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, quartz, C14H30O, cristobaltite, Si, LaB6, CeO2, LaB6_SRM660a, LaB6_SRM660b, LaB6_SRM660c, TiO2, ZnO, Al, Au or search in the American Mineralogist database.

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

--opengl, --gl

Enable OpenGL rendering (else matplotlib is used)

-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=12.398419739640717keV.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

-s SPLINE, --spline SPLINE

spline file describing the detector distortion

-n NPT, --pt NPT

file with datapoints saved. Example: basename.npt

-i FILE, --poni FILE

file containing the diffraction parameter (poni-file) [not used].

-b BACKGROUND, --background BACKGROUND

Automatic background subtraction if no value are provided [not used]

-d DARK, --dark DARK

list of comma separated dark images to average and subtract [not used]

-f FLAT, --flat FLAT

list of comma separated flat images to average and divide [not used]

--filter FILTER

select the filter, either mean(default), max or median [not used]

-l DIST_MM, --distance DIST_MM

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)