Modeling of Impact Ionization and Charge Trapping in SuperCDMS HVeV Detectors

A model for charge trapping and impact ionization and an experiment to measure these parameters are presented for the SuperCDMS HVeV detector. A procedure to isolate and quantify the main sources of noise (bulk and surface charge leakage) in the measurements is also described. This sets the stage to precisely measure the charge trapping and impact ionization probabilities in order to incorporate this model into future dark matter searches.