A Chopper Driven 11.4-GHz Traveling-Wave RF Generator*

We have tested a high-power 11.4-GHz rf generator which consists of a 5.7-GHz chopping system and two 11.4-GHz traveling-wave output structures. The device was designed to generate about 500 MW of pulsed rf power at 11.4 GHz when driven by a I-kA, 3-MeV induction beam. Problems with beam breakup in the output structures have limited the width of the rf output pulse for currents above 600 Amps, We have produced short rf pulses up to 420 MW. We are making modifications to decrease the growth of the beam-breakup fields in the output structures and will use the chopping section to study various extraction structures and to study reacceleration of a bunched beam by induction cells. (Traveling wave structures, 11.4 GH