Properties of Contoured Cavities

Mesh relaxation computer programs such as the Los Alamos LALA have been developed which determine the Q, shunt resistance and resonant frequency of radially contoured, cylindrical cavities supporting a TM 01-like mode. This program has been used in particular to optimize accelerator cavity designs for the sidecoupled standing wave structure. However, it is also possible to use these cavity designs for in-line structures. In this case ßp = (Vp /C)¿, so that, for example, the longitudinal 2¿/3-mode at the velocity of light corresponds to the phase velocity 0.66 in the standing wave notation. It is convenient to regulate the energy velocity in this structure by means of circumferential slots between cells, leaving the beam aperture unchanged. This report presents the results of experimental measurements to determine the properties of such a structure in the 2¿/ 3-mode.