Download or read book Advances in Measurement and Modeling of the High-confinement-mode Pedestal on the Alcator C-Mod Tokamak written by Jerry Wayne Hughes and published by . This book was released on 2005 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edge transport barrier (ETB) studies on the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)] investigate pedestal scalings and radial transport of plasma and neutrals. Pedestal profiles show trends with plasma operational parameters such as total current IP . A ballooning-like I2P dependence is seen in the pressure gradient, despite calculated stability to ideal ballooning modes. A similar scaling is seen in the near scrape-off-layer for both low-confinement (L-mode) and H-mode discharges, possibly due to electromagnetic fluid drift turbulence setting transport near the separatrix. Neutral density diagnosis allows examination of D0 fueling in H-modes, yielding profiles of effective particle diffusivity in the ETB, which vary as IP is changed. Edge neutral transport is studied using a 1D kinetic treatment. In both experiment and modeling, the C-Mod density pedestal exhibits a weakly increasing pedestal density and a nearly invariant density pedestal width as the D0 source rate increases. Identical modeling performed on pedestal profiles typical of DIII-D [Nucl. Fusion 42, 614, (2002)] reveal differences in pedestal scalings qualitatively similar to experimental results.