Calibration tool: pyFAI-calib2¶
Calibration - GUI tool for determining the geometry of a detector using a reference sample.
Please have a look at the Calibration of a diffraction setup using the Graphical User Interface (GUI) for a 5 minutes introduction.
Purpose¶
Calibrate the diffraction setup geometry based on Debye-Sherrer rings images without a priori knowledge of your setup. You will need to provide a calibrant or a “d-spacing” file containing the spacing of Miller plans in Angstrom (in decreasing order).
Calibrants available: Ni, CrOx, NaCl, Si_SRM640e, Si_SRM640d, Si_SRM640a, Si_SRM640c, alpha_Al2O3, Cr2O3, AgBh, Si_SRM640, CuO, PBBA, Si_SRM640b, mock, quartz, C14H30O, cristobaltite, Si, LaB6, CeO2, LaB6_SRM660a, LaB6_SRM660b, LaB6_SRM660c, TiO2, ZnO, Al, Au or search in the American Mineralogist database: http://rruff.geo.arizona.edu/AMS/amcsd.php
Usage:¶
pyFAI-calib2 [options] [input_image.edf]
Everything can be set by the GUI, but here are the command-line arguments.
Options:¶
- positional arguments:
- FILE List of files to calibrate
- optional arguments:
-h, --help show this help message and exit -V, --version show program’s version number and exit -o FILE, --out FILE Filename where processed image is saved -v, --verbose switch to debug/verbose mode --debug Set logging system in debug mode -c FILE, --calibrant FILE Calibrant name or file containing d-spacing of the reference sample (case sensitive) -w WAVELENGTH, --wavelength WAVELENGTH wavelength of the X-Ray beam in Angstrom. -e ENERGY, --energy ENERGY energy of the X-Ray beam in keV (hc=12.3984197396keV.A). -P POLARIZATION_FACTOR, --polarization POLARIZATION_FACTOR polarization factor, from -1 (vertical) to +1 (horizontal), default is None (no correction), synchrotrons are around 0.95 -D DETECTOR_NAME, --detector DETECTOR_NAME Detector name (instead of pixel size+spline) -m MASK, --mask MASK file containing the mask (for image reconstruction) -p PIXEL, --pixel PIXEL size of the pixel in micron -i FILE, --poni FILE file containing the diffraction parameter (poni-file). -b BACKGROUND, --background BACKGROUND Automatic background subtraction if no value are provided -d DARK, --dark DARK list of comma separated dark images to average and subtract -f FLAT, --flat FLAT list of comma separated flat images to average and divide -s SPLINE, --spline SPLINE spline file describing the detector distortion -n NPT, --pt NPT file with datapoints saved. Default: basename.npt --filter FILTER select the filter, either mean(default), max or median -l DISTANCE, --distance DISTANCE sample-detector distance in millimeter. Default: 100mm --dist DIST sample-detector distance in meter. Default: 0.1m --poni1 PONI1 poni1 coordinate in meter. Default: center of detector --poni2 PONI2 poni2 coordinate in meter. Default: center of detector --rot1 ROT1 rot1 in radians. default: 0 --rot2 ROT2 rot2 in radians. default: 0 --rot3 ROT3 rot3 in radians. default: 0 --fix-wavelength fix the wavelength parameter. Default: Activated --free-wavelength free the wavelength parameter. Default: Deactivated --fix-dist fix the distance parameter --free-dist free the distance parameter. Default: Activated --fix-poni1 fix the poni1 parameter --free-poni1 free the poni1 parameter. Default: Activated --fix-poni2 fix the poni2 parameter --free-poni2 free the poni2 parameter. Default: Activated --fix-rot1 fix the rot1 parameter --free-rot1 free the rot1 parameter. Default: Activated --fix-rot2 fix the rot2 parameter --free-rot2 free the rot2 parameter. Default: Activated --fix-rot3 fix the rot3 parameter --free-rot3 free the rot3 parameter. Default: Activated --npt NPT_1D Number of point in 1D integrated pattern, Default: 1024 --npt-azim NPT_2D_AZIM Number of azimuthal sectors in 2D integrated images. Default: 360 --npt-rad NPT_2D_RAD Number of radial bins in 2D integrated images. Default: 400 --qtargs QTARGS Arguments propagated to Qt –tilt Allow initially detector tilt to be refined (rot1, rot2, rot3). Default: Activated
--no-tilt Deactivated tilt refinement and set all rotation to 0 --saturation SATURATION consider all pixel>max*(1-saturation) as saturated and reconstruct them, default: 0 (deactivated) --weighted weight fit by intensity, by default not. --unit UNIT Valid units for radial range: 2th_deg, 2th_rad, q_nm^-1, q_A^-1, r_mm. Default: 2th_deg --no-gui force the program to run without a Graphical interface --no-interactive force the program to run and exit without prompting for refinements -r, --reconstruct Reconstruct image where data are masked or <0 (for Pilatus detectors or detectors with modules) -g GAUSSIAN, --gaussian GAUSSIAN Size of the gaussian kernel. Size of the gap (in pixels) between two consecutive rings, by default 100 Increase the value if the arc is not complete; decrease the value if arcs are mixed together. --square Use square kernel shape for neighbor search instead of diamond shape
Tips & Tricks¶
The output of this program is a “PONI” file containing the detector description and the 6 refined parameters (distance, center, rotation) and wavelength. An 1D and 2D diffraction patterns can also produced. (.dat and .azim files)