Bernstein instability driven by suprathermal protons in the ring current

Interaction of Energetic Ring Current Protons with Magnetospheric Hydromagnetic Waves

Alternating current driven instability in magnetic junctions.

An effect is considered of alternating (high-frequency) current on the spin-valve-type magnetic junction configuration. The stability with respect to small fluctuations is investigated in the macrospin approximation. When the current frequency is close to the eigenfrequency (precession frequency) of the free layer, parametric resonance occurs. Both collinear configurations, antiparallel and par...

Nonlinear current-driven ion-acoustic instability driven by phase-space structures

The nonlinear stability of current-driven ion-acoustic waves in collisionless electron-ion plasmas is analyzed. Seminal simulations from the 80’s are revisited. Accurate numerical treatment shows that subcritical instabilities do not grow from an ensemble of waves, except very close to marginal stability and for large initial amplitudes. Further from marginal stability, one isolated phase-space...

A cosmic ray current-driven instability in partially ionised media

Context. We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. Aims. It is known that transverse waves propagating parallel to the mean magnetic field are unstable to anisotropies in the cosmic ray distribution, and may provide a mechanism to substantially amplify the ambient magnetic field. We quantify the ex...

A current driven instability in parallel, relativistic shocks

Abstract. Recently, Bell [2] has reanalysed the problem of wave excitation by cosmic rays propagating in the pre-cursor region of a supernova remnant shock front. He pointed out a strong, non-resonant, current-driven instability that had been overlooked in the kinetic treatments by Achterberg [1] and McKenzie & Völk [10], and suggested that it is responsible for substantial amplification of the...