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| Titel |
On background density dependence of non-stationary collisionless magnetic reconnection. |
| VerfasserIn |
Andrey Divin, Yuri Khotyaintsev, Andris Vaivads, Mats André, Giovanni Lapenta, Stefano Markidis, Vyacheslav Olshevsky |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098511
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| Publikation (Nr.) |
 EGU/EGU2014-14193.pdf |
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| Zusammenfassung |
| Even the simplest 2D configuration susceptible to magnetic reconnection (namely, Harris
current sheet), possesses a number of "free parameters" that determine the dynamics and
energetics of the process. Among such parameters are Ti-Te ratio, guide field value, current
sheet thickness, etc. In this presentation we systematically study the effect of changing the
background density (from nb-n0 = 0.5 to nb-n0 = 0.003), which covers the range of lobe
density values observed in the Earth’s magnetotail.
Two-dimensional Particle-in-Cell (PIC) simulations are performed using implicit parallel
code iPIC3D with double-periodic configuration. Increase of the jet front magnetic
field (Bz) with nb decrease is in agreement with simulations by [Wu 2012]. The
elevated Bz region is several times larger (in the Z direction) than the initial current
layer thickness, whereas large normal electric field (Ex) area is focused between
the front and current sheet edge. Normal electric field has a bipolar profile (in the
X direction), intensity scales roughly as (nb-n0)-1-2 with changing nb. Intense
waves are generated at magnetic reconnection separatrices in the low density case.
The waves can be excited either by separatrix electron flow disruption or by EH
propagation.
We conclude that the ’standard’ picture of GEM-type reconnection is retained for various
nb-n0 ratios in two-dimensional configurations, with minor quantitative differences
attributed to steeper front shape and faster propagation at low nb densities. |
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