Gamma Vector Camera: A Gamma Ray and Neutron Directional Detector

We have built a proof-of-concept gamma-ray camera capable of imaging the Compton recoil electron tracks in 3D, and reconstructing the gamma-ray source direction and energy spectrum from those tracks. The electrons are tracked in a fiber-optic scintillating block made from polystyrene fibers arranged in alternating, orthogonal layers, and viewed by image intensifiers and CCD cameras. We have also demonstrated the detection of neutrons in the same gamma camera by recording the scintillation light from proton recoils in the fibers, and discriminating between protons and electrons based on their different ranges in polystyrene. We have developed software that reconstructs the energy and direction of the recoil electrons and reconstructs the energy spectrum and direction of the gamma rays from (1) single Compton scattering, by computing the mean electron direction of a statistical sample, and (2) double and triple Compton scattering by full kinematic reconstruction of the energy and direction of individual gamma rays.