Electronic scattering
Funtions to calculate electronic scattering cross sections for X-ray photons.
- nexus.KleinNishinaCrossSection(element, energy)
Calculates the Klein-Nishina cross section. After [KleinNishina]. Describes Thomson scattering of low energy photons and Compton scattering of high energy photons.
Also see https://en.wikipedia.org/wiki/Klein-Nishina_formula.
- Parameters:
element (
Element) – Element for which the cross section is calculated.energy (float) – X-ray energy (eV).
- Returns:
Klein-Nishina cross section (m 2).
- Return type:
float
- nexus.ComptonCrossSection(element, energy)
Alias for the Klein-Nishina cross section.
Also see https://en.wikipedia.org/wiki/Klein-Nishina_formula.
- Parameters:
element (
Element) – Element for which the cross section is calculated.energy (float) – X-ray energy (eV).
- Returns:
Klein-Nishina cross section (m 2).
- Return type:
float
- nexus.ThomsonCrossSection(element, energy)
Alias for the Klein-Nishina cross section.
Also see https://en.wikipedia.org/wiki/Klein-Nishina_formula.
- Parameters:
element (
Element) – Element for which the cross section is calculated.energy (float) – X-ray energy (eV).
- Returns:
Klein-Nishina cross section (m 2).
- Return type:
float
- nexus.PhotoCrossSection(element, energy)
Calculates the photoelectric cross section. After [Smith]. Valid in the range from Z = 1 to 100 and \(E_{\gamma}\) = 1 keV to 100 MeV.
- Parameters:
element (
Element) – Element for which the cross section is calculated.energy (float) – X-ray energy (eV).
- Returns:
Photo effect cross section (m 2).
- Return type:
float
- nexus.ElectronicCrossSection(element, energy)
Calculates the total electronic absorption scattering cross section for X-ray photons of energy \(E_{\gamma}\) = 1 keV to 100 MeV and element up to Z = 86. Returns the sum of the Klein-Nishma cross section and the photoelectric cross section. Pair production at high energies is not included. If you are interested in pair production cross sections see Maximon and Borsellino-Ghizzetti equations.
- Parameters:
element (
Element) – Element for which the cross section is calculated.energy (float) – X-ray energy (eV).
- Returns:
Total absorption scattering cross section (m 2).
- Return type:
float
Examples
Au = nx.Element("Au")
# Klein-Nishina cross section for photons of energy E = 10 keV at gold
cross_section = nx.KleinNishinaCrossSection(Au, 10000)
print(cross_section)
# Photoelectric cross section for photons of energy E = 10 keV at gold
cross_section = nx.PhotoCrossSection(Au, 10e3)
print(cross_section)
# Total cross section for photons of energy E = 10 keV at gold
cross_section = nx.ElectronicCrossSection(Au, 10e3)
print(cross_section)