Beamline X4A

  • General Information
    • Source Type
      Bending magnet


      General User Beamtime

      Energy Range
      3.5-20 keV

      Beamline Type
      Participating Research Team (PRT)

      Beamline Description
      Macromolecular crystallography, multiwavelength anomalous diffraction (MAD) analysis of crystalline biological macromolecules. This beamline’s primary focus is on MAD experiments for macromolecular crystal structure determinations, and was the first beamline in the world that was designed and dedicated, right from the start, for this purpose. It employs a Kohzu double crystal monochromator (with a sagittally focussing second crystal) and choice of two vertically focussing mirrors. The end station is a biosafety level BL-2 enclosure in which the ambient temperature can be maintained down to 13 deg C. It contains a four-circle Huber diffractometer, an ADSC Quantum-4 CCD x-ray area detector, and an Oxford Cryosystems 700 series cryostream system for sample freezing. Close by to the end station is a dedicated biochemical laboratory with a walk-in cold room.

      Multi wavelength anomalous diffraction
      Macromolecular crystallography

      Albert Einstein College of Medicine
      City University of New York (CUNY)
      Columbia University
      Cornell University
      Icahn School of Medicine at Mount Sinai (ISMMS)
      Memorial Sloan-Kettering Cancer Center
      New York Structural Biology Center
      New York University
      University at Buffalo, SUNY
      Wadsworth Center, New York State Department of Health (USA)

      Research Types
      Macromolecular crystallography, multiwavelength anom. diff. analysis of crystalline biological macromolecules.

  • Contact Information
    • Spokesperson The person from each beamline who acts as a contact point between the beamline management and NSLS administration. Contact for questions about the beamline scientific program, experimental capabilities, and beamline management.
      Wayne Hendrickson, Columbia University,, 212/305-3456

      Local Contact The beamline staff member who is typically responsible for overseeing the daily operation and maintenance of the beamline. Contact for questions about beamline instrumentation, experimental details, and training.
      Randy Abramowitz, New York Structural Biology Center,, 6313445604

      Beamtime Scheduler The beamline staff member responsible for coordination of beamline schedule every trimester. Contact for questions about beamtime scheduling.
      Randy Abramowitz, New York Structural Biology Center,, 6313445604

      Beamline Phone

  • Instrumentation
    • Beamline Characteristics

      Energy RangeMono Crystal or GratingResolution (ΔE/E)FluxSpot Size (mm)Total Angular Acceptance (mrad)
      ~4 – 20 keV Si(111) ~10-4 0.3H x 0.3V 1, 2, 3.5, 5

      Source Type
      Bending magnet

      Optical System
      Slits: Variable vertical and fixed horizontal slits. Monochromator: KOHZU double crystal monochromator with a water-cooled flat first crystal and a sagittally focused second crystal positioned for a fixed exit beam condition. Located ~18 m from source and ~6 m from sample position. Mirror: Mirror system consisting of two vertically stacked, fused silica, spherical mirrors, to provide vertical focusing and harmonic rejection. One of the mirrors is rhodium coated and the other is uncoated. Located ~19.7 m from source. Beam Monitor System: Includes ion chambers, attenuators, slits, experimental shutter, collimator and beam stop.

      Experimental Apparatus
      Crystalogic diffractometer with ADSC Q4R CCD detector mounted on a vertical translation axis; detector distance motor driven through beamline control program. Fluorescence detector and sample alignment camera mounted on diffractometer. Sample cooled with an Oxford Instruments “Cryostream”.

      Computer System Hardware & Software
      The beamline is controlled using a Windows based control program. Data processing computers available are several Linux workstations. Deata backup on DVDs or convenient connection to Firewire or USB2.0 external drives.

  • Links