High photopeak efficiency gamma-ray detector for upcoming Laue Lens missions

We present the design for a new detector configuration, specifically tailored to suit the needs of prospective Laue Lens Gamma-ray astronomy missions in the 10keV to 1MeV energy range. A Laue Lens uses transmission diffraction through crystal planes to focus the incoming gamma-rays. Diffraction is highly energy dependant and in order to recreate high resolution images, very accurate measurements of the total energy of the incident photon are necessary, as well as good spatial resolution. The aim is to absorb all the Compton scattered products of the incoming photons. The design uses a cavity geometry with the main germanium pixilated imaging detector embedded position sensitive cavity. The germanium is then enclosed in a veto to reduce background and to clean the imaging of unwanted non-photopeak events. This allows the majority of backscattered photons to be captured producing a detector with a photopeak efficiency of similar to 90% at 511keV and millimetric spatial resolution. The detector system has the added advantage that it functions extremely efficiently as a gamma-ray polarimeter.