Spiky electric and magnetic field structures in flux rope experiments.

Magnetic flux ropes are structures that are common in the corona of the sun and presumably all stars. They can be thought of as the building blocks of solar structures. They have been observed in Earth's magnetotail and near Mars and Venus.

Laboratory study of avalanches in magnetized plasmas.

It is demonstrated that a novel heating configuration applied to a large and cold magnetized plasma allows the study of avalanche phenomena under controlled conditions. Intermittent collapses of the plasma pressure profile, associated with unstable drift-Alfvén waves, exhibit a two-slope power-law spectrum with exponents near -1 at lower frequencies and in the range of -2 to -4 at higher frequencies. A detailed mapping of the spatiotemporal evolution of a single avalanche event is presented.

Kubo conductivity tensor for two- and three-dimensional magnetic nulls.

The complete Kubo conductivity tensor is computed in two- and three-dimensional linear magnetic null systems using collisionless single-particle simulations. Regions of chaotic charged-particle dynamics are constructed for each case. It is found that stochastic frequency mixing of particle bounce motion, as well as gyromotion, contribute significantly to the conductivity.

Plasmoid-induced turbulence in collisionless magnetic reconnection.

The dissipation mechanism in collisionless magnetic reconnection in a quasisteady period is investigated for the antiparallel field configuration. A three-dimensional simulation in a fully kinetic system reveals that a current-aligned electromagnetic mode produces turbulent electron flow that facilitates the transport of the momentum responsible for the current density. It is found that the electromagnetic turbulence is drastically enhanced by plasmoid formations and has a significant impact on the dissipation at the magnetic x-line.

Magnetowave induced plasma wakefield acceleration for ultrahigh energy cosmic rays.

Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultrahigh energies. Here we present simulation results that clearly demonstrate the viability of this mechanism for the first time. We invoke the high frequency and high speed whistler mode for the driving pulse.

Spin wave dynamics and the determination of intrinsic damping in locally excited Permalloy thin films.

Time-resolved scanning Kerr effect microscopy has been used to study magnetization dynamics in Permalloy thin films excited by transient magnetic pulses generated by a micrometer-scale transmission line structure. The results are consistent with magnetostatic spin wave theory and are supported by micromagnetic simulations. Magnetostatic volume and surface spin waves are measured for the same specimen using different bias field orientations and can be accurately calculated by k-space integrations over all excited plane wave components.