Conceptual design of the ECH upper launcher system for ITER

The challenge of developing the conceptual design of the ECH Upper Launcher system for MHD control in the ITER plasmas has been tackled by team of European Associations together with the European Domestic Agency ("F4E"). The launcher system has to meet the following requirements: (a) a mm-wave system extending from the interface to the transmission line up to the target absorption zone in the plasma and performing as an intelligent antenna; (b) a structural system integrating the mm-wave system and ensuring sufficient thermal and nuclear shielding; (C) port Plug remote handling and testing capability ensuring high Port plug system availability. The paper describes the reference launcher design. The mm-wave system is composed of waveguide and quasi-optical sections with a front steering system. An automated feedback control system is developed as a concept based on an assimilation procedure between predicted and diagnosed absorption location. The structural system consists of the blanket shield module, the port plug frame, and the internal shield for appropriate neutron shielding towards the launcher back-end. The specific advantages of a double walled structure are discussed with respect to adequate baking, to rigidity towards launcher deflection under plasma-generated loads and to removal of thermal loads, including nuclear ones. Basic Studies of remote handling (RH) to validate design development are initiated using a virtual reality simulation backed by experimental validation, for which a launcher handling test facility (LHT) is set LIP as a full scale experimental site allowing furthermore thermohydraulic studies with ITER blanket water parameters. (C) 2008 Elsevier B.V. All rights reserved.

Nearing final design of the ITER EC H&CD Upper Launcher

Robert Bertizzolo, René Chavan, Timothy Goodman, Jean-Daniel Landis, Emanuele Poli, Florian Ramseyer, Olivier Sauter, Matteo Vagnoni

The ITER ECRH system consists of 24 gyrotrons with up to 24 MW installed millimeter wave heating power at 170 GHz, power supplies, control system, transmission lines, one Equatorial and the four Upper Launchers. With its high frequency and small beam focus the ECRH has the unique capability of driving locally current. While the Equatorial Launcher mainly acts for central heating and current profile shaping, the Upper Launchers aim on suppressing MHD instabilities, especially neoclassical tearing modes (NTM) triggering plasma disruptions. The Upper Launchers inject millimeter waves through a quasi-optical section consisting of three fixed and the front steering mirror set. The eight overlapping beams have focal points optimized for suppression of the q = 3/2 and q = 2/1 NTMs. Several project change requests required the redesign of the Upper Launchers and the connected ex-vessel system. This redesign includes a new boundary geometry of the launchers as well as a newly designed cooling system for the Blanket Shield Module (BSM), a modified flange of the BSM to the structural main frame and a refined optical design. Additionally shield blocks with integrated in-vessel waveguides were added and the closure plate with waveguide and supply line feedthroughs was adapted. Further changes, not all caused by PCRs, include newly designed ex-vessel waveguide components with a reduced aperture and redesigned ultra low-loss CVD diamond windows. Finally several components originally foreseen as off-the-shelf components have become part of the design scope. The new launcher design status is presented with selected results on numerical design validation.

ELSEVIER SCIENCE SA2019

High-Power Testing of Guided-Wave Components for the ITER ECH Upper Launcher at the FALCON Test Facility

René Chavan, Timothy Goodman, Matteo Vagnoni

Each of the four ITER electron cyclotron heating (ECH) upper launchers (ULs) features eight transmission lines (TLs) made of guided-wave components used to inject 170-GHz microwave power into the plasma at a level of up to 1.31 MW per line, at the TL diamond window unit (DWU). The guided-wave components include a DWU, an isolation valve (IV), waveguides (WGs), and miter bends (MBs). These form part of the first confinement system (FCS) of the ITER UL. They must withstand the nominal mechanical structural stresses, the electromagnetic forces, and the dynamic loads (VDE, MD, and Seismic), while being compatible with the most stringent ITER vacuum and safety classification. Here, we report new results on plans for high-power testing of guided-wave components that the Swiss Plasma Center (SPC) of the Swiss Federal Institute of Technology Lausanne (EPFL) has developed for the FCS. FALCON is home to testing equipment provided by Fusion for Energy (F4E) and ITER, including an ITER-grade 170-GHz GYCOM gyrotron and a matching optics unit (MOU), an evacuated TL including a power monitor MB (PMMB), a downtaper (DT) to the 50-mm ITER TL diameter, and a matched RF load (RFL). The facility is operated by the SPC.

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Overview of the ITER EC H&CD system and its capabilities

Stefano Alberti, Robert Bertizzolo, René Chavan, Timothy Goodman, Jean-Philippe Hogge, Jean-Daniel Landis, Ioannis Pagonakis, Emanuele Poli, Laurie Porte, Francisco Sanchez, Olivier Sauter, Minh Quang Tran, Hartmut Zohm

The Electron Cyclotron (EC) system for the ITER tokamak is designed to inject >= 20 MW RF power into the plasma for Heating and Current Drive (H&CD) applications. The EC system consists of up to 26 gyrotrons (between 1 and 2 MW each), the associated power supplies, 24 transmission lines and 5 launchers. The EC system has a diverse range of applications including central heating and current drive, current profile tailoring and control of plasma magneto-hydrodynamic (MUD) instabilities such as the sawtooth and neoclassical tearing modes (NTMs). This diverse range of applications requires the launchers to be capable of depositing the EC power across nearly the entire plasma cross section. This is achieved by two types of antennas: an equatorial port launcher (capable of injecting up to 20 MW from the plasma axis to mid-radius) and four upper port launchers providing access from inside of mid radius to near the plasma edge. The equatorial launcher design is optimized for central heating, current drive and profile tailoring, while the upper launcher should provide a very focused and peaked current density profile to control the plasma instabilities.

Elsevier2011