title: Suite of three protein crystallography beamlines with single superconducting bend magnet as the source.
abstract: At the Advanced Light Source, three protein crystallography beamlines have been built that use as a source one of the three 6 T single-pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single-pole superconducting bend magnets enables the development of a hard X-ray program on a relatively low-energy 1.9 GeV ring without taking up insertion-device straight sections. The source is of relatively low power but, owing to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double-crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. aamacdowell@lbl.gov
authors.forename: Alastair A
authors.initials: AA
authors.lastname: MacDowell
authors.forename: Rich S
authors.initials: RS
authors.lastname: Celestre
authors.forename: Malcolm
authors.initials: M
authors.lastname: Howells
authors.forename: Wayne
authors.initials: W
authors.lastname: McKinney
authors.forename: James
authors.initials: J
authors.lastname: Krupnick
authors.forename: Daniella
authors.initials: D
authors.lastname: Cambie
authors.forename: Edward E
authors.initials: EE
authors.lastname: Domning
authors.forename: Robert M
authors.initials: RM
authors.lastname: Duarte
authors.forename: Nicholas
authors.initials: N
authors.lastname: Kelez
authors.forename: David W
authors.initials: DW
authors.lastname: Plate
authors.forename: Carl W
authors.initials: CW
authors.lastname: Cork
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Earnest
authors.forename: Jeffery
authors.initials: J
authors.lastname: Dickert
authors.forename: George
authors.initials: G
authors.lastname: Meigs
authors.forename: Corie
authors.initials: C
authors.lastname: Ralston
authors.forename: James M
authors.initials: JM
authors.lastname: Holton
authors.forename: Tom
authors.initials: T
authors.lastname: Alber
authors.forename: James M
authors.initials: JM
authors.lastname: Berger
authors.forename: David A
authors.initials: DA
authors.lastname: Agard
authors.forename: Howard A
authors.initials: HA
authors.lastname: Padmore
mesh_terms: D018360:Crystallography, X-Ray / Q000295:instrumentation* / Q000379:methods*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D011487:Protein Conformation; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D017356:Synchrotrons; D018511:Systems Integration
chemical_list: D011506:Proteins