Download or read book Pedestal Profiles and Measurements in C-Mod Enhanced D-alpha H-modes written by Amanda E. Hubbard and published by . This book was released on 2000 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution measurements on the Alcator C-Mod tokamak [I.H. Hutchinson et al, Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the "Enhanced Da" (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12 MPa/m. Evolution of the pedestal at the LH transition is consistent with a large, rapid drop in thermal conductivity across the barrier. A quasi-coherent fluctuation in density, potential and Bpol, with fo%7E50-150 kHz and kq%7E 4 cm-1, always appears in the barrier during EDA, and drives a large particle flux. Conditions to access the steady-state EDA regime in deuterium include d> 0.35, q95> 3.5 and L-mode target line average density> 1.2 x 1020 m-3. A reduced q95 limit is found for hydrogen discharges.