Studying cosmic-ray component in the background radiation on HPGe γ-spectrometer: Experiment and Geant4 Monte-Carlo simulation

High Pure Ge (HPGe) γ-spectrometers have been used widely for isotopes determination in environmental samples.Normally, for a gamma spectrometer with low radiation background meaning, the Ge detector is mounted inside a suitable passive shielding made of pure or very low-activity lead that can suppress most of the radiation from outside. However, background radiation still always exists in the energy spectrum of the Ge detector. One of the main contribution in the background radiation is cosmic rays. In this work, we study the cosmic-ray component of the total background radiation on a γ-spectrometer of HPGe detector. An experiment of radiation background is carried out on the γ-spectrometer of HPGe detector of from 0.04 MeV to 50 MeV. An Geant4 Monte-Carlo simulation on the HPGe γ-spectrometer for cosmic rays is performed in the energy region up to 100 MeV. We analyze the cosmic-ray component in the background radiation energy spectrum. Muonic and neutron cosmic rays is also evaluated in the cosmic ray component. (author)