Detector response of Cherenkov radiators for calorimetry in the energy range below 14 MeV

Abstract A study of the detector response of PbF 2  crystals and three different types of lead glass blocks to electrons from a 14-MeV beam of the Mainz Microtron MAMI is presented. For the first time, signal height, signal width, and homogeneity of the response of these Cherenkov radiators were determined for energies between 10 and 14 MeV. To complement the beam tests, optical properties of the materials, in particular measured transmittances in the near UV and visible spectrum, were studied. The measured detector responses were also compared to Monte Carlo simulations of energy-loss, light production, transport, and detection. These Cherenkov radiators are considered as active material of a low-energy calorimeter for the detection of light dark matter particles recoiling off electrons behind the beam-dump of the Mainz Energy Recovering Superconducting Accelerator MESA.