Neutron Damage in Ge(Hp) Coaxial Detectors

We report energy resolution, capacitance, and depletion voltage transients in neutron damaged coaxial Ge(HP) detectors fabricated from n-type and p-type germanium. The disordered region model for fast neutron degradation of germanium detectors was supported by 1) the large trapping cross sections observed (~ 10-11 cm2), 2) changes in the steady state charge on the traps over four decades of induced current density, and 3) the inability of the isolated defect hypothesis to self-consistently account for the ratio of thermal emission of holes in liquid nitrogen to liquid argon cooled detectors. The results of in-cryostat annealing of these detectors are reported.