Oxygen enhancement ratio for high energy neutrons

There have been reports in the literature that neutron energies higher than those currently in use may result in a lower OER; reports of experiments at the University of Maryland cyclotron indicated OER values of 1.3 and 1.2 for neutrons generated by 80 MeV deuterons and 101 MeV protons beryllium respectively. Because of the practical importance of this subject, the present communication reports the results of experiments with the 101 MeV and proton beam also with a beam generated by 80 MeV deuterons on a thin combination target of beryllium and tantalum. The results of this series of experiments are in direct conflict with the published data. We see no indication of a reduced OER for higher neutron energies