Theoretical and experimental study of electronic temperatures in heavy ion tracks from Auger electron spectra and thermal spike calculations

Electron spectra were measured at GANIL with different heavy ions (C-Mo) and various charge states q (q = 6-39) at fixed projectile velocity v (v = 19 atomic units, 9.2 MeV/u). A projectile dependent broadening of ion induced KVV Auger electron peaks from carbon targets was observed. From this broadening, one can deduce a mean 'electronic temperature' of the heavy ion induced track at the corresponding Auger decay time (10 fs). We compare the measured temperature values to the predictions of an inelastic-thermal spike model, which takes into account the electron-phonon coupling. The model underestimates the experimental values, but reproduces the increase with ion charge