Three-scale structure of diffusion region in the presence of cold ions
2016 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 121, no 12, 12001-12013 p.Article in journal (Refereed) Published
Kinetic simulations and spacecraft observations typically display the two-scale structure of collisionless diffusion region (DR), with electron and ion demagnetization scales governing the spatial extent of the DR. Recent in situ observations of the nightside magnetosphere, as well as investigation of magnetic reconnection events at the Earth's magnetopause, discovered the presence of a population of cold (tens of eV) ions of ionospheric origin. We present two-dimensional particle-in-cell simulations of collisionless magnetic reconnection in multicomponent plasma with ions consisting of hot and cold populations. We show that a new cold ion diffusion region scale is introduced in between that of hot ions and electrons. Demagnetization scale of cold ion population is several times (similar to 4-8) larger than the initial cold ion gyroradius. Cold ions are accelerated and thermalized during magnetic reconnection and form ion beams moving with velocities close to the Alfven velocity.
Place, publisher, year, edition, pages
2016. Vol. 121, no 12, 12001-12013 p.
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-316974DOI: 10.1002/2016JA023606ISI: 000393183300027OAI: oai:DiVA.org:uu-316974DiVA: diva2:1079420
FunderSwedish National Space Board, 136/11Swedish National Infrastructure for Computing (SNIC), m.2014-1-176 2014-8-38