Diffusion von18O in Eis-Einkristallen

The coefficient of¹⁸O diffusion in single crystals of ice was measured at various temperatures ranging from ?5°C to ?29,5°C. The¹⁸O concentration was determined by the nuclear reaction¹⁸O(p, n)¹⁸F caused by recoil protons due to fast neutron irradiation. It was found that the coefficients of¹⁸O and³H diffusion are of the same order of magnitude and that they have the same activation energy. This shows that¹⁸O and³H diffusion is caused by the migration of whole H₂O-molecules. A mechanism of migration over molecular vacancies is discussed.