Dynamics of quasineutral plasma beams and the structure of the beam-induced disturbances in ionospheric plasma

Phenomena accompanying the injection of a dense plasmabeam from the payload of a rocket into ionospheric plasmaare analyzed. The dynamics of both the quasineutral plasmabeam and the beam-induced disturbances in the ionospheric plasmaare investigated. It is shown that the electric field in the beam has a complicated structure, which leads to the generation of currents in both the beam and the ambient ionospheric plasma. The transverse size of the disturbance zone in the ionospheric plasmais found to greatly exceed the beam diameter. The proposed model of the current closing in the ionospheric plasmaagrees well with the experimental data. The xenon beam temperature at moderate distances from the injector is determined by using the plasmashadow theory. It is found that the ion beam temperature is at least four times lower than the plasmatemperature in the injection zone. This unexpected result is explained by the adiabatic cooling of the current system. The critical radiusbeyond which a constant temperature in the beam is established is found to be less than 11 m.