Formation of labelled molecular oxygen by 15O recoils from the reaction 16O(n,2n)15O

The distribution of radioactive O-15 from nuclear recoil among different fractions has been investigated in different salts of oxyanions. A qualitative relation has been observed between the yield of O-15 as molecular oxygen and the radiation chemical properties. Salts of anions with high oxidation potential tend to combine a high yield of O-O-15 with relatively high G(O2) values. Activation by the reaction O-16(n, 2n)O-15 has been performed in an external irradiation facility at the IKO synchrocyclotron. Fast neutrons were generated by a 0.5 μA beam of protons on beryllium. The incident proton energy of 52 MeV was first reduced to about 40 MeV by means of a gold foil as energy degrader with a comparatively low own neutron yield. A detailed description of the chemical separations and radioassay is presented. (T.I.)