Dependability analysis of a very large volume neutrino telescope

This work considers a first order approximation to the dependability analysis of complex large scale installations. The dependability criterion used here is quantitative unavailability, and an appropriate unavailability model is presented. The model assumes that the system is symmetrical, has various levels of hierarchy, and components found in the same level are similar and function independently. The application example comes from very large volume neutrino telescopes installed under water or ice, consisting of several thousands of optical modules. The readout architecture of the detector has several levels of multiplexing including optical detection towers, branches and tower sectors. The paper presents results for various alternative detector layouts and distances of the detector from the onshore facilities. It also develops dependability requirements for major components and/or subsystems consistent with an overall system performance target. The results depict the dependence of the system unavailability on the number of optical modules and the alternative deep sea infrastructure configurations for transferring the measured signals.