Cosmogenic production of ${}^{39}$Ar and ${}^{37}$Ar in argon

Abstract

We have experimentally determined the production rate of ${}^{39}$Ar and ${}^{37}$Ar from cosmic ray neutron interactions in argon at sea level. Understanding these production rates is important for argon-based dark matter experiments that plan to utilize argon extracted from deep underground because it is imperative to know what the ingrowth of ${}^{39}$Ar will be during the production, transport, and storage of the underground argon. These measurements also allow for the prediction of ${}^{39}$Ar and ${}^{37}$Ar concentrations in the atmosphere which can be used to determine the presence of other sources of these isotopes. Through controlled irradiation with a neutron beam that mimics the cosmic ray neutron spectrum, followed by direct counting of ${}^{39}$Ar and ${}^{37}$Ar decays with sensitive ultra-low background proportional counters, we determined that the production rate from cosmic ray neutrons at sea-level is expected to be $(759\pm 128)$ atoms/kg${}_{\text{Ar}}$/day for ${}^{39}$Ar, and $(51.0\pm 7.4)$ atoms/kg${}_{\text{Ar}}$/day for ${}^{37}$Ar. We also performed a survey of the alternate production mechanisms based on the state-of-knowledge of the associated cross-sections to obtain a total sea-level cosmic ray production rate of $(1048\pm 133)$ atoms/kg${}_{\text{Ar}}$/day for ${}^{39}$Ar, $(56.7\pm 7.5)$ atoms/kg${}_{\text{Ar}}$/day for ${}^{37}$Ar in underground argon, and $(92\pm 13)$ atoms/kg${}_{\text{Ar}}$/day for ${}^{37}$Ar in atmospheric argon.

arXiv comment13 pages, 9 figures, 6 tables; Minor updates to systematic uncertainty evaluation, formatting

References in corpus (21)

• DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS
• New potentialities of the Liège intranuclear cascade (INCL) model for reactions induced by nucleons and light charged particles
• Low-Mass Dark Matter Search with the DarkSide-50 Experiment
• First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso
• DarkSide-50 532-day Dark Matter Search with Low-Radioactivity Argon
• Background free search for neutrinoless double beta decay with GERDA Phase II
• First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory
• Results from the first use of low radioactivity argon in a dark matter search
• Extension of the Liège Intranuclear-Cascade model to reactions induced by light nuclei
• Underground operation of the ICARUS T600 LAr-TPC: first results
• Measurement of the specific activity of Ar-39 in natural argon
• First results from the DEAP-3600 dark matter search with argon at SNOLAB
• The background in the neutrinoless double beta decay experiment GERDA
• ACTIVIA: Calculation of Isotope Production Cross-sections and Yields
• Measurement of 37Ar to support technology for On-site Inspection under the Comprehensive Nuclear-Test-Ban Treaty
• First Large Scale Production of Low Radioactivity Argon From Underground Sources
• Stellar ${}^{36,38}$Ar$(n,\gamma {)}^{37,39}$Ar reactions and their effect on light neutron-rich nuclide synthesis
• Partial gamma-ray production cross sections for (n,xng) reactions in natural argon from 1 - 30 MeV
• Development of a low-level Ar-37 calibration standard
• On concentration of ${}^{42}$Ar in the Earth's atmosphere
• Some considerations about cosmogenic production of radioactive isotopes in Ar as target for the next neutrino experiments

Cited by in corpus (16)

• Excess Electronic Recoil Events in XENON1T
• Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel
• Large Low Background kTon-Scale Liquid Argon Time Projection Chambers
• Cosmogenic activation in double beta decay experiments
• Cosmogenic production of ${}^{37}$Ar in the context of the LUX-ZEPLIN experiment
• Evaluation of cosmogenic production of ${}^{39}Ar$ and ${}^{42}Ar$ for rare-event physics using underground argon
• Application of the Most Frequent Value Method for ${}^{39}$Ar Half-Life Determination
• Study of cosmogenic activation above ground for the DarkSide-20k experiment
• Cosmogenic activation of sodium iodide
• Liquid argon scintillation response to electronic recoils between $2.8$--$1275\mathrm{keV}$ in a high light yield single-phase detector
• Direct Measurement of the ${}^{39}$Ar Half-life from 3.4 Years of Data with the DEAP-3600 Detector
• Radioactive background for ProtoDUNE detector
• DArT, a detector for measuring the 39Ar depletion factor
• Preparation and measurement of an ${}^{37}$Ar source for liquid xenon detector calibration
• First experimental determination of the ${}^{40}$Ar($n,2n$)${}^{39}$Ar reaction cross section and ${}^{39}$Ar production in Earth's atmosphere
• Study of cosmogenic activation above ground of Ar for DarkSide-20k