128 research outputs found

    Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector

    Get PDF
    We report on several features present in the energy spectrum from an ultra low-noise germanium detector operated at 2,100 m.w.e. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss several possible causes for an irreducible excess of bulk-like events below 3 keVee, including a dark matter candidate common to the DAMA/LIBRA annual modulation effect, the hint of a signal in CDMS, and phenomenological predictions. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.Comment: 4 pages, 4 figures. v2: submitted version. Minimal changes in wording, one reference adde

    The Majorana Project

    Full text link
    Building a \BBz experiment with the ability to probe neutrino mass in the inverted hierarchy region requires the combination of a large detector mass sensitive to \BBz, on the order of 1-tonne, and unprecedented background levels, on the order of or less than 1 count per year in the \BBz signal region. The MAJORANA Collaboration proposes a design based on using high-purity enriched Ge-76 crystals deployed in ultra-low background electroformed Cu cryostats and using modern analysis techniques that should be capable of reaching the required sensitivity while also being scalable to a 1-tonne size. To demonstrate feasibility, the collaboration plans to construct a prototype system, the MAJORANA DEMONSTRATOR, consisting of 30 kg of 86% enriched \Ge-76 detectors and 30 kg of natural or isotope-76-depleted Ge detectors. We plan to deploy and evaluate two different Ge detector technologies, one based on a p-type configuration and the other on n-type.Comment: paper submitted for the 2008 Carolina International Symposium on Neutrino Physic

    The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

    Full text link
    The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76-Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76-Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76-Ge neutrinoless double-beta decay Q-value of 2039 keV.Comment: Submitted to AIP Conference Proceedings, 19th Particles & Nuclei International Conference (PANIC 2011), Massachusetts Institute of Technology, Cambridge, MA, USA, July 24-29, 2011; 3 pages, 1 figur

    Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector

    Full text link
    The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the MAJORANA Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure

    Impact of Cultural Tourism Upon Urban Economies: An Econometric Exercise

    Full text link
    In recent years, interest in tourism has spread rapidly throughout many small and medium European cities, which previously have not necessarily considered themselves as tourist destinations. Tourism is increasingly seen as a potential lever towards high economic growth, measured both in terms of income and employment. In the present Working Paper we report the analysis on the economic impact undertaken in the framework of the PICTURE Project, showing the results of a novel econometric exercise to statistically assess the impacts of cultural tourism upon European municipalities. More precisely the analysis aims at estimating the effects of tourism specialisation on local income and prices. The Working Paper is built as follows. Section 1 presents and discusses secondary data about tourism facts and figures, including the economic impact of tourism upon European economies, with a focus on cultural tourism. An extensive review of literature, which identifies the main categories of impacts and the currently available methodologies to assess them, is undertaken. Section 2 focuses on the state of the art. Section 3 describes the database built for the analysis, sources and variables. In order to visually represent the spatial variability of the main parameters, a series of thematic maps at NUTS 3 level(Maps of European tourism), using GIS (Geographical Information System) are also included in the Working Paper. Section 4 shows the results of the econometric analysis of European panel data for the estimation of the effects of tourism specialisation on both local incomes and prices. Section 5 concludes
    corecore