Fusion Science and Technology / Volume 58 / Number 1 / July/August 2010 / Pages 194-199
Chapter 4. MHD / Special Issue on Large Helical Device (LHD) / dx.doi.org/10.13182/FST10-A10806
Spontaneous dynamics of magnetic islands depending on various plasma parameters in the Large Helical Device (LHD) are described. The structure of the magnetic island undergoes deformation during a discharge. There are two states of magnetic island; they are the growth and self-healing of the magnetic island. The self-healing occurs in the higher-beta and lower-collisionality plasmas. The magnetic island, on the other hand, grows in the lower-beta and higher-collisionality region. The self-healing phenomenon is realized by the disappearance of the local flattening of the Te profile and the perturbed magnetic field structure compensating the externally imposed perturbation field to produce a seed magnetic island.