Analysis of multimode wakefield generation in accelerating structures with conductive dielectric loading

Wakefield generation by short electron bunches traveling along the vacuum channel of an accelerating structure loaded with a conductive ceramic dielectric has been investigated. The dielectric response is defined as no dispersion of the real part of permittivity and linear increase of loss tangent versus frequency. This model is in good agreement with measured microwave properties of some materials tested for Dielectric Wakefield Acceleration experiments. It has been shown that the dielectric conductivity has an essential impact on the wakefield. The loss factor influences most strongly on short electron bunch generation of the multimode wakefields.