Understanding 3D tokamak physics towards advanced control of toroidal plasma

Dr. Kimin Kim, KAIST
May 31 (Tue.) 4 PM, #1323(E6-2, 1st fl.)

Tokamaks that magnetically confine high-temperature toroidal plasmas are the most successful and promising fusion device. Tokamaks have been considered as 2D system due to toroidal symmetry along the magnetic axis, called axisymmetry. The axisymmetry, however, can never be perfect due to imperfections in the surrounding magnets and conductors, which produce toroidal non-axisymmetry.  Physics of the non-axisymmetric (3D) tokamaks has been of great importance in the recent fusion plasma research, as tokamaks are very sensitive to a small 3D magnetic field that can significantly degrade or improve the machine performance. This talk will introduce the research issues associated with the non-axisymmetry in tokamaks and describe the progress on the understanding of 3D tokamak physics. Plasma transport physics in the 3D tokamak will be presented along with numerical verifications using guiding-center particle simulation and experimental validations in the various devices. Control of plasma confinement and stability using externally applied 3D magnetic fields will be discussed.