We evaluated rates of transversing muons, muon-induced fast neutrons, and production of 40Cl and other cosmogenically produced nuclei that pose as potential sources of background to the physics program proposed for an argon-based long baseline neutrino experiment at the Sanford Underground Research Facility (SURF). The Geant4 simulations were carried out with muons and muon-induced neutrons for both 800 ft (0.712 km.w.e.) and 4850 ft levels (4.3 km.w.e.). We developed analytic models to independently calculate the 40Cl production using the measured muon fluxes at different levels of the Homestake mine. The muon induced 40Cl production rates through stopped muon capture and the muon-induced neutrons and protons via (n,p) and (p,n) reactions were evaluated. We find that the Monte Carlo simulated production rates of 40Cl agree well with the predictions from analytic models. A depth-dependent parametrization was developed and benchmarked to the direct analytic models. We conclude that the muon-induced processes will result in large backgrounds to the physics proposed for an argon-based long baseline neutrino experiment at a depth of less than 4.0 km.w.e.
@article{arxiv.1202.5000,
title = {Muon-Induced Background Study for an Argon-Based Long Baseline Neutrino Experiment},
author = {D. Barker and D. -M. Mei and C. Zhang},
journal= {arXiv preprint arXiv:1202.5000},
year = {2013}
}