The “hose type” instability of REB and microwave generation in a waveguide

The results of the computer simulation of the relativistic electron beam (REB) injection into vacuum waveguide through a conductive foil without the guide magnetic field are presented. The beam current is lower than that limiting current for this waveguide. The intense generation of TM-
_2n
-mode with 15%-25% efficiency resulting from the formation of “hose type” instability is observed.