A Self-Consistent, Integral-Equation Method for the ICRH Antennas Design
Abstract
A method is presented for the self-consistent evaluation of the current distribution and the input impedance of a strap antenna facing a plasma in a slab geometry, in the presence of a backwall. The calculation is based on the solution of an Electric Field Integral Equation (EFIE) in the spectral domain, applying the Galerkin, weighted residual method. Adopting first-order interpolating vector basis and test functions ("rooftops"), no assumptions have been made on the current distribution. The Green's function is derived from the cold plasma surface impedance by means of an equivalent transmission lines model, retaining both the slow and the fast wave contributions. A key feature is an efficient hybrid spectral-spatial extraction technique of the asymptotic Green's function behavior, leading to a drastic reduction of the spectral integration support and global computational effort. The theory has been implemented into a code, and a sample analysis has been made on an IGNITOR like antenna structure, demostrating the agreement with previous results. The code is modular both in its theory background and implementation, and therefore open to significant improvements as the introduction of a three-dimensional current distribution, the presence of the antenna recess and of the Faraday shield, and the adoption of a more accurate plasma model.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1997
- Bibcode:
- 1997APS..DPPhTP414M