1,721,025 research outputs found
Limits on different majoron decay modes of 100Mo and 82Se for neutrinoless double beta decays in the NEMO-3 experiment
No full textThe NEMO-3 tracking detector is located in the Fréjus Underground Laboratory. It was designed to study double beta decay in a number of different isotopes. Presented here are the experimental half-life limits on the double beta decay process for the isotopes 100Mo and 82Se for different majoron emission modes and limits on the effective neutrino–majoron coupling constants. In particular, new limits on “ordinary” majoron (spectral index 1) decay of 100Mo (T1/2>2.7×1022 yr) and 82Se (T1/2>1.5×1022 yr) have been obtained. Corresponding bounds on the majoron–neutrino coupling constant are gee<(0.4–1.8)×10−4 and <(0.66–1.9)×10−4
Status of the NEMO project
No full textActivities leading to the realization of a km3 Cherenkov neutrino detector, carried out by the NEMO collaboration, are described. Long term exploration of a 3500 m deep site in the Mediterranean close to the Sicilian coast has shown that it is optimal for the installation of the detector. A complete feasibility study, which has considered all the components of the detector, as well as its deployment, has been carried out demonstrating that technological solutions exist for the realization of the km3 detector. The realization of a technological demonstrator (the NEMO Phase 1 project) is under way
Status of NEMO
No full textThe activities towards the realization of an underwater km3 Čerenkov neutrino detector carried out by the NEMO Collaboration are described. Long term exploration of a 3500 m deep sea site close to the Sicilian coast has shown that it is optimal for the installation of the detector. The realization of a Phase-1 project, which is under way, will validate the proposed technologies for the realization of the km3 detector on a Test Site at 2000 m depth. The realization of a new infrastructure on the candidate site (Phase-2 project) will provide the possibility to test detector components at 3500 m depth
On line monitoring of the power control and engineering parameters systems of the NEMO Phase-2 tower
No full textThe NEMO Collaboration is presently carrying out an intense activity on "NEMO Phase-2" project for the realization of an underwater infrastructure on the deep-sea site of Capo Passero, including a fully instrumented 16 storey tower. In this paper the design of the electrical power control system and of a system for the monitoring of some engineering parameters, useful to study the dynamical behavior of the structure, are presented. The Proposed architecture is strongly modular and flexible. The entire architecture is described with a special focus on the electrical parameters monitoring, protection system and on the sensors fusion algorithm implemented to deduce the attitude through Micro Electro-Mechanical Systems (MEMS) accelerometers and magnetometer sensors. (c) 2009 Published by Elsevier B.V
Status of NEMO: results from the NEMO Phase-1 detector
No full textThe NEMO Collaboration installed art underwater detector including most of the critical elements of a possible km(3) neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box, including the data transmission, the power distribution, the timing calibration and the acoustic positioning systems. These technical Solutions will be evaluated, among others proposed for the construction of the km(3) detector, within the KM3NeT Consortium. The main test of this test experiment was the validation of the proposed design solutions mentioned above. We present results of the analysis of data collected with the NEMO Mini-Tower. The position of PMTs is determined through the acoustic position system; signals detected with PMTs are used to reconstruct the tracks of atmospheric muons. The angular distribution of atmospheric muons was measured and results were compared with Monte Carlo simulations
Capabilities of an Underwater Detector as a Neutrino Telescope and for the Neutrino Oscillation Search
No full textWe report on the results of a Monte Carlo simulation study of a km3 scale deep underwater Cherenkov detector aimed at detecting neutrinos of astrophysical origin. This analysis has been undertaken as part of the NEMO R&D project to develop such an experiment close to the Southern Italian coasts. We have studied the reconstruction capabilities of various arrays of phototubes in order to determine the detector geometries which optimize performance and cost. We have also investigated the possibility of designing a detector with characteristics suited to an experiment on atmospheric neutrino oscillations
Time calibration of the NEutrino Mediterranean Observatory (NEMO)
No full textLarge volume Cherenkov detectors are under construction or have been proposed for detection of astrophysical neutrinos Under water or ice. In all such cases, the neutrinos are inferred from the detection of the Cherenkov light emitted by the charged leptons created in neutrino interactions inside or around the apparatus. The event reconstruction is thus based on charge and time measurements performed by a system of widely spaced optical sensors. The time calibration is a very delicate operation for such experiments, as it may directly affect the reconstruction efficiency and pointing capabilities of the apparatus. In this paper, we illustrate the systems under study for the km(3)-scale project NEW (NEutrino Mediterranean Observatory), focusing Oil the implementations for the NEMO Phase-1 and Phase-2 prototyping campaigns. (c) 2008 Elsevier B.V. All rights reserved
The neutrino Mediterranean observatory project
No full textActivities leading to the realization of a km3 Cherenkov neutrino detector, carried out by the NEMO collabo- ration, are described. Long term exploration of a 3500 m deep site in the Mediterranean close to the Sicilian coast has shown that it is optimal for the installation of the detector. A complete feasibility study, that has considered all the components of the detector as well as its deployment, has been carried out demonstrating that technological solutions exist for the realization of the km3 detector. The realization of a technological demonstrator (the NEMO Phase 1 project) is under way
A km3 detector in the Mediterranean: Status of NEMO
No full textThe status of the NEMO project, which aims at characterizing and monitoring the Capo Passero (Sicily, Italy) candidate site for the km3 underwater Mediterranean detector and developing and testing the related key technological solutions, is described. NEMO Phase 1, which is a technological demonstrator aiming towards the Mediterranean km3 telescope, is under realization and is reported. © 2005 Elsevier B.V. All rights reserved
Data taking system for the NEMO experiment
No full textA four-floors prototype of the Nemo towers has been successfully deployed off the Sicily coast in December 2006. The detector is working and data acquisition is going on since then. The aim of this contribution is to give an overview of the NEMO electronic system and to explain the different stages of data acquisition and transport. The underwater electronics sample signals from photomultipliers and acquire slow-control data both from oceanographic instruments and dedicated sensors, allowing to monitor the operational conditions of the apparatus. The whole data are sent to laboratory through a fully bidirectional fiber optic link. On shore the data are received by dedicated boards that distribute them to first level-trigger and to the slow-control system. The NEMO data acquisition/transmission electronic system will be described, properties of acquired signals and of data flow will be discussed
- …
