PARTS OF THE 203D COAXIAL WAVEGUIDE IMPROVED AT KEK

The WX-203D Coaxial Waveguides are used at KEK to feed a high rf power to the proton linac tank, which is excited with 2 input couplers to suppress the TM011 mode. Usually, it is very troublesome that coaxial waveguides should be lined up with a good rf contact and the equal length. Hence, we have developed the L-type WX-203D waveguide and the variable-length straight waveguide with the new mechanical structure. In this report, we shall present the mechanical structure of the coaxial waveguides developed at KEK and high power test results.