Radiation chemical reactions in water radiolysis with therapeutic heavy ion beams

Yamashita, Shinichi

Water radiolysis with heavy-ion beams of energies up to 28 GeV provided from HIMAC, NIRS has been investigated from the viewpoint of correlation of products yields with track structure and its dynamics. For wide variety of heavy-ion beams in terms of LET, velocity, charge, etc., primary yields of major products in water radiolysis, e, OH and HO, have been measured by employing scavenging method to convert transient water radicals into stable and easily detectable species. Temporal behavior of approximate sum of water radicals has also been experimentally estimated. A Monte-Carlo simulation code of water radiolysis developed by a group of Universit de Sherbrooke, Canada was complementally used in discussion of microscopic track structure and its dynamics. In addition, a fluorescent probe was utilized in sensitive OH detection with HPLC-connected fluorometry.