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The ITER Electron Cyclotron Resonance Heating (ECRH) & Current Drive (ECCD) system is planned to be progressively installed and commissioned following the four stage approach of the ITER Research Plan. Starting with an injection of up to 5.8 MW from one Upper Launcher (UL) in the vacuum vessel to assist the plasma breakdown during First Plasma (FP) operation, the system will then be extended to achieve a capability of 20 MW injected power in Pre-Fusion Plasma Operation (PFPO) and Fusion Power Operation (FPO) phases. Development of optical modelling was required to characterize the optical performance of the FP configuration with the so-called First Plasma Protection Components. An optical 3D model using Zemax OpticStudio® has been developed and extended to the UL. Effects of higher order modes, thermal deformations and tolerances on the UL functionality have been characterized and are presented. Finally, in preparation of plasma operation and in the frame of the EC system upgrade layout optimisation, ECRH-ECCD modelling is being undertaken within the ITER Integrated Modelling and Analysis (IMAS) suite.

The ITER ECH&CD system is designed to inject 20 MW of millimetre-wave at 170 GHz into the vacuum vessel. The system is composed of many sub-systems, namely High-Voltage Power Supplies (HVPS), Gyrotrons, Transmission Lines (TL), Ex-vessel Waveguides (EW), Launchers. It is the role of the EC Plant Controller (ECPC) to integrate all the Sub-system Control Units (SCU), to prepare the system for operation and to execute the real-time requests coming from the plasma control system. The ECPC also implements plant level protection functions involving more than one sub-system and it interfaces with the ITER Central I&C. This paper gives an overview of the EC system and a description of the control system development focusing on the architecture and the interfaces. Control and protection functions are presented together with a functional allocation to better define interfaces and responsibilities. The preliminary design of the interface with the Plasma Control System to implement advanced control functions is also presented.

The ITER ECRH&CD system is designed to inject 20 MW of millimetre-wave at 170 GHz into the vacuum vessel. The system is composed of many sub-systems, namely High-Voltage Power Supplies (HVPS), Gyrotrons, Transmission Lines (TL), Ex-vessel Waveguides (EW), Launchers. It is the role of the EC Plant Controller (ECPC) to integrate all the Sub-system Control Units (SCU), to prepare the system for operation and to execute the real-time requests coming from the plasma control system. Plant level protections are also implemented by the ECPC, in charge of ensuring the safe operation of the plant, while optimizing the power availability. While control and protection functions are always pushed to the lower possible controller able to implement them, the operational requirements and flexibility of the system make it impossible to fully segregate many functions, since each gyrotron is connected to at least two different launching mirrors. To simplify the SCUs’ development and to respect the responsibility boundaries imposed by the procurement strategy, all the functions involving more than one sub-system are implemented in the ECPC, which exposes a single operational interface towards the ITER Central I&C. The status of the control system development is presented in this work.