On equilibrium functions of a pitch angte distribution of energetic particles in nonadiabatic scattering in the magnetotail current layer

Pitch-angle scattering of energetic particles in the region of the tail of magnetosphere with current layer is studied in detail by numerical methods. Thickness of the current layer in the units of hydroradius of scattered particles and the angle of ''break'' of magnetic force lines are the model parameters of the problem. Calculations of a large number of trajectories (about 20000 for each variant of the model) permitted to plot a matrix of pitch angle scattering and a nucleus of integral equation for equilibrium function of particle distribution. Solutions of this equation for different values of the model parameters are obtained. It proceeds from them that isotropic function of distribution forms only at not too small values of dimensionless thickness of the current layer. Considerable diviations from isotropy are observed for rather fine current layers