Temperature distribution in a swift ion-induced spike: an experimental approach

Abstract

Tracks induced by swift heavy ions are analyzed in insulating crystals. An empirical R _e (T _m) function is obtained (T _m—melting temperature; R _e —track radius); other material parameters are missing from it. It is derived from the analysis of the R _e (T _m) function that a universal Gaussian temperature distribution T ^max is formed at the moment when the melt diameter is maximal. The variance of T ^max is identical for all track forming insulators at any ion energy. The peak temperature of the radial distribution is T _p=⟨ s _e ⟩/3α k, where ⟨ s _e ⟩ is the electronic stopping power per atom, k is the Boltzmann constant and α=α _L and α=α _H are constants for irradiations with low (E < 2.2 MeV/nucleon) and high (E > 8 MeV/nucleon) velocity ions, respectively. The most important feature of the distribution T ^max is that it does not contain material parameters of the individual solids.

Keywords:

• Heavy ions
• Tracks
• Thermal spike
• Temperature distribution

Acknowledgements

This work was completed with the support of the National Scientific Research Fund (OTKA, Hungary) under contract no T046990.