The formation of surface tracks and tracks in an island gold film (island t
racks) on a surface of a single crystal of LIF was studied by means of elec
tron microscopy. The irradiation by Sn ions with an energy of 1 MeV/nucleon
was carried out at the angle of 1 degrees to the surface. Sizes and the sh
ape of surface and island tracks induced by the same ion are compared. Isla
nd tracks of abnormal large sizes are found. The possible reasons for the f
ormation of island track of such sizes are discussed. (C) 1998 Elsevier Sci
ence B.V. All rights reserved.