Cyclotron resonance in plasma flow

A. V. Artemyev (1, 2) , O. V. Agapitov (3, 1) , V. V. Krasnoselskikh (1)

1 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
2 IKI - Space Research Institute of the Russian Academy of Sciences
3 SSL - Space Sciences Laboratory [Berkeley]

This paper is devoted to the mechanism of particle acceleration via resonant interaction with the electromagnetic circular wave propagating along the inhomogeneous background magnetic field in the presence of a plasma flow. We consider the system where the plasma flow velocity is large enough to change the direction of wave propagation in the rest frame. This system mimics a magnetic field configuration typical for inner structure of a quasi-parallel shock wave. We consider conditions of gyroresonant interaction when the force corresponding to an inhomogeneity of the background magnetic field is compensated by the Lorentz force of the wave-magnetic field. The wave-amplitude is assumed to be about 10% of the background magnetic field. We show that particles can gain energy if kv(sw) > omega > kv(sw) - Omega(c) where k is the wave number, v(sw) is a plasma flow velocity, and omega and Omega(c) are the wave frequency and the particle gyrofrequency, respectively. This mechanism of acceleration resembles the gyrosurfing mechanism, but the effect of the electrostatic field is replaced by the effect of the magnetic field inhomogeneity.

Domains: Sciences of the Universe [physics]

A. V. Artemyev, O. V. Agapitov, V. V. Krasnoselskikh. Cyclotron resonance in plasma flow. Physics of Plasmas, 2013, 20 (12), pp.124502. ⟨10.1063/1.4853615⟩. ⟨insu-01258001⟩