607 research outputs found
Measurement of Atmospheric Neutrino Oscillations with a High-Density Detector
We propose an experiment to test the hypothesis that the reported anomaly on
atmospheric neutrino fluxes is due to nu_mu nu_x oscillations. It will rely
both on a disappearance technique, exploiting the method of the dependence of
the event rate on L/E, which was recently shown to be effective for detection
of neutrino oscillation and measurement of the oscillation parameters, and on
an appearance technique, looking for an excess of muon-less events at high
energy produced by upward-going tau neutrinos. The detector will consist of
iron planes interleaved by limited streamer tubes. The total mass will be about
30 kt. The possibility of recuperating most of the instrumentation from
existing detectors allows to avoid R&D phases and to reduce construction time.
In four years of data taking, this experiment will be sensitive to oscillations
nu_mu nu_x with Delta m^2 > 10^-4 eV^2 and a mixing near to maximal, and
answer the question whether nu_x is a sterile or a tau neutrino
Implementação de estratĂ©gias para minimização de resĂduos quĂmicos na Embrapa Pecuária Sudeste.
Determinação de boro em amostras de plantas: avaliação de procedimentos de extração e determinação.
GEMs with Double Layred Micropattern Electrodes and their Applications
We have developed and tested several new designs of GEM detectors with
micropattern electrodes manufactured by microelectronic technology. In one
design, the inner layer of the detector electrode consists of thin metallic
strips and the outer layer is made of a resistive grid manufactured by a screen
printing technology. In other designs, the electrodes were made of metallic
strips fed by HV via micro-resistors manufactured by a screen printing
technology. Due to these features, the new detectors have several important
advantages over conventional GEMs or ordinary thick GEMs. For example, the
resistive grid (in the first design) and the screen printed resistors (in other
designs) limited the current in case of discharges, making these detectors
intrinsically spark-protected.
We will here describe our tests with the photosensitive versions of these
detectors (coated with CsI layers) and the efforts of implementing them in
several applications. In particular, we will focus on our activity towards the
ALICE RICH detector upgrade and on tests of simplified prototypes of cryogenic
dark matter detectors.Comment: Presented at the IEEE Nucler Science Symposium, Dresden, 200
A New GEM-like Imaging Detector with Electrodes Coated with Resistive Layers
We have developed and tested several prototypes of GEM-like detectors with
electrodes coated with resistive layers: CuO or CrO. These detectors can
operate stably at gains close to 10E5 and they are very robust. We discovered
that the cathodes of these detectors could be coated by CsI layers and in such
a way the detectors gain high efficiency for the UV photons. We also
demonstrated that such detectors can operate stably in the cascade mode and
high overall gains (~10E6) are reachable. This opens applications in several
areas, for example in RICH or in noble liquid TPCs. Results from the first
applications of these devices for UV photon detection at room and cryogenic
temperatures are given.Comment: Presented at the IEEE Nuclear Science Symposium, San Diego,
California, October 200
A WIMP detector with two-phase xenon
Abstract We describe an important new technique to search for WIMPs. This technique employs a method of background discrimination using double phase xenon as detector target. We describe the construction of a two-phase, 1-kg xenon detector. The detector will be installed at the underground laboratory in the Mt. Blanc tunnel, which provides a low background rate. A comparison between the sensitivity curve of our detector and the theoretical events limit from SUSY calculations is presented
Performance Of A Liquid Argon Time Projection Chamber Exposed To The WANF Neutrino Beam
We present the results of the first exposure of a Liquid Argon TPC to a
multi-GeV neutrino beam. The data have been collected with a 50 liters
ICARUS-like chamber located between the CHORUS and NOMAD experiments at the
CERN West Area Neutrino Facility (WANF). We discuss both the instrumental
performance of the detector and its capability to identify and reconstruct low
multiplicity neutrino interactions.Comment: 14 pages, 12 figures. Submitted for publication to Physical Review
Search for anomalies in the {\nu}e appearance from a {\nu}{\mu} beam
We report an updated result from the ICARUS experiment on the search for
{\nu}{\mu} ->{\nu}e anomalies with the CNGS beam, produced at CERN with an
average energy of 20 GeV and travelling 730 km to the Gran Sasso Laboratory.
The present analysis is based on a total sample of 1995 events of CNGS neutrino
interactions, which corresponds to an almost doubled sample with respect to the
previously published result. Four clear {\nu}e events have been visually
identified over the full sample, compared with an expectation of 6.4 +- 0.9
events from conventional sources. The result is compatible with the absence of
additional anomalous contributions. At 90% and 99% confidence levels the limits
to possible oscillated events are 3.7 and 8.3 respectively. The corresponding
limit to oscillation probability becomes consequently 3.4 x 10-3 and 7.6 x 10-3
respectively. The present result confirms, with an improved sensitivity, the
early result already published by the ICARUS collaboration
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