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The ITER Research Plan (IRP) has undergone significant modifications based on the change of First Wall (FW) material from beryllium (Be) to tungsten (W). Such a change, together with the constraint of achieving Q=10 for 300s with a neutron fluence of ~1% of the total ITER lifetime fluence, calls for a modification of the heating mix, now dominated by Electron Cyclotron Heating (ECH), to ensure robust plasma operation and provide the most flexible operational space, w.r.t. to Ion Cyclotron Heating (ICH) and Neutral Beam Injection (NBI). This contribution gives first a brief overview of the revised heating mix in the new ITER baseline, with a description of the planned new configuration of the EC system, i.e. the set of Upper and Equatorial launchers needed to inject up to 60-67 MW to ITER plasmas. Delivery of this increased power requires the installation of a second equatorial launcher for the DT phase. The various contexts for which the EC system will be applied cover plasma initiation, wall conditioning, heating, current drive, W and MHD control, to achieve high-performance plasmas and ensure the completion of ITER milestones for the various phases of the IRP. The operational strategy for each phase will be described, in terms of optimal choice of launchers, applied power and polarization, taking into account the plasma evolution during a discharge. The operational conditions are adjusted to achieve the best plasma performance while ensuring that stray radiation does not damage in-vessel components.

A dedicated optical system is designed for the breakdown of the first ITER plasma, when the machine will not be equipped with the equatorial ECRH-launcher. Seven beams from the upper launcher will be transmitted via several in-vessel mirrors through the resonance layer to a beam-dump. The whole system was simulated with the PROFUSION package to obtain the beam parameters, estimate spill-over effects and determine the required polarization in the launcher in order to have X-mode polarization in the resonance.

This paper describes the modelling work carried out within the ITER Integrated Modelling and Analysis Suite (IMAS) [1] using the TORBEAM wave code [2] to estimate heat loads on the first wall (FW) from operating the Electron Cyclotron (EC) system in various scenarios of the ITER new baseline currently under preparation. These results provide guidance on how to best operate the EC system in terms of polarisation and operating launchers for the various phases of the Research Plan and of a pulse, to limit FW heat loads. Strategies to best protect the FW from EC power losses are also discussed.

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 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.