Lattice design for the High Energy Ring of the SLAC B-Factory (PEP-II)

Author

Donald, M H R ; Cai, Y. ; Irwin, J. ; Nosochkov, Y. ; Ritson, D.M. ; Seeman, J. ; Wienands, H.-U. ; Yan, Y.T.

Author_Institution

Stanford Linear Accel. Center, Stanford Univ., CA, USA

Volume

1

fYear

1995

fDate

1-5 May 1995

Firstpage

591

Abstract

The design of the lattice for the High Energy Ring (HER) of the SLAC B-Factory has several special features, notably provision for octupole compensation of amplitude dependent tune shift effects and a beta-beat scheme for semi-local chromaticity correction. In the arcs adjacent to the interaction point (IP) the beta functions are enhanced to allow the use of non-interlaced sextupoles to compensate the chromaticity of the interaction region. A closed bump of beta “mismatch” is generated by two vertically focusing quadrupoles spaced 2 betatron wavelengths apart. The beta-beat has two advantages: it enhances the ratio between the horizontal and vertical beta functions at the sextupoles and, because of the locally higher beta function, allows weaker sextupoles to be used. The standard design uses a 60 degree/cell lattice but a 90 degree/cell lattice may also be used if lower emittances and momentum compaction factor are desired

Keywords

electron accelerators; electron beam focusing; storage rings; High Energy Ring; PEP-II; SLAC B-Factory; amplitude dependent tune shift effects; beta functions; beta-beat scheme; chromaticity correction; emittances; lattice; momentum compaction factor; octupole; vertically focusing quadrupoles; Clocks; Compaction; Contracts; Electrons; Lattices; Linear accelerators; Magnetic fields; Positrons; Radio frequency; Storage rings;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1995., Proceedings of the 1995

Conference_Location

Dallas, TX

Print_ISBN

0-7803-2934-1

Type

conf

DOI

10.1109/PAC.1995.504729

Filename

504729