2020/06/30 by D. S. Akerib, C. W. Akerlof, D. Yu. Akimov +388 · 58 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Detector #Dynode #Particle physics theoretical and experimental studies #Photomultiplier #Quality assurance #Quantum Chromodynamics and Particle Interactions #Radon #Scintillator #Sensitivity (control systems) #WIMP #hep-ex #physics.ins-det
paper · pdf · open access · doi:10.1140/epjc/s10052-020-8420-x
published in The European Physical Journal C 80(11) (Springer Science+Business Media) · 45 pages (79 inc. tables), 7 figures, 9 tables
openalex created_date 2020/06/12 · openalex publication_date 2020/11/01 · arxiv created 2022/02/28 · arxiv updated 2022/03/02 · openalex updated_date 2026/08/06
LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above 1.4 × 10-48 cm2 for a WIMP mass of 40 GeV/c2 and a 1000 d exposure. LZ achieves this sensitivity through a combination of a large 5.6 t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.