Low frequency fluctuations near relaxed state of reversed field pinch (RFP) in the presence of stationary plasma flow

The frequencies of the fluctuations near the relaxed state of reversed fiel d pinch (RFP) plasma in the presence of a stationary toroidal flow are inve stigated using magnetohydrodynamical (MHD) theory in the approximation of t he infinite aspect ratio and finite resistivity. We treat the fluctuations as MHD waves and derive their dispersion relations at the edge plasma. It i s shown that there exists a new fluctuation mode with low frequency in the presence of a stationary toroidal flow, and that with the plasma resistivit y it can be unstable. The dispersion relations of the new fluctuation mode and other MHD modes of the compressible plasma are obtained. The magnitudes of the frequencies are estimated using the parameters of TPE-RX, MST and R FX devices.