A Theory about Electric Current and Heating in Plasma

TL;DR

This paper presents a new theoretical framework for understanding electric currents and heating in fully ionized plasma, challenging traditional concepts like magnetic reconnection and magnetic frozen-in conditions.

Contribution

It derives exact solutions for electron and ion velocities, showing that electric currents perpendicular to magnetic fields are absent without boundary effects, and clarifies plasma confinement and heating mechanisms.

Findings

Electric currents perpendicular to magnetic fields are absent without boundary effects.

Magnetic field variations directly transfer energy into plasma thermal energy.

Plasma confinement is due to magnetic fields, not coupled to plasma bulk velocity.

Abstract

The traditional generalized Ohm's law in MHD do not explicitly present the relation of electric currents and electric fields in fully ionized plasma, and lead to some unexpected concepts, such as "the magnetic frozen-in plasma", magnetic reconnection etc. In the present paper, we solve the balance equation can give exact solution of the velocities of electrons and ions, and then derived the electric current in fully ionized plasma. In the case ignoring boundary condition, there is no electric current in the plane perpendicular to the magnetic field when external forces are ignored. The electric field in the plane perpendicular to magnetic field do not contribute to the electric currents, so do the induced electric field from the motion of the plasma across magnetic field. The lack of induced electric current will keep magnetic field in space unaffected. The velocity of the bulk velocity of the plasma perpendicular to magnetic field is not free, it is decided by electromagnetic field and the external forces. We conclude that the bulk velocity of the fully ionized plasma is not coupled with the magnetic field. The motion of the plasma do not change the magnetic field in space, but the plasma will be confined by magnetic field. Due to the confinement of magnetic field, the plasma kinetic energy will be transformed into plasma thermal energy by the Lamor motion and collisions between the same species of particles inside plasma. Because the electric field perpendicular to magnetic field do not contribute electric current, the variation of magnetic field will transfer energy directly into the plasma thermal energy by induced electric field. The heating of plasma could be from the kinetic energy and the variation of magnetic field.