Influence of ion-charge state on damage morphology of ion tracks in dark mica

Lang, M.*; Hasenkamp, W.*; Ishikawa, Norito   ; Medvedev, N.*; Neumann, R.*; Papalo, R.*; Trautmann, C.*; Voss, K.-O.*; Yamaki, Tetsuya

We report how the ion charge state affects the track morphology of phlogopite, a dark mica mineral. The phlogopite samples were irradiated with nickel-58 ions at three different accelerators (GSI, Tokai/JAEA, and Takasaki/JAEA). The charge state of the Ni beams from both the JAEA accelerators was non-equilibrium, whereas at GSI it was adjusted to the equilibrium by passing the ions through three Al-foils. After chemical etching in a hydrogen fluoride aqueous solution, the tracks from different charge states of +15 (388 MeV) and +23 (373 MeV) were inspected by scanning force microscopy. The significant difference in etch-pit size and shape indicates the direct influence of the charge state in the track morphology.