Structure of heavy ion tracks in Ag-Cl detectors.

The microdosimetric lateral structure of tracks of charged nuclear particles in monocrystalline layers of AgCl-detectors has been measured by means of a videoelectronic computer-controlled image analysing system. The lateral optical density profiles, recorded along the track in sequential steps of 0.2 micrometer show compact tracks with a density maximum around the track axis as well as "coreless" tracks with a density minimum towards the axis. This minimum is more pronounced for particles of high effective charge mean q exceeding approximately 25. The effect of fading of the core depends on the charge state mean q of the particle rather than on its (high) LET. This finding points towards an increased atomic displacement by Coulomb-repulsion into the lattice of the detector of Ag(+)-atoms which are needed for the formation of the track. Examples of measurements and of tracks are presented.