Radiolysis of NaCl at high and low temperatures: development of size distribution of bubbles and colloids

New experimental results are presented on low temperature irradiation (18 °C) of rock-salt samples which had been exposed to initial doses up to 320 GRad at 100 °C. Differential scanning calorimetry (DSC) shows that the latent heat of melting (LHM) of sodium colloids decreases during subsequent low-temperature irradiation, whereas the stored energy (SE) increases slowly, indicating that the process of radiolysis continues. The decrease of the LHM is due to dissolution of large colloids, because the intensities of the melting peaks decrease during the second stage irradiation at low temperature. The model is formulated to describe the nucleation kinetics and the evolution of the size distribution of chlorine precipitates and sodium colloids in NaCl under high dose irradiation. It is shown that the mechanism of dissolution of large Na colloids during low temperature irradiation can be related to melting of sodium colloids.

Investigation of the Surface of Poly(ethylene terephthalate) Films Modified by Vacuum Ultraviolet Irradiation in Air

This paper reports on the results of measuring the changes in the characteristics of the surface of poly(ethylene terephthalate) films upon radiation-induced oxidation of the polymer under vacuum ultraviolet irradiation in an oxygen-containing medium. The films were irradiated by light from a sealed-off deuterium lamp with the maximum photon energy within the band (10 +/- 1 eV) in air under conditions where thermal destruction of poly(ethylene terephthalate) could be ignored. The functional relationship between the decrease in the film thickness and the growth of surface irregularities in the course of photoetching was established from measurements of the optical transmission spectra T(lambda) of the films and investigations of the surface microrelief by atomic-force microscopy. The hydrophilic properties of the surface of the sample regions irradiated with different doses were examined by measuring the contact angle