Design and Benchmarking of a Proton Recoil Neutron Detector
A neutron spectroscopy detector was designed for analysis of neutrons produced by Lawrence Livermore National Laboratory's neutron imaging project. The detector was built and benchmarked at Lawrence Berkeley National Laboratory's Deuteron-Breakup Neutron Facility. Similar to a proton-recoil telescope, the setup detects protons elastically scattered from neutrons incident on a thin sheet of polyethylene. A silicon charged-particle detector several centimeters away detects the protons in a small angular range, such that the energies of the incident neutrons can be reconstructed from the energy of the detected proton and the scattering angle. A quick benchmarking experiment demonstrated that large backgrounds would be a significant challenge, and that additional measures must be taken to reduce these backgrounds. A Geant4 model of the detector was used to predict the sources of these backgrounds and how best to reduce them.