Fluctuations with long-distance correlation in quasi-stationary and transient plasmas of LHD

摘要

Electron temperature fluctuations with long-distance correlation have been discovered in LHD. This paper reports the extended observations recently made on the spatiotemporal structure of the long-range fluctuations both in quasi-stationary and transient plasmas. The detailed characteristics or spatiotemporal characteristics of long-range temperature fluctuations are revealed successfully using correlation analysis. Particularly, the dynamics of the long-range fluctuations is investigated to find that the amplitude of the fluctuations decreased and their radial correlation lengths shortened during the transient phase induced by pellet injection. Temporal changes of radial correlation structure and amplitude of fluctuations at the onset of change in the plasma state are discussed.