Study of a Gyrotron Traveling Wave Amplifier Based on Helically Corrugated Waveguide
A gyrotron traveling wave amplifier with an operating frequency range of 200-220 GHz and an output power of 7kW is introduced.The third harmonic cyclotron mode of a 70 keV,1.5 A,large-orbit electron beam resonates with the TE31-like mode propagating in the five-fold helically corrugated interac-tion region,achieving broadband amplification.The large-orbit beam is generated by a CUSP electron gun.The TE31-like waveguide mode exhibits ideal dispersion characteristics.The dispersion characteris-tics are optimized through theoretical calculations and numerical simulations.The three-dimensional parti-cle-in-cell(CST PIC)simulation predicts a saturated output power of 7 kW and a gain of 51.5 dB.When the input signal power is 50mW,the 3 dB Instantaneous gain bandwidth is about 20 GHz.