getelec.constants

Physical constants.

This module defines physical constants and derived constants used in the GETELEC model for electron emission. It includes fundamental constants such as the electron mass, Planck's constant, and the elementary charge, as well as derived constants relevant to the calculations of tunneling probabilities and image potentials.

Attributes

Q : float Elementary charge in Coulombs ($C$). C : float Dimensionless scale multiplier or elementary charge unit reference. HBAR : float Reduced Planck constant ($\hbar$) in units of electron-volt femtoseconds ($eV \cdot fs$). H : float Planck constant ($h$) in units of electron-volt femtoseconds ($eV \cdot fs$). M_E : float Rest mass of an electron ($m_e$) in units of $eV \cdot fs^2 / nm^2$. KB : float Boltzmann constant ($k_B$) in units of electron-volts per Kelvin ($eV / K$). HBAR2_2M : float Derived kinetic prefactor $\frac{\hbar^2}{2 m_e C}$ in units of $eV \cdot nm^2$. WKB_PREFACTOR : float Derived Wentzel-Kramers-Brillouin tunneling prefactor $\frac{\sqrt{2 m_e}}{\hbar}$ in units of $1 / (nm \cdot \sqrt{eV})$. COULOMB_CONST : float Coulomb electrostatic constant ($k_e$) in units of $eV \cdot nm$. IMAGE_PREFACTOR : float Derived prefactor for classical image potential tracking ($\frac{k_e}{4}$) in units of $eV \cdot nm$. J_PREFACTOR_CONST : float Derived current density factor tracking supply function normalization scaling ($\frac{4 \pi m_e C k_B}{h^3}$) in units of $1 / (nm^2 \cdot fs \cdot K)$.

UNITS

Inputs Energy in eV Distance in nm Time in fs Temperature in K

Outputs Current density in A/cm2 Nottingham heat P_N in W/cm2 TED & NED in A/(eV cm2)

Examples

>>> from getelec import constants as const
>>> print(const.Q)
1.60217663e-19
>>> print(const.WKB_PREFACTOR)