Study well-shaped germanium detectors for low-background counting

Abstract

Radiogenic particles are known as the main sources of background for all ultra-low background experiments in the detection of dark matter and neutrino properties. In particular, the radiogenic gamma rays from PMTs are a main component of the observed backgrounds in the noble liquid detectors such as XENON100 and LUX. This suggests a more accurate screening of PMTs is needed for the next generation experiments such as LUX-Zplin or Xenon1T. Hence, we propose to develop well-shaped germanium detectors for a better understanding of the radiogenic background from PMTs. A well-shaped germanium detector array and PMT (R11410MOD) have been designed in a Geant4-based Monte Carlo simulation, in which three radiogenic background isotopes from 238U, 232Th and 40K have been studied. In this work, we show the detector performance including the detector efficiency, energy resolution and the detector sensitivity for low-background counting in the detection of rare event physics.