Microwave analysis of the damped detuned accelerator structure

Damped and detuned accelerating structures (DDS), designed to minimize the effects of long range wakefields excited by bunchtrains, are presently under investigations at SLAC. The authors report the first studies of beam-induced microwave signals in a prototype DDS. The DDS is a 206 cell, nearly constant gradient structure, employing Gaussian detuning, and four symmetrically placed waveguide manifolds to damp the first-band dipole modes. They describe the manifold and output coupler design, bench measurements, and measurements with beam during the ASSET experiment. Dipole mode signals have been used to steer the beam to the structure center and minimize the wakefield kick.