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.