Advanced Photon Source

An Office of Science National User Facility

6-BM Home Page

Welcome to the 6-BM beamline at the Advanced Photon Source (APS) located at Argonne National Laboratory (ANL).
  • 6-BM-A is operated by the Materials Physics & Engineering Group (MPE) of the APS X-ray Science Division (XSD).
  • 6-BM-B is operated by Consortium for Materials Properties Research in Earth Sciences (COMPRES).

6-BM beamline provide brilliant, polychromatic x-ray beams for a variety of scientific applications. The 6-BM-A and 6-BM-B are accessible to outside users through various mechanisms including General User program. For information pertaining to 6-BM-B, users are encouranged to contact COMPRES.

Energy dispersive diffraction (EDD) is the primary measurement mode to characterize:

  • the phase transformation behavior in geological materials.
  • the residual stress field in large engineering components.
  • the evolution of complex material systems embedded in various types of sample environments such as furnaces and battery cyclers.

A set of new measurement modalities and capabilities will be coming on-line in the near future. 

Energy dispersive diffraction (EDD)

This technique employs a transmission geometry and germanium point detector(s) to measure quantities such as the phase composition and internal strains in a polycrystalline material. The experimental geometry is illustrated in the following figure.

 

In this figure, a series of slits (slits 1 - 3) reduce the size of the polychromatic x-ray beam from APS bending magnet and act as guard slits to reduce parasitic scattering. Filter hardens the x-ray beam to pick out only the high energy component of the polychromatic x-ray beam. Typically, two germanium detectors are used; the vertical detector is placed in the YL-ZL plane and the horizontal detector is placed in the XL-ZL plane. Both detectors and associated slits are setup such that they both point at O in space. This ensures that the same volume of material is interrogated by the two detectors. The distances between O and the detectors are approximately 1 m which translates to approximately 1 degree in azimuthal coverage.

As a first order approximation, the size of the material interrogated (so called the gauge volume) is determined by the size of the slit openings and the scattering angle as illustrated in the following figure. As the measurement relies on having many grains in the gauge volume, the setup is optimized to maximize the gauge volume while ensuring that the required spatial resolution is met. Typical spatial resolution in XL and YL is approximately 20 um; in ZL is on the order of mm's. Typical strain resolution is on the order of 1 x 10-4.

Beamline Equipments
  • Bending magnet source - based on the sample dimensions, material, and required resolution, the setup is optimized to reduce measurement time.
  • 2x canberra germanium solid state detector and associated slits.
  • Various sample translation and rotation stages. Contact the beamline personnel for suitable stage stack.
  • Battery cycler.
  • Miniature load frame capable of unixial tension and compression up to 2000 N force.
  • Various mounting hardware from Newport or Thorlabs.

Control and data acquisition
Beamline controls and data acquisition are done through EPICS and SPEC.
Data analysis

Basic data visualization and analysis tools based on Matlab are available upon request. Typically, calibration data are provided along with these tools to facilitate the analysis.

Contact

Users are encouraged to contact the beamline staff. Users with upcoming beam time are particularly encouraged to contact the beam line staff to discuss the scientific goals and experimental procedures.

Name Phone E-mail
Jonathon Almer (630) 252-1049 almer@aps.anl.gov
Andrew (Chihpin) Chuang (630) 252-5891 cchuang@aps.anl.gov
John Okasinski (630) 252-0162 okasinski@aps.anl.gov
Jun-Sang Park (630) 252-9194 parkjs@aps.anl.gov

 

Frequently asked questions