Tore Supra ITER-like antenna characterization by fem analysis
The Ion Cyclotron (IC) technique for plasma heating and current drive is widely applied to the TORE SUPRA experiment to develop an efficient, reliable and stationary system for the next step application like ITER. A new four-elements (2poloidalx2 toroidal) IC array designed to launch up to 4 MW in the plasma in the frequency range 40-60 MHz and in pulses up to for 30 s long has been installed in TORE SUPRA vacuum vessel at the beginning of 2004. The array features with the same electric scheme adopted in the ITER reference design, for which a significant tolerance to resistive load variations (such as those induced by ELMs is predicted1). This paper describes the high-frequency electromagnetic (EM) analysis by 3D Finite Elements Modelling (FEM) of the array and of its associated tuning system, consisting of a set of variable capacitive reactances, connected in series with each element and paired poloidally in parallel. The finite element analysis is based on a full-wave formulation of Maxwell's equations in terms of the time-harmonic electric field E implemented in the ANSYS commercial code. The array/tuning system is first decomposed sections suitable to establish boundary conditions and each section is accurately modelled to deduce RF electric fields and currents distribution, so as to assess its voltage standoff capability and ohmic losses. Global (S) parameters are then computed as function of frequency (10 to 80MHz) for each component in standard matching conditions. The array is finally re-synthesized by a computer code, which uses the S-parameter description to assess field and current distributions at the appropriate tuning conditions. This method is a new approach to the design of high frequency systems, when its physical dimensions are a non-negligible fraction of the wavelength, and the effects of local modes cannot be accounted for by a pure transversal electromagnetic mode analysis.
Bibliographic Reference: An oral paper given at: 23rd Symposium on Fusion Technology Organised by: Consorzio RFX (IT) Held at: Fondazione Cini, Venice (IT)
Availability: Available from Association EURATOM-CEA, Département de Recherches sur la Fusion Contrôlée, 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: email@example.com
Record Number: 200517977 / Last updated on: 2005-03-10
Original language: en
Available languages: en