DOI: 10.1029/2018JA025370
Scopus记录号: 2-s2.0-85051054142
论文题名: Ion Trapping and Acceleration at Dipolarization Fronts: High-Resolution MHD and Test-Particle Simulations
作者: Ukhorskiy A.Y. ; Sorathia K.A. ; Merkin V.G. ; Sitnov M.I. ; Mitchell D.G. ; Gkioulidou M.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 5580
结束页码: 5589
语种: 英语
英文关键词: injections
; plasma pressure
; ring current
; trapping
英文摘要: Much of plasma heating and transport from the magnetotail into the inner magnetosphere occurs in the form of mesoscale discrete injections associated with sharp dipolarizations of magnetic field (dipolarization fronts). In this paper we investigate the role of magnetic trapping in acceleration and transport of the plasma sheet ions into the ring current. For this purpose we use high-resolution global magnetohydrodynamic (MHD) and three-dimensional test-particle simulations. It is shown that trapping, produced by sharp magnetic field gradients at the interface between dipolarizations and the ambient plasma, affects plasma sheet protons with energies above approximately 10 keV, enabling their transport across more than 10 Earth radii and acceleration by a factor of 10. Our estimates show that trapping is important to the buildup of the ring current plasma pressure of injected particles; depending on the plasma sheet temperature and energy spectrum, trapped protons can contribute between 20% and 60% of the plasma pressure. It is also shown that the acceleration process does not conserve the particle first invariant; on average protons are accelerated to higher energies compared to a purely adiabatic process. We also investigate how trapping and energization vary for deferent ions species and show that in accordance with recent observations, ion acceleration is proportional to the ion charge and is independent of its mass. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113662
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, United States
Recommended Citation:
Ukhorskiy A.Y.,Sorathia K.A.,Merkin V.G.,et al. Ion Trapping and Acceleration at Dipolarization Fronts: High-Resolution MHD and Test-Particle Simulations[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)