MEASUREMENTS OF HIGHER ORDER MODE IN AN X-BAND ACCELERATOR

In this paper, a cage of metallic wires is used as a perturbing object to measure the longitudinal electric fields of higher order modes (HOMs) in an X-Band accelerating structure. The cage is made by sputtering copper film onto nylon thread through a specially designed fixture. The "form factors" of cage are calibrated in a pillbox cavity. By using of a cage and a cylinder, the longitudinal electrical fields on TM110 mode in an X- Band accelerating structure are determined by perturbation technique. This results are compared with the calculated ones from URMELT code. And the measurements with cage produce the true field profiles.