T. Markovic Y. Q. Liu P. Cahyna R. Pánek M. Peterka M. Aftanas P. Bílková P. Bohm M. Imríek P. Há?ek J. Havlicek A. Havránek M. Komm J. Urban The COMPASS Team
It has been shown on several tokamaks that application of a Resonant Magnetic Perturbation (RMP) eld on plasma can under certain conditions lead to suppression or mitigation of Edge-Localized Mode (ELM) instabilities. Due to the rotation of the plasma in the RMP eld reference system, currents are induced on resonant surfaces within the plasma, co…
Preprint PublishedJakub Urban Joan Decker Yves Peysson Josef Preinhaelter Vladimir Shevchenko Gary Taylor Linda Vahala George Vahala
The electron Bernstein wave (EBW) is typically the only wave in the electron cyclotron (EC) range that can be applied in spherical tokamaks for heating and current drive (H&CD). Spherical tokamaks (STs), which feature relatively high neutron flux and good economy, operate generally in high-ß regimes, in which the usual EC O- and X- modes are cut-o…
PublishedJ. Urban J. Decker Y. Peysson J. Preinhaelter V. Shevchenko et al.
Spherical tokamaks (STs), which feature relatively high neutron flux and good economy, operate generally in high-ß regimes, in which the usual EC O- and X- modes are cut-off. In this case, electron Bernstein waves (EBWs) seem to be the only option that can provide features similar to the EC waves—controllable localized heating and current drive …
PublishedJakub Urban Michal Stránsky Vladimíir Fuchs Irina Voitsekhovitch Martin Valovic
The COMPASS tokamak, a mid-sized flexible device with ITER-like shape, which can operate in H-mode, is starting its re-established operation at the Institute of Plasma Physics in Prague. A new 600 kW, 40 keV neutral beam injection (NBI) system is foreseen as a major upgrade. Reported here are predictive simulations with the ASTRA transport code, in…
PublishedJ. Preinhaelter G. Taylor V. Shevchenko J. Urban M. Valovic P. Pavlo L. Vahala G. Vahala
The interpretation of EBW emission from spherical tokamaks is nontrivial. We report on a 3D simulation model of this process that incorporates Gaussian beams for the antenna, a full wave solution of EBW-X and EBW-X-O conversions using adaptive finite elements, and EBW ray tracing to determine the radiative temperature. This model is then used to in…
PublishedJosef Preinhaelter Jakub Urban Pavol Pavlo
The effect of the direction of the detected beam on the intensity of ECE is studied. It is found that the combined effects of the strong dependence of the conversion efficiencey of O mode at the plasma resonance on the direction of the incident wave and the partial screening of the beam waist by the MAST vessel wall, can be responsible for the weak…
Published