The interaction region of KEKB

An asymmetric-energy collider of <f>8 GeV</f> electrons and <f>3.5 GeV</f> positrons, KEKB, has been operating at KEK since 1998. On July 9, 2001 it achieved the highest record of luminosity, <f>4.5×1033 cm−2 s−1</f>. This paper describes the interaction region (IR) extending about <f>8 m</f> from the interaction point (IP) along each beam direction. The main machine components in the IR are focusing quadrupole magnets, compensation solenoids, and vacuum chambers, which are positioned on movable stages. They are designed to focus both beams into collisions with a finite angle crossing. [Copyright &y& Elsevier]