Measurement of Turbulence Decorrelation during Transport Barrier Evolution in a High Temperature Fusion Plasma

Nazikian, R. ; Shinohara, K. ; Kramer, G.J. ; Valeo, E. ; Hill, K. ; Hahm, T.S. ; Rewoldt, G. ; Ide, S. ; Koide, Y. ; Oyama, Y. ; Shirai, H. ; Tang, W.

Princeton University. Plasma Physics Laboratory.

关键词: Jt-60U Tokamak;    70 Plasma Physics And Fusion Technology;    Microwaves;    Transport;    Turbulence;   

DOI  :  10.2172/840434
RP-ID  :  PPPL-4074
RP-ID  :  AC02-76CH03073
RP-ID  :  840434

美国|英语

来源: UNT Digital Library

【 摘 要 】

A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast to the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation.