Operation Analysis of High Power Tetrode Tube for the Wideband Cavity in CSNS-II

Two high-power tetrode tubes operated in push-pull mode were employed as the final stage amplifier for the wideband magnetic alloy (MA) loaded cavity in the China Spallation Neutron Source Phase II (CSNS-II). However, the anode voltage of the tetrode tubes exhibits significant waveform distortion due to the wideband load impedance and dynamic tube characteristics. This distortion poses a threat to beam stability and results in additional power dissipation within the cavity. Consequently, it is imperative to address the compensation of higher harmonics. Prior to achieving this, a comprehensive and intricate analysis of tetrode tube operation is required, involving the simultaneous resolution of numerous variables to obtain accurate solutions for anode voltage and anode current. This article introduces a new method for analyzing tetrode tube operation in the presence of multiharmonics. The efficacy of this method is verified through high-power tests.