R.M. JONES* (SLAC), T. HIGO, Y. HIGASHI (KEK), N.M. KROLL* **, (UCSD & SLAC), R.H. MILLER*, J.W. WANG (SLAC)
In fabricating the first X-Band RDDS (Rounded Damped Detuned Structure) linac measurements are made on short groups of cells prior to bonding the cells. The design dispersion curves are compared with the frequency measurements. The theory utilised is based on a circuit model with boundary conditions appropriate to a short stack of non-uniform cells (the iris radius for example is slowly varying along the stack). The model reveals the nature of the modes in the structure and is also used to refit the experimental data to the parameters in a model of the wakefield given earlier . This method allows a more faithful determination of the wakefield that a beam will experience as it traverses the structure. Excellent results are obtained on the frequencies compared to the original design, indicating that the tolerances given for the fabrication of the cells have been met.
 R.M.Jones et al, 'Equivalent Circuit Analysis of the SLAC Damped Detuned Structure', Proc. of the 5th European Particle Accelerator Conference (EPAC), p1292,(1996)
*Work supported at SLAC under U.S. Department of Energy grant number DE-AC03-76SF00515.
**Work supported under U.S. Department of Energy grant number DE-FG03-93ER40759
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