Results of charge sharing tests in a Ge-strip detector

We have investigated the effects of charge sharing and loss in the gap between strips in a prototype 19 × 19 germanium strip detector. Our measurements indicate some charge loss for events occurring in the gap between strips, We find that this "dead" region where charge is lost (which leads to an underestimated incident photon energy) is narrower than the physical strip width, and confined to a small region below the gap surface. This is illustrated by observing coincidence spectra between nearest neighbor strips as a function of energy (and therefore interaction depth), and confirmed with coincidence spectra between non-adjacent strips. To first order the photon energy can be corrected simply by knowing the ratio of charge collected on two adjacent strips. However, with additional z information on the interaction depth these corrections should theoretically become nearly exact.