Optimization of Processing Parameters and Development of a Radon Trapping System for the NEWS-G Dark Matter Detector

• Author / Creator

  O'Brien, Patrick

• The direct detection for a dark matter particle is reaching increasingly lower sensitivities and the New Experiments With Spheres-Gas (NEWS-G) collaboration is one of the experiments at the forefront of this. Currently being installed at SNOLAB two kilometres underground, the Spherical Proportional Counter (SPC) used by NEWS-G is designed to detect Weakly Interacting Massive Particles (WIMPs) with a mass less than 1 GeV/c², with a corresponding cross-section of $10¯⁴¹$ cm².
  A calibration run using pure methane was commissioned at the Laboratoire Souterrain de Modane (LSM) using argon-37, a radioactive gas with two well-characterized decay energies (270 eV and 2.8 keV). The signals from these decay events within the volume of the detector can then be analyzed to accurately map the energy of an event to the detector response. In the presented work, I optimized several processing parameters to ensure the characteristic values from the signals are accurate.
  In addition, I designed and constructed a radon trapping system in the Piro Lab at the University of Alberta to find the optimal conditions and material to trap radon from detector gases for the NEWS-G experiment at SNOLAB. A closed-loop circulation system was constructed to test two radon trapping materials: Carboxen® 1000 (Sigma Aldrich) and silver zeolite produced by Extraordinary Adsorbents, a company based in Edmonton, Canada. The radon adsorption in nitrogen, argon, and an argon-methane mixture at ambient and dry ice temperatures was then measured, and the performance of each material with different combinations of the above parameters was determined and compared.

• Subjects / Keywords

  • Physics
  • Dark Matter
  • Astroparticle Physics
  • Radon
  • Radon Trapping
  • Particle Detector
  • Particle Physics
  • NEWS-G

• Graduation date

  Fall 2021

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-qr9t-9n98

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.