On Quasineutral Plasma Flow in the Magnetic Nozzle

TL;DR

This paper derives exact solutions for quasineutral plasma acceleration in a magnetic nozzle, highlighting the necessity of a non-monotonic magnetic field for potential formation and discussing solution properties under a polytropic electron model.

Contribution

It provides the first exact solutions for quasineutral plasma flow in magnetic nozzles, emphasizing the role of magnetic field profiles and regularity conditions in potential formation.

Findings

Non-monotonic magnetic fields are necessary for potential structures.

The accelerating potential is globally constrained by sonic point conditions.

Solutions are discussed for polytropic electron equations of state.

Abstract

Exact solutions for quasineutral plasma acceleration of magnetized plasma in the paraxial magnetic nozzle are obtained. It is shown that the non-monotonic magnetic field with a local maximum of the magnetic field is a necessary condition for the formation of the quasineutral accelerating potential structure. A global nature of the accelerating potential that occurs as a result of the constraint due to the regularity condition at the sonic point is emphasized and properties of such solutions are discussed for the case of general polytropic equation of state for electrons.