Atomic force microscopic analyses of heavy ion tracks in CR-39

The track evolution for high energy C and Si ions in CR-39 was studied usin g an atomic force microscope (AFM). The image processing method of AFM obse rvations and the 3-D images of C and Si tracks are reported. The track diam eter increased linearly with the amount of bulk etch of CR-39, but the reta rdation of growth of the track length was observed at the early stage of th e etching. As a result, considerable discrepancies between the track sensit ivities calculated by using the track diameter and the length appeared espe cially in the early stage of the etching. The results reported here show th at AFM observations are very useful in practical application to the quantit ative analysis for minute etch pits in a track detector. (C) 1999 Elsevier Science B.V. All rights reserved.