PIC simulation study of a 35 GHz, 200 kW Gyroklystron

A three-dimensional PIC simulation of a 35 GHz, 200 kW two cavity gyroklystron amplifier has been performed to study the electron beam and RF wave interaction behavior using a commercial PIC code 'MAGIC'. The electromagnetic field analysis of the RF structure in the absence of the electron beam and beam-wave interaction study in the presence of the electron beam have been carried out for the performance evaluation of the device. Electromagnetic field analysis has been done using the eigenmode solver, which ensures the structure operation in the desired TE01 operating mode at 35 GHz frequency. Electron beam and RF wave interaction simulation confirm that the present gyroklystron meet the required specification in terms of output power and gain. Moreover, the particles phase space behavior along the interaction length has been also demonstrated to realize the energy transfer phenomena. An output power around 200 kW at 34.95 GHz with ~35% efficiency and a bandwidth of 0.29% have been obtained considering no spread in electrons velocity. Our simulated result matches with the experimental values within 8%.