COMPUTER-SIMULATION OF THE COLLISIONLESS RELAXATION OF AN UNCOMPENSATED ELECTRON-BEAM INJECTED IN THE IONOSPHERE

The particle method (CIC) is used for the simulation of the collisionless relaxation of the cylindrically symmetric quasi-stationary electron beam injected in plasma along the geomagnetic field. The beam is assumed to be uncompensated in a charge, as well as in a current. The analytic shape of the beam equilibrium distribution function is found as a result of beam phase space mixing in collective electromagnetic fields. In nonrelativistic limit, simple analytic equations for beam characteristics in equilibrium state (density, average energy etc.) are obtained. The results of the analytic theory turn out to be in good agreement with the results of the simulation. The results of the computer simulation are also compared to the solution of the envelope equation.