Articles | Volume 13, issue 3
Ann. Geophys., 13, 242–246, 1995
https://doi.org/10.1007/s00585-995-0242-5
Ann. Geophys., 13, 242–246, 1995
https://doi.org/10.1007/s00585-995-0242-5

  31 Mar 1995

31 Mar 1995

Centrifugal trapping in the magnetotail

D. C. Delcourt, R. F. Martin, J. A. Sauvaud, and T. E. Moore D. C. Delcourt et al.

Abstract. Particles leaving the neutral sheet in the distant magnetotail at times display adiabatic trajectory sequences characterized by an inflection toward the equator and subsequent mirroring in its vicinity. We demonstrate that this low-latitude mirroring results primarily from a centrifugal deceleration due to the fast direction-changing E×B drift. This effect which we refer to as "centrifugal trapping" appears both in guiding centre and full particle treatments. It thus does not directly relate to nonadiabatic motion. However, pitch angle scattering due to nonadiabatic neutral sheet interaction does play a role in reducing the parallel speed of the particles. We show that centrifugal trapping is an important mechanism for the confinement of the slowest (typically below the equatorial E×B drift speed) plasma sheet populations to the midplane vicinity.