Electric field measurements of directly converted lower hybrid waves at a density striation

Ultrahigh resolution simulations of mode converted ion cyclotron waves and lower hybrid waves

Full Wave studies of mode conversion (MC) processes in toroidal plasmas have required prohibitive amount of computer resources in the past because of the disparate spatial scales involved. The TORIC code [1] solves the linear sixth order reduced wave equation for the ion cyclotron range of frequencies (ICRF), in toroidal geometry using a Fourier representation for the poloidal dimension and fin...

Measurements of the parallel wavenumber of lower hybrid waves in the scrape-off layer of a high-density tokamak

Modulational instability of lower hybrid waves at the magnetopause

The role of lower hybrid waves at the magnetopause is reexamined. It is found that for the maximum observed wave power, the lower hybrid waves are unstable to a modulational instability on the magnetosheath side of the magnetopause. The modulational instability leads to localized field structures , oriented predominantly along the magnetic field. Such patchy lower hybrid turbulence has been obs...

Electric-field-controlled unpinning of scroll waves.

Three-dimensional excitation vortices exist in systems such as chemical reactions and the human heart. Their one-dimensional rotation backbone can pin to unexcitable heterogeneities, which greatly affect the structure, dynamics, and lifetime of the vortex. In experiments with the Belousov-Zhabotinsky reaction, we demonstrate vortex unpinning from a pair of inert and impermeable spheres using ex...

Laboratory studies of field-aligned density striations and their relationship to auroral processes*

Magnetic field-aligned structures in current, density, and temperature are common features of the auroral ionospheric plasma. These structures both generate and transform low frequency waves in the plasma. The results of laboratory studies of two processes involving magnetic field-aligned density depletions ~striations! that play a role in auroral plasma dynamics are presented. The first proces...