  The peak energy resolution of germanium detectors deteriorates with
increasing neutron fluence. This is due to hole capture at neutron-created
defects in the crystal which prevents the full energy of the gamma-ray from
being recorded by the detector. A phenomenological model of coaxial HPGe
detectors is developed that relies on a single, dimensionless parameter that is
related to the probability for immediate trapping of a mobile hole in the
damaged crystal. As this trap parameter is independent of detector dimensions
and type, the model is useful for predicting energy resolution as a function of
neutron fluence.
