Study on Electron Optics System and Oscillation Suppression of an <i>X</i>-Band Multibeam Klystron

An electron optics system of an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</i>-band gate-controlled multibeam klystron has been designed and tested. This tube operates in the high-order mode of TM<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{210}}~2\pi $ </tex-math></inline-formula> and has two independent modules of the cathode and heater. The primary difficulties of the electron optics system operated in high-order mode are the low electron beam transmission and the mode oscillations. Through simulation and mode analysis, this article has obtained methods to improve electron beam transmission and suppress oscillations. Several tubes have been manufactured and tested. Both design considerations and experimental results have been presented. The agreement between the test results and the simulations further validates the rationality of the design.