Particle-in-Cell Simulation and Analysis of 28-Vane Megawatt-Class Pulsed Power Coaxial Magnetron in X-Band

This article presents the design and analysis of a 28-vane megawatt-class pulsed power coaxial magnetron operating in $X$ -band for medical linear accelerator (LINAC) applications. The systematic design procedure of the coaxial magnetron is presented. The proposed coaxial magnetron is analyzed using particle-in-cell (PIC) simulations. The output is taken from the standard WR112 waveguide through a rectangular slot in the outer wall of the coaxial cavity. The maximum total efficiency of 62.04& x0025; is obtained at 9.2987 GHz, having a 2.12-MW peak output power for stable $\pi $ -mode operation. The $\pi $ -mode operation is determined by 14 spokes of electrons in the PIC simulation. Electronic efficiency and circuit efficiency of the designed coaxial magnetron are obtained as 73.86& x0025; and 84& x0025;, respectively. The output peak power can be enhanced by optimizing the applied magnetic field in the operating region of $\pi $ -mode. Total efficiency is improved by 2.74& x0025; by changing the shape of the cathode end hats from conventional to conical. The dielectric properties of the slot-mode suppressor are optimized based on the output performance of coaxial magnetron. The optimal values of dielectric constant and loss tangents are obtained as 21 and 0.08, respectively. The frequency-tuning characteristics of the magnetron are also analyzed, and the tuning range is obtained as 9.2987 GHz & x00B1; 20 MHz.