Large Scale CW ECRH Systems: Some considerations

¹ Max Planck Institut für Plasmaphysik, EURATOM-Association, Teilinstitut Greifswald, Germany
² Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
³ Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
⁴ Karlsruher Institut für Technologie, KIT, Association EURATOM-KIT, IHM, D-76021 Karlsruhe, Germany

Abstract

Electron Cyclotron Resonance Heating (ECRH) is a key component in the heating arsenal for the next step fusion devices like W7-X and ITER. These devices are equipped with superconducting coils and are designed to operate steady state. ECRH must thus operate in CW-mode with a large flexibility to comply with various physics demands such as plasma start-up, heating and current drive, as well as configurationand MHD - control. The request for many different sophisticated applications results in a growing complexity, which is in conflict with the request for high availability, reliability, and maintainability. ‘Advanced’ ECRH-systems must, therefore, comply with both the complex physics demands and operational robustness and reliability. The W7-X ECRH system is the first CW- facility of an ITER relevant size and is used as a test bed for advanced components. Proposals for future developments are presented together with improvements of gyrotrons, transmission components and launchers.