Calculation of the self-consistent current distribution and coupling of an RF antenna array
A self-consistent calculation of the antenna current distribution and fields in an axisymmetric cylindrical geometry for the ICRH antenna-plasma coupling problem is presented. Several features distinguish this calculation from other codes: (i) the formulation of the self-consistent antenna current problem in a variational form allows good convergence and stability of the algorithm; (ii) the use of multiple straps allows modelling of the current distribution across the width of the strap (by dividing it up into sub straps), side limiters and septrum, and antenna cross coupling; (iii) analytic calculation of the antenna field and calculation of the antenna self-consistent current distribution (given the surface impedance matrix) gives rapid calculation; (iv) framing the calculation for parallel computation on several different parallel architectures (as well as serial) gives a large speed improvement. Results are presented for both Alfvén wave heating and current drive antenna arrays, showing the optimal coupling to be achieved for toroidal mode numbers between 8 and 10 for typical ASDEX Upgrade plasmas. Simulations of the ASDEX Upgrade antenna show the importance of the current distribution across the antenna and of image currents flowing in the side limiters. An analysis of a proposed asymmetric ITER antenna is presented.
Bibliographic Reference: Report: IPP 4/263 EN (1993)
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199410052 / Last updated on: 1994-11-28
Original language: en
Available languages: en