Measurement of the Compton scattering in germanium with a p-type point-contact germanium detector for dark matter detection

Abstract

Low-energy background through Compton scattering from the ambient $\gamma$ rays can be contaminated in direct dark matter search experiments. In this paper, we report comparable measurements on low-energy spectra via Compton scattering from several $\gamma$-ray sources with a p-type point-contact germanium detector. The spectra between 500 eV and 18 keV have been measured and analyzed. Moreover, the features of the electron binding effect, particularly at the edges of the K- and L-shells in the germanium atom, were observed with different gamma sources and were consistent with the models in the Geant4 simulation. An empirical background model is proposed that provides insights into understanding the low-energy background in germanium for direct dark matter experiments.

7 pages, 5 figures and 2 tables; version accepted by JINST

References in corpus (4)

• The China Jinping Underground Laboratory and its Early Science
• Limits on light WIMPs from the CDEX-1 experiment with a p-type point-contact germanium detector at the China Jingping Underground Laboratory
• Measurement of low energy ionization signals from Compton scattering in a CCD dark matter detector
• Precision measurement of Compton scattering in silicon with a skipper CCD for dark matter detection