BTO HIGH POWER MICROWAVE SOURCE FOR NSWC

MISSION RESEARCH CORPORATION (MRC) PROPOSES TO INVESTIGATE THE FEASIBILITY OF DEVELOPING, AND IMPLEMENTING AT NSWC, A NEW COMPACT AND LOW-WEIGHT HIGH-POWER MICRO-WAVE GENERATOR. THIS DEVICE USES AN ELECTRON BEAM TO EXCITE NONAXISYMMETRIC MODES IN A CAVITY VIA ITS TRANSVERSE OSCILLATION, AND THE DEVICE PERFORMANCE IS INSENSITIVE TO ELECTRON BEAM PARAMETERS SUCH AS ENERGY AND CURRENT. THE PHYSICAL EFFECT EXPLOITED AND OPTIMIZED IS THAT OF THE WELL-KNOWN BEAM-BREAKUP (BBU) INSTABILITY. COUPLING THE INSTABILITY WITH THE TRANSIT-TIME EFFECT OF THE ELECTRON BEAM IN THE CAVITY, RAPID EXCHANGE OF ENERGY BETWEEN THE ELECTRON BEAM AND THE PRESELECTED ELECTROMAGNETIC MODE CAN OCCUR RESULTING IN THE GENERATION OF HIGH-POWER MICRO WAVES. TO EMPHASIZE THE PHYSICAL PROCESSES INVOLVED, WE NAMED THIS DEVICE THE BEAM-BREAKUP TRANSIT-TIME OSCILLATOR (OR BTO FOR SHORT). THE LINEAR GROWTH RATE IS PROPORTIONAL TO THE MODE FREQUENCY AND UNDER OPTIMAL CONDITIONS, THE CAVITY MODE TM110 EXPONENTIATES IN ONLY 10 OSCILLATION PERIODS. IN ADDITION, THE TRANSIT TIME RESONANCE NATURALLY LEADS TO VERY NARROWBANDOUTPUT WITH A TYPICAL WAVELENGTH IN THE RANGE OF 1-30 CM DEPENDING ON THE CAVITY RADIUS. THE BTO REQUIRES NO EXTERNAL MAGNETIC FIELD ANDCAN ACHIEVE HIGH-EFFICIENCY (26-47PERCENT) FOR HIGH-POWER (>>1 GW) OPERATION.