skip to main content

Title: The BetaCage, an ultra-sensitive screener for surface contamination

Material screening for identifying low-energy electron emitters and alpha-decaying isotopes is now a prerequisite for rare-event searches (e.g., dark-matter direct detection and neutrinoless double-beta decay) for which surface radiocon-tamination has become an increasingly important background. The BetaCage, a gaseous neon time-projection chamber, is a proposed ultra-sensitive (and nondestructive) screener for alpha-and beta-emitting surface contaminants to which existing screening facilities are insufficiently sensitive. Sensitivity goals are 0.1 betas keV{sup −1} m{sup −2} day{sup −1} and 0.1 alphas m{sup −2} day{sup −1}, with the former limited by Compton scattering of photons in the screening samples and (thanks to tracking) the latter expected to be signal-limited; radioassays and simulations indicate backgrounds from detector materials and radon daughters should be subdominant. We report on details of the background simulations and detector design that provide the discrimination, shielding, and radiopurity necessary to reach our sensitivity goals for a chamber with a 95 × 95 cm{sup 2} sample area positioned below a 40 cm drift region and monitored by crisscrossed anode and cathode planes consisting of 151 wires each.
Authors:
; ; ;  [1] ; ; ; ; ;  [2] ;  [3] ;  [4]
  1. Department of Physics, Syracuse University, Syracuse, NY 13244 (United States)
  2. California Institute of Technology, Pasadena, CA 91125 (United States)
  3. University of Alberta, Edmonton, AB, T6G 2R3 (Canada)
  4. Department of Physics, Syracuse University, Syracuse, NY 13244, USA and Pacific Northwest National Laboratory, Richland, WA 99352 (United States)
Publication Date:
OSTI Identifier:
22218166
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1549; Journal Issue: 1; Conference: LRT 2013: 4. international workshop on low radioactivity techniques, Assergi (Italy), 10-12 Apr 2013; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ALPHA DECAY; ANODES; CATHODES; COMPTON EFFECT; ELECTRONS; KEV RANGE; NEON; RADIOASSAY; RADON; SENSITIVITY; SHIELDING; SIGNALS; SIMULATION; SURFACE CONTAMINATION; TIME PROJECTION CHAMBERS