  In the offered paper the kinetic theory of equilibrium and stability of the
nonelectroneutral current sheaths formed at arbitrary values of medium
parameters was developed. Equilibrium distribution function of a current sheath
(Harris's function) considering anisotropy of temperature of plasma along and
across the layers is summarized. The procedure of examination of a current
sheath stability with due regard to plasma polarization effect is offered.
Tensor of dielectric permeability is calculated and dispersion equation for
investigation of possible instability modes of non-electroneutral current
sheath is derived. Non-electroneutral equilibrium solution for a current sheath
in the magnetospheric tail is derived and its instability is explored. A
possible mechanism of magnetic field annihilation in the magnetospheric tail
and acceleration of charged particles in the process of magnetospheric substorm
development is considered.
