During recent years an overwhelming body of evidence show that the overall transport of heat and particles is to a large part caused by intermittency (or bursty events) related to coherent structures. A crucial question in plasma confinement is thus the prediction of the probability distribution functions (PDFs) of the transport due to these structures and of their formation. This work provides...

We report on recent developments in the theory of secondary instability in drift-ITG turbulence. Specifically, we explore secondary instability as a mechanism for avalanche formation. A theory of radially extended streamer cell formation and self-regulation is presented. Aspects of streamer structure and dynamics are used to estimate the variance of the drift-wave induced flux. The relation bet...

The article reports on recent developments in the theory of secondary instability in drift–ion temperature gradient turbulence. Specifically, the article explores secondary instability as a mechanism for zonal flow generation, transport barrier dynamics and avalanche formation. These in turn are related to the space–time statistics of the drift wave induced flux, the scaling of transport with c...

High energy collisions of cosmic ray (CR) nuclei with interstellar gas are believed to be the mechanism producing the majority of CR antiprotons. The distinguishing spectral shape with a maximum at 2 GeV and a sharp decrease towards lower energies makes antiprotons a unique probe of the models of particle propagation in the Galaxy and modulation in the heliosphere. Besides, accurate calculation...

Electromigration ~EM! drift velocity ~DV! experiments in polycrystalline pure Cu lines are simulated numerically with the level set method. The simulation is based on a grain boundary ~GB! grooving model, incorporating an electric field. The model is distinguished by two key requirements imposed at the triple point where two surfaces and a GB meet: that of GB and surface flux coupling ~flux con...

Abstract The efficiency and combustion performance of propulsion systems, like internal (IC) engines gas turbines, is known to be related the fuel air mixing process. Operating conditions fuels are rapidly changing, therefore new CFD models which accurately accounts for all physical aspects, still maintaining a simple framework, extremely important. In this work we consider drift velocity contr...

This report explores the feasibility of explaining the observed proton heating in the inner heliosphere (1) by tapping the field-aligned relative drift between alpha particles and protons in the solar wind plasma and (2) by tapping the strahl-electron heat flux from the Sun. The observed reduction of the alpha-proton drift kinetic energy from 0.3 to 1 AU and the observed reduction of electron h...

The high-order fluid model developed in part I of this series is employed here to study the propagation of negative planar streamer fronts in pure nitrogen. The model consists of the balance equations for electron density, average electron velocity, average electron energy and average electron energy flux. These balance equations have been obtained as velocity moments of Boltzmann’s equation an...

Customary two-dimensional flux transport models for the evolution of the magnetic field at the solar surface do not account for the radial structure and the volume diffusion of the magnetic field. When considering the long-term evolution of magnetic flux, this omission can lead to an unrealistic long-term memory of the system and to the suppression of polar field reversals. In order to avoid su...