was performed is shown.[]{data-label="fig:DetBWater"}](NumPE_MeasVsSim_Water_2GeV_ModGeom3_dashed.pdf){width="0.8\columnwidth"}

Results {#sec:Results}
=======

Detector B
----------

The simulated and measured photoelectron (PE) distributions are given in figures \[fig:DetBResults\] and \[fig:DetBWater\]. Cuts were applied to the hodoscope pulse amplitude and timing, as well as the relative PMT-hodoscope timing to select single proton events from the incident beam. The cuts effectively removed the pedestal noise and did not bias the photoelectron distribution. The measurement of 475 MeV and 210 MeV protons on a water target are not shown as few events were observed during this measurement, and those events that were registered were of very low amplitude. We attribute the events observed in these measurements to the detection of Cherenkov emission from secondary electrons. The mean number of observed photoelectrons for all measurements and simulations are given in table \[tab:MeansDetB\]. In addition to the statistical uncertainty arising from the $\chi^2$ analysis of the simulated data, we estimate that there is an additional systematic uncertainty component of $\approx$ 10% with the main contributions due to uncertainties in the simulation model’s input data (such as the refractive index, PMT quantum efficiency, and re-emission probability), the simplified treatment of optical photon scattering, and the effect of two-proton events (Section \[sec:BeamInfo\]). This 