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dc.contributor.authorAmole, Chanpreeten
dc.date.accessioned2017-08-22T23:37:21Z
dc.date.available2017-08-22T23:37:21Z
dc.identifier.urihttp://hdl.handle.net/1974/22036
dc.description.abstractThe PICO-2L program commenced in 2013 with the deployment of a 2 litre bubble chamber filled with superheated C3F8 and over the next three years, conducted two separate WIMP-search experiments. The first run was conducted at 4 different energy thresholds ranging from 3.2 keV to 8.1 keV and a total of 12 candidate events were observed during a total exposure of 211.5 kg-days. Due to the non-uniform time distribution of the candidate events, no evidence for a WIMP-signal was claimed and upper limits on WIMP-nucleon scattering cross-sections were reported. These results represented the world leading limits at the time on spin-dependant WIMP- proton cross-sections with a 90% confidence upper limit of σ < 9.7 × 10^−40 cm^2 for a 30 GeV/c^2 WIMP. PICO-2L was redeployed in 2015 with modifications that aimed to control particulate contamination in the superheated fluid, and a follow- up WIMP-search experiment was conducted. During 129 kg-day exposure with the detector operating at an energy threshold of 3.3 keV, only 1 candidate event was observed, consistent with the predicted background rate from neutrons. These data showed that the measures taken to control the particulate contamination resulted in the eradication of the previously observed anomalous background events and provided the most stringent limits on WIMP-proton spin-dependent cross-sections with a 90% confidence upper limit of σ < 5.9 × 10^−40 cm2 for a 30 GeV/c^2 WIMP.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsCC0 1.0 Universalen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.rights.urihttp://creativecommons.org/publicdomain/zero/1.0/
dc.subjectPICOen
dc.subjectPICO-2Len
dc.subjectDark Matteren
dc.subjectDirect Detectionen
dc.subjectBubble Chamberen
dc.subjectWIMPen
dc.subjectSNOLABen
dc.subjectC. Amoleen
dc.subjectAmoleen
dc.titleThe PICO-2L program: Towards Background-Free Dark Matter Direct Detection Using Bubble Chambersen
dc.typethesisen
dc.description.degreePhDen
dc.contributor.supervisorNoble, Anthonyen
dc.contributor.departmentPhysics, Engineering Physics and Astronomyen
dc.degree.grantorQueen's University at Kingstonen


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CC0 1.0 Universal
Except where otherwise noted, this item's license is described as CC0 1.0 Universal