Wide Angle Compton Coincidence technique for determining scintillator nonlinearity

The energy response of most scintillator materials is nonlinear at some level. The linearity of a scintillation detector can be measured using Compton scattering into a known-to-be-linear detector. In the Wide Angle Compton Coincidence (WACC) technique, Compton scattering events (from the scintillation detector under test) are sampled over many angles at once, enabling the energy response to be efficiently mapped out over a range of energies. We report on the implementation of this technique with a portable WACC setup based on a HPGe detector and a multi-channel digital data acquisition system.