Radiation yield of oxygen-based radicals in hyperquenched glassy water gamma-irradiated at 77 K

Hyperquenching of liquid water with cooling rates of 10⁶–10⁷ K s⁻¹ yields glassy water. Upon γ-irradiation at 77 K, the only paramagnetic species accumulating in hyperquenched glassy water are the hydroxyl and hydroperoxyl radicals. There are no hydrogen atoms or electrons seen by the ESR technique. For irradiation doses up to about 70 kGy, the relative contributions of hydroxyl and hydroperoxyl radicals to the total amount of paramagnetic species remain virtually constant. The total amount of paramagnetic species, n, is sublinear in dose, d, well approximated by n=8.55×10¹⁶d^0.8 for n in spin g⁻¹ and d in kGy.