Pedestal Physics: EX/3 & TH/2
- Richard J. Buttery (General Atomics)
Mr Vladimir Rozhansky (Russian Federation)
10/15/14, 2:00 PM
Modeling of the impurities distribution in the pedestal region of ASDEX-Upgrade H-mode shot was done using the B2SOLPS5.2 transport code. Strong LFS-HFS asymmetry of B+5 density and strong decoupling between parallel velocity distribution of the impurities and the main ions was obtained in qualitative agreement with the experimental observations . Similar asymmetry was obtained earlier in...
Ms Eleonora Viezzer (Germany)
10/15/14, 2:20 PM
Extensive studies have shown that the pedestal Er profile in H-mode and asymmetric density and flow profiles of impurity ions are consistent with neoclassical predictions. While the ions set the background flow profile and their transport properties can be described by neoclassical modelling, the mechanisms which determine the electron density and temperature profiles are more varied. A...
Mr Jerry Hughes (USA)
10/15/14, 2:40 PM
Improvement in global confinement and fusion performance are found to be correlated with the pressure at the top of the edge barrier ("pedestal height") both in experiments and theory. Performance predictions for future devices such as ITER rely on experimental validations of the hypothesis in the predictive models. To date, the leading model for pedestal structure prediction is EPED. This...
Ms Costanza Maggi (Germany)
10/15/14, 3:00 PM
The pedestal confinement of JET-ILW H-modes is presented and their stability investigated in the framework of P-B stability and the predictive code EPED. The changes in wall composition from C to Be/W point to the possible role of neutral recycling, low-Z impurities and scrape-off-layer physics in pedestal stability, highlighting the need for refinement of models predicting the pedestal...
509. Super H-mode: Theoretical Prediction and Initial Observations of a New High Performance Regime for Tokamak Operation
Mr Philip B. Snyder (USA)
10/15/14, 3:20 PM
A new “Super H-mode” regime is predicted at very high pedestal pressure, enabling pedestal height and predicted fusion performance substantially higher than for H-mode operation. This new regime exists due to a bifurcation of the pedestal solution that occurs in strongly shaped plasmas above a critical density. The Super H-mode regime is predicted to be accessible, and to increase fusion...
Mr Scott Parker (USA)
10/15/14, 3:40 PM
For a better understanding of the complicated physics of the inter-related "intermittent plasma objects (blobs)" and divertor heat-load footprint, the full-function gyrokinetic PIC code XGC1 has been used in realistic diverted geometry. Neoclassical and turbulence physics are simulated together self-consistently in the presence of Monte Carlo neutral particles. Blobs are modeled here as...