Monte-Carlo simulation of the low-LET radiolysis of liquid water over the range 25 to 350C

Sanguanmith, S.*; Muroya, Yusa*; Meesungnoen, J.*; Lin, M.; Katsumura, Yosuke*; Mirsaleh Kohan, L.*; Guzonas, D. A.*; Stuart, C. R.*; Jay-Gerin, J.-P.*

A re-examination of our Monte-Carlo modeling of the high-temperature radiolysis of liquid water by low linear energy transfer (LET 0.3 keV/m) radiation was undertaken in an attempt to reconcile our computed g-values of the various radiolytic products with newly measured or recently re-assessed experimental data over the range from 25 up to 350C. Using a global-fit procedure, experimental data were found to be best reproduced when a discontinuity in the temperature dependence of certain physicochemical parameters was introduced at 100-150C. The presence of such a discontinuity was hypothesized to be associated with a change in the liquid structure of water around these temperatures. In addition to the physicochemical factors intervening in the radiolysis, the importance of the reaction of H atoms with water in contributing to the unexplained yield of H above 200C was also investigated.