SUBJECT: Ph.D. Dissertation Defense
BY: John-Patrick Floyd
TIME: Tuesday, October 7, 2014, 3:00 p.m.
PLACE: Boggs, 3-47
TITLE: Evolution of Edge Pedestal Transport Between ELMs in DIII-D
COMMITTEE: Dr. W. M. Stacey, Chair (NRE)
Dr. A. Erickson (NRE)
Dr. R. J. Groebner (General Atomics)
Dr. R. T. McGrath (MSE)
Dr. T. T. Utschig (NRE)


Evolution of measured profiles of densities, temperatures and velocities in the edge pedestal region between successive ELM (edge-localized mode) events are analyzed and interpreted in terms of the constraints imposed by particle, momentum and energy balance in order to gain insights regarding the underlying evolution of transport processes in the edge pedestal between ELMs in a series of DIII-D [J. Luxon, Nucl. Fusion 42, 614, 2002] discharges. The data from successive inter-ELM periods during an otherwise steady-state phase of the discharges were combined into a composite inter-ELM period for the purpose of increasing the number of data points in the analysis. Variation of diffusive and non-diffusive (pinch) particle, momentum, and energy transport over the inter-ELM period are examined for discharges with plasma currents from 0.5 to 1.5 MA and inter-ELM periods from 50 to 220 ms. Diffusive transport is dominant for ρ < 0.925, while non-diffusive and diffusive transport are very large and nearly balancing in the sharp gradient region 0.925 < ρ < 1.0. During the inter-ELM period, diffusive transport increases slightly more than non-diffusive transport, increasing total outward transport. Both diffusive and non-diffusive transport in the sharp gradient region have a strong inverse correlation with plasma current.