We consider the effects of finite ExB on the residual and neoclassical ion heat transport and ion flow in the pedestal. For a tokamak pedestal with a density scale of the poloidal ion gyroradius the finite ExB drift modfies the ion orbits, moving the trapped-passing boundary towards the tail of the ion distribution function. Introduction In many tokamak plasmas the width of the pedestal is obse...

An H-mode Edge Pedestal (HEP) plasma transport Benchmarking Exercise (BE) was undertaken for a single DIII-D pedestal. Transport modeling codes used include 1.5D interpretive (ONETWO, GTEDGE), 1.5D predictive (ASTRA) and 2D ones (SOLPS, UEDGE). The particular DIII-D discharge considered is 98889, which has a typical low density pedestal. Profiles for the edge plasma are obtained from Thomson an...

Predictions are developed for the structure of plasma parameter profiles of high-confinement (H)-mode pedestals in transport quasi-equilibrium in tokamaks. They are based on assuming paleoclassical radial plasma transport processes dominate throughout the pedestal. The key physical process in this model is that the electron temperature gradient increases to the magnitude required for paleoclass...

A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-con...

The application of lower hybrid waves (LH) in H-mode plasmas on Alcator C-Mod can result in significant reduction of core particle inventory, with no significant degradation of energy confinement. This phenomenon has been observed in steady enhanced Dα (EDA) H-mode targets, which are sustained by ion cyclotron RF auxiliary heating, in which pedestal density nped is usually tied firmly to plasma...

We studied the binocular organization of motion opponency and its relationship to contrast gain control. Luminance contrast thresholds for discriminating direction of motion were measured for drifting Gabor patterns (target) presented on counterphase flickering Gabor patterns (pedestal). There were four presentation conditions: binocular, monocular, dichoptic, and half-binocular. For the half-b...

Achieving high pedestal pressures in H(high)-mode plasmas confined in tokamaks is critical for obtaining fusion burning plasmas in ITER. Recent characterizations of quasi-equilibrium plasma parameter profiles in low collisionality H-mode pedestals in the DIII-D tokamak are briefly summarized. Critical plasma transport properties (large radial electron heat flow, density pinch) that establish th...

We measured contrast detection thresholds for a small (3.6 x 3.6 arc min) square target in the presence and absence of spatially identical pedestal stimuli, and of a spatially non-overlapping inducing line (3.6 x 23 arc min). Results for the pedestal stimuli replicated the classical "dipper function", thresholds being reduced by near-threshold pedestals and increased at higher pedestal contrast...

Solitary perturbations (SPs) localized both poloidally and radially are detected within ~100 μs before the partial collapse of the high pressure gradient boundary region (called pedestal) of magnetized toroidal plasma in the KSTAR tokamak device. The SP develops with a low toroidal mode number (typically unity) in the pedestal ingrained with quasi-stable edge-localized mode (QSM) which commonly...

We used a dual-masking paradigm to study how contrast discrimination is influenced by the presence of adjacent stimuli differing in orientation. The task of the observer was to detect a vertical Gabor target superimposed on a vertical Gabor pedestal in the presence of flankers. The Gabor flankers had orientations ranging from 0 degrees (parallel to the target) to 90 degrees (orthogonal). The fl...