constants¶
Constants
Elemental data¶
Tools for working with elemental constants.
Object to return basic elemental information |
X-ray fluorescence data¶
The c library xraylib provides a programmatic interface to x-ray fluorescence constants. We provide dictionary-like wrapping classes to provide easy access to the data. For the most part users should access this data through the Element object which manages the creation and access to these objects.
High-level interface to xraylib. |
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This is an interface to wrap xraylib to perform calculation on fluorescence cross section, or other incident energy related quantity. |
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Find elements which have an emission line near an energy |
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Object to return all the elemental information related to fluorescence |
Powder Diffraction Standards¶
Module for xray scattering
Mapping of known calibration standards and their reflections |
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Class for providing safe access to powder calibration standards data. |
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Namedtuple sub-class for scattering reflection information |
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Namedtuple sub-class miller indicies (HKL) |
Converting \(2\theta\) between wavelengths¶
Given that
\[\frac{\lambda_c}{2 a} \sqrt{h^2 + k^2 + l^2} = \sin\left(\frac{2\theta_c}{2}\right)\]If we multiply both sides by \(\frac{\lambda_n}{\lambda_c}\) then we have
\[ \begin{align}\begin{aligned}\frac{\lambda_n}{2 a} \sqrt{h^2 + k^2 + l^2} = \frac{\lambda_n}{\lambda_c} \sin\left(\frac{2\theta_c}{2}\right)\\\sin\left(\frac{2\theta_n}{2}\right) = \frac{\lambda_n}{\lambda_c} \sin\left(\frac{2\theta_c}{2}\right)\end{aligned}\end{align} \]which solving for \(2\theta_n\) gives us
\[2\theta_n = 2 \arcsin\left(\frac{\lambda_n}{\lambda_c} \sin\left(\frac{2\theta_c}{2}\right)\right)\]