Design parameters for the damped detuned accelerating structure

The advanced accelerating cavities for the NLCTA (and anticipated for NLC) will incorporate damping as well as detuning. The damping is provided by a set of four waveguides (which also serve as pumping manifolds) that run parallel to the structure, with strong iris coupling to each cavity cell and terminated at each end by absorbers. The previously reported equivalent circuit analysis has been refined and the dependence upon design parameters explored. We find that adequate damping can be provided by a single waveguide mode, leading to designs which are more compact than those initially considered. The design parameters and their rationale will be presented