Fusion Science and Technology / Volume 51 / Number 3 / April 2007 / Pages 317-341
Technical Paper / Alcator C-Mod Tokamak
H-mode research on Alcator C-Mod is described, with a focus on the edge transport barrier (ETB). ETB pedestals are characterized using several diagnostics, leading to a thorough description of profile structure in H-mode. L-H transition criteria are discussed, along with the fast evolution of the pedestal following the L-H transition. H-mode regimes are described in terms of their edge transport characteristics and the local edge parameters favoring each. Empirical scalings of the pedestal with operational parameters are found, helping to illuminate physics governing the pedestal structure, and the relationship between edge transport and global confinement is discussed. Dimensionless comparisons between discharges on different tokamaks are discussed. Finally, ongoing work and directions for the future are described.