Chi Gradient Correction#

Apply chi COM optical correction to remove the geometrical gradient introduced by the DFXM imaging optics.

The correction subtracts a position-dependent angular shift along the horizontal direction:

\[\chi_\text{corr}(y) = \chi_\text{meas}(y) - \frac{\xi \cdot y_s}{2 \sin(\theta)}\]

where:

  • \(y_s\) — horizontal position relative to image center (meters)

  • \(\theta\) — half Bragg angle \(= \theta_\text{obpitch} / 2\)

  • \(\xi = 1 / d_1\)

with \(d_1 = \frac{obx}{\cos(\theta_\text{obpitch})}\)

(algorithm by Marcelo Demetrio De Magalhaes).

Signals#

Inputs: GrainProperties

Outputs: GrainProperties

Note

This widget has no visualisation. Connect a second Grain Plot to its output to display the corrected maps.

Prerequisites#

Pixel Size (Legacy Transformation Widget) must be placed upstream to provide the pixel size in microns, which the correction algorithm requires.