Abstract
We make a calculation of the evolution in time of locally heated regions, produced by the impact of 6 keV Xe+ -ions on Ar and RbBr. The heating is supposed to be conducted away by lattice conduction. We consider the question of the establishment of local thermal equilibrium within the spike and compare the time, needed to achieve this with the duration of the initial collision cascade and the lifetime of the spike as determined by the heat conduction.