Spectroscopic observation of fluctuation-induced dynamo in the edge of thereversed-field pinch

The fluctuation-induced dynamo [(v) over tilde x (b) over tilde] has been i nvestigated by direct measurement of (v) over tilde and (b) over tilde in t he edge of a reversed-field pinch and is found to be significant in balanci ng Ohm's law. The velocity fluctuations producing the dynamo emf have poloi dal mode number m = 0, consistent with MHD calculations and in contrast wit h the core In = 1 dynamo. The velocity fluctuations exhibit the parity rela tive to their resonant surface predicted by linear MHD theory.