Title: Status of the KM3NeT project Author: A. Margiotta (on behalf of the KM3NeT Collaboration)
KM3NeT is a deep-sea research infrastructure being constructed in the Mediterranean Sea. It will be installed at three sites: KM3NeT-Fr, offshore Toulon, France, KM3NeT-It, offshore Portopalo di Capo Passero, Sicily (Italy) and KM3NeT-Gr, offshore Pylos, Peloponnese, Greece. It will host the next generation Cherenkov neutrino telescope and nodes for a deep sea multidisciplinary observatory, providing oceanographers, marine biologists, and geophysicists with real time measurements. The neutrino telescope will search for Galactic and extra-Galactic sources of neutrinos, complementing IceCube in its field of view. The detector will have a modular structure and consists of six building blocks, each including about one hundred Detection Units (DUs). Each DU will be equipped with 18 multi-PMT digital optical modules. The first phase of construction has started and shore and deep-sea infrastructures hosting the future KM3NeT detector are being prepared in France near Toulon and in Italy, near Capo Passero in Sicily. The technological solutions for KM3NeT and the expected performance of the detector are presented and discussed.
Title: The Sound Emission Board of the KM3NeT Acoustic Positioning System Authors: C. D. Llorens, M. Ardid, T. Sogorb, M. Bou--Cabo, J. A. Martínez-Mora, G. Larosa, S. Adrián-Martínez
We describe the sound emission board proposed for installation in the acoustic positioning system of the future KM3NeT underwater neutrino telescope. The KM3NeT European consortium aims to build a multi-cubic kilometre underwater neutrino telescope in the deep Mediterranean Sea. In this kind of telescope the mechanical structures holding the optical sensors, which detect the Cherenkov radiation produced by muons emanating from neutrino interactions, are not completely rigid and can move up to dozens of meters in undersea currents. Knowledge of the position of the optical sensors to an accuracy of about 10 cm is needed for adequate muon track reconstruction. A positioning system based on the acoustic triangulation of sound transit time differences between fixed seabed emitters and receiving hydrophones attached to the kilometre-scale vertical flexible structures carrying the optical sensors is being developed. In this paper, we describe the sound emission board developed in the framework of KM3NeT project, which is totally adapted to the chosen FFR SX30 ultrasonic transducer and fulfils the requirements imposed by the collaboration in terms of cost, high reliability, low power consumption, high acoustic emission power for short signals, low intrinsic noise and capacity to use arbitrary signals in emission mode.
Undersea neutrino observatory to be second-largest human structure
An audacious project to construct a vast infrastructure housing a neutrino observatory at the bottom of the Mediterranean Sea is being undertaken by a consortium of 40 institutes and universities from ten European countries. The consortium claims that KM3NeT, as it is known, will "open a new window on the Universe," as its "several" cubic kilometre observatory detects high-energy neutrinos from violent sources in outer space such as gamma-ray bursts, colliding stars and supernovae. Read more
Whales sing at the same wavelength as the neutrinos emitted by stars. This happy coincidence gave physicists the idea to share their undersea telescopes with marine biologists. By helping the development of a bioaccoustics network to monitor the deep sea environment, they have already enabled the discovery of the unexpected presence of sperm whales in the Mediterranean Sea. It is even possible to listen to the song of whales live from home with a personal computer connected to the web, thanks to the LIDO platform (Listen to the Deep Ocean). Read more
Title: Neutrino Telescopes in the Mediterranean Sea Authors: Juan José Hernández-Rey (IFIC) for the ANTARES Collaboration, for the KM3NeT Consortium
The observation of high energy extraterrestrial neutrinos can be an invaluable source of information about the most energetic phenomena in the Universe. Neutrinos can shed light on the processes that accelerate charge particles in an incredibly wide range of energies both within and outside our Galaxy. They can also help to investigate the nature of the dark matter that pervades the Universe. The unique properties of the neutrino make it peerless as a cosmic messenger, enabling the study of dense and distant astrophysical objects at high energy. The experimental challenge, however, is enormous. Due to the weakly interacting nature of neutrinos and the expected low fluxes very large detectors are required. In this paper we briefly review the neutrino telescopes under the Mediterranean Sea that are operating or in progress. The first line of the ANTARES telescope started to take data in March 2006 and the full 12-line detector was completed in May 2008. By January 2009 more than one thousand neutrino events had been reconstructed. Some of the results of ANTARES will be reviewed. The NESTOR and NEMO projects have made a lot of progress to demonstrate the feasibility of their proposed technological solutions. Finally, the project of a km3-scale telescope, KM3NeT, is rapidly progressing: a conceptual design report was published in 2008 and a technical design report is expected to be delivered by the end of 2009.
Title: KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea Authors: P. A. Rapidis (Democritos Nucl. Res. Ctr.), for the KM3NeT consortium
High energy neutrinos produced in astrophysical processes will allow for a new way of studying the universe. In order to detect the expected flux of high energy neutrinos from specific astrophysical sources, neutrino telescopes of a scale of a km^3 of water will be needed. A Northern Hemisphere detector is being proposed to be sited in a deep area of the Mediterranean Sea. This detector will provide complimentary sky coverage to the IceCube detector being built at the South Pole. The three neutrino telescope projects in the Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design, and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a 3-year Design Study; the status of the Design Study is presented and some technical issues are discussed.
Title: KM3NeT: A Next Generation Neutrino Telescope in the Mediterranean Sea Authors: A. Kappes (University Erlangen-Nuremberg), for the KM3NeT Consortium
To complement the IceCube neutrino telescope currently under construction at the South Pole, the three Mediterranean neutrino telescope projects ANTARES, NEMO and NESTOR have joined forces to develop, construct and operate a km³-scale neutrino telescope in the Mediterranean Sea. Since February 2006, the technical specifications and performance of such a detector are studied in the framework of a 3-year EU-funded Design Study. In 2009 a technical design report will be released laying the foundations for the construction of the detector. In the following, the current status of the Design Study is presented and examples of solutions for the technical challenges are discussed.