Fluctuation characteristics in detached SOL/Divertor plasmas of JT-60U

Tanaka, Hirohiko*; Ono, Noriyasu*; Asakura, Nobuyuki; Tsuji, Yoshiyuki*; Kajita, Shin*

We have investigated fast temporal electrostatic fluctuations measured in detached SOL/divertor plasmas of JT-60U. Application of statistical analysis techniques clarified that fluctuations of ion saturation current measured around X-point had a number of positive spikes under the detached condition, but not under the attached condition. This result suggests that an intermittent phenomenon occurred near the detached divertor leg would generate blob-like structures in divertor region. In this presentation, we will show the results obtained by using several analysis techniques (e.g. spectral analysis, conditional averaging, and so on). After that, we will compare the results between under the detached and attached condition.