Dissipative instability of overlimiting electron beam in no uniform cross-section system

Paper presents a type of streaming instabilities with new, previously unknown physics. It realizes under very high, overlimiting beam current in no uniform cross section systems with dissipation. In this case two factors that lead to excitation of the beam wave with negative energy superimpose and this superposition results in instability of new type - dissipative instability of overlimiting electron beam. Physics of this instability in no uniform cross section system sharply differs from that in uniform cross section system. The growth rate of presented instability has more critical dependence on dissipation. (author)