Rotating magnetohydrodynamic and trapped hot-ion induced internal kinks

As a new and significant contribution to the tokamak literature, the linear internal MHD kink modes in finite aspect-ratio axisymmetric toroidally rotating tokamak equilibria and their kinetic modifications owing to the presence of hot ions are computationally studied herein using a bilinear form derived using a Lagrangian perturbation procedure. As a practical application, the rotating MHD and kinetic internal kinks are calculated in finite aspect-ratio TFTR- and ITER-like geometries. The MHD and kinetic modes of the rotating tokamak plasmas are found to be significantly destabilized by the centrifugal effects at rotation speeds in the range of $10\sp4$-10$\sp5$ rad/s at normal discharge densities. The kinetic instability model provides a unified description of several features of the 'fishbone'-like oscillations such as the slow mode rotating at the plasma rotation frequency, the fast mode with high rotation frequency, and variation of the slow as well as fast mode frequencies with plasma rotation. The slow kinetic modes rotate close to mean plasma rotation speeds, and the fast kinetic modes rotate at about 10$\sp5$ rad/s. The fast mode rotation frequencies are in the range of the magnetic-precession frequencies of the deeply trapped ions. Also, the kinetic kink modes are found to be excitable in ITER-like ignited tokamak configurations owing to hot fusion products such as alphas.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Varadarajan, V.

Contributors dc:contributor

• Miley, George H.

• Engineering, Nuclear
• Physics, Fluid and Plasma

Statement dc:rights

• Copyright 1993 Varadarajan, V.

Language dc:language

eng

Identifier

AAI9411809
(UMI)AAI9411809

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21572