Conceptual design of vacuum system for super KEKB

摘要

Conceptual design of the vacuum system for the upgrade of KEKB (Super KEKB) is presented. For its large storage current, the synchrotron radiation (SR) power is much higher than ever before. The beam chamber will have an ante-chamber structure to reduce the irradiated SR power density. To accommodate the intense higher order mode (HOM) arising from the short bunch length, the careful R&Ds are required for bellows, movable masks (collimators), HOM absorbers and so on. The first step of R&D has just begun using the KEKB.