5,366 research outputs found

    Frequency Domain Functional Near-Infrared Spectrometer (fNIRS) for Crew State Monitoring

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    A frequency domain functional near-infrared spectrometer (fNIRS) and accompanying software have been developed by the NASA Glenn Research Center as part of the Airspace Operations and Safety Program (AOSP) Technologies for Airplane State Awareness (TASA)SE211 Crew State Monitoring (CSM) Project. The goal of CSM was to develop a suite of instruments to measure the cognitive state of operators while performing operational activities. The fNIRS was one of the instruments intended for the CSM, developed to measure changes in oxygen levels in the brain noninvasively

    Characterization of the Hamamatsu R11265-103-M64 multi-anode photomultiplier tube

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    The aim of this paper is to fully characterize the new multi-anode photomultiplier tube R11265-103-M64, produced by Hamamatsu. Its high effective active area (77%), its pixel size, the low dark signal rate and the capability to detect single photon signals make this tube suitable for an application in high energy physics, such as for RICH detectors. Four tubes and two different bias voltage dividers have been tested. The results of a standard characterization of the gain and the anode uniformity, the dark signal rate, the cross-talk and the device behaviour as a function of temperature have been studied. The behaviour of the tube is studied in a longitudinal magnetic field up to 100 Gauss. Shields made of a high permeability material are also investigated. The deterioration of the device performance due to long time operation at intense light exposure is studied. A quantitative analysis of the variation of the gain and the dark signals rate due to the aging is described.Comment: 22 page

    Large area Si low-temperature light detectors with Neganov-Luke effect

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    Next generation calorimetric experiments for the search of rare events rely on the detection of tiny amounts of light (of the order of 20 optical photons) to discriminate and reduce background sources and improve sensitivity. Calorimetric detectors are the simplest solution for photon detection at cryogenic (mK) temperatures. The development of silicon based light detectors with enhanced performance thanks to the use of the Neganov-Luke effect is described. The aim of this research line is the production of high performance detectors with industrial-grade reproducibility and reliability.Comment: 4 pages, 2 figure

    First bolometric measurement of the two neutrino double beta decay of 100^{100}Mo with a ZnMoO4_4 crystals array

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    The large statistics collected during the operation of a ZnMoO4_4 array, for a total exposure of 1.3 kg \cdot day of 100^{100}Mo, allowed the first bolometric observation of the two neutrino double beta decay of 100^{100}Mo. The observed spectrum of each crystal was reconstructed taking into account the different background contributions due to environmental radioactivity and internal contamination. The analysis of coincidences between the crystals allowed the assignment of constraints to the intensity of the different background sources, resulting in a reconstruction of the measured spectrum down to an energy of \sim300 keV. The half-life extracted from the data is T1/22ν_{1/2}^{2\nu}= [7.15 ±\pm 0.37 (stat) ±\pm 0.66 (syst)] \cdot 1018^{18} y.Comment: 6 pages, 2 figure, Accepted for publication in Journal of Physics G: Nuclear and Particle Physic

    Response of microchannel plates to single particles and to electromagnetic showers

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    We report on the response of microchannel plates (MCPs) to single relativistic particles and to electromagnetic showers. Particle detection by means of secondary emission of electrons at the MCP surface has long been proposed and is used extensively in ion time-of-flight mass spectrometers. What has not been investigated in depth is their use to detect the ionizing component of showers. The time resolution of MCPs exceeds anything that has been previously used in calorimeters and, if exploited effectively, could aid in the event reconstruction at high luminosity colliders. Several prototypes of photodetectors with the amplification stage based on MCPs were exposed to cosmic rays and to 491 MeV electrons at the INFN-LNF Beam-Test Facility. The time resolution and the efficiency of the MCPs are measured as a function of the particle multiplicity, and the results used to model the response to high-energy showers.Comment: Paper submitted to NIM

    Searches for axioelectric effect of solar axions with BGO-scintillator and BGO-bolometer detectors

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    A search for axioelectric absorption of 5.5 MeV solar axions produced in the p+d3He+γ (5.5 MeV)p + d \rightarrow {^3\rm{He}}+\gamma~(5.5~ \rm{MeV}) reaction has been performed with a BGO detectors. A model-independent limit on the product of axion-nucleon gAN3g_{AN}^3 and axion-electron gAeg_{Ae} coupling constants has been obtained: gAe×gAN3<1.9×1010| g_{Ae}\times g_{AN}^3|< 1.9\times 10^{-10} for 90\% C.L..Comment: 5 pages, 3 figures, Proceedings of the 10th Patras Workshop on Axions, WIMPs and WISP 29 June - 4 July 2014, CERN, Geneva, Switzerlan
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