skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches

Abstract

The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $$^{238}$$U$$_{e}$$~$<$1.6~mBq/kg, $$^{238}$$U$$_{l}$$~$<$0.09~mBq/kg, $$^{232}$$Th$$_{e}$$~$$=0.28\pm 0.03$$~mBq/kg, $$^{232}$$Th$$_{l}$$~$$=0.25\pm 0.02$$~mBq/kg, $$^{40}$$K~$<$0.54~mBq/kg, and $$^{60}$$Co~$<$$0.02~mBq/kg (68\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $$0.160\pm0.001$(stat)$$\pm0.030$$(sys) counts.

Authors:
 [1]
  1. et al.
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
LZ
OSTI Identifier:
1354875
Alternate Identifier(s):
OSTI ID: 1395351; OSTI ID: 1419425; OSTI ID: 1436647
Report Number(s):
FERMILAB-PUB-17-069-AE-PPD; arXiv:1702.02646; PNNL-SA-129064
Journal ID: ISSN 0927-6505; 1512771
Grant/Contract Number:  
AC02-07CH11359; AC05-76RL01830; AC02-76SF00515; SC0012704; SC0010010; AC02-05CH11231; SC0012161; SC0014223; FG02- 13ER42020; FG02-91ER40674; NA0000979; SC0011702; SC0006572; SC0012034; SC0006605; FG02-10ER46709; NSF PHY-110447; NSF PHY-1506068; NSF PHY-1312561; NSF PHY-1406943; NSF PHY-1642619; ST/K006428/1; ST/M003655/1; ST/M003981/1; ST/M003744/1; ST/M003639/1; ST/M003604/1; ST/M003469/1; CERN/FP/123610/2011; PTDC/FIS-NUC/1525/2014; IE141517; UW PRJ82AJ; SC005336
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Astroparticle Physics
Additional Journal Information:
Journal Volume: 96; Journal ID: ISSN 0927-6505
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Akerib, D. S. Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches. United States: N. p., 2017. Web. doi:10.1016/j.astropartphys.2017.09.002.
Akerib, D. S. Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches. United States. doi:10.1016/j.astropartphys.2017.09.002.
Akerib, D. S. Mon . "Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches". United States. doi:10.1016/j.astropartphys.2017.09.002. https://www.osti.gov/servlets/purl/1354875.
@article{osti_1354875,
title = {Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches},
author = {Akerib, D. S.},
abstractNote = {The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $^{238}$U$_{e}$~$<$1.6~mBq/kg, $^{238}$U$_{l}$~$<$0.09~mBq/kg, $^{232}$Th$_{e}$~$=0.28\pm 0.03$~mBq/kg, $^{232}$Th$_{l}$~$=0.25\pm 0.02$~mBq/kg, $^{40}$K~$<$0.54~mBq/kg, and $^{60}$Co~$<$0.02~mBq/kg (68\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $0.160\pm0.001$(stat)$\pm0.030$(sys) counts.},
doi = {10.1016/j.astropartphys.2017.09.002},
journal = {Astroparticle Physics},
number = ,
volume = 96,
place = {United States},
year = {Mon Sep 25 00:00:00 EDT 2017},
month = {Mon Sep 25 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share: