STATUS OF KEKB PROJECT

The KEK B-Factory, KEKB, is an asymmetric-energy, two-ring, electron-positron collider for B physics. Eight GeV electrons stored in a high-energy ring (HER) and 3.5 GeV positrons in a low-energy ring (LER) collide at an interaction point (IP), which BELLE detector surrounds. In order to facilitate detection of CP-violation effect at the bottom-quark sector, the machine is designed to reach a luminosity of 1034cm-2s-1. Even with a high beam-beam tuneshift of 0.05 and a small βy * of 1 cm at IP, necessary currents in the rings amount to 1.1 A at HER and 2.6 A at LER. KEKB adopts new schemes to reach the goal, such as ±11 mrad finite-angle collision at IP, non-interleaved-sextupole chromaticity correction to have large dynamic apertures, higher-order-mode-free normal conductin