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Return To: Session EX6 - Transport & Divertors 2 (Thursday,
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The JET Team 1 (presented by V. V. Parail )
1 see Appendix to IAEA-CN-69/OV1/2
JET Joint Undertaking, Abingdon, Oxfordshire, United Kingdom
Abstract
Two type of high performance scenarios have been produced in
JET during DTE1 campaign. One of them is the well known and extensively used
in the past ELM-free hot ion H-mode scenario which has two distinct regions-
plasma core and the edge transport barrier. The results obtained during DTE-1
campaign with D, DT and pure T plasmas confirms our previous conclusion that
the core transport scales as a gyroBohm in the inner half of plasma volume,
recovers its Bohm nature closer to the separatrix and behaves as ion
neoclassical in the transport barrier. Measurements on the top of the barrier
suggest that the width of the barrier is dependent upon isotope and moreover
suggest that fast ions play a key role. The other high performance scenario is
a relatively recently developed Optimised Shear Scenario with small or
slightly negative magnetic shear in plasma core. Different mechanisms of
Internal Transport Barrier (ITB) formation have been tested by predictive
modelling and the results are compared with experimentally observed
phenomena. The experimentally observed non-penetration of the heavy impurities
through the strong ITB which contradicts to a prediction of the conventional
neo-classical theory is discussed.
IAEA 1999