Simulating the Ion-trapping Acceleration at Rippled Reconnection Fronts

Reconnection fronts (RFs) play a vital role in particle acceleration and energy transport in the terrestrial magnetosphere. It is widely believed that RFs have planar monotonic profiles that determine the particle dynamics. However, recent in situ studies have revealed that the front surface is not...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2022-01, Vol.925 (1), p.26
Main Authors: Bai, Kun, Yu, Yiqun, Huang, Hongtao, Cao, Jinbin
Format: Article
Language:English
Subjects:
Astrophysics
Electric fields
Energy transport
Fronts
Interplanetary particle acceleration
Ions
Magnetospheres
Particle acceleration
Particle dynamics
Particle physics
Ripples
Space plasmas
Terrestrial environments
Trapping
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Reconnection fronts (RFs) play a vital role in particle acceleration and energy transport in the terrestrial magnetosphere. It is widely believed that RFs have planar monotonic profiles that determine the particle dynamics. However, recent in situ studies have revealed that the front surface is not planar as expected but rather rippled. How the surface irregularities of RFs’ impact particle energization and transport is still an open issue. Using a particle-tracing technique, we traced the trajectories of ions near fronts with or without surface ripples at different scales to understand how ions are mediated by such rippled structures. We find that the ion relative energy gain increases considerably when the rippled surface of RFs appears. The main acceleration mechanism is ion-trapping acceleration, in which ions are confined at the RFs for a longer time by the rippled structure and are accelerated by the duskward electric field. Moreover, ions can be accelerated effectively when their gyroradius is comparable to the size of the ripple. Formulas of relative energy gain as a function of the ripple size are presented.
ISSN:0004-637X
1538-4357
DOI:10.3847/1538-4357/ac3a08