Author
L. DeViveiros
Bio: L. DeViveiros is an academic researcher from University of Coimbra. The author has contributed to research in topics: ZEPLIN-III & Scintillation. The author has an hindex of 10, co-authored 14 publications receiving 535 citations.
Topics: ZEPLIN-III, Scintillation, Scintillator, Neutron, Detector
Papers
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TL;DR: In this article, the authors report experimental upper limits on WIMP-nucleon elastic scattering cross sections from the second science run of ZEPLIN-III at the Boulby Underground Laboratory.
178 citations
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07 Dec 2011TL;DR: An iterative method was developed for in-situ reconstruction of the PMT light response functions from calibration data taken with an uncollimated γ -ray source, and the possibility of using this technique for improving performance and reducing cost of scintillation cameras for medical applications is currently under study.
Abstract: We studied the application of statistical reconstruction algorithms, namely maximum likelihood and least squares methods, to the problem of event reconstruction in a dual phase liquid xenon detector An iterative method was developed for in-situ reconstruction of the PMT light response functions from calibration data taken with an uncollimated γ -ray source Using the techniques described, the performance of the ZEPLIN-III dark matter detector was studied for 122 keV γ-rays For the inner part of the detector (R <; 100 mm) , spatial resolutions of 13 mm and 16 mm FWHM were measured in the horizontal plane for primary and secondary scintillation, respectively An energy resolution of 81% FWHM was achieved at that energy The possibility of using this technique for improving performance and reducing cost of scintillation cameras for medical applications is currently under study
74 citations
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TL;DR: In this article, the authors present an experimental study of single electron emission in ZEPLIN-III, a two-phase xenon experiment built to search for dark matter WIMPs, and discuss appli-cations enabled by the excellent signal-to-noise ratio achieved in detecting this signature.
Abstract: We present an experimental study of single electron emission in ZEPLIN-III, a two-phase xenon experiment built to search for dark matter WIMPs, and discuss appli-cations enabled by the excellent signal-to-noise ratio achieved in detecting this signature. Firstly, we demonstrate a practical method for precise measurement of the free electron lifetime in liquid xenon during normal operation of these detectors. Then, using a realistic detector response model and backgrounds, we assess the feasibility of deploying such an instrument for measuring coherent neutrino-nucleus elastic scattering using the ionisation channel in the few-electron regime. We conclude that it should be possible to measure this elusive neutrino signature above an ionisation threshold of ~3 electrons both at a stopped pion source and at a nuclear reactor. Detectable signal rates are larger in the reactor case, but the triggered measurement and harder recoil energy spectrum afforded by the accelerator source enable lower overall background and fiducialisation of the active volume.
66 citations
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TL;DR: In this article, a measurement of the neutron production rate in lead by high energy cosmic-ray muons at a depth of 2850 m water equivalent and a mean muon energy of 260 GeV was presented.
43 citations
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TL;DR: In this article, an experimental study of single electron emission in ZEPLIN-III, a two-phase xenon experiment built to search for dark matter WIMPs, and discuss applications enabled by the excellent signal-to-noise ratio achieved in detecting this signature.
Abstract: We present an experimental study of single electron emission in ZEPLIN-III, a two-phase xenon experiment built to search for dark matter WIMPs, and discuss applications enabled by the excellent signal-to-noise ratio achieved in detecting this signature. Firstly, we demonstrate a practical method for precise measurement of the free electron lifetime in liquid xenon during normal operation of these detectors. Then, using a realistic detector response model and backgrounds, we assess the feasibility of deploying such an instrument for measuring coherent neutrino-nucleus elastic scattering using the ionisation channel in the few-electron regime. We conclude that it should be possible to measure this elusive neutrino signature above an ionisation threshold of $\sim$3 electrons both at a stopped pion source and at a nuclear reactor. Detectable signal rates are larger in the reactor case, but the triggered measurement and harder recoil energy spectrum afforded by the accelerator source enable lower overall background and fiducialisation of the active volume.
43 citations
Cited by
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01 Jan 1998
561 citations
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University of Amsterdam1, University of Bologna2, University of Mainz3, University of Coimbra4, University of Bern5, Columbia University6, Weizmann Institute of Science7, New York University Abu Dhabi8, University of Zurich9, Rensselaer Polytechnic Institute10, Max Planck Society11, Stockholm University12, University of Nantes13, Karlsruhe Institute of Technology14, University of Münster15, University of Chicago16, Arizona State University17, Purdue University18, Rice University19, University of California, San Diego20, University of Freiburg21, Dresden University of Technology22, Imperial College London23, University of California, Los Angeles24
TL;DR: DARk matter WImp search with liquid xenoN (DARWIN) as mentioned in this paper is an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core.
Abstract: DARk matter WImp search with liquid xenoN (DARWIN(2)) will be an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core. Its primary g ...
553 citations
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TL;DR: The DarkSide-20k detector as discussed by the authors is a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active mass of 23 t (20 t).
Abstract: Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23 t (20 t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant 39Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of $>3 \times 10^{9}$
is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than $< 0.1$
events (other than $
u$
-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of $1.2 \times 10^{-47}$
cm2 (
$1.1 \times 10^{-46}$
cm2) for WIMPs of 1 TeV/c2 (10 TeV/c2) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background.
534 citations
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Case Western Reserve University1, Imperial College London2, South Dakota School of Mines and Technology3, University of Maryland, College Park4, University of Edinburgh5, Yale University6, Lawrence Livermore National Laboratory7, University of California, Santa Barbara8, Brown University9, University of South Dakota10, University of California, Davis11, University of Coimbra12, Lawrence Berkeley National Laboratory13, University College London14, University of Rochester15, University of California, Berkeley16, SLAC National Accelerator Laboratory17, Texas A&M University18, State University of New York System19
TL;DR: This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV.
Abstract: We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4} kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c^{-2} WIMP mass.
460 citations
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TL;DR: This work discusses important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
Abstract: The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
459 citations