NECAT Beamline

The Northeastern Collaborative Access Team (NE-CAT) facility at the Advanced Photon Source at Argonne National Laboratory is managed by Cornell University and consists of seven member institutions:

  • Columbia University
  • Cornell University
  • Harvard University
  • Memorial Sloan-Kettering Cancer Center
  • Massachusetts Institute of Technology
  • Rockefeller University
  • Yale University.

    • Primary funding for this project comes from the National Center for Research Resources (NCRR), a division of the National Institutes of Health (NIH). Additional financial support for NE-CAT comes from the member institutions.

    Status of NE-CAT Sector 24 Activities

     

    May 2007  

     

    Beam Line Activities

    During the month of May, APS accelerator operation was shut down for scheduled maintenance. Consequently, there are no users’ activities and beam line operations experiences to report. However, the staff used this scheduled APS maintenance period as an opportunity to install new capabilities as well as conduct its own preventive maintenance activities on the beam lines in order to insure a high degree of reliability of operation for the next user run. In particular during this shutdown, the staff concentrated on completion of the installation of the MD2 micro-diffractometer on the 24-ID-E fixed-energy beam line.

    As reported last month, just before shut down of operations, data was taken for the first time with the MD2, demonstrating that the MD2 was fully integrated into the beam line control and data acquisition systems. Based on this limited operating experience with the MD2 several areas of needed improvement were identified and implemented during the shut down. To further minimize the background due to air scattering, the beam line vacuum path was extended to the rotary photon shutter which is mounted on the upstream side of the MD2. A helium- filled beam path was then installed from the shutter through the MD2 sample visualizer optics. These installations are shown in the following photograph.

    The cold nitrogen gas stream used to keep the sample frozen also impinges on the case of the MD2. There was concern that the variable cooling of the case and the complex internal mechanisms would cause misalignments due to thermal expansion-contraction changes when the aperture-capillary-beam stop assembly was moved in and out of the case. To alleviate this potential problem, a heated block was attached to the MD2 at the position where the cold stream bathed the case. A temperature controller now maintains the case and internal temperature constant. The following photograph shows the “business” end of the MD2 with the heated block attached.

    The beam position monitor was relocated earlier as close as possible to the MD2 (moved 1.3 m downstream) as shown in the first photograph to reduce parallax errors in alignment of the beam. Software changes have now been made to the real-time beam position stabilization system to correct small positional errors in the measurement of the beam position by the beam position monitor due to scattering effects when different thicknesses of absorbers were introduced in the attenuator stack, up steam from the beam position monitor..

    By the end of May all the planned improvements to the MD2 were completed and the MD2 was ready for operation as soon as APS restores the beam. Two institutional groups are scheduled to begin experiments with the MD2 early in June.

     

    Professional Activities

    A. NE-CAT presented the following three posters during the APS Users Meeting held May 7-12, 2006.

    1. Microdiffraction Capabilities at North Eastern CAT, Malcolm Capel, Steven Ealick, and Kanagalaghatta Rajashanker
    2. Northeastern Collaborative Access Team ( NE-CAT) Beamlines at the Advanced Photon Source, Steven E. Ealick, Malcolm Capel, Igor Kourinov, Ed Lynch, Kanagalaghatta Rajashanker, Narayanasami Sukumar, John Unik, and James Withrow
    3. Protein-protein Interaction: Crystal Structure of an Electronic Transfer Complex between Aromatic Amine Dehydrogenase and Azurin, N. Sukumar, Z. Chen, D. Ferrari, A. Merli, G.L. Rossi, V.L. Davidson, and F.S. Mathews

    B. The following will be presented at the 2007 Meeting of the American Crystallographic Association, Salt Lake, Utah, July 22-27, 2007

    1. Implementation of Microdiffraction Techniques at the Northeastern Collaborative Access Team Beamlines, M. Capel, Steven Ealick, Kanagalaghatta Rajashanker. (Invited talk at the Micro-Crystals, Micro-Beams, and Multiple Crystals Work Shop)
    2. Northeastern Collaborative Access Team ( NE-CAT) Beamlines at the Advanced Photo Source, Igor Kourinov, Steven E. Ealick, Malcolm Capel, Ed Lynch, Kanagalaghatta Rajashanker, Narayanasami Sukumar, John Unik, and James Withrow (Poster).

     

    C. Narayanasami Sukumar presented the following invited talk at the University of Madras, Chennai, India on May 10, 2007, “Crystal Structure of Mammalian Vitamin B12 Transport Protein”

    D. Malcolm Capel is currently serving on the following internal APS committess:

    1. Bio-CAT Executive Committee
    2. IMCA-CAT Beam Line Design Review Board
    3. Sector 12 Large-Offset Monochromator Design Review Committee
    4. LS-CAT Optics Design Committee

     

     

     

    © 2005 Northeastern Collaborative Access Team

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