Measurement of the gamma ray background in the Davis cavern at the Sanford Underground Research Facility

(The LUX-ZEPLIN (LZ) Collaboration)

Research output: Contribution to journalArticle

2 Scopus citations

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.

Original languageEnglish (US)
Article number102391
JournalAstroparticle Physics
Volume116
DOIs
StatePublished - Mar 2020

Keywords

  • Dark matter
  • Gamma rays
  • Gamma spectroscopy
  • Low background
  • Radiation
  • Underground

ASJC Scopus subject areas

  • Astronomy and Astrophysics

Fingerprint Dive into the research topics of 'Measurement of the gamma ray background in the Davis cavern at the Sanford Underground Research Facility'. Together they form a unique fingerprint.

  • Cite this