Variation of total current during REB instability development

Total current variations during heavy current REB interactionwith dense gas mixture under conditions of instability development are analyzed. Investigations were carried out in ''Tonus'' accelerator, the electron energy being 1 MeV, the beam current 12-21kA. Metallic drift tubes 92 and 300 mm in diameter filled with N2:O2=4:1 mixture at different pressure were used. The given mixture is thought initial in plasmachemical reactor operation, in fusion of nitrogen oxides. It is shown that during large-scale beam instability development in gas total current may more than 3 times exceed electron current measured in one cross section of interaction chamber. Different conditions of REB propagation in gas medium, during beam current variation, pressure and geometry of interaction volume are investigated