Measurement and Calculation of High-Energy Reflected Neutrons from Aluminum

Using six different high-threshold neutron-activation detectors, the activation reaction rates are obtained with and without the Al reflector. Measured reflectivities of high-energy neutrons from Al reflector are also obtained as the ratio of measured data and range from 1 to 1.14. For different activation detectors, the shape of the reflectivities as function of measurement angles is rather similar. The intensity of the reflected high-energy neutron field is high at large angles and smaller towards smaller angles. With increasing thresholds of the activation detectors, the reflectivities decrease. Evaluated total uncertainties of reflectivities are 3.4%—4.2%. Calculated results of reflectivities agree with the experimental results at the majority of the measuring points.