Speaker
Description
Photomultiplier tubes are susceptible to radiation damage within high energy and nuclear physics detectors, particularly due to neutrons. More specifically, the integrity of the photocathode materials responsible for the emission of the primary electron that then interacts with the electron dynodes that create cascades of electrons moving through the photomultiplier, are affected. The photocathodes are made of low electron work function materials. We aim to assess the radiation damage and radiation hardness of different electron emitting materials suitable as photocathodes. The electron emission of the materials will be assessed before and after radiation with a setup based on electron microscopy which is being developed in the School of Physics of the University of the Witwatersrand. The materials are exposed to different gamma radiation doses. The Co-60 facility based at the CERN Prevessin site was used for the gamma irradiation. To compliment these measurements, we will also study the structural damage induced in the materials by using Raman Spectroscopy.
