Simulations of muon-induced neutron flux at large depths underground

Abstract

The production of neutrons by cosmic-ray muons at large depths underground is discussed. The most recent versions of the muon propagation code MUSIC, and particle transport code FLUKA are used to evaluate muon and neutron fluxes. The results of simulations are compared with experimental data.

Neutron background in large-scale xenon detectors for dark matter searches

“…The uncertainties associated with the calculations of such probabilities were not negligible, however. The differences as large as (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)% exist between different calculations of the transition probabilities in the SOURCES library. If the excited levels were not in the code library, as was the case for elements for which the cross-sections were absent too, then in adding the cross-section we assumed that the transition was occuring to the ground state only.…”

“…Kudryavtsev et al [27] studied neutron production by muons in various materials with FLUKA using a calculated spectrum and an angular distribution of muons at the Boulby Underground Laboratory. This study is extended in the present work by including shielding materials and the production of nuclear recoils in the xenon detector.…”

“…[27] for description). Normalisation of the muon (and neutron) spectrum was done using the measured value for the muon flux at the Boulby Underground Laboratory: (4.09 ± 0.15) × 10 −8 cm −2 s −1 , which corresponds to a rock overburden at vertical of 2805 ± 45 m w. e. [17,28].…”

“…Tests of muon-induced neutron simulations with FLUKA can be found in [25,27]. The neutron production rate in NaCl at Boulby was found to be 7.6×10 −4 neutrons per muon per 1 g/cm 2 of muon path.…”

Measuring muon-induced neutrons with liquid scintillation detector at Soudan mine

“…Because they behave in a manner similar to WIMPs, fast neutrons are taken as a vital background for these rare event physics experiments at deep underground. Although the cosmogenic effects are dramatically suppressed by rock overburden [16], the energy spectrum, angular and multiplicity distribution of the fast neutrons induced by muons underground are not well understood [16][17][18][19][20][21][22][23]. Muoninduced neutron production rates in different targets have been recently measured by many experiments [24- * Corresponding Author: Dongming.Mei@usd.edu 26] through measuring neutron captures.…”