Experimental investigations of the TE11 mode radiation from a relativistic magnetron with diffraction output

Abstract

Directly radiating microwaves at TE11 mode, a relativistic magnetron with diffraction output (MDO) is experimentally investigated. Two important factors, transition section and working condition, significantly affecting the microwave powers, efficiencies, and pulse durations are analyzed. The experimental results on our designed MDO show that the optimized transition section with the parameters, 46 mm in height and 70 mm in length, is beneficial for producing high power TE11 mode microwaves. Under the low applied voltage condition (less than 650 kV), the power conversion efficiency will be higher than that obtained from the high applied voltage condition. ∼24 ns of the microwave duration is a typical value under the voltage duration of 56 ns. Pulse shortens will happen if the applied voltage is higher than 650 kV. When the applied voltage reaches 880 kV, the microwave duration is only just ∼12 ns. Impendence mismatch between the accelerator and the diode is the chief reason causing the pulse shortens.