TEMPERATURE DEPENDENCE OF THE SPUR EXPANSION TIME IN THE LOW-LET RADIOLYSIS OF WATER OVER THE RANGE 25 TO 350 °C
The radiolysis of pure, deaerated liquid water by low-linear energy transfer (LET), sparsely ionizing radiation (such as 60Co -rays, fast electrons, or high-energy protons) leads to the formation of radical and molecular species, namely, e aq (the hydrated electron〃), OH, H+, H, OH, H2, H2O2, HO2 /O2(pKa = 4.8 at 25 C), etc. Under usual irradiation conditions (i.e., at modest dose rates), these species are generated nonhomogeneously on sub-picosecond time scales in small, spatially well-separated regions of dense ionization and excitation events, called ¨spurs〃, along the track of the incident radiation.1 Owing to diffusion from their initial positions, the radiolytic products then either react within the spurs as they develop in time or escape into the bulk solution. At ambient temperature and pressure, the lifetime of a spur is generally taken to be ~10-7-10-6 s. By this time, the species that have escaped from spur reactions become homogeneously distributed throughout the bulk of the solution and the track of the radiation no longer exists. The radical and molecular products are then available to react with dissolved solutes (if any) present (in moderate concentrations) at the time of irradiation.
S.Sanguanmith J.Meesungnoen J.-P.Jay-Gerin
Université de Sherbrooke,Sherbrooke,Québec,Canada sxykdxxb-jcyxjyb201206047
国际会议
3rd China-Canada Joint Workshop on Supercritical Water-Cooled Reactors(第三届中国-加拿大超临界水堆研讨会 (CCSC-2012)
西安
英文
1-14
2012-04-18（万方平台首次上网日期，不代表论文的发表时间）