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Full-Text Articles in Physical Sciences and Mathematics

New Promise For Electron Bulk Energization In Solar Flares: Preferential Fermi Acceleration Of Electrons Over Protons In Reconnection-Driven Magnetohydrodynamic Turbulence, Ted La Rosa, Ronald L. Moore, James A. Miller, Steven N. Shore Aug 1996

New Promise For Electron Bulk Energization In Solar Flares: Preferential Fermi Acceleration Of Electrons Over Protons In Reconnection-Driven Magnetohydrodynamic Turbulence, Ted La Rosa, Ronald L. Moore, James A. Miller, Steven N. Shore

Faculty and Research Publications

The hard X-ray luminosity of impulsive solar flares indicates that electrons in the low corona are bulk energized to energies of order 25 keV. LaRosa & Moore pointed out that the required bulk energization could be produced by cascading MHD turbulence generated by Alfvénic outflows from sites of strongly driven reconnection. LaRosa, Moore, & Shore proposed that the compressive component of the cascading turbulence dissipates into the electrons via Fermi acceleration. However, for this to be a viable electron bulk energization mechanism, the rate of proton energization by the same turbulence cannot exceed the electron energization rate. In this paper …


Ion Viscosity Mediated By Tangled Magnetic Fields: An Application To Black Hole Accretion Disks, P. Subramanian, P. A. Becker, Menas Kafatos Jan 1996

Ion Viscosity Mediated By Tangled Magnetic Fields: An Application To Black Hole Accretion Disks, P. Subramanian, P. A. Becker, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

We examine the viscosity associated with the shear stress exerted by ions in the presence of a tangled magnetic field. As an application, we consider the effect of this mechanism on the structure of black hole accretion disks. We do not attempt to include a self-consistent description of the magnetic field. Instead, we assume the existence of a tangled field with coherence length λcob• which is the average distance between the magnetic "kinks" that scatter the particles. For simplicity, we assume that the field is self-similar, and take λcob to be a fixed fraction ξ of the local disk height …