Phenomenological model for predicting the energy resolution of   neutron-damaged coaxial HPGe detectors
  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. 
C. DeW. Van Siclen, E. H. Seabury, C. J. Wharton, and A. J. Caffrey
physics.ins-det