High power microwave emission from cyclotron autoresonance maser (CARM) interactions in microsecond, intense electron beams

Summary Form only given, as follows. Experiments have been performed in which multimegawatt, frequency-tunable, microwave radiation has been generated in the K-band and X band by means of cyclotron maser mechanisms on intense electron beams with microsecond pulse lengths. Two long-pulse, intense electron beam accelerators were used. Initial experiments have been performed using a generator with parameters: voltage=0.4 Mv, current=1 kA, and pulse length=0.3-0.4 mu s. Over 3 MW of K-band microwave radiation, magnetically tunable from 14 through 15.5 GHz, have been generated. The frequency of this radiation corresponds to the CARM forward wave interaction. In the same experiments, megawatt-level X-band radiation, magnetically tunable from 10 to 12 GHz, was observed. The frequency of this emission indicates that it originates from the cyclotron maser backward wave interaction or absolute instability. Microwave pulse lengths of 0.1 to 0.2 mu s were generated in these initial experiments.<>