Beamline Specifications

GM/CA @ APS operates two undulator-beamline stations for macromolecular crystallography, 23ID-D and 23ID-B. They are based on two independently tunable undulators and their optical components are located in hutches 23ID-A and 23ID-C. Respective experimental stations are located in the hutches 23ID-D and 23ID-B.

BEAMLINE OPTICS

23ID-D consists of double crystal monochromator and K-B pair of bimorph mirrors for vertical and horizontal focusing. Design parameters for this beamline are:

• Monochromator energy range 5 – 20 keV
• Monochromator energy resolution ΔE/E < 2x10^-4 over full energy range
• Flux (photons/sec) at 12KeV: 1.3x10¹³
• Minimum focal size 25 μm vertically and 80 μm horizontally
• Minibeam collimators: 5 μm, 10 μm, and 20 μm
• Detector: Dectris Pilatus3-6M (6,224,001 pixels, 423.6x434.6 mm² sensitive area and 172 μm pixel size)
• Automounter: 288 samples capacity (18 pucks)
• More information is available at the APS website

23ID-B contains similar optical components as 23-ID-D and two additional horizontally deflecting mirrors. Design parameters for this beamline are:

• Monochromator energy range 3.5 – 20 keV
• Monochromator energy resolution ΔE/E < 2x10^-4 over full energy range
• Flux (photons/sec) at 12KeV: 6.4x10¹²
• Minimum focal size 20 μm vertically and 70 μ horizontally
• Minibeam collimators: 5 μm, 10 μm, and 20 μm
• Detector: Dectris Eiger-16M (18,139,650 pixels, 311.2 x 327.8 mm² sensitive area and 75 μm pixel size)
• Automounter: 288 samples capacity (18 pucks)
• More information is available at the APS website

After each optical component, there is Beam Position Monitor (BPM) to maintain beam stability.

ENDSTATIONS

GONIOMETRY

• Single horizontal axis, based on an air bearing system. It allows very fast rotation for sample centering and a small Sphere of Confusion for small sample crystals.
• Rotation speed up to 360^o/sec for sample centering, adjustable for data collection
• Beamstop-to-sample distance adjustable in 30-109 mm range

MINIBEAM CAPABILITIES

• User-selectable quad collimators with one-click switching between 5µm, 10µm, and 20µm pinholes or 300µm scatterguard

SAMPLE VISUALIZATION

• On-axis and off-axis cameras, allows robust and speedy centering, as well as beam visualization and sample monitoring during the experiment.
• Maximum magnification is 32x

DETECTOR SUPPORT

• Decoupled from the goniometer
• Sample-to-detector distance 200-3000 mm (23ID-D) and 200-1000 mm (23ID-B)
• Maximum 2θ angle is from 0^o to 45^o depending on the detector distance

ATTENUATION

• Attenuation is provided by Al and Hg attenuators of varying thicknesses (16 total)
• Allows to achieve beam attenuation from 0 to 100%

FLUORESCENCE DETECTOR (KETEK)

• Energy resolution ~150 eV @ 1000 cps
• Anomalous diffraction experiments can be carried out over entire energy range

SAMPLE CRYO COOLING

• Cryo cooling with Cryojet
• Assortment of cryo tools and Dewars provided

AUTOMOUNTERS

• An improved, high capacity (18 puck, 288 pins) automounter, based on the Berkeley Automounter (BAM), is implemented on both GM/CA ID beamlines.

ADDITIONAL FACILITIES

COLD ROOM

• Microscopes in the wet lab, cold room and X-ray hutches are provided

LN2 STATION

• There is in-house liquid nitrogen fill station at GM/CA, located close to the center of the sector 23. Users will fill their Dewars directly from the fill line. Instructions will be given as part of the user orientation. Used liquid nitrogen can be dumped into a dedicated large Dewar, located at the LN2 station.

WETLAB

• Biochemical laboratory is equipped with cold room, high power microscopes (one with dedicated CCD camera), room temperature incubator, emergency shower, emergency eye wash, scales, small desktop centrifuge, pH meter etc. Some basic chemicals and cryo tools are also provided, including assortment of small, open mouth Dewars for sample handling.

COMPUTING FACILITIES

• Each of the stations is provided with two dedicated user areas, DAY-1 and DAY-2.
• These areas are equipped with multiple CentOS-7 Linux computers (about 12 per beamline) for data collection and management. Three of these computers at each station are accessible remotely or from users laptops on Argonne Wi-Fi network: two computers in DAY-1 area are dedicated to data acquisition and data processing respectively and one computer in DAY-2 area is configured for data processing and data backups.
• Users collecting data will stay in DAY-1 area; they may also use DAY-2 area if it is vacant. Users staying an additional day after data collection, will be relocated to the adjacent user area (DAY-2 area). Remote users will have access to computers in both areas on day-1 and to computer in DAY-2 area on day-2.

SOFTWARE

• Experiment setup and data collection with JBluIce, the GM/CA software resembling interface of SSRL BluIce.
• Automated data processing pipelines are run parallel to data collection on a cluster
• For data processing, HKL2000, HKL3000 and CCP4 provided and supported
• All popular crystallographic programs and packages are provided (some unsupported)

USER DATA BACKUPS

• Globus online is recommended for fast remote data transfers.
• SFTP out to the home lab is feasible, but slower than Globus. Three computers per beamline (ws2, ws5, ws6) are available for outside SFTP access during experiment.
• External USB disks (USB-3 is strongly advised due to high transfer rate).
• No other devices (tape drives, DVD burners etc) are supported or provided.
• Supported formats:
  • FAT32, NTFS, ext3, exFAT, and HFS+ are all supported on external USB drives
  • FAT32, NTFS, ext3, exFAT formatted drives can be connected to any Linux computer except for ws2 and ws3
  • HFS+ needs a commercial driver and therefore it is supported by only three Linux computers per beamline: ws4, ws5, and ws7
• Users can bring disks with ANY FORMAT if they are connected to users’ own portable computers. In this case backup may be slower as you will have to SSH over Wi-Fi from your portable computer to ws2, ws5, or ws6.
• Please check back for the latest updates. Our standards may change as new drivers become available.