• X.D. He, S. Dong, Y.J. Pei, C.-F. Wu
  USTC/NSRL, Hefei, Anhui

Funding: the National Nature Science Foundation of China, Grant No. 10375060, 10375061 and 10675116

One of the major concerns in the development of hybrid dielectric-iris-loaded structure is the performance of the used dielectric. The previous dielectric is machinable but the loss tangent is slightly high. So we adopt the new dielectric (Mg-Ca-Ti-O) with loss tangent of about 2·10^-4. Because of its high hardness and brittleness, the machining technology and methods are attempted. In this paper, we present a new design of the structure. The model cavities and the coupler for this structure with the new dielectric are investigated experimentally. The experiment results are accorded with the simulated results. In the end, the amplitude and phase shift of the electric field and R/Q of this structure at the operation frequency are even got by a bead-pull experiment.

• Z.P. Li
  USTC, Hefei, Anhui
• S. Dong, X.D. He, C.-F. Wu
  USTC/NSRL, Hefei, Anhui

Funding: National Nature Science Foundation of China, Grant No. 10675116 and 10375060

We present the new experimental results for an X-band (11.42GHz) metallic PBG accelerating cavity. A coupler of a single cavity was fabricated and cold tested. An X-band traveling-wave PBG accelerator was designed based on CST MWS transient analysis. The X-band PBG accelerator is now under construction, future work will focus on the structure to be cold tested and tuned.

• H.Z. Zhang, S. Dong, C.-F. Wu
  USTC/NSRL, Hefei, Anhui
• Z.P. Li
  USTC, Hefei, Anhui

Photonic crystals have been suggested for use as laser driven particle accelerator structures with higher accelerating gradients and effective damping of unwanted higher order modes. Here we selected Photonic band gap (PBG) fibers with hollow core defects to design such an accelerating structure. To achieve this design, Out-plane-wave mode in photonic crystal fiber was selected for longitudinal electric field. The out-plane-wave plane wave expansion method was deduced for confinement and the dispersive curve versus variation of kz and speed of line for synchronization. Then super cell approximation was also introduced for calculating the defected photonic crystal structure. After the design of appropriate geometry and the dimensions of photonic crystal fiber accelerating structure, the field distribution was simulated with RSOFT Bandsolve software for this structure.