A more physical approach to model the surface treatment of scintillation counters and its implementation into DETECT

DETECT is a Monte Carlo simulation capable of realistically modeling the optics of scintillation detectors. A limitation of this widely used program is its lack of realism and flexibility in dealing with the surface finish and reflector coating of photon counters. To address these limitations, we initiated the implementation into DETECT of a more physical model to treat the interactions of scintillation photons with dielectric surfaces. Inspired from the initial work of Nayar et al. (1991), this approach has the particular advantage of unifying, into a single parametrization, models that usually apply over a very limited range of surface roughness values. This flexibility is ensured by using the standard deviation of the surface slope as a model parameter that can be extracted from simple measurements.