A potential alternative to conventional disk-loaded copper structures is dielectric-loaded accelerating (DLA) structures, which utilizes dielectrics to slow down the phase velocity of travelling wave in the vacuum channel. The simplicity of the DLA structure offers a great advantage for RF-driven accelerating structures as compared with conventional metal structures which demand extremely tight fabrication tolerances. This is of a great importance in the case of linear collider where tens of thousands accelerating structures have to be built.
In this talk, a dielectric disk accelerating(DDA) structure is proposed and optimized to greatly reduce the wall power loss, thereby resulting in an extremely high quality factor, high shunt impedance and low group velocity. Such a structure can be travelling-wave type or standing-wave type. The geometry for standing-wave type including regular cells and end cells are described in detail. In addition, the wakefield studies on the DDA structures are also included in this talk.