An investigation of the degraded neutron flux in a 14-MeV neutron-activation cell

Measurements have been made of the fluxes of thermal and indium resonance neutrons near the target of a 14-MeV neutron generator in a small irradiation cell. These measurements can be used to assess the importance of interfering reactions in fast-neutron activation analysis. For a fast-neutron output of 109 neutrons per second the measured sub-cadmium flux was 3·8 × 104 neutrons per cm2 per second, and the flux at the 1·4-eV indium resonance was 1·3 × 103 neutrons per cm2 per second per eV.