Potential Barrier in the Electrostatic Sheath Around Geotail, Cluster and BepiColombo spacecraft

In this paper, a fully self-consistent model of the plasma around an electron emitting central body in a spherically symmetric geometry is applied to analyse the electrostatic sheath around magnetospheric spacecraft in low density plasma. For all the case studied, it is shown that non-monotonic potential with negative potential barrier can exist. The magnitude and the location of the potential barrier in regions of the magnetosphere with large Debye length plasma are discussed.