Systematic linear-stability assessment of Alfvén eigenmodes in the presence of fusion α-particles for ITER-like equilibria. (30th June 2015)

• Record Type: Journal Article
• Authors: Rodrigues, P.; Figueiredo, A.; Ferreira, J.; Coelho, R.; Nabais, F.; Borba, D.; Loureiro, N.F.; Oliver, H.J.C.; Sharapov, S.E.
• Is Part Of: Nuclear fusion. Volume 55:Number 8(2015:Aug.)
• Publication Date: 2015-06-30
• Subjects: Alfvén eigenmodes -- alpha-particles -- wave-particle interaction -- tokamaks; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/55/8/083003
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: A systematic approach to evaluate the linear stability of Alfvén eigenmodes in the presence of fusion-born -particles is reported. The techniques developed are particularly useful when dealing with scenarios where no experimental guidance is available about which eigenmodes are more easily destabilized by the supra-thermal population. The advantages and limitations of the underlying model chosen to describe the wave-particle interaction are discussed, along with the parallelization of the designed workflow in order to take advantage of massively parallel computer systems. This workflow is tested using a ITER baseline scenario, showing that it is able to routinely single out the most linearly unstable eigenmodes for a given equilibrium configuration. The eigenmodes with highest growth rate were found to be core-localised Toroidal Alfvén Eigenmodes with toroidal mode number, placed near the maximum of the -particle density gradient and within a low magnetic-shear region.