Electric fields in solar magnetic structures due to gradient driven instabilities: heating and acceleration of particles

Abstract

The electrostatic instabilities driven by the gradients of the density, temperature and magnetic field, are discussed in their application to solar magnetic structures. Strongly growing modes are found for some typical plasma parameters. These instabilities i) imply the presence of electric fields that can accelerate the plasma particles in both perpendicular and parallel directions with respect to the magnetic field vector, and ii) can stochastically heat ions. The perpendicular acceleration is to the leading order determined by the $\bmath{E}\times \bmath{B}$-drift acting equally on both ions and electrons, while the parallel acceleration is most effective on electrons. The experimentally confirmed stochastic heating is shown to act mainly in the direction perpendicular to the magnetic field vector and acts stronger on heavier ions. The energy release rate and heating may exceed for several orders of magnitude the value accepted as necessary for a self-sustained heating in the solar corona. The energy source for both the acceleration and the heating is stored in the mentioned background gradients.

To appear in MNRAS

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Cited by in corpus (7)

• Drift waves in the corona: heating and acceleration of ions at frequencies far below the gyro frequency
• Kinetic instability of drift-Alfven waves in solar corona and stochastic heating
• Viscosity effects on waves in partially and fully ionized plasma in magnetic field
• Self Heating of Corona by Electrostatic Fields Driven by Sheared Flows
• New features of ion acoustic waves in inhomogeneous and permeating plasmas
• Different effects of suprathermal electrons and ions on drift instabilities in non-uniform plasmas
• Energy in density gradient