Orateur
Dr
Marco Circella
(INFN Bari)
Description
This presentation will describe the time calibration system proposed for the NEMO (NEutrino Mediterranean Observatory) underwater neutrino telescope. The time calibration is a very critical task to perform in such a large apparatus, as its track reconstruction capabilities strongly depend on the accuracy of the time alignment of the measurements made by the different sensors. In the prototype apparatus of NEMO Phase 1, which was deployed at a test site off the coast of Sicily, at 2000 m depth, in December 2006, a system based on an optical fibre network which distributed calibration signals from fast optical pulsers to groups of photomultipliers was used. A similar approach, but now based on a network of copper cables, is under development for the NEMO Phase 2 test apparatus, which is planned to be installed at 3500 m depth. Both calibration systems are controlled from an onshore console, which also delivers GPS-syncronized clock signals to the whole apparatus. We will illustrate the performance of the time calibration system of NEMO Phase 1, comparing the results from the laboratory tests before deployment to the measurements made in situ, and we will then illustrate the new system under implementation for NEMO Phase 2. The possible implications toward the design of a km3 apparatus will be also discussed.
Auteur principal
Dr
Marco Circella
(INFN Bari)
