JET-P(99)42

Modelling of SOL Flows and Target Asymmetries in JET Field Reversal Experiments with EDGE2D Code

The EDGE2D code with drifts can reproduce the main trends of target asymmetries observed in field reversal experiments. It also re-produces qualitatively the main feature of recent JET results obtained with double-sided reciprocating Langmuir probes introduced near the top of the torus: the reversal of parallel plasma flow with toroidal field reversal. The code results suggest that the major contributor to the observed target asymmetries is the co-current toroidal momentum generated inside the scrape-off layer (SOL) by jr×B forces due to the presence of large up-down pressure asymmetries. Contrary to previous expectations of the predominant role of E×B drifts in creating target asymmetries, ∇B and centrifugal drifts were found to be mainly responsible for both parallel flows and target asymmetries.
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JETP99042 119.17 Kb