The Effect of Bonner Sphere Borehole Orientation on Neutron Detector Response

This thesis investigates the differences in Bonner Sphere detector response for anisotropic neutron fields as a function of borehole orientation. Monte Carlo simulations using MCNPX were used to calculate the difference for a borehole oriented directly behind a unidirectional neutron field and one in which the borehole is normal to the neutron flux. The differences in detector response depend on the size of the Bonner Sphere and the energy of the incident flux, which could introduce significant error in the determination of the neutron field’s energy spectrum.