Application of Geant4 simulation in measurement of cosmic-ray muon flux and studies of muon-induced background

• Published in: European physical journal plus Vol. 138; no. 11; p. 1006
• Main Authors: Joković, Dejan, Maletić, Dimitrije, Dragić, Aleksandar, Veselinović, Nikola, Savić, Mihailo, Udovičić, Vladimir, Banjanac, Radomir, Knežević, David
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 10.11.2023; Springer Nature B.V
• Subjects: Applied and Technical Physics; Atomic; Charged particles; Complex Systems; Condensed Matter Physics; Cosmic rays; Data acquisition systems; Energy; Focus Point on Physics in the Balkans: Perspectives and Challenges; Gamma ray detectors; Gamma rays; Gamma spectroscopy; Germanium; Laboratories; Mathematical and Computational Physics; Molecular; Monte Carlo simulation; Muons; Neutrons; Optical and Plasma Physics; Physics; Physics and Astronomy; Radiation; Regular Article; Sensors; Simulation; Spectrometers; Spectroscopic analysis; Spectrum analysis; Theoretical
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-023-04639-1

The low-level underground laboratory at the Institute of Physics Belgrade is a facility for gamma-ray spectroscopy measurements and for measurements of cosmic-ray muon intensity. Related to the two research subjects, studies of cosmic-ray muon-induced background in gamma spectroscopy are of particular interest. Continuous measurements of cosmic muon intensity at the ground level and underground sites have been carried out by means of plastic scintillation detectors. The detector response, interpretation of the experimental spectra and their calibration were obtained and verified using a Geant4-based simulation. The results of the simulation were used in measurement of muon flux at the surface and shallow underground (25 m w e)—the measured fluxes are (170 ± 6) m −2  s −1 and (44 ± 1) m −2  s −1 , respectively. An underground muon detector can operate in coincidence with a high-purity germanium gamma-ray detector, which allows investigations of muon-induced processes in germanium spectrometers. In low-level gamma spectroscopy, neutrons produced by muons in the lead shielding of a germanium detector contribute to the detector background. Simulation of prompt muon-induced background as well as simulation of neutron production by cosmic muons in lead were carried out. Estimated neutron yield in lead is (3.1 ± 0.4) × 10 –5  neutrons per g/cm 2 , per tagged muon. Also the average neutron multiplicity is calculated.