Thermal and electrical properties of the divertor channel of tokamak plasmas

The electrical and thermal properties of the divertor channel of tokamak plasmas are discussed in relation to H-mode discharges recently observed in neutral-beam--heated tokamak plasmas with divertors. The conditions for the existence of a thermal barrier and its effects on thermal and electrical conduction are analyzed, and the condition for effective line tying by divertor plate is discussed.