of the Venus rocks by the ''Venera-13' and ''Venera-14'' space probes

The device and X-ray measurement technique, used for the elemental analysis of Venerus' rocks by the ''Venera-13'' and ''Venera-14'' space probes, are described. The X-ray fluorescence spectrometer device, characteristics of Fe55 and Pu238 radioisotope sources, used in the device, the proportional counter and the structural flowsheet of the pulse amplitude analyzer, is briefly represented. Venerus' rock is sampled by a special coring tool, transported through the sluice port into the lander and irradiated by radioisotope sources. The excited fluorescence is recorded by a 256-channel spectrometer. The information is transmitted to the Earth telemetrically. The devices of both landers operate reliably. The chemical composition of the rock samples is determined as a result of these experiments