Design of a mechanically actuated RF grounding system for the ITER ICRH antenna

David Hancock, Mark Shannon, Bertrand Beaumont, Pierre Dumortier, Frederic Durodie, Volodymyr Kyrytsya, Fabrice Louche, Robert McKinley, Keith Nicholls

Research output: Contribution to journalArticle

2 Citations (Scopus)


In the ITER equatorial ports containing ICRH antennas, parasitic electrical resonances can be excited in the nominal 20 mm clearance gap between the port walls and the plug contained within it. RF calculations have established that these resonances can be effectively mitigated by a series of suitably located electrically conducting contacts between the port and plug. These contacts must allow installation and removal of the antenna but must also make reliable electrical contact during antenna operation. In addition, the contacts must be compliant enough to survive deflection of the port during seismic and disruption events without transmitting large forces to the vacuum vessel. The distance to be spanned is subject to significant uncertainty, due to the large manufacturing tolerances of the surrounding components, and this also must be considered during the design process. This paper outlines progress made in the design of the grounding system, as well as detailing a number of concepts which have been investigated and abandoned, leading up to the current reference design. The current reference design is a simple and robust mechanical solution consisting of sprung Copper-plated Inconel flaps which use part of the range of the shimming system included in the antenna design as the actuation mechanism. This paper also details practical testing of a number of aspects of the design, including building and testing a prototype to validate mechanical and thermal analyses. © 2013 Elsevier B.V.
Original languageEnglish
Pages (from-to)2100 - 2104
Number of pages5
JournalFusion Engineering and Design
Issue number9-10
Publication statusPublished - Oct 2013
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Hancock, D., Shannon, M., Beaumont, B., Dumortier, P., Durodie, F., Kyrytsya, V., ... Nicholls, K. (2013). Design of a mechanically actuated RF grounding system for the ITER ICRH antenna. Fusion Engineering and Design, 88(9-10), 2100 - 2104.