ESR spin trapping of radicals in methanol solution irradiated by heavy ion beams. Dependence on specific energy and LET

Radicals produced by the heavy ion (He, C, Ne, Si, Ar, and Fe) irradiation of methanol were spin trapped with PBN. Three kinds of radicals, PBN-CH 3 O, PBN-CH 2 OH, and PBN-H, were observed similar to those by γ-irradiation. The relative radical yields, PBN-CH 3 O/PBN-CH 2 OH and (PBN-CH 3 O + PBN-CH 2 OH)/PBN-H, varied depending on the LET value, the specific energy and mass of ions.