Stochastic ion and electron heating on drift instabilities at the bow shock

Abstract

The analysis of the wave content inside a perpendicular bow shock indicates that heating of ions is related to the Lower-Hybrid-Drift (LHD) instability, and heating of electrons to the Electron-Cyclotron-Drift (ECD) instability. Both processes represent stochastic acceleration caused by the electric field gradients on the electron gyroradius scales, produced by the two instabilities. Stochastic heating is a single particle mechanism where large gradients break adiabatic invariants and expose particles to direct acceleration by the DC- and wave-fields. The acceleration is controlled by function $\chi =m_i{q}_i^{-1}{B}^{-2}$div($\mathbf{E}$), which represents a general diagnostic tool for processes of energy transfer between electromagnetic fields and particles, and the measure of the local charge non-neutrality. The identification was made with multipoint measurements obtained from the Magnetospheric Multiscale spacecraft (MMS). The source for the LHD instability is the diamagnetic drift of ions, and for the ECD instability the source is ExB drift of electrons. The conclusions are supported by laboratory diagnostics of the ECD instability in Hall ion thrusters.

arXiv commentMNRAS, accepted, 6 pages, 5 figures

References in corpus (3)

• Stochastic Ion Heating by a Lower Hybrid Wave: II
• Drift waves in the corona: heating and acceleration of ions at frequencies far below the gyro frequency
• Acceleration of solar wind ions to 1 MeV by electromagnetic structures upstream of the Earth's bow shock

Cited by in corpus (7)

• Ion acceleration to MeV by the ExB wave mechanism in collisionless shocks
• Quasi-adiabatic and stochastic heating and particle acceleration at quasi-perpendicular shocks
• Free energy sources in current sheets formed in collisionless plasma turbulence
• Stochastic and quasi-adiabatic electron heating in quasi-parallel shocks
• Local acceleration of protons to 100 keV in a quasi-parallel bow shock
• The electron cyclotron drift instability: a comparison of particle-in-cell and continuum Vlasov simulations
• Thresholdless stochastic particle heating by a single wave