Electron-beam bifurcation in the field of an open cavity

Current density modulation has been examined for a broad strip beam in the field of an open cavity. An expression has been obtained for the spectrum of the convection current at the output from the modulator with allowance for the beam bifurcation in the standing-wave field. Averaging the harmonic amplitudes over the beam cross section shows that the bifurcation only slightly reduces the mean energy stored in the beam at the modulating frequency.