Optimization of Antenna Current Feeding for the Alfv,n Eigenmodes Active Diagnostic System of JET

Author(s)

Albarracin Manrique, Marcos A. ^{[1, 2]} ; Ruchko, L. ^[1] ; Pires, C. J. A. ^[1] ; Galvao, R. M. O. ^{[1, 3]} ; Elfimov, A. G. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Fis, Sao Paulo - Brazil

^[2] Inst Super Inovacao & Tecnol ISITEC, Sao Paulo - Brazil

^[3] Inst Nacl Pesquisas Espaciais, Sao Jose Dos Campos - Brazil

• Document type: Journal article
• Source: Brazilian Journal of Physics; v. 48, n. 2, p. 146-154, APR 2018.
• Web of Science Citations: 0

Abstract

The possibility of exploring proper phasing of the feeding currents in the existing antenna of the Alfv,n Eigenmodes Active Diagnostic system of JET, to excite pure toroidal spectra of Toroidal Alfv,n Eigenmodes, is numerically investigated. Special attention is given to the actual perturbed fields excited in the plasma, which are calculated self-consistently using the antenna version of the CASTOR code. It is found that due to the close spacing of the JET antenna modules and quasi degeneracy of modes with medium to high values of the toroidal mode number n, although a proper choice of the phasing of the feeding currents of the antenna modules indeed leads to an increase of the perturbed fields of the selected mode, modes with nearby values of n are also excited with large amplitudes, so that a scheme to proper select the detected modes remains necessary. A scheme using different antenna position distribution is proposed to achieve successful optimization. (AU)

• FAPESP's process: 11/50773-0 - Center of excellence in physics and applications of plasmas
• Grantee: Ricardo Magnus Osório Galvão
• Support Opportunities: Research Projects - Thematic Grants