The Effect of Wavelength Shifting Fibers on Cherenkov Glass Detectors for Gamma-Ray Measurements

Abstract

Cherenkov detectors have been developed and used in several fields since the discovery of Cherenkov radiation. They do have several advantages compared with other detector types, such as low noise due to the low-energy threshold of Cherenkov radiation and short decay constant (on the order of picoseconds). However, the light yield of Cherenkov detectors is low. Only several hundreds of Cherenkov photons can be generated per megaelectron-volt. The objective of this work is to manufacture and test Cherenkov glass detectors for detection of high-energy gammas. The focus is to improve the light output of Cherenkov detectors by implementing wavelength shifting (WLS) fibers inside the glass samples. Without the WLS materials, most Cherenkov photons are likely to be absorbed within the glass sample before they can reach the photon sensor. WLS fibers do not directly increase the number of Cherenkov photons, but they can reduce the energy of Cherenkov photons and direct them toward the photon sensor. This photon energy reduction helps increase the efficiency of light collection and improves matching between the photon wavelength and photon detector quantum efficiency.