Edge Transport Barrier in JET Hot-ion H-modes
The isotopic effects on the edge transport barrier are investigated for the ELM-free-ion H-mode discharges from the recent D-T experiments on JET. The role of fast particles is most clearly illustrated by comparing the pressure at the top of the edge transport barrier for the discharges with deuterium and tritium fast particle sources. The scaling of the experimental data from the D-D and D-T hot-ion H-modes supports the hypothesis that the width of the edge transport barrier can be controlled by the orbit losses of fast ions with a sufficient concentration in the edge. Based on this width scaling, the neoclassical theory predicts that the power losses through the separatrix scale. It has now been demonstrated that this is consistent with the experimental data from the MkI and MkII divertors. However, a systematic increase in the loss power has been observed between the two divertor campaigns. A connection is proposed between this observation and the changes in the impurity production between the MkI and MkII divertors. A connection is proposed between this observation and the changes in the impurity production between the MkI and MkII divertors. The role of gas puff and edge recycling is also investigated.
Bibliographic Reference: Article: JET-P(98)79
Record Number: 199910834 / Last updated on: 1999-06-11
Original language: en
Available languages: en