[1] We present the first observations at an interplanetary shock of large‐amplitude (> 100 mV/m pk‐pk) solitary waves and large‐amplitude (∼30 mV/m pk‐pk) waves exhibiting characteristics consistent with electron Bernstein waves. The Bernstein‐like waves show enhanced power at integer and half‐integer harmonics of the cyclotron frequency with a broadened power spectrum at higher frequencies, co...

Direct observations of magnetic-field-aligned (parallel) electric fields in the downward current region of the aurora provide decisive evidence of naturally occurring double layers. We report measurements of parallel electric fields, electron fluxes and ion fluxes related to double layers that are responsible for particle acceleration. The observations suggest that parallel electric fields orga...

A general theoretical study of the dynamics of ions interacting with multiple elec-trostatic waves, propagating perpendicularly to a uniform magnetic field, is performed. For appropriately chosen frequencies and wavenumbers we discover a new nonlinear phenomenon of coherent acceleration (or deceleration) which energizes (or extracts energy from) ions. Ions whose initial energies are below the l...

The conversion of static electric fields to electromagnetic radiation by the incidence of a superluminous ionization front on plasma is investigated. For extremely superluminous fronts, the radiation is close to the plasma frequency and is converted with efficiency of order unity. A proof-of-principle experiment was conducted using semiconductor plasma containing an alternately charged capacito...

One of the interesting observations from the FAST satellite is the detection of strong spiky waveforms in the parallel electric field in association with ion cyclotron oscillations in the perpendicular electric fields. We report here an analytical model of the coupled nonlinear ion cyclotron and ion-acoustic waves, which could explain the observations. Using the fluid equations for the plasma c...

The conditions under which a magnetized ion can be accelerated through a nonlinear interaction with a pair of beating electrostatic waves are explored. It has been shown [Benisti et al., Phys. Plasma 5, 3224 (1998)] that the electric field of the beating waves can, under some conditions, accelerate ions from arbitrarily low initial velocity in stark contrast with the well-known nonlinear thresh...

The excitation of electrostatic ion-cyclotron (EIC) waves is studied in a single-ended Q machine in a two-ion-component plasma (Cs+ and K+). Over a large range of relative concentrations of Cs+ and K+ ions, two modes are excited with frequencies w , z Q,,, and w2 t QK+, where the Q's are the respective cyclotron frequencies. The results are discussed in terms of a fluid theory of electrostatic ...

A single electrostatic, lower-hybrid wave, propagating across a magnetic eld,can energize ions only if the ion dynamics becomes chaotic [1]. We show that low energy ions, which would not gain energy from a single wave, can gain energy from two or more waves provided the wavelengths and frequencies are chosen appropriately. An appropriate choice can also lead to an extraction of ion energy by th...

The generation of large-scale zonal flows by small-scale electrostatic drift waves in electron temperature gradient(ETG) driven turbulence model is considered. The generation mechanism is based on the modulational instability of a finite amplitude monochromatic drift wave. The threshold and growth rate of the instability as well as the optimal spatial scale of zonal flow are obtained.

The stochastic threshold for the heating of ions in a magnetized plasma with two electrostatic waves is experimentally characterized. Two obliquely propagating electrostatic modes are launched in a magnetized plasma with frequencies that differ by the ion cyclotron frequency. The values of the wave amplitudes where a rapid increase in the local ion temperature occurs is then parametrically inve...