title: Quadruple-bend achromatic low emittance lattice studies.
abstract: A quadruple-bend achromatic (QBA) cell, defined as a supercell made of two double-bend cells with different outer and inner dipole bend angles, is found to provide a factor of 2 in lowering the beam emittance relative to the more conventional double-bend achromat. The ratio of bending angles of the inner dipoles to that of the outer dipoles is numerically found to be about 1.5-1.6 for an optimal low beam emittance in the isomagnetic condition. The QBA lattice provides an advantage over the double-bend achromat or the double-bend nonachromat in performance by providing a small natural beam emittance and some zero-dispersion straight sections. A lattice with 12 QBA cells and a preliminary dynamic aperture study serves as an example.
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
authors.forename: M H
authors.initials: MH
authors.lastname: Wang
authors.forename: H P
authors.initials: HP
authors.lastname: Chang
authors.forename: H C
authors.initials: HC
authors.lastname: Chao
authors.forename: P J
authors.initials: PJ
authors.lastname: Chou
authors.forename: C C
authors.initials: CC
authors.lastname: Kuo
authors.forename: H J
authors.initials: HJ
authors.lastname: Tsai
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: W M
authors.initials: WM
authors.lastname: Tam
authors.forename: F
authors.initials: F
authors.lastname: Wang
mesh_terms: D017076:Computer-Aided Design; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D017356:Synchrotrons / Q000295:instrumentation*; D014159:Transducers