Charge collection physics in germanium detectors

Ethan Hull
Lawrence Berkeley National Laboratory
June 21, 2002

Abstract:
Charge collection physics in germanium detectors include surface channel effects, charge trapping effects, and signal induction effects. Surface channel effects cause electric field lines to stray from being perfectly straight, causing losses in efficiency in germanium detectors and Si(Li) detectors. Charge trapping effects from radiation damage and natural grown-in electron trapping can degrade the energy resolution of detectors. All of these effects show themselves differently depending on the electrode geometry of the particular detector used. Examples of these effects in coaxial, planar, and orthogonal strip planar detectors are discussed.