Magnetron simulations using a moving wavelength computer code

A moving wavelength particle in cell computer code has been used to study the interaction in magnetrons. Current, power, and efficiency results produced by the code correlate well with the experimental performance of X-band and S-band magnetrons. The code diagnostics show the existence of three different space-charge states that depend on the kind (primary or secondary) and amount of emission. Most high-power magnetrons operate in a secondary emission dominated state. The code shows a surprising amount of space-charge turbulence in this state. The magnetron efficiency remains high in spite of this turbulence. Some low-frequency or low-power magnetrons operate in a primary emission dominated state. Space charge turbulence is reduced in this state. A new current density scaling parameter has been added to the characteristic parameter set for magnetrons. The current density at which the transition from secondary to primary emission dominance occurs has been expressed in terms of this parameter. When secondary emission is negligible, and primary emission is further reduced, an emission limited state is reached. Internal space-charge turbulence is completely eliminated in this state