About the temperature distribution in track forming insulators after the impact of swift heavy ions

Track radii Re are related to the maximum width of the ion-induced radial temperature increase ΔT(r, t) at T = Tm (Tm – melting temperature). This maximum is reached at t = 0. When Se/N = constant (Se, N are the electronic stopping power and the number density of atoms), the experimental Re, Tm data pairs measured in various insulators form a Gaussian curve Θ(r) for the ranges E < 2 MeV/nucleon and E > 8 MeV/nucleon (E – specific ion energy). Θ(r) does not depend on materials parameters. It has the same width w = 4.5 nm for a broad range of E while its maximum temperature depends on Se/N and the velocity of the projectiles. The experimental relation between Re and Tm described by Θ(r) is possible only if ΔT(r, 0) = Θ(r). Thus the ion-induced temperature distribution ΔT(r, 0) is identical for a number of insulators when Se/N = constant in the two ranges of E. The results prove that the heat flow equation is not valid under spike conditions.