NEUTRON-ACTIVATION DETERMINATION OF ELEMENTS IN THE PRODUCTS OF EXPLOSIVE IMPACT PROCESSES

In model experiments simulating the processes of interaction of bodies in high-velocity collisions, i.e., processes that play an important r ole in the accretion of matter in the early stages of formation of the bodies of the solar system, it is extremely important to determine th e composition of the products formed during vaporization in impact pro cesses and to identify the mechanism of redistribution of elements in the target-projectile-condensate system. In such experiments, the vapo rized substance deposits on a cold substrate in the form on an ultrath in layer of condensate practically inseparable from the substrate. Thi s considerably complicates the analysis, since it is necessary to dete rmine the composition of the substance against a substrate of substant ially greater mass. Data on the redistribution of petrogenic elements present in the original targets in amounts exceeding 0.1% were obtaine d by secondary-ion mass spectrometry [1]. However, the sensitivity of this method was found to be insufficient for determining trace element s whose content in the target is less than 0.001 % (and many times low er in the vaporized substance). However, data on the behavior of such elements, in particular, U, Th, Sc, Co, REE, etc., are very important, since they characterize the general geochemical direction of an impac t process in the early stages of evolution of planetary matter. Determ ination of these elements often involves the use of the neutron activa tion method of analysis, which is characterized by high sensitivity an d has an instrumental variant (INAA) that makes it possible to preserv e unique samples for further studies. The purpose of this paper was to estimate the possibility of applying INAA to the study of the behavio r of trace elements in impact processes.