102 research outputs found
CDMSlite: A Search for Low-Mass WIMPs using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment
SuperCDMS is an experiment designed to directly detect Weakly Interacting
Massive Particles (WIMPs), a favored candidate for dark matter ubiquitous in
the Universe. In this paper, we present WIMP-search results using a
calorimetric technique we call CDMSlite, which relies on voltage- assisted
Luke-Neganov amplification of the ionization energy deposited by particle
interactions. The data were collected with a single 0.6 kg germanium detector
running for 10 live days at the Soudan Underground Laboratory. A low energy
threshold of 170 eVee (electron equivalent) was obtained, which allows us to
constrain new WIMP-nucleon spin-independent parameter space for WIMP masses
below 6 GeV/c2.Comment: 7 pages, 4 figure
Results from the Super Cryogenic Dark Matter Search (SuperCDMS) experiment at Soudan
We report the result of a blinded search for Weakly Interacting Massive
Particles (WIMPs) using the majority of the SuperCDMS Soudan dataset. With an
exposure of 1690 kg days, a single candidate event is observed, consistent with
expected backgrounds. This analysis (combined with previous Ge results) sets an
upper limit on the spin-independent WIMP--nucleon cross section of () cm at 46 GeV/. These results set the
strongest limits for WIMP--germanium-nucleus interactions for masses 12
GeV/
Improved WIMP-search reach of the CDMS II germanium data
CDMS II data from the five-tower runs at the Soudan Underground Laboratory were reprocessed with an improved charge-pulse fitting algorithm. Two new analysis techniques to reject surface-event backgrounds were applied to the 612 kg days germanium-detector weakly interacting massive particle (WIMP)-search exposure. An extended analysis was also completed by decreasing the 10 keV analysis threshold to ~5  keV, to increase sensitivity near a WIMP mass of 8  GeV/c[superscript 2]. After unblinding, there were zero candidate events above a deposited energy of 10 keV and six events in the lower-threshold analysis. This yielded minimum WIMP-nucleon spin-independent scattering cross-section limits of 1.8 × 10[superscript −44] and 1.18 × 10[superscript −41] at 90% confidence for 60 and 8.6  GeV/c[superscript 2] WIMPs, respectively. This improves the previous CDMS II result by a factor of 2.4 (2.7) for 60 (8.6)  GeV/c[superscript 2] WIMPs.National Science Foundation (U.S.)United States. Dept. of EnergyNatural Sciences and Engineering Research Council of CanadaSpain. Ministerio de Economia y Competitividad (MultiDark
Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches
The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two 210 Pb sources producing ∼130 beta decays/hr. In ∼800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10−5 at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment
- …