Mechanism of cell inactivation by different ions: Damage induction   probabilities per single tracks
  Biological effects of proton and light ion irradiations have been studied in detail by analyzing published cell survival data with the help of the probabilistic two-stage radiobiological model. Probabilities of single ion tracks to induce lesions of different severity have been assessed in dependence on their linear energy transfer (LET). The results are presented and their interpretation in terms of $Z_{eff}^2/\beta^2$ (the effective charge over velocity squared) is discussed. 
Pavel Kundr\'at, Milo\v{s} Lokaj\'i\v{c}ek, Hana Hrom\v{c}\'ikov\'a,   Libor Judas