Abstract
Effect of surface wettability on boiling heat transfer was studied by applying radiation induced surface activation. Oxidized metal surfaces were irradiated by ultraviolet light, gamma ray, and proton beam, to investigate the radiation effect on the surface wettability. Proton irradiation experiments were performed at the FFAG accelerator complex of Kyoto University with 100MeV proton energy. Wettability enhancement on the oxidized metal surface was observed in each radiation method, where the radiation conditions were 20 minutes exposure with 5mW/cm^2 for ultraviolet, 97kGy for gamma ray, and 50 hours irradiation with 4.7nA for 100MeV proton beam, respectively. In addition, boiling heat transfer experiment was also performed with and without gamma ray irradiation. Experimental results show that the critical heat flux increases with the gamma-ray irradiated copper surface, however the heat transfer enhancement was not obvious at present experimental conditions.