Diffraction pattern from an oriented fiber of a dendrimer liquid crystal with helical correlations. Small-angle diffraction pattern from a smetic liquid crystal with in-plane correlations. The smectic layer spacing (determined from the bright ring) is 54.5 angstroms, while the length scale of the inplane modulation (weaker inner rings) is 315 angstrom.   Plot of intensity versus q for the smectic pattern shown in center image.

  Multi-Angle X-ray
    Scattering Facility

Location: LRSM Building
Coordinators:
    Prof. P. A. Heiney (Physics) 215/898-7918
    e-mail: heiney@sas.upenn.edu
    Prof. Karen Winey (MSE) 215/898-0593
    e-mail: winey@lrsm.upenn.edu

Available Angular Ranges / Access / User Schedule

The multi-angle x-ray diffractometer system (MAXS) incorporates a high-brightness rotating-anode x-ray generator, focusing optics, and a two-dimensional detector. The Bruker Nonius FR591 rotating-anode x-ray generator delivers up to 4.0 kW in a 0.2 x 2 mm² spot, making it the highest-brightness laboratory source currently available. Doubly-focusing mirror-monochromator optics designed by Molecular Metrology, Inc. provide 1:1 focusing at the detector, resulting in both high flux at the sample and high angular resolution. A Bruker Hi-Star multiwire detector provides highly sensitive area detection with very low dark current. An integral vacuum is maintained between the generator and the detector, with only two windows, one at each end. This arrangement substantially reduces both attenuation and small-angle scattering by air and windows. An entire diffraction pattern from a liquid crystal or polymer can be measured in several minutes, to be compared with the hours required for a conventional triple-axis, single-channel diffractometer. (However, such a triple-axis diffractometer is also available for cases where very high angular resolution and/or detailed lineshape measurements are required).

The MAXS system incorporates three fixed positions for sample placement, corresponding to different ranges of probed d-spacing. See table below for details.

A temperature control stage can be mounted in any of the three fixed positions. It provides temperature control to better than 0.1 C in the range 00-300 C. It provides temperature control to better than 0.1 C in the range 30-200 C.

A variety of specimen holders are available to readily mount samples in a transmission geometry. The specimen holders can accommodate capillaries (powders or fluids), fibers, gels, and films (perpendicular or parallel orientation).

Available Angular Ranges

Equipment

Click on images to enlarge them.

From left to right: wire detector, three sample chambers, monochromator box.	From right to left: generator, mirror box, 2 sets of slits, monochromator box, first sample chamber (black).

Access

The facility is free to members of the Penn community collaborating with the facility supervisors. Other users are welcome to use the facility subject to availability. For academic users performing nonproprietary research, the rates are $30/hour or $400/day; for nonacademic users the rates are $200/hour or $1200/day. Additional charges for expert support should be discussed with Profs. Heiney or Winey.

Location

The Multi-Angle X-ray Scattering Facility is located in room 119 of the Laboratory for Research on the Structure of Matter at the University of Pennsylvania . It is jointly supervised by Prof. Paul A. Heiney Department of Physics and Astronomy , and Prof. Karen Winey, Department of Materials Science and Engineering.

Schedule

The user schedule for theLRSM Multiple-Angle X-ray Scattering facility can be accessed here:

http://dept.physics.upenn.edu/~heiney/xraysched.html

Back to LRSM Facilities Home Page