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On the polarization of shear Alfvén and acoustic continuous spectra in toroidal plasmas

Published online by Cambridge University Press:  16 September 2020

M. V. Falessi*
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy INFN – Rome section, Piazz.le Aldo Moro 2, 00185Roma, Italy
N. Carlevaro
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy Consorzio RFX, Corso Stati Uniti 4, 35127Padova, Italy
V. Fusco
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy
E. Giovannozzi
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy
P. Lauber
Affiliation:
Max Planck Institute for Plasma Physics, 85748Garching, Germany
G. Vlad
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy
F. Zonca
Affiliation:
Fusion and Nuclear Safety Department, ENEA, C. R. Frascati, Via E. Fermi 45, 00044Frascati (Roma), Italy Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou310027, PR China
*
Email address for correspondence: matteo.falessi@enea.it

Abstract

In this work, the FALCON code is adopted for illustrating the features of shear Alfvén and sound continuous spectra in toroidal fusion plasmas. The FALCON codes employ the local Floquet analysis discussed in (Phys. Plasmas, vol. 26, issue 8, 2019, 082502) for computing global structures of continuous spectra in general toroidal geometry. As particular applications, reference equilibria for the divertor tokamak test and ASDEX Upgrade plasmas are considered. In particular, we illustrate the importance of mode polarization for recognizing the physical relevance of the various branches of the continuous spectra in the ideal magnetohydrodynamics limit. We also analyse the effect of plasma compression and the validity of the slow sound approximation.

Type
Research Article
Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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References

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