High-gradient testing of single-cell test cavities at kek / nextef

So far, we have developed X-band high-gradient accelerating structures of prototypes for normal-conducting linear colliers in a comprehensive way, establishing a full production process including fabrication and test. On the other hand, focusing on the fact that we do not know both the high-gradient limit of performance and breakdown trigger mechanism on the normal-conducting RF acceleration, we have built a new test stand for fresh basic study on RF breakdown in vacuum, where we use compact test structures with an RF field concentrated in a single test cell. In this paper, we report on the status of the new test stand called “Nextef / Shield-B,” including its trigger system and various detectors installed to Shield-B.