SOME RELATIONS OF THE DIFFUSION CONSTANT OF LATENT TRACKS IN POLYMERSAND THE ION ENERGY-LOSS

Measurements of the diffusion constant and the permeability of ion irr adiated Makrofol KG (polycarbonate) sheets have been done with Argon a nd Nitrogen as diffusion gas. The polymers were irradiated at the ''Ge sellschaft fur Schwerionenforschung'' (GSI, Germany) with Uranium and Gold ions with energies of about 10 MeV/nuc. The fluence varies from 3 .10(9) to 4.10(11) ions/cm(2). For the irradiation the material was pu t together in stacks with layers of 8 mu m thickness. This allows to r elate a definite amount of energy loss to each layer and to examine th e dependence of the diffusion constant and the permeability on it. For comparison electron irradiated and pristine material (i.e. the untrea ted material) were also measured. The general tendency shows an increa se of the diffusion constant and the permeability with growing energy loss up to a certain limit. In case of the highest energy loss the mat erial changes its appearance and the diffusion constant and the permea bility values are remarkable lower than those of the pristine material . A first trail of explanation might give the three-zone-model present ed in this paper.