Plasma dielectric properties and ICRF antenna impedance matrices
Ion Cyclotron Range of Frequencies (ICRF) waves will be coupled to ITER plasma with arrays of radiating straps. Such arrays are fully characterized by input impedance matrix [Z(ij)], relating RF voltage Vi on strap feeder i to RF current l(j) on feeder j, thus summarizing all antenna coupling properties. Modelling Z precisely has recently become a priority : both experiments with the new Tore Supra (TS) ITER-like antenna and modelling for JET-EP  suggest that the new �conjugate-T� matching scheme foreseen for ITER  is sensitive to strap cross-talk, i.e. to off-diagonal Z(ij) elements. However no numerical tool is presently able to account accurately both for the geometrical details of the wave launching structure and for the dielectric properties of a realistic plasma. Simulation would be substantially simplified if the plasma could be reduced to a high permittivity dielectric medium, as in . Yet both measurements and modelling in other contexts [3,4] suggest that some information is always lost in such reduction. This paper investigates the impact on the structure of Z of some dielectric properties specific to a plasma, with emphasis on the coupling imbalance between identical straps.
Bibliographic Reference: An oral paper given at: 31st EPS Conference on Controlled Fusion and Plasma Physics Organised by: CCLRC Rutherford Appleton Laboratory (GB); EURATOM/UKAEA Fusion Association (GB) Held at: Imperial College London(GB)
Availability: Available from Association EURATOM-CEA, Departement de Recherches sur la Fusion Controlee, CEA Cadarache, F-13108 St Paul-Lez-Durance, France Tel: (+33) 4 42 25 70 01; Fax: (+33) 4 42 25 64 21 E-mail: firstname.lastname@example.org
Record Number: 200417670 / Last updated on: 2004-07-30
Original language: en
Available languages: en