Design and High-Power Testing of a Hybrid Photonic Band-Gap (PBG) Accelerator Structure at 17 GHz

JieXi Zhang, Alan Cook, Brian Munroe, Michael Shapiro, Richard Temkin, Haoran Xu, Schaa, Volker R.W. (Ed.), Henderson, Stuart (Ed.), Akers, Evelyn (Ed.), Satogata, Todd (Ed.)
An overmoded hybrid Photonic Band Gap (HPBG) structure used as an accelerator cavity has been theoretically designed and high power tested at 17.1 GHz. The HPBG structure consists of a triangular lattice of dielectric (sapphire) and metallic (copper) rods. Due to the frequency selectivity, the hybrid PBG cavity can be operated in a TM02 mode. The maximum surface fields are on the triple point of the innermost row of the sapphire rods. The relatively high value of the surface fields resulted in
more » ... fields resulted in a high breakdown rate (BDR) at a low gradient in the HPBG structure. Breakdown damage on the triple point edge and the metallization of copper onto the sapphire surface have been observed in the post-testing images. An improved HPBG design, that reduces the peak fields, has been developed. It will be built and tested in an effort to improve the HPBG performance.
doi:10.18429/jacow-ipac2015-wepwa062 fatcat:ouq6fhci6bfodgxs25xs6rfcqu