Preliminary design of ITER cryopumps front-end cryodistribution system instrumentation and controls

The ITER Tokamak, designed to study deuterium-tritium fusion reactions and to demonstrate its viability as a sustainable and clean energy source, is currently being built in South France, on Cadarache site. Its vacuum system, one of the largest and most complex vacuum systems ever to be built, will use purpose built cryopumps to provide high vacuum conditions to the torus vessel, neutral beam injectors and cryostat vessel. In this paper the preliminary design of the vacuum controls and instrumentation for the ITER front-end cryogenic distribution systems is described. The overall development of the controls satisfying the stringent vacuum processes necessary for the successful operation of ITER is explained within the full picture of plasma scenarios. Instrumentation and control system design is described, considering the harsh environment, the integration constrains, and the need for flexibility while maintaining high system availability and strong coordination between the cryopumps for successful operation. Details of the selection of sensors and actuator technologies are given herein with emphasis on remote controlled solutions developed to solve environmental condition and integration issues.