Availability Requirement for ITER Plasma Parameter Measurements

The diagnostics are critical systems for the operation and research program of ITER, as they are used to protect the components, to control the plasma discharge, to understand the behaviour of the plasma and to measure its performance. Representing more than 50 subsystems, they add an extra level of complexity and technical challenge to the project. In order to ensure that the overall ITER machine will be able to reach its ambitious availability objective, a Reliability, Availability, Maintainability and Inspectability (RAMI) approach has been defined and applied to the diagnostics as well as all the other ITER core systems. The purpose of this study is to estimate the inherent availability of the measurements groups used for machine protection and basic control in order to ensure that the ITER machine reaches its inherent availability objectives.