Experimental study of a Ka-band gyrotron backward-wave oscillator

A gyrotron backward-wave oscillator (gyro-BWO) has been operated and magnetically tuned over the frequency range 27-32 GHz. Tuning by varying the electron beam voltage was effective over a smaller frequency range ( Delta f approximately 1 GHz). Output power was as large as 7 kW, corresponding to a device efficiency of 19%. This large efficiency value was unexpected, and related analysis indicates it may be associated with the nonuniform magnetic field profile in the interaction region.<
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