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, University of Leeds.

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

National Responsible: C. De Marzo (Bari)

1. Goal of the experiment

The realization 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 realization 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 strings are 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.

More on the experiment...

2.

Activities during 2002

Construction of the detector components and related facilities are progressing without substantial problems. The prototype string (‘sector line’) and the Junction Box were deployed in December 2002. Connections to the optical cable, depending on the Nautile submarine, were delayed to March 2003 because of an emergency. The submarine was commanded to monitor the wreckage of the Prestige oil ship.

The assembling of a neutrino telescope in the open sea is a pioneer activity. Today the only prototype in water working all over the world is the BAIKAL experiment in Lake Baikal, Siberia. By necessity constructions in ANTARES must depend on our own experience only, that we obtain by deploying more and more sophisticated prototypes. This activity is substantially limited by availability of the submarine for electrical and optical connections. For this reason the deployment of the first string as well as the instrumented line have been shifted
to 2004.

The Off-line Physics Filter is almost complete; the 25% delay depends on the delivery of the DAQ control code, in charge of another group of the international collaboration.

The following achievements have been obtained:

- Deployment of sector line with a steel Bottom String Socket (100 %)
- Deployment of the mini-instrumented line (delayed to 31-03-03 (*))
- Deployment of the complete instrumented line (delayed to 2004)
- Completion of Local Control Modules (LCM) Test Bench and test of the first modules (75 % (**))
- Realization and test of 120 Power Units and test of 60 LCM (delayed due to late funding)
- Design and completion of the String Control Module Test Bench (75 % (**))
- Design and realization of a String Test Bench (not funded)
- Realization of the Offline Physics Filter (75 % (**))

Notes:

(*) Since the mini-instrumented line (MIL) is equipped with a seismograph (from the french geophysics group) powered by limited duration batteries, it is preferred to deploy the MIL close in time to the intervention of the submarine doing the required connections.

(**) The LCM and SCM prototypes are ready. The test procedure is still not completely defined, depending on the general review of the Antares electronics after the experience of sector-line construction.

Milestones 2003:

Delivery of 4 BSS | 30-04-2003
Instrumented-line end of construction | 30-06-2003
Starting of the production and qualification chains for SCM | 31-03-2003
Final delivery for deployment of 3 SCM | 31-12-2003
Starting of the production and qualification chains of LCM | 31-03-2003
Final delivery for deployment of 96 power units and 96 LCM | 31-12-2003
Qualification of the "Offline Physics Filter" using sector-line | 30-06-2003
Delivery of Montecarlo and data analysis algoritms | 31-12-2003

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 20.2 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 2003: 4.1% of the CSN2 budget for 2003.

4. Publications in refereed journals (in 2002):

5. Conference talks (in 2002): 5

6. Number of undergraduate and doctoral thesis on the experiment:

- Undergraduate theses (discussed in 2002): 2
- Undergraduate theses (in progress): 5

7. Leadership roles in the experiment

- C. De Marzo – spokesperson of the Italian collaboration
- M. Anghinolfi – leader of the Mechanics Working Group and member of the Steering Committee of the experiment
- T. Montaruli – leader of the Neutrino Astronomy Working Group
- A. Capone and T. Montaruli – members of the Publication Committee
- A. Capone, L. Caponetto, 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 Institution Board of the Collaboration

8. Innovative Instruments

Today the Cherenkov light technique for neutrino detection has been demonstrated by BAIKAL Coll. in the Lake and by the AMANDA Coll. in the ice at South Pole. ANTARES detector will be the first demonstrator of this technique in the deep sea.

9. Competing experiments

Two astrophysics neutrino experiments are presently taking data. One is located in lake Baikal (Russia). Its capabilities are limited by the 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 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).