Experimental Study on a 0.5 GW Relativistic Backward Wave Oscillator (RBWO)

A RBVVO is capable of high efficiency by a relatively long interaction region between a backward wave and an electron beam. But the pulse shortening problem occurs frequently in experiments of RBWOs because of the mode competition, the RF breakdown and so on (S.D. Korovin et al., 2000). In our previous research of the 100MW RBWO, it shows that the mode competition can depends on the beam radii and the diode impedance (F. Hegeler et al., 2000). An X-band 0.5GW RBWO avoiding a mode competition is designed and simulated, using 10 uniform ripples that the average radius is 14.5mm and the amplitude is 2.5mm. 520MW stable RF power is estimated by MAGIC simulation when the applied voltage is 500kV and the current is 5.2kA..