Nagashima Yoshihiko, Inagaki Shigeru, Kamakaki Kunihiro, Arakawa Hiroyuki, Yamada Takuma, Shinohara Shunjiro, Kawai Yoshinobu, Yagi Masatoshi, Fujisawa Akihide, Itoh Sanae-I, Itoh Kimitaka, Takase Yuichi
GSFS, The University of Tokyo, Kashiwa, Chiba 816-8561, Japan.
Rev Sci Instrum. 2011 Mar;82(3):033503. doi: 10.1063/1.3557384.
A new radially movable multichannel azimuthal probe system has been developed for measuring azimuthal and radial profiles of electrostatic Reynolds stress (RS) per mass density of microscale fluctuations for a cylindrical laboratory plasma. The system is composed of 16 probe units arranged azimuthally. Each probe unit has six electrodes to simultaneously measure azimuthal and radial electric fields for obtaining RS. The advantage of the system is that each probe unit is radially movable to measure azimuthal RS profiles at arbitrary radial locations as well as two-dimensional structures of fluctuations. The first result from temporal observation of fluctuation azimuthal profile presents that a low-frequency fluctuation (1-2 kHz) synchronizes oscillating Reynolds stress. In addition, radial scanning of the probe system simultaneously demonstrates two-dimensional patterns of mode structure and nonlinear forces with frequency f = 1.5 kHz and azimuthal mode number m = 1.
