The presence of inward heat flows in tokamaks is analysed using a transport model for turbulent transport based on temperature gradient driven drift waves. The conditions needed for inward (pinch) heat flows are discussed and the results are compared with some experimental observations. In particular, it is shown that the differences observed between the off-axis heated discharges at DIII-D, where nondiffusive transport was observed, and similar discharges at JET are consistent with the predictions of the transport model.
Transport in toroidal devices-experimentalist's view