Direct measurement of poloidal long-wavelength E x B flows in the HT-7 tokamak.

摘要: The poloidal long-wavelength $E\ifmmode\times\else\texttimes\fi{}B$ time-varying flows were directly measured using a forked Langmuir probe in the HT-7 tokamak. Low-frequency ($l10\text{ }\text{ }\mathrm{k}\mathrm{H}\mathrm{z}$) observed at plasma edge, which possess many of characteristics zonal flows, including (${k}_{\ensuremath{\theta}}{\ensuremath{\rho}}_{i}\ensuremath{\sim}0$) and narrow radial extent (${k}_{r}{\ensuremath{\rho}}_{i}\ensuremath{\sim}0.1$). cross bicoherence turbulent Reynolds stress indicates existence nonlinear three-wave coupling processes generation low-frequency flows. estimated flow-shearing rate is same order magnitude as turbulence decorrelation may thus regulate fluctuation level thereby turbulence-driven transport.