Operation characteristics of a 12-cavity relativistic magnetron with diffraction output when considering secondary and backscattered electrons emission

The former particle-in-cell simulation (PIC) of 12-cavity relativistic magnetron with diffraction output (MDO
¹
) was demonstrated a splitting of the radiation frequency for each eigenmode owing to its different longitudinal distribution. And scenarios and frequency switching for this 12-cavity magnetron was considered in our earlier work
^2,3
. The PIC simulation found when 12-cavity MDO driven using a 400kV applied voltage, the energetic electrons emitted from cathode strike on the relativistic magnetron's anode block, emitting secondary and backscattered electrons. The resultant secondary and backscattered electron current lowers the output power, especially when the relativistic magnetron was driven using a short applied voltage pulse. And this phenomenon leads to the operation spectrum for 12-cavity MDO more complicated that when considering mode switching, the boundary of neighbour modes should be considered carefully.