Variational full wave calculation of fast wave current drive in DIII-D using the ALCYON code
This report describes the main features of the ALCYON 2D-full wave code, and its application to the modelling of the first fast wave current drive experiments in DIII-D. The advantage of this code lies in the weak electron damping which is inherent to the fast magnetosonic wave. The two cases considered differ in their toroidal magnetic field and temperature. The field structure in the plasma is shown to be very different from a single pass structure, and the build up of high poloidal mode numbers leads to strong modifications in the absorbed spectrum. In particular, the local extension of the poloidal mode number spectrum increases with minor radius and therefore the local j/p decreases slightly, from the plasma centre to the edge, despite the density decrease. Since the electron temperature plays a major role in the absorption, the power deposition profiles are already peaked, and therefore the RF current profiles are also very peaked.
Bibliographic Reference: Report: EUR-CEA-FC-1439 EN (1991) 37 pp.
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 199210407 / Last updated on: 1994-12-02
Original language: en
Available languages: en