To better serve a diverse user community, 11-BM mail-in data is available in different formats. Users may select the format(s) most appropriate for their analysis needs. A description of these different formats is given below.
During an 11-BM scan individual patterns from the sample are collected simultaneously on all 12 detectors. These data are later merged into a pseudo-single pattern. Data consisting of a single merged pattern are appropriate for nearly all 11-BM users.
Corrections are applied to the data when it is merged. The corrections are necessary to merge the data from the 12 separate detectors, and correct for small offset variations, differences in sensitivity, and minor fluctuations in wavelength (typically ~ 0.003%). The correction values are determined by a Rietveld refinement performed regularly on scans of a mixture of NIST standard reference materials, Si (SRM 640c) and Al2O3 (SRM 676), where the Si lattice constant determines the wavelength for each detector.
The pattern intensity and uncertainties (e.g. error or esd) are corrected to account for the number of contributing detectors at each 2θ value. The final merged single pattern has a 2θ offset of exactly zero degrees, and a single wavelength value that is provided with the dataset. Users may request the calibration data set used for their samples be sent by contacting beamline staff
; please reference the name of the calibration file (e.g. aug09/11bmb_0311.calib)
The free program CMPR
opens GSAS (.fxye) files from 11-BM, and can be used to view your data and convert to a several popular alternative formats.
Still having trouble with data formats? The 11-BM FAQ
page answers a few common questions, or contact us
: 11-BM staff may be able to help.
Merged Data Formats
GSAS data (.fxye)
GSAS data (.raw)
TOPAS data (.xye)
pdCIF data (.cif)
Spreadsheet text format (.csv)
Raw Data Formats
For expert users, 11-BM can also provide raw un-merged datasets. These files contain the 12 individual patterns collected by each detector during the scan. Although there may be certain circumstances requiring this raw data, one of the merged formats described above will be more useful for the majority of users. Please feel free to contact 11-BM staff
if you feel raw 11-BM data might be appropriate for your research.
EPICS MDA (.mda)