title: P13, the EMBL macromolecular crystallography beamline at the low-emittance PETRA III ring for high- and low-energy phasing with variable beam focusing.
abstract: The macromolecular crystallography P13 beamline is part of the European Molecular Biology Laboratory Integrated Facility for Structural Biology at PETRA III (DESY, Hamburg, Germany) and has been in user operation since mid-2013. P13 is tunable across the energy range from 4 to 17.5 keV to support crystallographic data acquisition exploiting a wide range of elemental absorption edges for experimental phase determination. An adaptive Kirkpatrick-Baez focusing system provides an X-ray beam with a high photon flux and tunable focus size to adapt to diverse experimental situations. Data collections at energies as low as 4 keV (λ = 3.1 Å) are possible due to a beamline design minimizing background and maximizing photon flux particularly at low energy (up to 1011photons s-1at 4 keV), a custom calibration of the PILATUS 6M-F detector for use at low energies, and the availability of a helium path. At high energies, the high photon flux (5.4 × 1011photons s-1at 17.5 keV) combined with a large area detector mounted on a 2θ arm allows data collection to sub-atomic resolution (0.55 Å). A peak flux of about 8.0 × 1012photons s-1is reached at 11 keV. Automated sample mounting is available by means of the robotic sample changer `MARVIN' with a dewar capacity of 160 samples. In close proximity to the beamline, laboratories have been set up for sample preparation and characterization; a laboratory specifically equipped for on-site heavy atom derivatization with a library of more than 150 compounds is available to beamline users.
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Michele
authors.initials: M
authors.lastname: Cianci
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Gleb
authors.initials: G
authors.lastname: Bourenkov
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Pompidor
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Ivars
authors.initials: I
authors.lastname: Karpics
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Kallio
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Isabel
authors.initials: I
authors.lastname: Bento
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Roessle
authors.affiliation: European Molecular Biology Laboratory, Institut Laue-Langevin, BP 181, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Cipriani
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fiedler
authors.affiliation: Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, 22603 Hamburg, Germany.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Schneider
keywords: 2θ-detector arm; low-energy data collection; phasing; softer X-rays; sulfur SAD; tunability; variable beam