Design and simulation of a megawatt class conventional magnetron

Summary form only given. A Megawatt class conventional strapped magnetron (diode voltages <; 100kV) design is simulated using the Improved Concurrent Electromagnetic Particle-in-Cell code (ICEPIC). ICEPIC is designed to run on massive parallel architecture, consequently field and particle resolution requirements for these simulations are satisfied. Simulations are carried out at over 22 million grid cells with a resolution of one grid length = 0.5 mm or less. Numerical results yield a design capable of a mean RF output power exceeding 1.5 MW at greater than 85% efficiency at ~53 kV. The magnetron consistently oscillates in the π mode with no mode competition at ~900 MHz across a range of magnetic fields and voltages extending from 0.18-0.3 T and 45-60 kV. RF output power extends from 500 kW to ~ 4 MW over this range. Moreover RF output efficiency remains stable above 85% over these voltages and magnetic fields. Oscillations at these field parameters were consistent with single particle Buneman-Hartree analysis. For all cases, RF power is extracted axially through three conducting rod excitations. Field stresses remained below the Kilpatrick limit for simulations with diode voltage <; 52 kV and exceeded the limit above 53 kV. Field stress maximums were observed between the straps and the anode as well as between the straps. Major power loss mechanisms were particle collisions with the slow wave structure and cathode, which accounted for a loss of over 10% of the input power.