Influence of Fabrication Errors on the Wakefield and Emittance Growth for the Next Linear Collider

The heart of the NLC (Next Linear Collider) will consist of several thousand X-band accelerator structures which damp the transverse wakefield via detuning the modal frequencies such that the amplitudes of the modes destructively interfere and by four damping manifolds per structure. Errors in the fabrication of the individual cells, which constitute each structure, will result in a poor cancellation of the modes and here the authors explore the effects of random errors within a particular structure and errors which are systematically repeated within a given accelerator and are distributed randomly over the whole collider. The beneficial effects of an effective interleaving of cells due to these fabrication errors is discussed together with results of tracking a multi-bunch beam through 11km of accelerator structures.