Energetics of kinetic reconnection in a three-dimensional null points cluster

TL;DR

This study uses 3D Particle-in-Cell simulations to explore magnetic reconnection at null point clusters, revealing significantly higher energy conversion and complex three-dimensional dynamics compared to traditional models.

Contribution

It demonstrates the energetics and evolution of magnetic reconnection in 3D null point clusters, highlighting differences from classical 2D reconnection scenarios.

Findings

Magnetic energy conversion is five times higher than in Harris sheet models.

Over 85% of magnetic energy is transferred to particles within 25 ion cyclofrequencies.

Reconnection occurs in multiple small patches with no 2D symmetry.

Abstract

We performed three-dimensional Particle-in-Cell simulations of magnetic reconnection with multiple magnetic null points. Magnetic field energy conversion into kinetic energy was about five times higher than in traditional Harris sheet configuration. More than 85% of initial magnetic field energy was transferred to particle energy during 25 reversed ion cyclofrequencies. Magnetic reconnection in the cluster of null points evolved in three phases. During the first phase, ion beams were excited, that then gave part of their energy back to magnetic field in the second phase. In the third phase, magnetic reconnection occurs in many small patches around the current channels formed along the stripes of low magnetic field. Magnetic reconnection in null points presents essentially three-dimensional features, with no two dimensional symmetries or current sheets.