Investigations of the electromagnetic properties of finite length X-band slow-wave structures

Summary form only given. Cold tests have been performed on a slow-wave structure made from a cylindrical waveguide with sinusoidally varying radius. To study the dispersion relation, a cavity was formed by shorting a section of the structure between metal plates placed at planes of mirror symmetry. A simple axial wire antenna was used to launch azimuthally symmetric TM (transverse magnetic) modes. The end reflection was measured on the 8-period beam test structure to include the effect of the output taper. Since the input side was cutoff to all TM modes, one only needed to measure reflection for the output side of the structure. This reflection was found by measuring the diffractive quality factor of the structure.