Review of Monte Carlo simulations for backgrounds from radioactivity

Journal Article · Thu Aug 08 00:00:00 EDT 2013 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4818111· OSTI ID:22224175

Selvi, Marco ^[1]

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1. INFN - Sezione di Bologna (Italy)

For all experiments dealing with the rare event searches (neutrino, dark matter, neutrino-less double-beta decay), the reduction of the radioactive background is one of the most important and difficult tasks. There are basically two types of background, electron recoils and nuclear recoils. The electron recoil background is mostly from the gamma rays through the radioactive decay. The nuclear recoil background is from neutrons from spontaneous fission, (α, n) reactions and muoninduced interactions (spallations, photo-nuclear and hadronic interaction). The external gammas and neutrons from the muons and laboratory environment, can be reduced by operating the detector at deep underground laboratories and by placing active or passive shield materials around the detector. The radioactivity of the detector materials also contributes to the background; in order to reduce it a careful screening campaign is mandatory to select highly radio-pure materials. In this review I present the status of current Monte Carlo simulations aimed to estimate and reproduce the background induced by gamma and neutron radioactivity of the materials and the shield of rare event search experiment. For the electromagnetic background a good level of agreement between the data and the MC simulation has been reached by the XENON100 and EDELWEISS experiments, using the GEANT4 toolkit. For the neutron background, a comparison between the yield of neutrons from spontaneous fission and (α, n) obtained with two dedicated softwares, SOURCES-4A and the one developed by Mei-Zhang-Hime, show a good overall agreement, with total yields within a factor 2 difference. The energy spectra from SOURCES-4A are in general smoother, while those from MZH presents sharp peaks. The neutron propagation through various materials has been studied with two MC codes, GEANT4 and MCNPX, showing a reasonably good agreement, inside 50% discrepancy.

• OSTI ID: 22224175
• Journal Information: AIP Conference Proceedings, Vol. 1549, Issue 1; Conference: LRT 2013: 4. international workshop on low radioactivity techniques, Assergi (Italy), 10-12 Apr 2013; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BACKGROUND RADIATION
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DOUBLE BETA DECAY
ELECTRONS
G CODES
GAMMA DETECTION
M CODES
MONTE CARLO METHOD
MULTIPARTICLE SPECTROMETERS
NEUTRINOS
NEUTRON DETECTION
NEUTRON TRANSPORT THEORY
NONLUMINOUS MATTER
PARTICLE IDENTIFICATION
RADIOACTIVITY
RECOILS
REVIEWS
SHIELDING
SPONTANEOUS FISSION