Space charge oscillations in the cylindrical magnetron†

Abstract

It is found that in a smooth anode cylindrical magnetron oscillations due to slipping stream interactions have frequencies which are linearly dependent on the magnetic field strength and are independent of the anode voltage. An earlier theory predicting a different field and voltage dependence is shown to be incorrect. For thin cathodes and low emission current the frequencies are integral multiples of the cyclotron frequency. This is confirmed by experiments, which also indicate that the oscillations cause the flow of anomalous anode current.