rizer.misc.units

Physical constants and unit conversions.

All units are by default in the International System of Units (SI).

Attributes

m_e	Electron mass [kg].
e	Elementary charge [C].
k_b	Boltzmann constant [J/K].
N_a	Avogadro's number [mol^-1].
M_e	Electron molar mass [kg/mol].
eV_to_K	Conversion factor from eV to K.
K_to_eV	Conversion factor from K to eV.
eV_to_J	Conversion factor from eV to J.
J_to_eV	Conversion factor from J to eV.
K_to_J	Conversion factor from K to J.
J_to_K	Conversion factor from J to K.
kJ_per_mol_to_J_per_particle	Conversion factor from kJ/mol to J/particle.
Da	Dalton or atomic mass constant [kg].
m_N2	N2 mass [kg].
R	Ideal gas constant [J/(mol K)].
R_kmol	Ideal gas constant [J/(kmol K)].
P_1_bar	1 bar [Pa].
h	Planck constant [J s].
hbar	Reduced Planck constant [J s].
c	Speed of light [m/s].
epsilon_0	Vacuum permittivity [F/m].
stefan_boltzmann	Stefan-Boltzmann constant [W/(m^2 K^4)].
spitzer_constant	Spitzer conductivity constant in Ohm^(-1) . m^(-1) . K^(-3/2).
element_radius	Element radius [m].

Module Contents

rizer.misc.units.m_e = 9.1093837015e-31

Electron mass [kg].

rizer.misc.units.e = 1.602176634e-19

Elementary charge [C].

rizer.misc.units.k_b = 1.380649e-23

Boltzmann constant [J/K].

rizer.misc.units.N_a = 6.02214076e+23

Avogadro’s number [mol^-1].

rizer.misc.units.M_e = 5.485799088728283e-07

Electron molar mass [kg/mol].

rizer.misc.units.eV_to_K = 11604.518121550082

Conversion factor from eV to K.

rizer.misc.units.K_to_eV = 8.617333262145179e-05

Conversion factor from K to eV.

rizer.misc.units.eV_to_J = 1.602176634e-19

Conversion factor from eV to J.

rizer.misc.units.J_to_eV = 6.241509074460763e+18

Conversion factor from J to eV.

rizer.misc.units.K_to_J = 1.380649e-23

Conversion factor from K to J.

rizer.misc.units.J_to_K = 7.24297051603992e+22

Conversion factor from J to K.

rizer.misc.units.kJ_per_mol_to_J_per_particle = 1.6605390671738467e-21

Conversion factor from kJ/mol to J/particle.

rizer.misc.units.Da = 1.6605390666e-27

Dalton or atomic mass constant [kg].

rizer.misc.units.m_N2 = 4.651734508829244e-26

N2 mass [kg].

rizer.misc.units.R = 8.31446261815324

Ideal gas constant [J/(mol K)].

rizer.misc.units.R_kmol = 8314.46261815324

Ideal gas constant [J/(kmol K)].

rizer.misc.units.P_1_bar = 100000.0

1 bar [Pa].

rizer.misc.units.h = 6.62607015e-34

Planck constant [J s].

rizer.misc.units.hbar

Reduced Planck constant [J s].

rizer.misc.units.c = 299792458

Speed of light [m/s].

rizer.misc.units.epsilon_0 = 8.85418782e-12

Vacuum permittivity [F/m].

rizer.misc.units.stefan_boltzmann

Stefan-Boltzmann constant [W/(m^2 K^4)].

rizer.misc.units.spitzer_constant

Spitzer conductivity constant in Ohm^(-1) . m^(-1) . K^(-3/2).

The conductivity of a fully-ionized plasma is given by the Spitzer conductivity:

\[\sigma = \text{Spitzer constant} \times \frac{T_e^{3/2}}{\log(\lambda)}\]

with :

• \(T_e\) the electron temperature in K,

• \(\log(\lambda)\) the Coulomb logarithm.

The constant is given by:

\[\begin{align} \text{Spitzer constant} &= \left(\frac{4 \pi \varepsilon_0}{e}\right)^2 \times \left(\frac{k_b^{3/2}}{\frac{4}{3} \sqrt{2 \pi m_e} }\right) \times 1.96 &= 1.53 \times 10^{-2} \, \Omega^{-1} \, \text{m}^{-1} \, \text{K}^{-3/2} \end{align}\]

with:

• \(\varepsilon_0\) the vacuum permittivity,

• \(e\) the elementary charge,

• \(k_b\) the Boltzmann constant,

• \(m_e\) the electron mass.

rizer.misc.units.element_radius: dict[str, float]

Element radius [m].

Data taken from https://en.wikipedia.org/wiki/Atomic_radius#Empirically_measured_atomic_radius.