Hydroxyl radical yields in the tracks of high energy 13C6+ and 36Ar18+ ions in liquid water

This article reports the determination of the OH radiolytic yields in water irradiated by high energy C6+ and Ar18+ ions with LET values of 32 ± 2 and 280 ± 10 eV nm−1. The time evolution of the yields between 9 × 10−11 and 9 × 10−8 s was deduced using the scavenging method with SCN− and Br− and pulse radiolysis with pulses of 5 and 10 μs. The thiocyanate chemical system is less affected with the local high dose rates specific to the high LET particles than the bromide system. At 32 eV nm−1 with C6+ ions, G(OH) reaches a maximum of 1.5 × 10−7 mol J−1 at 1 ns and decreases at earlier times. With Ar18+ ions of 280 eV nm−1G(OH) is always increasing at early times up to 1.6 × 10−7 mol J−1 at 9 × 10−11 s. In this case the evolution of the hydroxyl radical yields agrees with the high local concentrations obtained with Ar18+ and C6+ ions and depicted in recent literature with the yields of the hydrated electron in the ns range.