Energetic‐Particle‐Driven Instabilities in General Toroidal Configurations

Beiträge aus der Plasmaphysik 07/2010; 50(8):708 - 712. DOI: 10.1002/ctpp.200900066
Source: OAI

ABSTRACT Energetic-particle driven instabilities have been extensively observed in both tokamaks and stellarators. In order for such devices to ultimately succeed as D-T fusion reactors, the super-Alfvénic 3.5 Mev fusion-produced alpha particles must be sufficiently well confined. This requires the evaluation of losses from classical collisional transport processes as well as from energetic particle-driven instabilities. An important group of instabilities in this context are the discrete shear Alfvén modes, which can readily be destabilized by energetic particles (with velocities of the order of vAlfvén) through wave-particle resonances. While these modes in three-dimensional systems have many similarities to those in tokamaks, the detailed implementation of modeling tools has required development of new methods. Recent efforts in this direction will be described here, with an emphasis on reduced models (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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    ABSTRACT: Energetic particle populations in magnetic confinement systems are sensitive to symmetry-breaking effects due to their low collisionality and long confined path lengths. Broken symmetry is present to some extent in all toroidal devices. As such effects preclude the existence of an ignorable coordinate, a fully three-dimensional analysis is necessary, beginning with the lowest order (equilibrium) magnetic fields. Three-dimensional techniques that have been extensively developed for stellarator configurations are readily adapted to other devices such as rippled tokamaks and helical states in reversed field pinches. This paper will describe the methods and present an overview of recent examples that use these techniques for the modeling of energetic particle confinement, Alfvén mode structure and fast ion instabilities.
    Physics of Plasmas 04/2011; 18(5):056109-056109-8. · 2.38 Impact Factor

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