The influence of energy density inside the nuclear track on the secondary-ion emission

Secondary ion emission yields from polycrystalline LiF and deuterated amorphous carbon a-C:D, bombarded by isotachic projectiles at 1.4 MeV/u, were studied as a function of the projectile atomic number (C, N, Ar, Kr, Sn) and consequently, as a function of the electronic stopping power. The emitted, positively charged secondary ions were analysed by a time of flight mass spectrometer. The H+ ions originate on the top surface near the track core, while heavier secondary ions (e.g. hydrocarbons) originate from the region of the track halo. Emission of Li+ from LiF was observed for all projectiles. On the other hand, only Sn projectiles were able to produce D+ emission from a-C:D. The results are discussed considering the deposited energy density. (C) 2003 Elsevier B.V. All rights reserved.