@article{d6ea1c2d26dd45558bbd2a20041b6d00,
title = "Measurement of the gamma ray background in the Davis cavern at the Sanford Underground Research Facility",
abstract = "Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from γ-rays emitted by 40K and the 238U and 232Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4850-foot level. In order to characterise the cavern background, in-situ γ-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0–3300 keV) varied from 596 Hz to 1355 Hz for unshielded measurements, corresponding to a total flux from the cavern walls of 1.9 ± 0.4 γ cm−2s−1. The resulting activity in the walls of the cavern can be characterised as 220 ± 60 Bq/kg of 40K, 29 ± 15 Bq/kg of 238U, and 13 ± 3 Bq/kg of 232Th.",
author = "{(The LUX-ZEPLIN (LZ) Collaboration)} and Akerib, {D. S.} and Akerlof, {C. W.} and Alsum, {S. K.} and N. Angelides and Ara{\'u}jo, {H. M.} and Armstrong, {J. E.} and M. Arthurs and X. Bai and J. Balajthy and S. Balashov and A. Baxter and Bernard, {E. P.} and A. Biekert and Biesiadzinski, {T. P.} and Boast, {K. E.} and B. Boxer and P. Br{\'a}s and Buckley, {J. H.} and Bugaev, {V. V.} and S. Burdin and Busenitz, {J. K.} and C. Carels and Carlsmith, {D. L.} and Carmona-Benitez, {M. C.} and M. Cascella and C. Chan and A. Cole and A. Cottle and Cutter, {J. E.} and Dahl, {C. E.} and {de Viveiros}, L. and Dobson, {J. E.Y.} and E. Druszkiewicz and Edberg, {T. K.} and A. Fan and S. Fiorucci and H. Flaecher and T. Fruth and Gaitskell, {R. J.} and J. Genovesi and C. Ghag and Gilchriese, {M. G.D.} and S. Gokhale and {van der Grinten}, {M. G.D.} and Hall, {C. R.} and S. Hans and J. Harrison and Haselschwardt, {S. J.} and Hertel, {S. A.} and Hor, {J. Y.K.}",
note = "Funding Information: We would like to thank Keenan Thomas, now at Lawrence Livermore National Laboratory (LLNL), for his work on the HPGe measurements in the Davis Cavern. Additionally, we wish to thank the staff at SURF who helped with this measurement; in particular, those who were involved in tracking down a [Formula presented] inch floppy disk so that this data could actually leave the Davis Cavern! We are also grateful to the manufacturers of floppy disk-to-USB adaptors, making it possible (albeit through a further adaptor) to remove this data from the disk and analyse it. This work was partially supported by the U.S. Department of Energy (DOE) Office of Science under contract number DE-AC02-05CH11231 and under grant number DE-SC0019066; by the U.S. National Science Foundation (NSF); by the U.K. Science & Technology Facilities Council under award numbers, ST/M003655/1, ST/M003981/1, ST/M003744/1, ST/M003639/1, ST/M003604/1, and ST/M003469/1; and by the Portuguese Foundation for Science and Technology (FCT) under award numbers CERN/FP/123610/2011 and PTDC/FISNUC/1525/2014; and by the Institute for Basic Science, Korea (budget numbers IBS-R016-D1, and IBS-R016-S1). University College London and Lawrence Berkeley National Laboratory thank the U.K. Royal Society for travel funds under the International Exchange Scheme (IE141517). We acknowledge additional support from the Boulby Underground Laboratory in the U.K.; the University of Wisconsin for grant UW PRJ82AJ; and the GridPP Collaboration, in particular at Imperial College London. This work was partially enabled by the University College London Cosmoparticle Initiative. Furthermore, this research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We acknowledge many types of support provided to us by the South Dakota Science and Technology Authority (SDSTA), which developed the Sanford Underground Research Facility (SURF) with an important philanthropic donation from T. Denny Sanford as well as support from the State of South Dakota. SURF is operated by the SDSTA under contract to the Fermi National Accelerator Laboratory for the DOE, Office of Science. The University of Edinburgh is a charitable body, registered in Scotland, with the registration number SC005336. Funding Information: We would like to thank Keenan Thomas, now at Lawrence Livermore National Laboratory (LLNL), for his work on the HPGe measurements in the Davis Cavern. Additionally, we wish to thank the staff at SURF who helped with this measurement; in particular, those who were involved in tracking down a 3 1 2 inch floppy disk so that this data could actually leave the Davis Cavern! We are also grateful to the manufacturers of floppy disk-to-USB adaptors, making it possible (albeit through a further adaptor) to remove this data from the disk and analyse it. This work was partially supported by the U.S. Department of Energy (DOE) Office of Science under contract number DE-AC02-05CH11231 and under grant number DE-SC0019066 ; by the U.S. National Science Foundation (NSF); by the U.K. Science & Technology Facilities Council under award numbers, ST/M003655/1, ST/M003981/1, ST/M003744/1, ST/M003639/1, ST/M003604/1, and ST/M003469/1; and by the Portuguese Foundation for Science and Technology (FCT) under award numbers CERN/FP/123610/2011 and PTDC/FISNUC/1525/2014 ; and by the Institute for Basic Science, Korea (budget numbers IBS-R016-D1, and IBS-R016-S1). University College London and Lawrence Berkeley National Laboratory thank the U.K. Royal Society for travel funds under the International Exchange Scheme (IE141517). We acknowledge additional support from the Boulby Underground Laboratory in the U.K.; the University of Wisconsin for grant UW PRJ82AJ; and the GridPP Collaboration, in particular at Imperial College London. This work was partially enabled by the University College London Cosmoparticle Initiative. Furthermore, this research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 . We acknowledge many types of support provided to us by the South Dakota Science and Technology Authority (SDSTA), which developed the Sanford Underground Research Facility (SURF) with an important philanthropic donation from T. Denny Sanford as well as support from the State of South Dakota. SURF is operated by the SDSTA under contract to the Fermi National Accelerator Laboratory for the DOE, Office of Science. The University of Edinburgh is a charitable body, registered in Scotland, with the registration number SC005336. Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",
year = "2020",
month = mar,
doi = "10.1016/j.astropartphys.2019.102391",
language = "English (US)",
volume = "116",
journal = "Astroparticle Physics",
issn = "0927-6505",
publisher = "Elsevier",
}