Development and performance of large fine-pitch germanium strip detectors

We present the initial performance results obtained with a double-sided planar germanium strip detector with 1.25 mm pitch and 64 cm² of active area. The detector is 2 cm thick and was manufactured with an amorphous contact technology. The germanium crystal is 10×9×2 cm³ and was extracted from the long direction of a germanium boule. The detector has 64 strips on each side, with one side AC coupled to the front-end electronics and the other side DC coupled to the front-end electronics. An energy resolution of 2.4 keV and a pixellization of 1.25 mm are achieved. A depth resolution of 1 mm was obtained by using a timing technique. Gamma-ray imaging and spectroscopy are demonstrated using diffuse gamma-ray sources and collimators. Images created using coded apertures are also shown.