The ideal magnetohydrodynamic (MHD) stability limits for the edge transport barrier (ETB) region in tokamaks are explored, concentrating in particular on the intermediate to high toroidal mode number, n, modes. These calculations take full account of the effect of the edge bootstrap current on the stability of both ballooning and peeling modes. Because the current plays an important role in MHD...

The peeling-ballooning model for edge localized modes (ELMs) and pedestal constraints, based upon ideal MHD instabilities driven by pressure gradients and current in the edge barrier region, has been broadly applied toward understanding ELM and pedestal behavior in a number of tokamak experiments. Due in part to multiple driving terms, multiple wavelengths and second stability access physics, t...

Poloidal rotation is routinely observed in present-day tokamak experiments, in particular near the plasma edge and in the high-confinement mode of operation. According to the magnetohydrodynamic (MHD) equilibrium theory [R. Betti and J. P. Freidberg, Phys. Plasmas 7, 2439 (2000)], radial discontinuities form when the poloidal velocity exceeds the poloidal sound speed (or rather, more correctly,...

A dedicated series of ELMing H-Mode discharges on Alcator C-Mod spanning a broad range of plasma parameters, including plasma current (400-1000kA), magnetic field (3.5-8T), and plasma shaping, are presented with experimental scalings of the plasma pedestal with bulk plasma and engineering parameters. The H-modes presented achieve pedestals with densities spanning 5 × 10 − 2.5 × 10 m−3 and tempe...

In order to understand how attention affects visual processing, we investigated the degree to which attention effects can be accounted for by increases in the contrast gain of the contrast response function, CRF (represented by an increase in effective contrast) vs. increases in the response gain (represented by an overall amplification of response). To this end, we used a dual-task paradigm to...

The goal of this study was to investigate the role of inferred parvocellular (PC) and magnocellular (MC) pathways in spatial contrast sensitivity. Localized, spatially narrow-band patterns (sixth derivatives of Gaussians, D6s) were presented at various peak spatial frequencies. When the D6 appeared on a pulsed luminance pedestal (Pulsed-Pedestal Paradigm), the spatial contrast sensitivity showe...

The pulsed-pedestal paradigm consists of the simultaneous brief presentation of a test stimulus and luminance pedestals. Processing with this paradigm is thought to be mediated by the parvocellular pathway. The steady-pedestal paradigm consists of the brief presentation of a test stimulus against a continuously presented luminance pedestals. Processing with this paradigm is thought to be mediat...

Enteropathogenic Escherichia coli (EPEC) is a human pathogen that attaches to intestinal epithelial cells and causes chronic watery diarrhea. A close relative, enterohemorrhagic E. coli (EHEC), causes severe bloody diarrhea and hemolytic-uremic syndrome. Both pathogens insert a protein, Tir, into the host cell plasma membrane where it binds intimin, the outer membrane ligand of EPEC and EHEC. T...

Developing a validated predictive capability is critical to the design, optimization and successful operation of fusion experiments. However, in part because of the coupled, multi-physics nature of tokamak plasmas, it can be challenging to isolate physics and control an experiment sufficiently to precisely test predictions. Here we report on experience with planning, execution and analysis of e...