Control of instabilities by Alfvén waves and resonant magnetic perturbations in magnetized plasmas

• Grant number: 14/50794-6
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2015
• End date: August 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Agreement: CNRS
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal Investigator: Iberê Luiz Caldas
• Grantee: Iberê Luiz Caldas
• Principal researcher abroad: Sadrudrin Benkkada
• Institution abroad: Aix-Marseille Université (AMU), France
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/19296-1 - Nonlinear dynamics, AP.TEM

Abstract

The MHD instabilities driven by fast particles, produced by fusion reactions, are an important issue for tokamak plasmas. The effects of these instabilities on the confinement and on other MHD instabilities are still unclear. We will investigate the excitation threshold and dynamics of these modes in order to evaluate models used to predict their effect in next fusion devices. Resonant magnetic perturbations and Alfvén waves are an important tool to mitigate the instabilities in plasmas and to improve the confinement of energy and particles. Considering the EMEDGE3D code, the full MHD three-dimensional model will be used to study the instabilities mitigation along with simplified one-dimensional models to provide a better understanding of the physical mechanisms for plasma confinement. We will also investigate wave-particle interactions using the travelling wave tube (TWT) of the Aix-Marseille University. In the TWT, an electron beam moves under the action of an axial magnetic field and electrostatic waves. A system similar to the TWT has been studied on a theoretical basis by the Plasma Group of the University of São Paulo. As part of this contribution, we will analyses 14 the dynamics of both low and high-density beams, and check experimentally the validity of theoretical results and numerical codes. (AU)