Electric field measurements in klystron cavities

A qualitative comparison is made between computed and measured electric fields in typical TM010klystron cavities. The computer code LALA is shown to apply effectively to cavities with offset gaps which are difficult to solve analytically, and a bead-pull technique using a highly directive perturbing needle is utilized to verify the theoretical results. The magnitude of the radial field components is discussed as well as the shape of the axial field resulting from shaping the drift tube noses and offsetting the gap.