Measurement of the reflectivities and absorption lengths at different wavelengths of plastic scintillator and acrylglass: Calculations of the light attenuation in large area detectors

Abstract

The results of measurements of the optical parameters determining light attenuation in plastic scintillators and light pipes are reported. It is shown that the absorption lengths deduced from pulse height measurements are generally too optimistic and that the reflection losses especially at polished surfaces have an unexpectedly large influence on the light output of large area counters. Using the measured parameters in a computer program, attenuation curves for flat plates of various thicknesses have been established which can serve as design information for plastic scintillation counters. Performance calculations were also carried out for a large anticoincidence dome.