New Interpretation of Ion Cyclotron Emission from a Tokamak
ORAL
Abstract
The tempting interpretation of Ion Cyclotron Emission (ICE) in terms of compressional Alfv´en eigenmodes involving energetic ions is inconsistent with recent TCV experimental observations in some important aspects, such as i) the perturbed poloidal field is exceeding the parallel perturbed magnetic field significantly, and ii) the modes are near cyclotron harmonic and exhibit Alfv`en scaling of their frequency. We show that these characteristics can be explained by considering finite Larmor radius effects of thermal ions in shear Alfv´en waves that allow such waves to exist well above the ion cyclotron frequency in the form of wavepackets bouncing within the plasma volume.
*This work was supported byU.S. Department of Energy Contract Nos. DEFG02-04ER54742, by the EPSRC Energy Program [Grant numberEP/W006839/1], and by National Research Foundationof Ukraine [Grant 2023.03/0101]. This work hasbeen carried out within the framework of the EUROfusionConsortium, funded by the European Union viathe Euratom Research and Training Programme [GrantAgreement No 101052200 — EUROfusion]. Views andopinions expressed are however those of the authors onlyand do not necessarily reflect those of the EuropeanUnion or the European Commission. Neither the EuropeanUnion nor the European Commission can be heldresponsible for them.
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Presenters
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Boris Breizman
- University of Texas at Austin