English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The excitation of toroidicity induced Alfv{\'e}n eigenmodes (TAEs) usingprescribed external electromagnetic perturbations (hereafter ``antenna") actingon a confined toroidal plasma as well as its nonlinear couplings to other modesin the system is studied. The antenna is described by an electrostaticpotential resembling the target TAE mode structure along with its correspondingparallel electromagnetic potential computed from Ohm's law. Numerically stablelong-time linear simulations are achieved by integrating the antenna within theframework of a mixed representation and pullback scheme [A. Mishchenko, et al.,Comput. Phys. Commun. \textbf{238} (2019) 194]. By decomposing the plasmaelectromagnetic potential into symplectic and Hamiltonian parts and using Ohm'slaw, the destabilizing contribution of the potential gradient parallel to themagnetic field is canceled in the equations of motion. Besides evaluating thefrequencies as well as growth/damping rates of excited modes compared toreferenced TAEs, we study the interaction of antenna-driven modes with fastparticles and indicate their margins of instability. Furthermore, we show firstnonlinear simulations in the presence of a TAE-like antenna exciting other TAEmodes, as well as Global Alfv\'en Eigenmodes (GAE) having different toroidalwave numbers from that of the antenna.

Linear and nonlinear excitation of TAE modes by external electromagnetic perturbations using ORB5