Observation of core electron temperature rise in response to an edge cooling in toroidal helical plasmas

Abstract

The first observation of a significant rise of core electron temperature in response to edge cooling in a helical plasma has been made on the Large Helical Device [O. Motojima et al., Phys. Plasmas 6, 1843 (1999)]. When the phenomenon occurs, the electron heat diffusivity in the core region is reduced abruptly without changing local parameters in the region of interest. Therefore the phenomenon can be regarded as a so-called “nonlocal” electron temperature rise observed so far only in many tokamaks.