Beam-transport system of KEKB

The transport lines of the KEKB for positrons and electrons convey the beams separately from the injector linac to the KEKB rings. The length is about <f>500 m</f> for each line. In order to make the maximum use of the existing tunnels and also to avoid interference with the AR, the beam lines took a serpentine course, resulting in a rather large curvature in the arcs. The consequences were a large number of bends in the arcs with high fields and also a large dispersion function and, thus, a large <f>R56</f> component. The latter issue is crucial for the KEKB rings, since it results in a longer bunch length at injection. We adopted a special optics that reduces the <f>R56</f> coefficient sufficiently. We have developed novel water-cooled ceramic chambers for kickers, eddy-current-type septum magnets for injection, and a beam-abort system for the rings. The present paper describes the design and current status of the beam lines, the injection system, and the beam-abort system. [Copyright &y& Elsevier]