Low Energy 8B Solar Neutrinos in SNO+: Controlling and Constraining Radon Backgrounds

Abstract

SNOLAB located in Sudbury, Canada, is hosting a new liquid scintillator experiment for studying neutrinos which is called SNO+. Many interesting physics topics such as measuring low energy solar neutrinos and searching for neutrinoless double beta decay are expected to be performed using the SNO+ detector. SNO+ is designed to measure the solar neutrino flux at a lower energy range than SNO, and therefore it is able to study LMA-MSW oscillations at this range of energy. This research is concerned with extracting low energy 8B solar neutrinos while studying the tagging and reduction of 214Bi by 99.8%, one of the main backgrounds in the energy range of interest. Ways to measure and control radon were also studied since it is the source of the 214Bi background. Scintillation material, zinc sulfide, was selected for use in fabrication of radon detectors known as Lucas cells. The fabrication of cover gas bags employed in the SNO+ experiment to react to mine air pressure fluctuations is described and the interior radon emanation of these bags was measured and calculated.