Fusion Science and Technology / Volume 53 / Number 4 / May 2008 / Pages 958-988
Technical Paper / Special Issue on Joint European Torus (jet)
A review of the development of advanced tokamak scenarios at the Joint European Torus (JET) is presented. It has been established that the current profile plays an important role in these regimes, and the presentation of the experimental achievement has been organized with this in mind. The main achievements are discussed: from high beta plasmas starting with a fully diffused plasma current; from hybrid scenarios with a flat current profile and central q around unity; from pellet-enhanced modes where the role of reversed magnetic shear (transiently) was first established; from optimized shear configurations with weakly reversed shear allowing the establishment of internal transport barriers in D-T plasmas for the first time, including the production of 8.2 MW of fusion power; and from strongly reversed shear and steady-state scenarios. The required development of the control techniques for these advanced scenarios is also described. The results obtained have significantly contributed to the development of advanced scenarios for ITER operation. The prospects for further development of hybrid and steady-state scenarios for ITER are indicated in view of the ongoing upgrades to additional heating systems in JET.