Radical Ion Saturation in Some Sulfur Compounds X-Irradiated at 4.2°K

Abstract

Single crystals of dimethylthiourea and dibenzoyldisulfide were exposed to ionizing radiation at 4.2°K. At this temperature positive and negative free radical ions are stable and can be identified from their electron spin resonance (esr) absorption spectra. The concentration of radical ions was measured as a function of dose and it was found that the concentrations approach limiting values of the order of 1018 radicals per gram. This saturation effect is attributed to nongeminate recombination of electrons with cations.