2/1 mode is one of the most frequent magnetohydrodynamic instabilities in tokamaks. The rapid growing of 2/1 mode (e.g. Locked mode) frequently leads to disruptions and associated vertical displacements when operating near density limit.

Recently, scientists in Institute of Plasma Physics, Hefei Institutes of Physical Science have found that the rapid growth of m=2 island can convert to m=1 mode in very high density plasma, and only leads to series of internal disruptions, whichtherefore successfully avoids the major disruption.

This m=2 island onset occurs when the ohmic heating input is less than the radiative cooling loss, which agrees with the mode onset behavior of the thermo-resistive model.

Link to the paper: Radiation-driven m=2 island formation and dynamics near density limit in experimental advanced superconducting tokamak ohmic plasma

Repetitive burst of m=2 island in high density operation plasma (XU Liqing)

Contact:

XU Liqing

Institute of Plasma Physics (http://english.ipp.cas.cn/)

Tel: +86-551-65592987

Email: lqxu@ipp.ac.cn