Detector Configuration
Parameter description
- Detector pixel size (p): The size of the detector pixels in mm.
- Detector layer thickness (t): The thickness of the sensitive layer of the detector surface in mm.
- Detector material: The material of which the detector's sensitive layer is composed.
- Linear absorption coefficient: The linear absorption coefficient in cm-1 of the radiation in the detector's sensitive layer.
- Positional correction: Select if a correction of the peak position and shape due to penetration into the detector surface layer is applied.
- None: Skip the positional correction.
- exGaussian: Use an exponentially modified Gaussian function. Note: The Pseudo-Voigt shape parameter will be ignored.
- Pseudo-Voigt Convolution: Use a convolution of a Pseudo-Voigt peak with an exponential decay function. If the shape parameter is set to 0 (for a pure Gaussian function),
the result will be identical to the exGaussian function.
- Apply cutoff: (only for Pseudo-Voigt convolution) Limits the exponential decay function to the path length in the sensitive detector layer.
Checkboxes are used for fitting the parameters to support peaks. See page "Support Peaks" for more information.
Setup
Additional detector materials can be added in the Preferences.
If the detector material is unkonwn, but the linear absorption coefficient is known, set the detector material to <unknown> and enter the absorption coefficient directly.
Description
The profile calculation applies two corrections to the intensity and shape:
- A 2θ dependent correction of the intensity if a significant amount of the radiation passes the detector layer without being absorbed.
- A 2θ dependent distortion and displacement of the profiles due to penetration of the beams into the detector layer at an inclined angle.
Both the wavelength and absorption coefficient must be known for the two corrections. If the option "Positional correction" is set to "None", the intensity correction will still
be applied. To disable the intensity correction, enter an absorption coefficient of 0.0.