Characterization of photomultiplier tubes for heavy water detector

The COHERENT collaboration uses the Spallation Neutron Source at Oak Ridge National Laboratory as a source of pion-decay-at-rest neutrinos. The absolute neutrino flux from this source will be measured using a planned dual-module heavy water Cherenkov detector. To determine how the photomultiplier tubes (PMTs) used in the detector will be affected by the Earth's magnetic field, data provided by the manufacturer's specification sheets was used to calculate the loss in collection efficiency due to a magnetic field with a similar magnitude. We analyzed data taken with a PMT in a light water tank. We report progress on a spectral comparison between simulated and detected cosmic ray muons and subsequent Michel electrons.