Bastian Weinhorst

Cooling design and analysis of the ITER EC Upper launcher

ITER will be equipped with four EC (Electron Cyclotron) upper launchers of 8 MW microwave power each with the aim to counteract plasma instabilities during operation. The launcher antennas will be installed into four upper ports of the ITER vacuum vessel. All in-vessel microwave components of an EC antenna, comprising several sets of mirrors and waveguides are mounted into so-called upper port plugs. These are basically hollow casks which fit into the ports as cantilevered built-in components, forming thus integrated systems which guarantee optimum performance and simplify assembly and maintenance.

The ITER ECH & CD Upper Launcher: Steps towards final design of the first confinement system

The ITER Electron Cyclotron Heating and Current Drive (ECH&CD) Upper Launcher, whose preliminary design was approved in 2009, is on its way towards the final design. The design work is being done by a consortium of several European research institutes in tight collaboration with F4E. The main focus is the finalization of the design of all components for the First Confinement System (FCS), which forms the vacuum and Tritium barrier. The FCS comprises structural components as well as the external waveguide components in the port cell. Structural components of the FCS include the flange seal, backend frame and closure plate. The external waveguide components include the isolation valve, CVD diamond windows, miter bends and straight waveguides. Because finalizing of the design of these components is directly influenced by the layout of many in-vessel components, the design work includes also further development of the entire launcher. This paper summarizes the most recent status of the design work on the structural components of the launcher FCS, which are the support flange, the socket, the closure plate and feed-throughs for waveguides and cooling pipes. The design work includes the engineering layout of these components in accordance with system requirements, load specifications and Quality and Safety classification. An outline of the overall design of the launcher will be presented. The design progress was based on a set of related analyses, of which particular results are given. Also the integration of the associated mm-wave components, assembly strategies, neutronic aspects and the design of the shielding components will be described.

The ITER EC-H&CD Upper Launcher: FEM analyses of the blanket shield module with respect to surface and nuclear heat loads

In the frame of the new grant signed in November 2011 between Fusion for Energy (F4E) and the ECHUL-CA consortium, the development process of the Electron Cyclotron Heating and Current Drive (EC H&CD) Upper Launcher (UL) in ITER has moved a step towards the final design phase. The Blanket Shield Module (BSM) is a plasma facing component located at the tip of the launcher. The structure consists of a first wall panel (FWP) and a shell both with embedded cooling channels. A flange on the rear part allows the BSM to be connected by bolts to the main frame of the UL. Being a plasma facing component, the BSM is subjected to severe heat loads due to both thermal and nuclear irradiation. The current baseline value of surface heat load during normal plasma operation is 0.5 MW/m2, while the volumetric nuclear heating is responsible for a total generation of about 160 kW. The temperature gradients resulting from the abovementioned heat loads have been assessed by FEM analyses. The temperature distributions are then transferred to a structural model for calculation of the induced thermal stresses. The surface heat load is applied to the FWP as a constant flux. The nuclear loads, instead, were assessed by MCNP calculations and are provided by means of a mesh tally with a grid step of 1 cm. The results have shown that the temperature reaches 260 °C at the FWP and at the flange of the BSM. As a consequence of large temperature gradients, high stresses (in the order of 200 MPa) are also induced at the inner cooling channels of the BSMs structure.