Numerical modeling of two magnetized counter-propagating weakly collisional plasma flows in arch configuration

TL;DR

This paper uses numerical modeling to study the complex interactions of two counter-propagating plasma flows in an arched magnetic field, revealing non-stationary behaviors, magnetic reconnection, and instabilities relevant for upcoming experiments.

Contribution

It presents a detailed numerical analysis of plasma flow interactions in an arch magnetic configuration, highlighting effects like reconnection and turbulence at different magnetic Mach numbers.

Findings

Magnetic reconnection occurs in the interaction region.

Flow filamentation due to Weibel instability is observed.

Surface waves near the ion-cyclotron frequency are excited.

Abstract

Numerical modeling of the interaction process of two counter-streaming supersonic plasma flows with an arched magnetic field configuration in the regime of a magnetic Mach number of the order of unity $M_m \sim 1$ is carried out. The flows were launched from the bases of the arch along the direction of the magnetic field. It is shown that the interaction has non-equilibrium and non-stationary nature. It is accompanied by an expansion of the resulting magnetic plasma arch due to $E \times B$ drift with the formation of a region with oppositely directed magnetic fields, in which magnetic reconnection is observed. In the subcritical regime Mm < 1 the reconnection process is slow, and in the overcritical one Mm > 1 it is more intense and leads to plasma turbulization. Filamentation of flows due to the development of Weibel instability, as well as excitation of surface waves near the ion-cyclotron frequency on the surface of the plasma tube are also observed. The modeling was carried out for the parameters of an experiment planned for the near future, which made it possible to formulate the conditions for observing the effects discovered in the modeling.