Department of Physics and Astronomy

Permanent link for this collectionhttps://hdl.handle.net/2022/22354

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Browsing Department of Physics and Astronomy by Author "Archambault, Simon"

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    Constraints on low-mass WIMP interactions on 19F from PICASSO
    (Elsevier, 2012) Archambault, Simon; Behnke, Ed; Grace, Emily A.; Levine, Ilan
    Recent results from the PICASSO dark matter search experiment at SNOLAB are reported. These results were obtained using a subset of 10 detectors with a total target mass of 0.72 kg of 19F and an exposure of 114 kgd. The low backgrounds in PICASSO allow recoil energy thresholds as low as 1.7 keV to be obtained which results in an increased sensitivity to interactions from Weakly Interacting Massive Particles (WIMPs) with masses below 10 GeV/c2. No dark matter signal was found. Best exclusion limits in the spin dependent sector were obtained for WIMP masses of 20 GeV/c2 with a cross section on protons of σ SD p = 0.032 pb (90% C.L.). In the spin independent sector close to the low mass region of 7 GeV/c2 favoured by CoGeNT and DAMA/LIBRA, cross sections larger than σ S I p = 1.41 × 10−4 pb (90% C.L.) are excluded. Keywords: Dark matter, WIMPs, Superheated droplets, SNOLAB
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    New Insights into Particle Detection with Superheated Liquids
    (IOP Publishing, 2010-11) Archambault, Simon; Behnke, Ed; Behnke, Joshua; Hinnefeld, Jerry; Levine, Ilan; Vander Werf, Nathan P.
    We report new results obtained in calibrations of superheated liquid droplet detectors used in dark matter searches with different radiation sources (n,α,γ). In particular, detectors were spiked with alpha-emitters located inside and outside the droplets. It is shown that the responses are different, depending on whether alpha particles or recoil nuclei create the signals. The energy thresholds for α-emitters are compared with test beam measurements using mono-energetic neutrons, as well as with theoretical predictions. Finally a model is presented which describes how the observed intensities of particle induced acoustic signals can be related to the dynamics of bubble growth in superheated liquids. An improved understanding of the bubble dynamics is an important first step in obtaining better discrimination between particle types interacting in detectors of this kind.