A new method to measure energy, direction, and polarization of gamma rays

A new method to measure the energy, direction, and polarization of gamma rays in the sub-MeV to few MeV range is proposed. We found that the first Compton scattering of the gamma-ray energy degrading process can be correctly reconstructed with a high probability if energies and positions of recoil electrons are recorded with 4-10 keV (rms) and ≅ 1x1x1 mm3 for the first 4-5 steps. If a silicon detector stack is used, we get an angular resolution of about 10 (rms) per gamma ray without collimators. We have started development work to make such a device using 2-dimensional silicon strip detectors. (orig.)