Speaker
Description
A dielectric assist accelerating (DAA) structure, which consists special dielectric cell structures operating in the TM02n mode, is greatly superior in power efficiency compared with the conventional normal conducting copper structures. On the other hand, DAA structures stays at a low achievable accelerating gradient due to multipactor and breakdowns. To overcome these problems, we try to develop X-band standing-wave DAA structures and work to understand the physics of the breakdown phenomena occurring inside them.
A two-cell DAA structure composed by sapphire cell structures has been developed. The unloaded Q was measured to be above 60,000 at room temperature, in good agreement with the simulation results. This DAA structure is to be tested using the X-band high power test facility, Nextef2 at KEK. In the high-power test, we plan to perform a short pulse RF excitation using step pulse input in DAA structures to verify the potential of them to generate a high accelerating field. In this conference, we will present the status and progress in the development of the X-band DAA structure.
