Status of the OPERA experiment Medinaceli, E
Journal of physics. Conference series,
01/2013, Letnik:
442, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The OPERA neutrino detector at the Gran Sasso underground laboratory (LNGS) has been designed to perform the first detection of neutrino oscillations in direct appearance mode, through the study of ...the νμ → ντ channel. Tau leptons produced in the charged current interactions are identified by their decay topologies, using nuclear emulsions. After a brief description of the experimental setup, the first two tau candidates found in the runs 2008 to 2010 are reported. The OPERA experiment has measured the velocity of neutrinos sent from the CERN CNGS beam over a baseline of about 730 km. The measurement is based on data taken from 2009 to 2011. An arrival time of CNGS muon neutrinos with respect to the one computed, assuming the speed of light in vacuum, of (6.5±7.4(stat)+3.4−3.3(sys)) ns was measured.
The SLIM
1
1
The
SLIM collaboration: S. Balestra, S. Cecchini, M. Cozzi, M. Errico, F. Fabbri, G. Giacomelli, R. Giacomelli, M. Giorgini, A. Kumar, S. Manzoor, J. McDonald, G. Mandrioli, S. ...Marcellini, A. Margiotta, E. Medinaceli, L. Patrizii, J. Pinfold, V. Popa, I.E. Qureshi, O. Saavedra, Z. Sahnoun, G. Sirri, M. Spurio, V. Togo, A. Velarde, A. Zanini.
experiment was an array of 427
m
2 of nuclear track detectors (NTDs), exposed at a high altitude laboratory (Chacaltaya, Bolivia, 5230
m a.s.l.), for ∼4.22 years. SLIM was sensitive to downgoing intermediate mass magnetic monopoles with masses of 10
5
GeV/c
2
≤
M
M
≤
10
12
GeV/c
2. The analysis of the full detector gives a flux upper limit of 1.3
×
10
−15
cm
−2
s
−1
sr
−1 with the 90% Confidence Level (C.L.) for downgoing fast intermediate mass magnetic monopoles.
NESSiE (Neutrino Experiment with SpectrometerS in Europe) is an experiment dedicated to the search for sterile neutrinos beyond the Standard Model with the CERN-SPS neutrino beam. The experiment is ...based on two identical LAr-TPC's followed by magnetized spectrometers, observing the electron and muon neutrino events at the “Near” (600m) and “Far” (1300m) positions from the proton target. The main characteristics of the spectrometers are described here. Spectrometers will exploit a classical dipole magnetic field with iron slabs, and a new concept air-core magnet will perform charge identification and muon momentum measurements in the energy range from ∼100MeV to few GeV over a large transverse area (>50m2).
The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m a.s.l.). The detector was in particular sensitive to intermediate mass ...magnetic monopoles, with masses 10
5
GeV <M
M
< 10
12
GeV. From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3×10
-15
cm
-2
s
-1
sr
-1
for downgoing fast intermediate mass monopoles was established at the 90% C.L.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The SLIM experiment at the Chacaltaya high altitude laboratory was sensitive to nuclearites and Q-balls which could be present in the cosmic radiation as possible Dark Matter components. It was ...sensitive also to strangelets, i.e. small lumps of Strange Quark Matter predicted at such altitudes by various phenomenological models. The analysis of 427 m
2
of Nuclear Track Detectors exposed for 4.22 years showed no candidate event. New upper limits on the flux of downgoing nuclearites and Q-balls at the 90% C.L. were established. The null result also restricts models for strangelets propagation through the Earth atmosphere.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Improving the detection efficiency in nuclear emulsion trackers Alexandrov, A.; Bozza, C.; Buonaura, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2015, Letnik:
776
Journal Article
Recenzirano
Nuclear emulsion films are a tracking device with unique space resolution. Their use in nowadays large-scale experiments relies on the availability of automated microscope operating at very high ...speed. In this paper we describe the features and the latest improvements of the European Scanning System, a last-generation automated microscope for emulsion scanning. In particular, we present a new method for the recovery of tracking inefficiencies. Stacks of double coated emulsion films have been exposed to a 10GeV/c pion beam. Efficiencies as high as 98% have been achieved for minimum ionising particle tracks perpendicular to the emulsion films and of 93% for tracks with tan(θ)≃0.8.
CAKE (Cosmic Abundances below Knee Energies) was a prototype balloon experiment for the determination of the charge spectra and abundances of the primary cosmic rays (CR) with
Z
>
10. It was a ...passive instrument made of layers of CR39® and Lexan®/Makrofol® nuclear track detectors; it had a geometric acceptance of ∼0.7
m
2
sr for Fe nuclei. Here, the scanning and analysis strategies, the algorithms used for the off-line filtering and for the tracking in automated mode of the primary cosmic rays are presented, together with the resulting CR charge distribution and their abundances.
New calibrations of CR39 and Makrofol nuclear track detectors have been obtained using 158AGeV Pb82+ and In49+ions; a new method for the bulk etch rate determination, using both cone height and base ...diameter measurements, was developed. The CR39 charge resolution based on the etch-pit base area measurements is adequate to identify nuclear fragments in the interval 7⩽Z/β⩽49. For CR39 the detection threshold is at REL ∼50MeVcm2g−1, corresponding to a nuclear fragment with Z/β∼7. Base cone area distributions for Makrofol foils exposed to Pb82+ ions have shown for the first time all peaks due to nuclear fragments with Z>50; the distribution of the etched cone heights shows well separated individual peaks for Z/β∼78 to 83 (charge pick-up). The Makrofol detection threshold is at REL ∼2700MeVcm2g−1, corresponding to a nuclear fragment with Z/β=50.
A fast automatic plate changer for the analysis of nuclear emulsions Balestra, S.; Bertolin, A.; Bozza, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2013, Letnik:
716
Journal Article
Recenzirano
This paper describes the design and performance of a computer controlled emulsion Plate Changer for the automatic placement and removal of nuclear emulsion films for the European Scanning System ...microscopes. The Plate Changer is used for mass scanning and measurement of the emulsions of the OPERA neutrino oscillation experiment at the Gran Sasso lab on the CNGS neutrino beam. Unlike other systems it works with both dry and oil objectives. The film changing takes less than 20s and the accuracy on the positioning of the emulsion films is about 10μm. The final accuracy in retrieving track coordinates after fiducial marks measurement is better than 1μm.
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