Electrostatic and magnetic measurements of turbulence and transport in Extrap T2

Langmuir probe and magnetic pick-up coil measurements are used to study edg e turbulence in the Extrap T2 reversed field pinch. Magnetic fluctuations r esonant outside the toroidal field reversal surface are observed where prev iously only fluctuations in the spectra of potential and electron density a nd temperature have been measured. Results are presented which imply that t hese fluctuations are coupled to and also correlated to the internally reso nant tearing mode fluctuations. Evidence of coupling between low-frequency (<100 kHz) and high-frequency fluctuations is also presented. The normalize d floating potential fluctuations are seen to increase with the edge electr on temperature. This causes an increase of the potential and density fluctu ation driven transport with the temperature which is faster than linear. Th ese results, in combination, are consistent with a picture where internally resonant fluctuations couple to edge fluctuations through radial heat cond uction from the stochastic core to the edge.