def pure(cls, z, absorption_energy_eV=None):
"""
Returns the material for the specified pure element.
:arg z: atomic number
:type z: :class:`int`
:arg absorption_energy_eV: absorption energy of the different particles
:type absorption_energy_eV: :class:`dict`
"""
name = ep.name(z)
composition = {z: 1.0}
density_kg_m3 = ep.mass_density_kg_m3(z)
return cls(composition, name, density_kg_m3, absorption_energy_eV)
def kanaya_okayama(composition, energy):
"""
Returns the electron range (in meters).
:arg composition: composition in weight fraction.
The composition is specified by a dictionary.
The keys are the atomic numbers and the values are the weight fractions
between ]0.0, 1.0].
:type composition: :class:`dict`
:arg energy: beam energy in eV
"""
r = 0.0;
for z, fraction in composition.items():
dr = (0.0276 * (ep.atomic_mass_kg_mol(z) * 1000.0) * (energy / 1000.0) ** 1.67) / \
(z ** 0.89 * (ep.mass_density_kg_m3(z) / 1000.0))
r += fraction / (dr * 1e-6)
return 1.0 / r;
def calculate_density(composition):
"""
Returns an estimate density from the composition using the pure element
density and this equation.
.. math::
\\frac{1}{\\rho} = \\sum{\\frac{1}{\\rho_i}}
:arg composition: composition in weight fraction.
The composition is specified by a dictionary.
The key are atomic numbers and the values weight fractions.
No wildcard are accepted.
:type composition: :class:`dict`
"""
density = 0.0
for z, fraction in composition.items():
density += fraction / ep.mass_density_kg_m3(z)
return 1.0 / density
def testmass_density(self):
self.assertAlmostEqual(7.1900, ep.mass_density_kg_m3(24) / 1000.0)
def testmass_density(self):
self.assertAlmostEqual(7.1900, ep.mass_density_kg_m3(24) / 1000.0)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 85)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 87)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 118)
def testmass_density(self):
self.assertAlmostEqual(7.1900, ep.mass_density_kg_m3(24) / 1000.0)
def testmass_density(self):
self.assertAlmostEqual(7.1900, ep.mass_density_kg_m3(24) / 1000.0)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 85)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 87)
self.assertRaises(ValueError, self.ep.mass_density_kg_m3, 118)