G.R. Spence, “A Boron Loaded Approach to Directionally Sensitive Neutron Detectors”, 52nd Annual Meeting of the Institute for Nuclear Materials Management (INMM), Palm Desert, CA, July 17-21, 2011.
With an increase in the capabilities and sophistication of terrorist networks worldwide comes a corresponding increase in the probability of a radiological or nuclear device being detonated within the borders of the United States. In order to reduce this threat, new types of radiation detectors are being developed which allow for dependence upon both energy and angular resolution. Directional sensitivity can be gained by observing the n + 10B reaction, and the resultant de-excitation Doppler broadened photon provided 94% of the time from the reaction. By measuring a combination of the reactant products and the energy of the Doppler broadened de-excitation photon emitted from 7Li, a conic series of solution vectors for the incoming neutron angle can be determined. Data for a prototype detector was developed using simulations with MCNPX. Results for this detector and the sensitivity of the uncertainty in the predicted incoming neutron angle to measurement parameters are given.