Theory and computer simulation of electron beam-plasma interactions in unbounded systems

Computer simulation experiments of linear and nonlinear collisionless interactions between electron beams and background plasmas, for conditions relevant to active magnetospheric experiments, were carried out. Both electrostatic and electromagnetic interactions were simultaneously considered. The beam-plasma systems were infinite and homogeneous. The relative beam concentrations considered were epsilon = nsub(b)/nsub(p) = 1,0.1 and 0.01. In all cases, the background plasma (1 eV thermal energy) was penetrated by an electron beam of 1 keV streaming energy and 5% thermal spread in the streaming direction. A full description of the results and a brief discussion of their relevance to magnetospheric active experiments are presented. The off-angle propagation case in unmagnetized plasma is also briefly discussed. (author)