5,366 research outputs found
Frequency Domain Functional Near-Infrared Spectrometer (fNIRS) for Crew State Monitoring
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
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
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 Mo with a ZnMoO crystals array
The large statistics collected during the operation of a ZnMoO array, for
a total exposure of 1.3 kg day of Mo, allowed the first
bolometric observation of the two neutrino double beta decay of 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 300 keV. The half-life extracted from the data is
T= [7.15 0.37 (stat) 0.66 (syst)] 10
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
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
A search for axioelectric absorption of 5.5 MeV solar axions produced in the
reaction has been
performed with a BGO detectors. A model-independent limit on the product of
axion-nucleon and axion-electron coupling constants has
been obtained: 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
Liver fibrosis: concordance analysis between APRI and FIB-4 scores, evolution and predictors in a cohort of HIV patients without HCV and HBV infection
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