A method to study light attenuation effects in wavelength shifting fibres Cavasinni, V; Del Prete, T; Flaminio, V ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2004, Letnik:
517, Številka:
1
Journal Article
Recenzirano
The quality of wavelength shifting fibres depends on two basic parameters: the transparency of the core material, polystyrene, and the reflection coefficients at the fibre internal interfaces ...(core–clad and clad–clad in double-clad fibres). We have developed a model to parameterize these effects. The model has been applied to study the light attenuation in fibres used in the ATLAS hadronic calorimeter (TILE Calorimeter), as well as in the ones produced by several firms.
Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric
energy spectrum in the energy ...range 0.1–200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is ∼25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index
γ
meas
=3.58±0.12. With the present statistics the contribution of prompt neutrinos cannot be established.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A (0.83×2π) sr sky was monitored for a total of 334 days of ...equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an E−2 flux spectrum, a 90% c.l. upper limit on the diffuse νμ flux of E2Φ90%=5.3×10−8 GeVcm−2s−1sr−1 in the energy range 20 TeV–2.5 PeV is obtained. Other signal models with different energy spectra are also tested and some rejected.
Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric
νμ + ¯νμ energy spectrum in the ...energy range 0.1–200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall,
the measured flux is ∼25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements
reported in ice. The flux is compatible with a single power-law dependence with spectral index γmeas = 3.58 ± 0.12. With the present statistics the contribution of prompt neutrinos cannot be established.
We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽Eν⩽40 GeV. The significance of this ...measurement is its precision, ±4% in 2.5⩽Eν⩽10 GeV, and ±2.6% in 10⩽Eν⩽40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.
The results of the analysis of the data collected with the NEMO Phase-2 tower, deployed at 3500m depth about 80km off-shore Capo Passero (Italy), are presented. Čerenkov photons detected with the ...photomultipliers tubes were used to reconstruct the tracks of atmospheric muons. Their zenith-angle distribution was measured and the results compared with Monte Carlo simulations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is also included. The associated depth intensity relation was evaluated and compared with previous measurements and theoretical predictions. With the present analysis, the muon depth intensity relation has been measured up to 13km of water equivalent.
In the deep sea, the sense of time is dependent on geophysical fluctuations, such as internal tides and atmospheric-related inertial currents, rather than day-night rhythms. Deep-sea neutrino ...telescopes instrumented with light detecting Photo-Multiplier Tubes (PMT) can be used to describe the synchronization of bioluminescent activity of abyssopelagic organisms with hydrodynamic cycles. PMT readings at 8 different depths (from 3069 to 3349 m) of the NEMO Phase 2 prototype, deployed offshore Capo Passero (Sicily) at the KM3NeT-Italia site, were used to characterize rhythmic bioluminescence patterns in June 2013, in response to water mass movements. We found a significant (p < 0.05) 20.5 h periodicity in the bioluminescence signal, corresponding to inertial fluctuations. Waveform and Fourier analyses of PMT data and tower orientation were carried out to identify phases (i.e. the timing of peaks) by subdividing time series on the length of detected inertial periodicity. A phase overlap between rhythms and cycles suggests a mechanical stimulation of bioluminescence, as organisms carried by currents collide with the telescope infrastructure, resulting in the emission of light. A bathymetric shift in PMT phases indicated that organisms travelled in discontinuous deep-sea undular vortices consisting of chains of inertially pulsating mesoscale cyclones/anticyclones, which to date remain poorly known.
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