Modeling of a Directional Scintillating Fiber Detector for 14 MeV Neutrons

The GEANT4 Monte Carlo simulation tool was used to model a prototype 14 MeV neutron fiber detector. Detail features of the prototype were implemented in the modeling to assess the directionality and detector performance. The prototype was built using plastic fibers consisting of a core scintillating material and an acrylic outer cladding. A total of 64 square fibers were used in parallel with a fiber pitch of 2.3 mm. Recoil protons scattered by an incident mono-directional 14 MeV neutrons were tracked to enable reconstruction of a two-dimensional (2-D) direction of the incident neutrons. Simple kinematics of neutron scattering together with a backprojection technique was implemented. Reconstructed direction has a peak with a full width at half maximum (FWHM) of 10degrees and rests on a pedestal of uniform counts. Results from the present GEANT4 simulation have demonstrated promising directionality of a prototype scintillating fiber detector