rizer.misc.units#

Classes#

Units

Physical constants and unit conversions.

Module Contents#

class rizer.misc.units.Units#

Physical constants and unit conversions.

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

m_e = 9.1093837015e-31#

Electron mass [kg].

e = 1.602176634e-19#

Elementary charge [C].

k_b = 1.380649e-23#

Boltzmann constant [J/K].

N_a = 6.02214076e+23#

Avogadro’s number [mol^-1].

M_e = 5.485799088728283e-07#

Electron molar mass [kg/mol].

eV_to_K = 11604.518121550082#

Conversion factor from eV to K.

K_to_eV = 8.617333262145179e-05#

Conversion factor from K to eV.

eV_to_J = 1.602176634e-19#

Conversion factor from eV to J.

J_to_eV = 6.241509074460763e+18#

Conversion factor from J to eV.

K_to_J = 1.380649e-23#

Conversion factor from K to J.

J_to_K = 7.24297051603992e+22#

Conversion factor from J to K.

kJ_per_mol_to_J_per_particle = 1.6605390671738467e-21#

Conversion factor from kJ/mol to J/particle.

Da = 1.6605390666e-27#

Dalton or atomic mass constant [kg].

m_N2 = 4.651734508829244e-26#

N2 mass [kg].

R = 8.31446261815324#

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

R_kmol = 8314.46261815324#

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

P_1_bar = 100000.0#

1 bar [Pa].

h = 6.62607015e-34#

Planck constant [J s].

hbar#

Reduced Planck constant [J s].

c = 299792458#

Speed of light [m/s].

epsilon_0 = 8.85418782e-12#

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).

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.

element_radius: dict[str, float]#

Element radius [m].

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