MAGNETIC HELICITY TRANSPORT AND REVERSED FIELD PINCH
The Reversed Field Pinch plasma is described by a model based on magnetic helicity transport. It is shown that the mean correlation between fluctuations in fluid velocity and in magnetic field, <"bf u"times"bf B">, provides non-dissipative transport of helicity that persists whether or not the plasma is fully relaxed, as well as a non-Ohmic energy sink that vanishes when the fully relaxed state is attained. Such energy losses account for the anomaly in loop voltage or resistance seen in experiment, which can be interpreted as a loss of helicity associated with obstruction of parallel current flow and magnetic flux emerging from the plasma due to plasma-wall contact. Loss of magnetic flux through the bounding surface of the plasma enhances the helicity transport which increases the loop voltage necessary to sustain the toroidal current. The increase which is shown to be proportional to the flux intercepted and the local electron temperature compares well with that observed in experiments.
Bibliographic Reference: WRITE TO THE LIBRARIAN, UKAEA, CULHAM LABORATORY, ABINGDON, OXON OX14 3DB (UK), MENTIONING REPORT CLM-P819, 1987
Record Number: 1989126117700 / Last updated on: 1989-06-01
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