DTU and IST design diagnostic system for ITER

Image: ITER Organization Image: ITER Organization

In February, F4E and a consortium comprising the Danish and Portuguese Research Units DTU and IST-IPFN signed the Framework Partnership Agreement for the design of a Collective Thomson Scattering diagnostic system for ITER. The contract will run for the next four years.

The Collective Thomson Scattering (CTS) diagnostic system will monitor the dynamics of the fast ions produced in the deuterium-tritium fusion process as well as by ion heating (NBI and ICRH). It sends powerful and high frequency microwaves (1 MW and 60 GHz) into the plasma and records the scattered electromagnetic waves. The measurement enables establishing the dynamics and distribution of the ions in the plasma – especially the fast ions from the fusion processes.

For Denmark, this is the biggest order to date from F4E. The Danish research unit – now at DTU Physics – has been developing the Collective Thomson Scattering diagnostic system at over the past decade on TEXTOR and ASDEX Upgrade in collaboration with MIT and other European partners. This has put the DTU Physics CTS group in the international forefront of development and operation of such systems. In the project, DTU will be responsible for the overall project coordination and seven Specific Grant contracts. These cover specification, development and design of the CTS diagnostic system, evaluation of the diagnostic performance, prototype testing etc.

IPFN will be responsible for three Specific Grant Contracts. These include engineering and development of the front end sub-components, which collect the scattered electromagnetic waves – for example horns, mirrors and waveguides. The design also covers the mounting and fixtures for integrating the diagnostic into the foreseen ITER port plug. Studies to ensure the remote handling capability of the design and modelling to evaluate the performance of the components under the high neutron flux of the deuterium-tritium plasma are also carried out. Overall, the activity will lead to development and description of the front-end component manufacturing technique. Together with the ITER Plasma Position Reflectometry System, this is another major contract for IPFN’s Group of Engineering and Systems Integration, in cooperation with IST-CTN in the area of Neutronics.
Søren Bang Korsholm, DTU, is technically responsible for the FPA
Bruno Gonçalves, IST

Probing ITER’s plasma core

Forschungszentrum Jülich leads a consortium to design a diagnostic system for ITER

Example layout of components in the charge exchange port plug. (Image: Forschungszentrum Jülich) Example layout of components in the charge exchange port plug. (Image: Forschungszentrum Jülich)

Subject of the contract is the Charge Exchange Recombination Spectroscopy diagnostic, which determines various properties of the ITER plasma core. The Framework Partnership Agreement was signed with F4E in February and it will run for four years with an F4E contribution of 4.9 million Euros. Members of the consortium are FZ Jülich, KIT, University of technology in Budapest, TU Eindhoven, DIFFER, and CCFE. Contributing third parties include CIEMAT and WIGNER.

Charge Exchange Recombination Spectroscopy (CXRS) utilises a powerful particle beam sent into the plasma core by the Neutral Beam Heating system. These neutral hydrogen particles collide with plasma particles and impurity ions. In the process they lose their electrons, often passing them to the ions. As these electrons decay from excited states they emit light, whose wavelength and spatial distribution yield the respective ion temperature and density. In particular, one can determine the density of helium, a product of the fusion reactions which must be removed from the plasma as it harms its performance.

A CXRS diagnostic system views the region of the plasma core illuminated by the neutral beam and measures the emitted light. Besides the detection unit, it comprises a dedicated mirror system guiding the light from the plasma to the detectors. Especially the mirrors nearest to the plasma need to be designed in a way that contamination with particles from the vessel wall and stress from the plasma exhaust are minimised. FZ Jülich has already developed a mirror station employing shutters as protective manner (See Fusion in Europe 2/2012). The results from this project will contribute to the CXRS design. Once the CXRS diagnostic is designed, it will be procured by F4E and assembled into an ITER port plug.

Dr. Philippe Mertens, FZ Jülich, ph.mertens AT fz-juelich DOT de


KIT_International School Fusion Technologies8th Karlsruhe International School on Fusion Technologies
Karlsruhe, Germany, 8-19 September 2014
Deadline for application: 31. July 2014

This international course is intended for students of engineering and physics currently in technical high schools and universities, particularly after a successful intermediate diploma. PhD students and post-docs in relevant subjects are welcome as well.

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Garching, Germany, 15 – 19 September 2014
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The IPP Summer-University covers the main aspects of plasma physics with emphasis on nuclear fusion. Lectures are held in English. The course is designed for physics and engineering students who passed their bachelor courses or just started their PhD.

More information: http://www.ipp.mpg.de/2767344/su_14