197Au ion irradiated modification in CR-39 by positron annihilation

CR-39 is a polycarbonate widely used as SSNTD for recording nuclear charged particles and in other applications. Latent ion tracks produced in the polymers due to the damage produced by the passage of Swift Heavy Ions contain amorphous material with highest degree of disorder, changing the free volume properties which have strong correlation with the macroscopic properties of the material. Positron Annihilation Lifetime Spectroscopy (PALS) provides direct information about the dimension, content and hole size distribution of free volume in polymers. The effect of irradiation of Au-197 (13.5 MeV/n) ions on CR-39 polycarbonate by Positron Annihilation Lifetime Spectroscopy (PALS) is reported here. PALS provides a non-destructive and non-interfering probe, having high detection efficiency for free volume hole properties. PAL measurement shows 8.9% increase in free volume size.