The critical temperature gradient model of plasma transport: Applications to JET and future tokamaks

The diversity and complexity of behaviour in tokamak plasmas place strong constraints on any model attempting a description in terms of a single underlying phenomenon. On the assumption that turbulence in the magnetic topology is the underlying phenomenon, specific expressions for electron and ion heat flux are derived from heuristic and dimensional arguments. When used in plasma transport codes, rather satisfactory simulations of experimental results are achieved in tokamaks of different sizes in various regimes of operation. Predictions are given for the expected performance of JET at full planned power and implications for next step tokamaks are indicated. (author). 23 refs, 3 figs, 2 tabs