Collective ion acceleration during Buneman instability of high-current electron beams injected into a low pressure gas

A new model of ion acceleration during high-current electron beam injection into a low pressure neutral gas is presented. The model is based on a mechanism of ion capture by the charge densty wave during buneman instability development in a non-compensated electron beam and their further acceleration with the growth of phase wave velocity as for as the beam charge is compensated. The developed model is shown to allow one to explain the majority of facts collected at present in experiments with the given method of collective ion acceleration. Estimations of maximum energy of accelerated ions are obtained within the frame of the model; the optimal range of gas pressure for acceleration and its dependence on beam parameters are determined; the explanation of accelerated ion current pulse shape as well as their positions relatively to the beam front and the effect of acceleration suppression by an external magnetic field are given. By certain points the developed model agrees better with experiments than the known model of the ionization front and its diffirent modifications