Progress toward a Stable Orthogonal Strip Germanium Gamma Camera

Following exposure to room ambient air, the radiation response of orthogonal strip detectors fabricated from high purity germanium for use in a gamma camera has been found to undergo deterioration due to changes which take place at the exposed surfaces between the electrode strips and at the edges of each device. Based upon data obtained from small test detectors subjected to a commercial passivation process, long term stability (greater than one year) following room ambient exposure appears feasible.