The fractions Θβ and ΘX of spin-correlated singlet radical-ion pairs in alkane solutions irradiated by β-particles and X-rays were got from experiments on magnetic field effects and quantum beats in recombination fluorescence. The ratio Θβ/ΘX values of 1.3−2.8 for the solvent series studied were found both from magnetic effect and quantum beats. The Monte Carlo calculations were made to explain the variations of Θβ/ΘX in different solvents. The high value of Θβ/ΘX = 2.8 for isooctane is probably due both to large separation between ions in pair and to high concentration of neutral radical in the spur.
Radiat.Physi.Chem. 1998, V.51, No.1, pp. 31-36