Spin trapping of radicals in methanol solution irradiated by heavy ion beams. Effect of specific energy and LET

Radicals produced by the ion (He, C, Ne, Si, Ar, and Fe) irradiation of methanol were spin trapped with PBN (phenyl-t-butylnitrone). Three kinds of radicals, PBNCH₃O, PBN-CH₂OH, and PBN-H, were observed. The relative radical yield between PBN-CH₃O and PBN-CH₂OH reflected the localization of initial distribution of radicals by ion irradiation. Because the diffusion of protons which is a precursor of PBN-H, will be fast enough to escape from the ion track, the yield of PBN-H was not affected by the specific energy and the LET value. (author)