model the intensity correction for defocusing in a tilted Bragg–Brentano measurement

Syntax

psi = SchulzDefocusingKernel(theta=45*degree, r=1, w=2, d=200, dtheta=0.5*degree)
factor = psi.eval(np.cos(alpha))
factors = psi.defocusing(pf)

Description

Tilting the specimen spreads the diffracted beam relative to the receiving slit. The returned correction factor is one at zero tilt and increases as intensity is lost; it is infinite at tilts of 90 degrees or greater. Evaluation takes the cosine of the tilt angle, rather than the angle itself. The defocusing method evaluates the factor at the specimen directions of a PoleFigure.

Input

mu_t absorption parameter retained for compatibility; the current defocusing formula does not use it
theta Bragg angle in radians; default 45*degree
r beam width parameter; default 1
w receiving-slit width parameter; default 2
d specimen-to-slit distance, in the same length unit as r; default 200
dtheta angular broadening parameter in radians; default 0.5*degree

Output

psi SchulzDefocusingKernel

See also

PoleFigure.correct, SchulzDefocusingKernel.eval, SchulzDefocusingKernel.defocusing

Members

defocusing the correction on the specimen directions of a pole figure, one at the pole
eval the defocusing factor at t = cos(alpha) of the tilt alpha, 1 at no tilt, infinite at 90 degrees

MATLAB’s SchulzDefocusingKernel_index

source

Citing this page. This page is part of the documentation of MTEX, a free and open source MATLAB toolbox for analyzing and modeling crystallographic textures. It was written by The MTEX Developers and is published at https://mtex-toolbox.github.io/SchulzDefocusingKernel_index_py.html. If you use MTEX, or reuse text or figures from this page, in your research, please cite

F. Bachmann, R. Hielscher, H. Schaeben: Texture Analysis with MTEX - Free and Open Source Software Toolbox, Solid State Phenomena 160 (2010), 63-68. 10.4028/www.scientific.net/SSP.160.63

BibTeX 
@article{bachmann2010mtex,
  author  = {F. Bachmann and R. Hielscher and H. Schaeben},
  title   = {Texture Analysis with MTEX - Free and Open Source Software Toolbox},
  journal = {Solid State Phenomena},
  volume  = {160},
  pages   = {63-68},
  year    = {2010},
  doi     = {10.4028/www.scientific.net/SSP.160.63},
  url     = {https://doi.org/10.4028/www.scientific.net/SSP.160.63}
}

Other papers describing specific MTEX methods are listed under Publications — please cite the one that best fits your application. The MTEX source code is licensed under the GNU General Public License v2.0; the text and figures of this documentation are licensed under CC BY 4.0, which permits reuse — including by automated systems — provided The MTEX Developers and this page are credited.