Abstract
An innovative tool has been realized for the 3D/1D simulation of Ion Cyclotron Radio
Frequency (ICRF), i.e. accounting for antennas in a realistic 3D geometry and with an
accurate 1D plasma model. The approach to the problem is based on an integral-equation
formulation for the self-consistent evaluation of the current distribution on the conductors.
The environment has been subdivided in two coupled region: the plasma region and the
vacuum region. The two problems are linked by means of electromagnetic current
distribution on the aperture between the two regions. In the vacuum region all the
calculations are executed in the spatial domain while in the plasma region an extraction in
the spectral domain of some integrals is employed that permits to significantly reduce the
integration support and to obtain a high numerical efficiency leading to the practical
possibility of using a large number of sub-domain (rectangular or triangular) basis functions
on each solid conductor of the system. The plasma enters the formalism via a surface
impedance matrix; for this reason any plasma model can be used; at present the FELICE
code has been adopted, that affords density and temperature profiles, and FLR effects. The
source term directly models the TEM mode of the coax feeding the antenna and the current
in the coax is determined self-consistently, giving the input impedance/admittance of the
antenna itself. Calculation of field distributions (both magnetic and electric), useful for
sheath considerations, is included. This tool has been implemented in a suite, called
TOPICA, that is modular and applicable to ICRF antenna structures of arbitrary shape. This
new simulation tool can assist during the detailed design phase and for this reason can be
considered a "Virtual Prototyping Laboratory" (VPL). The TOPICA suite has been tested
against assessed codes and against measurements and data of mock-ups and existing
antennas. The VPL has been used in the design of various ICRF antennas and also for the
performance prediction of the ALCATOR C-MOD D and E antenna. An extensive set of
comparisons between measured and simulated antenna parameters during ALCATOR CMOD operation will be presented.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 31st European Physical Society Conference on Plasma Physics, 28 June-2 July 2004, London, United Kingdom |
| Publisher | European Physical Society (EPS) |
| Pages | 28G-1/4 |
| Publication status | Published - 2004 |