1,721,002 research outputs found
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
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
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
On-line monitoring of underwater acoustic background at 2000 m depth.
No full textThe NEMO (NEutrino Mediterranean Observatory) Collaboration is constructing, 25 km E from Catania
(Sicily) at 2000 m depth, an underwater test site to perform long-term tests of prototypes and new technologies
for astrophysical HE neutrino telescopes. In this framework the collaboration deployed an electro-optical
cable equipped with several e.o. terminations. An experimental apparatus for the measurement of underwater
acoustic background was also installed and connected on 22 Jan 2005, allowing continuous on-line monitoring
of deep-sea noise. The station is equipped with 4 hydrophones operational in the range 30 Hz - 40 kHz. This
interval of frequencies matches the range suitable for acoustic detection of HE neutrino-induced showers in
water. Hydrophones signals are digitized (96 kHz - 24 bits) underwater and continuously transmitted to shore
via optical bre. Underwater noise spectra were produced and classication of transient signals is under way.
The NEMO-test site is also equipped with an on-line seismic observatory developed by INGV (the Italian
National Institute for Geophysics and Volcanology).Published on CDROM and in 10 printed volume
Slow abyssal clockwise rotating eddies in the Ionian sea
No full textThe dynamical characteristics of the deep currents flowing over the KM4 site (36◦ 30’N; 15◦50’E) measured, from July 2001 to March
2003, through two Aanderaa RCM 7-8 current meters set at 2700 m and 3050 m depth (230 m from the bottom) are here investigated. The
presence of 8 large scale slow barotropic vortices, clockwise rotating, is discussed
Instrumentation interfacing and parameters monitoring for underwater neutrino telescope
No full textOne of the tasks of an electronic system designed to monitor environmental parameters is to provide the user with a point-to-point connection to several remotely located instruments and probes. In this paper, we describe in detail the electronics developed to fulfill this task. Environmental parameters generally vary slowly in time such that the overall data rate needed to monitor their time dependency do not exceed few tens of kb/s. For this reason, we called the electronic board devoted to their monitoring 'Slow Control Interface'. (c) 2006 Elsevier B.V. All rights reserved
Short Term and Long Term Bioacoustic Monitoring of the Marine Environment. Results from NEMO ONDE Experiment and Way Ahead.
Full text linkThe INFN NEMO-OνDE (Ocean Noise Detection Experiment) station, deployed on the seafloor at 2000 m depth 25 km offshore Catania (Sicily, Italy) in year 2005, was designed to continuously transmit broad-band acoustic data through optical cables to the INFN lab located in the port of Catania. It was operational until November 2006, when it was replaced by other experimental equipment. During the operational period, 5 minutes of recording (4 hydrophones, 45 kHz bandwidth, 96 kHz sampling rate at 24 bits resolution) were taken every hour. The experiment provided long-term data on the underwater noise and an unique opportunity to study the acoustic emissions of marine mammals living in, or transiting through the area east of Sicily. The recordings revealed a more frequent and consistent presence of sperm whales than previously believed
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