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

• The relative yield among radicals produced by ion irradiation of methanol was studied.
• The ratio varied depending on the LET value, the specific energy and mass of ions.
• The recombination of ionic species will occur effectively for Ar and Fe-ion irradiation.

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-CH3O, PBN-CH2OH, and PBN-H, were observed similar to those by γ-irradiation. The relative radical yields, PBN-CH3O/PBN-CH2OH and (PBN-CH3O + PBN-CH2OH)/PBN-H, varied depending on the LET value, the specific energy and mass of ions.