The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is ...increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nuovere energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.
During the last couple of decades, the use of arrays of bolometers has represented one of the leading techniques for the search for rare events. CUORE, an array of 988 TeO2 bolometers that is taking ...data since April 2017 at the Laboratori Nazionali del Gran Sasso (Italy), exploits the large mass, low background, good energy resolution and low energy threshold of these detectors successfully. Thanks to these characteristics, they could be also sensitive to low energy rare processes, such as galactic dark matter interactions. In this paper we describe the data acquisition system that was developed for the CUORE experiment. Thanks to its high modularity, the data acquisition here described has been used in different setups with similar requirements, including the pilot experiment CUORE-0 and the demonstrator for the next phase of the project, CUPID-0, also taking data at LNGS.
In this report, we assess muon multiple scattering tomography as a non-destructive inspection technique in several typical areas of interest to the nuclear power industry, including monitoring ...concrete degradation, gate valve conditions, and pipe wall thickness. This work is motivated by the need for imaging methods that do not require the licensing, training, and safety controls of x-rays, and by the need to be able to penetrate considerable overburden to examine internal details of components that are otherwise inaccessible, with minimum impact on industrial operations. In some scenarios, we find that muon tomography may be an attractive alternative to more typical measurements.
We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the ...WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.
Imaging the dome of Santa Maria del Fiore using cosmic rays Guardincerri, E; Bacon, J D; Barros, N ...
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
12/2018, Letnik:
377, Številka:
2137
Journal Article
Recenzirano
Odprti dostop
The dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are under way ...to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only known reinforcement is a wood chain 7.75 m above the springing of the Cupola. Multiple scattering muon radiography is a non-destructive imaging method that can be used to image the interior of the dome's wall and therefore ascertain the layout and status of any iron substructure in it. A demonstration measurement was performed at the Los Alamos National Laboratory on a mock-up wall to show the feasibility of the work proposed, and a lightweight and modular imaging system is currently under construction. We will discuss here the results of the demonstration measurement and the potential of the proposed technique, describe the imaging system under construction and outline the plans for the measurement.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.
The CUORE Data Acquisition System Copello, S.; Di Domizio, S.; Branca, A. ...
Journal of low temperature physics,
04/2020, Letnik:
199, Številka:
1-2
Journal Article
Recenzirano
Odprti dostop
Large mass bolometers, thanks to their good energy resolution and high radiopurity, can be used for rare event searches, such as neutrinoless double beta decay or dark matter direct detection. The ...bolometric technique has been adopted by the CUORE experiment which is composed by an array of 988 tellurium dioxide bolometers with a total active mass of 741 kg. The experiment started taking data in April 2017 at the Laboratori Nazionali del Gran Sasso (LNGS), Italy, with the scientific goal of searching for neutrinoless double beta decay of 130-Te. Given the increasing number of channels to be acquired, the readout chain became an important aspect of the construction of bolometer arrays. The CUORE data acquisition system here described, called Apollo, was initially developed for CUORE, but its high modularity and flexibility make it possible to use it also in other experiments, regardless of the specific characteristics of the setup such as the number of channels and the bolometer characteristics. Indeed, it has been used not only in CUORE but also in its predecessor CUORE-0, R&D projects and upgrades such as CUPID-0.
The authors present here a new method to image reinforcement elements inside thick structures and the results of a demonstration measurement performed on a mock-up wall built at Los Alamos National ...Laboratory. The method, referred to as “multiple scattering muon radiography”, relies on the use of cosmic-ray muons as probes. The work described in this article was performed to prove the viability of the technique as a means to image the interior of the dome of Florence Cathedral Santa Maria del Fiore, one of the UNESCO World Heritage sites and among the highest profile buildings in existence. Its result shows the effectiveness of the technique as a tool to radiograph thick structures and image denser object inside them.
As part of the ongoing study of Brunelleschi's great dome in Florence, the Opera di Santa Maria del Fiore has approved a proposal to solve the age-old problem of the possible presence of hoops or ...iron stirrups within the dome's inner wall by exploiting the flux of natural muons traversing the dome. Ascertaining presence of a metal hoop in the dome would obviously be relevant to assess the static and seismic safety of the monument. The project, proposed by Dr. Elena Guardincerri from LANL and by Prof. Carlo Blasi, began in 2016 at LANL with the construction of special prototype-panels for the tracking of muons, and has expanded this year to include researchers from the Department of Physics of the University of Florence and INFN-Florence.
A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. The system consists of a pair of drift-tube tracking ...detectors of 7.2x 7.2-m super(2) area. Each muon tracker consists of 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-mu Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when the core is imaged from outside the reactor building.
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