Low-energy electron ionization and recombination model for a liquid argon detector

Detailed understanding of the ionization process in noble liquid detectors is important for their use in applications such as the search for dark matter and coherent elastic neutrino-nucleus scattering. The response of noble liquid detectors to low-energy ionization events is poorly understood at this time. We describe a new simulation tool which predicts the ionization yield from electronic energy deposits ( E < 10 keV ) in liquid Ar, including the dependence of the yield on the applied electric drift field. The ionization signal produced in a liquid argon detector from 37Ar beta decay and 55Fe X-rays has been calculated using the new model.