Wavelength Shifters for Water Cherenkov Detectors

TL;DR

This paper investigates the use of wavelength shifters to enhance water Cherenkov detector performance by testing various compounds, analyzing their optical and chemical properties, and simulating their impact on detector light yield.

Contribution

It introduces a comprehensive evaluation of multiple wavelength shifters for water Cherenkov detectors, including experimental testing and Monte Carlo simulations.

Findings

WLS compounds improve light yield in water Cherenkov detectors.

Optical and chemical compatibility of WLS candidates confirmed.

Simulations show increased detector sensitivity with WLS.

Abstract

The light yield of a water-based Cherenkov detector can be significantly improved by adding a wavelength shifter. Wavelength shifter (WLS) molecules absorb ultraviolet photons and re-emit them at longer wavelengths where typical photomultiplier tubes are more sensitive. In this study, several wavelength shifter compounds are tested for possible deployment in the Sudbury Neutrino Observatory (SNO). Test results on optical properties and chemical compatibility for a few WLS candidates are reported; together with timing and gain measurements. A Monte Carlo simulation of the SNO detector response is used to estimate the total light gain with WLS. Finally, a cosmic ray Cherenkov detector was built to investigate the optical properties of WLS.