Year
2016
Abstract
Accelerators producing monochromatic neutrons and gamma photons have become common tools in nonproliferation work. The complex emission spectra and inferior detector performance at high energies limit the understanding of these accelerator beams. This study investigates the detector responses to gamma photons up to 16 MeV in order to characterize the gamma flux from a deuteron on boron accelerator. The results will provide researchers a detailed understanding of the accelerator beam for simulation. First, a gamma spectrum was measured from the accelerator from a high light output scintillation detector LaBr. The nonlinear energy spectrum was calibrated using known gamma spectra. Then, using Geant4, a response function matrix was synthesized and processed with the energy resolution data from known gamma sources and the beam itself. Using an inverse matrix method yields the monochromatic gamma source distribution from the accelerator. The result is a collection of impulses at energies of that photon energy. This method demonstrates that capacity to characterize gamma spectra up to 15.11 MeV, accounting for nonlinear energy resolution and calibration and for extensive scattering from high-energy gamma photons. In future beam characterizations, researchers should account for nonlinear detector responses and the implications of increased inscatter from photons at higher energies.