Stability of irradiation-induced voids based on the cusp catastrophe

The aim is to investigate the stability of irradiation-induced voids. It is shown that catastrophe theory, which already turned out to be an excellent method to treat questions of stability in many fields of science and engineering, can also be applied to deal with the stability of voids. It admits to analyze the sensitive interplay of irradiation and material parameters as well as the key role of transmutant helium to void stability. Assuming that the helium gas within the cavities obeys the ideal gas law the proposed framework leads to an elementary catastrophe of the cusp type which demonstrates the range of the number of gas atoms being of physical importance. The potential associated with this catastrophe as a function of the cavity radius is characterized by one minimum and one maximum indicating the stable bubble radius and the unstable critical cavity radius, respectively. (orig.)