Design and Thermal Study of 5 MW S-Band Tunable Pulsed Magnetron for Linear Accelerator System

This study presents a step-by-step design of 16 vanes hole and slot type high-power
$S$
-band pulse magnetron of 5 MW peak power at an operating frequency of 2.998 ± 0.005 GHz. The eigen-mode solver finds the
$\pi $
-mode and neighboring mode frequencies for unstrapping, single-ring, and double-ring strapping cases. The nature of the coupling and the circuit efficiency of the magnetron is estimated using the frequency domain solver quality factor analysis. The designed mechanical capacitive-type frequency tuner is used to tune the frequencies up to 21.7 MHz. According to the Hull-Hartree diagram, the applied electric and magnetic fields are found to be 57 kV and 1960 Gauss, respectively. The particle-in-cell (PIC) simulation confirms the output performance parameters like output power, anode current, and efficiency, which are found to be 5.136 MW, 140 A, and 64.36%, respectively. The thermal study is carried out under the ANSYS workbench to find the temperature-withstanding capability of the complete magnetron. The helix-shaped heater is designed to heat the cathode surface indirectly. The calculated and simulated temperatures of the heater are found in good agreement. The maximum temperatures on helix, cathode, and anode are 2235° C, 776° C, and 309° C, respectively, which are in a safe operating range.