Monte-Carlo calculation of the primary H atom yield in liquid water radiolysis: effects of radiation type and temperature

Monte-Carlo simulations are used to calculate the primary yield of hydrogen atoms (GH) of water radiolysis versus linear energy transfer (LET) up to ∼100 keV/μm, at 25°C and 300°C. The GH values calculated at 25°C using protons show a maximum near 6.5 keV/μm before decreasing steeply at higher LET. At 300°C, GH remains constant below ∼7 keV/μm, while at higher LET it decreases faster than do its corresponding 25°C values. For different radiation types (protons, 2H+, 4He2+, 7Li3+, and 12C6+) of equal LET>10 keV/μm, GH increases as the incident ion velocity increases. The results compare generally well with experiment.