Electron-beam distortion in the region of a klystron gap

Some klystrons incorporate a very dense magnetically focused electron beam. Such a beam is distorted in the region of each tunnel gap by the local changes in the electric-field pattern. The effect has been evaluated in a way allowing its magnitude to be found in any particular case by reference to a set of graphs. The solution includes the effect in the tunnel near the gap and considers both radial motion and axial velocity reduction. The results can be applied to annular and solid beams. The distortion is shown to be small in practical cases, but it does not follow that the overall effects are small.