ANTARES

Collaboration

- INFN: Bari, Bologna, Catania, Genova, LNS, Roma1.
- France: Centre de Physique des Particules de Marseille, Marseille; DAPNIA Saclay; Groupe de Recherches en Physique des Hautes Energies, Mulhouse; France Institut de Recherches Subatomiques, Strasbourg; Observatoire de la Cote d’Azur, Nice; Laboratoire d’Astronomie Spatiale, Marseille; Observatoire de Marseille, Marseille; Centre d’Oceanologie de Marseille, Marseille; Ifremer, Centre de Toulon; Ifremer, Centre de Brest.
- Germany: Friedrich-Alexander Universitaet, Erlangen.
- The Netherlands: NIKHEF, Amsterdam.
- Russia: Institut for Theoretical and Experimental Physics, Moscow.
- Spain: Instituto de Physica Corpuscular, Valencia.
- United Kingdom: University of Oxford, University of Sheffield.

Experiment home page: http://antares.in2p3.fr/

National Responsible: E. Migneco (LNS)

1. Goal of the experiment

The realisation of a telescope for high energy neutrinos of astrophysical origin is considered nowadays one of the most important aims in the astroparticle physics field. The detection of these neutrinos could help to investigate the mechanisms that give rise to the most energetic phenomena in the Universe such as the Active Galactic Nuclei and the Gamma Ray Bursts. It is believed that such a detector must have an active volume of 1 km3 and should be shielded by atmospheric cosmic rays. The most promising technique seems to be the detection of the Cherenkov light emitted by the secondary muons produced by neutrino interaction by means of an array of detectors located in the sea abysses at a depth of more than 3000 m.

As an intermediate step ANTARES aims at the realisation of a 0.1 km2 active area neutrino telescope installed at a depth of 2400 m at about 40 km offshore Toulon (France). The detector will be constituted by 10 strings moored on the sea bottom and tensioned by an appropriate buoyancy. Each string will host 90 optical modules arranged in 30 storeys. Each storey will be connected with a Junction Box, located on the sea bottom close to the detector, that will be in turn connected to the shore by means of an electro-optical cable.

2.

Activities during 2001

The design and realisation of the detector components are in well advanced state. In september 2001 the 40 km electro-optical cable that will link the underwater site to the shore has been deployed. The Junction Box that will distribute power and optical fibre data links from the main electro-optical cable to the detector strings is almost ready and will be deployed in 2002.

The responsibilities of the Italian collaboration concern the realisation of:

- the mechanical structure of the Junction Box (JB);
- the mechanical structures that will allow the mooring and the connection of the lines (called Bottom String Sockets or BSS);
- the Test Bench and the test of the electronic modules located at each storey of the line (called Local Contral Modules or LCM) and realization of some mechanical parts of the LCM;
- the Test Bench and the test of the electronic modules located at the base of each line (called String Control Modules or SCM) and realization of some mechanical parts of the SCM;
- a line equipped with instruments to monitor the water environmental parameters (light absorption and attenuation, sea currents, water temperature and salinity, sound velocity in water) inside the detector (Instrumented Line);
- the software for the Offline Physics Filter of the experiment.

The milestones that were expected to be achieved in 2001 were:

- Completion and first deployment of the Junction Box — (Status at 31-12-2001: 80%) JB mechanics is completed but the deployment has been postponed to may 2002 to allow some modifications of the internal electronics of the JB;
- Realization and test of a prototype of BSS - (Status at 31-12-2001: 100%) completed and tested in deep water;
- Realization of the Electronics Test Bench System for the String Control Modules — (Status at 31-12-2001: 70%) design completed and construction under way;
- Realization of the Electronics Test Bench System for the Local Control Modules (Status at 31-12-2001: 90%) hardware assembling almost completed and software realisation under way;
- Setting up of one segment of the Instrumented Line: (Status at 31-12-2001: 100%) mechanics and instruments assembled, control software under development, system under test.

Milestones 2002

Deployment of sector line and mini Instrumented line | 31-05-2002
Recovery of the mini Instrumented line | 31-08-2002
Deployment of the complete instrumented line | 31-10-2002
Realization and test of 120 Power Units and test of 60 LCM | 31-12-2002
Completion of LCM Test Bench and test of the first modules | 31-07-2002
Design and realization of a String Test Bench | 31-12-2002
Realization of the Offline Physics Filter | 31-12-2002

3. INFN contribution to the experiment in terms of manpower and financial support

Manpower:

The INFN participation in the experiment amounts to 42 physicists and engineers for a total of 20.4 FTE. Support is also given from the mechanics and electronics workshops of the INFN’s "Sezioni" and Laboratori that are involved in the project.

Budget for the Year 2002: 769 kE

4. Publications in refereed journals (in 2001):

5. Conference talks (in 2001): 4

6. Number of undergraduate and doctoral thesis on the experiment

- Undergraduate theses (in progress) 1
- Undergraduate theses (completed in 2001) 2
- PhD theses (in progress) 1

7. Leadership roles in the experiment

- E. Migneco — Spokesperson of the italian collaboration
- M. Anghinolfi — Leader of the Mechanics group and member of the Steering Committee
- T. Montaruli — Leader of the Neutrino Astrophysics Working Group
- L. Caponetto, A. Capone, M. Circella, P. Piattelli, M. Spurio are responsible of subprojects
- M. Anghinolfi, A. Capone, C. De Marzo, A. Margiotta, P. Piattelli, G.V. Russo are members of the Intitution Board of the Collaboration

8. Innovative Instruments

9. Competing experiments

Two astrophysics neutrino experiments are presently taking data. One is located in lake Baikal (Russia). Its capabilities are limited by the poor water properties and by the shallowness of the detector. The second running experiment, AMANDA, is located in the South Pole ice cap. It is located at only 2000 m depth and its tracking capabilities are limited by light scattering in ice. An expansion of the detector to reach the 1 km2 effective area (project ICE-CUBE) will start soon.

10. International committee which has reviewed the experiment

The experiment is reviewed by the funding authorities of the collaborating institutions. In particular by: IN2P3 and CEA (France), INFN (Italy), NIKHEF (Netherlands).