Influence of dissipation on instability of overlimiting electron beam

Interaction of overlimiting electron beam with spatially separated plasma in waveguide is investigated. In wide range of system parameters the instability is caused by growing of beam slow wave of negative energy. In this case dissipation in the system leads to a new type of dissipative beam instability with inverse proportional dependence on dissipation. Growth rate of this instability is obtained for arbitrary level of dissipation.