Uniform behavior of insulators irradiated by swift heavy ions

Ion induced Re track radii are derived from a universal relation Θ(r) without involving any materials parameter apart from the melting point Tm. The effect is related to the formation of identical ion-induced temperature distributions in track forming insulators for 〈se〉=Se/N = constant, where Se, and N are the electronic stopping power and the atomic density. Based on Θ(r), an Re2-〈se〉/(Tm-Tir) plot is applied where the experimental curves coincide for various insulators without adjustable parameters (Tir - temperature of irradiation). The analysis extends to all track-forming insulators studied up until now. The application of the equilibrium value of Tm is justified in thermal spike calculations. The physical meaning of the condition 〈se〉=Se/N = constant is discussed. Θ(r) may be valid in those insulators as well in which tracks are not induced. The Fourier equation is not valid under spike conditions.