Host: The Japan Radiation Research Society
High energetic heavy ions give unique irradiation effects on target materials, and are promising tool for the applications in chemical and biological fields. These unique irradiation effects are resulted in the high density and non-homogeneous distributions of radicals and subsequent diffusions and reactions in track. Reactions in water under heavy ion irradiation are mainly induced by OH (hydroxyl) radicals. In the present study, we used aqueous solutions to estimate the primary yield of the OH radicals as the basic knowledge for the application of heavy ions to advanced cancer therapy, and so on. The primary yields of the OH radicals have been investigated by the product analysis. The aqueous phenol solutions were irradiated with He, C and Ne ions ranging from 2 to 18 MeV/n. The yields of irradiation products of phenol super-linearly increased with the incident energy of the ions. The yields of the OH radicals were estimated by analyzing the yields of the irradiation products of phenol. The yields of the OH radicals increased with the specific energy for each ion, but decreased with both the mass of each ion at the same specific energy and elapsed time after irradiation.
