Influence of the q-profile shape on plasma performance in JET
The fusion performance of JET plasmas can be enhanced by the generation of internal transport barriers. The influence of the q-profile shape in the local and global plasma performance has been investigated in cases where the core magnetic shear ranges from small and positive to large and negative. Internal barriers extending to large plasma radii can be effective in raising the global performance of the plasma. It is found that such barriers tend to be generated more easily if the q-profile contains a region of negative magnetic shear. The formation is favoured by neutral beam injection compared with ion cyclotron resonance heating in scenarios where the two systems are used together. The minimum power level required to observe a local transport reduction is significantly lower than the value at which very steep pressure gradients can be achieved. This results in a practical threshold in the power to access a regime of high plasma performance that is sensitive to the q-profile shape.
Bibliographic Reference: An article published in: Plasma Physics and Controlled Fusion, 44 (July 2002), pp. 1031-1055
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://stacks.iop.org/0741-3335/44/1031
Record Number: 200215049 / Last updated on: 2002-07-29
Original language: en
Available languages: en