#!/usr/bin/env python3
"""
xraylib handling functions.
@author: Nicola VIGANÒ, CEA-IRIG, Grenoble, France
"""
from typing import Union
import numpy as np
import xraylib
xraylib.XRayInit()
[docs]
def get_element_number(element: Union[str, int]) -> int:
"""Return the element number from the symbol.
Parameters
----------
element : str | int
The element symbol (or number, which won't be converted).
Returns
-------
int
The corresponding element number.
"""
if isinstance(element, int):
return element
else:
return xraylib.SymbolToAtomicNumber(element)
[docs]
def get_element_number_and_symbol(element: Union[str, int]) -> tuple[str, int]:
"""Return both the element symbol and number from either the symbol or the number.
Parameters
----------
element : str | int
The element symbol (or number, which won't be converted).
Returns
-------
tuple[str, int]
The element symbol and number.
"""
if isinstance(element, str):
el_sym = element
el_num = xraylib.SymbolToAtomicNumber(element)
else:
el_sym = xraylib.AtomicNumberToSymbol(element)
el_num = element
return el_sym, el_num
[docs]
def get_compound(cmp_name: str, density: Union[float, None] = None) -> dict:
"""
Build a compound from the compound composition string.
Parameters
----------
cmp_name : str
Compund name / composition.
density : float, optional
The density of the compound. If not provided it will be approximated from the composing elements.
The default is None.
Returns
-------
cmp : dict
The compound structure.
"""
try:
cmp = xraylib.GetCompoundDataNISTByName(cmp_name)
except ValueError:
cmp = xraylib.CompoundParser(cmp_name)
cmp["name"] = cmp_name
if density is None:
density = 0
for ii, el in enumerate(cmp["Elements"]):
density += xraylib.ElementDensity(el) * cmp["massFractions"][ii]
cmp["density"] = density
return cmp
[docs]
def get_compound_cross_section(compound: dict, mean_energy_keV: float) -> float:
"""Compute a compound cross section for the given incoming photon energy.
Parameters
----------
compound : dict
The compound structure (as returned by `get_compound`)
mean_energy_keV : float
The average photon energy
Returns
-------
float
The computed cross-section
"""
try:
return xraylib.CS_Total_CP(compound["name"], mean_energy_keV)
except ValueError:
elemets_cs = [
xraylib.CS_Total(el, mean_energy_keV) * compound["massFractions"][ii] for ii, el in enumerate(compound["Elements"])
]
return np.sum(elemets_cs, axis=0)