ON DENSITY EFFECTS IN POINT-DEFECT SOLUTIONS UNDER IRRADIATION .1. QUALITATIVE CONSIDERATION OF QUASI-EQUILIBRIUM STATES

In the paper, an open system of point defects in metals under irradiat ion at temperatures below one third part of the melting point is consi dered. A consideration is based on an analysis of chemical potentials of interstitials and vacancies in their supersaturated solid solutions . Density effects in supersaturated solutions that can be naturally as cribed to terms of higher orders in an expansion of the chemical poten tial over the concentration of the solute species are tken into accoun t. It is shown that the mean square values of spatial fluctuations in the supersaturated solution remarkably increase. Such a situation take s place when, for some irradiation conditions, the temperature of a sa mple is low enough to reduce mobilities of point defects;The density e ffects would be expected as to be able to cause a spontaneous clusteri ng process at high supersaturations. Possible consequences of the prop osed effect for irradiation experiments are discussed.