The physics of a locked magnetic island chain maintained in the pedestal of an H-mode tokamak plasma by a static, externally generated, multi-harmonic, helical magnetic perturbation is investigated. The non-resonant harmonics of the external perturbation are assumed to give rise to significant toroidal flow damping in the pedestal, in addition to the naturally occurring poloidal flow damping. F...

Vertical cavity surface emitting laser (VCSEL) arrays and photodiode (PD) arrays have emerged on the market for short reach fiber communications and other applications. However, the lack of efficient, low-cost methods for light coupling and electrical connection has become a barrier to new products incorporating their high-density and parallel advantages. To address these challenges, we have de...

The physics of a locked magnetic island chain maintained in the pedestal of an H-mode tokamak plasma by a static, externally generated, multi-harmonic, helical magnetic perturbation is investigated. The non-resonant harmonics of the external perturbation are assumed to give rise to significant toroidal flow damping in the pedestal, in addition to the naturally occurring poloidal flow damping. F...

Abstract The stability of microtearing (MT) in the JET H-mode pedestal is investigated by means both linear gyrokinetic simulations using GENE code and a theoretical calculation. In order to determined role played MT tokamak evaluate physical parameters, on destabilization reduced model has been presented compared with simulations. analytical allows good prediction impact different like collisi...

Theoretical study of ELMs as a relaxation phenomenon has been performed. It is motivated by the balance between plasma heating and the loss of energy during ELM turbulences. The energy balance is examined for particular heating scheme with neutral beam injection (NBI) in steady state scenarios of ASDEX Upgrade, JET, DIII-D and JT-60U with ELM oscillations. In this approach we have calculated th...

JET data for the correlations between pedestal plasma temperature and density with the frequency of different type ELMs are analyzed in the framework of a classical Focker-Planck approach. In first approximation we derive a functional dependence in steady state of ELMs assuming equality between the outward flux of plasma from the core and the loss of plasma from the pedestal into the SOL. In th...

PURPOSE To assess contrast-discrimination thresholds in patients with migraine who have manifest visual field loss. This study was undertaken to determine whether contrast processing abnormalities in migraineurs are more readily identified by using stimuli that elicit a response from the subject that depends, at least in part, on adaptation mechanisms, and if so, whether deficits appear more pr...

The purpose of this study was to define the spatial frequencies that underlie judgments of Landolt C orientation under test conditions designed to favor either the magnocellular (MC) or parvocellular (PC) pathway. Contrast thresholds of two observers were measured for briefly presented Landolt Cs of four sizes, using steady- and pulsed-pedestal paradigms to bias performance toward the MC and PC...

Many sensory discriminations, including the discrimination of speed, obey Weber's law and thus become more difficult as the stimuli get larger. Using one-jump apparent motion stimuli, we find that the opposite can occur: displacement discrimination improves with larger jumps. This pedestal effect occurs for small jumps near and below the detection threshold. Finding a pedestal effect in motion ...

Plasma equilibria reconstructed from the Mega-Amp Spherical Tokamak have sufficient resolution to capture plasma evolution during the short period between edge-localized modes (ELMs). Immediately after the ELM, steep gradients in pressure, P, and density, n(e), form pedestals close to the separatrix, and they then expand into the core. Local gyrokinetic analysis over the ELM cycle reveals the d...