Purpose and Vision
SuperKEKB is the upgrade of KEKB to increase the luminosity 40 times, to 8 x 10 35 cm -2 s -1. The construction started in 2010 and will have the first beam in early 2015 in the collider rings.
SuperKEKB's basic scheme to achieve the very high goal luminosity is called nano-beam scheme. It is an idea developed by Pantaleo Raimondi to allow a very strong vertical focusing at the interaction point (IP) by making the crossing angle even larger than the previous machine, together with smaller beam emittances. The resulting beam sizes at the IP are about 10 μm x 50 nm (horizontal x vertical), which are bout 20 times smaller than KEKB. The beam currents are also increased by a factor of 2. Various new technologies are incorporated in SuperKEKB. The beam pipes for the positron beam are replaced with electron-cloud free design using antechamber, TiN-coating, grooves, electron-cloud suppressing electrodes. Higher stored currents need upgrades in the ARES and Superconducting cavities as well as new higher order mode resistant vacuum components. The most difficult part is the high-precision superconducting quadrupole magnets at the interaction region with very complicated assembly within the Belle-II detector. All subsystems including magnets and power supply, low-level and high-power RF systems, vacuum, beam diagnostics and feedback, injection and beam abort systems, control and safety systems need significant upgrade. The injector Linac needs serious upgrades in the RF gun, positron source, beam transport and control as well as the new positron damping ring.