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  2. Number density - Wikipedia

    en.wikipedia.org/wiki/Number_density

    The number density (symbol: n or ρ N) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric number density, two-dimensional areal number density, or one-dimensional linear number density.

  3. Charge carrier density - Wikipedia

    en.wikipedia.org/wiki/Charge_carrier_density

    Charge carrier density, also known as carrier concentration, denotes the number of charge carriers per volume. In SI units, it is measured in m −3. As with any density, in principle it can depend on position. However, usually carrier concentration is given as a single number, and represents the average carrier density over the whole material.

  4. Electron density - Wikipedia

    en.wikipedia.org/wiki/Electron_density

    Spin density is electron density applied to free radicals. It is defined as the total electron density of electrons of one spin minus the total electron density of the electrons of the other spin. One of the ways to measure it experimentally is by electron spin resonance, [14] neutron diffraction allows direct mapping of the spin density in 3D ...

  5. Boltzmann relation - Wikipedia

    en.wikipedia.org/wiki/Boltzmann_relation

    A simple derivation of the Boltzmann relation for the electrons can be obtained using the momentum fluid equation of the two-fluid model of plasma physics in absence of a magnetic field. When the electrons reach dynamic equilibrium , the inertial and the collisional terms of the momentum equations are zero, and the only terms left in the ...

  6. Drude model - Wikipedia

    en.wikipedia.org/wiki/Drude_model

    The number density of the electron gas was assumed to be =, where Z is the effective number of de-localized electrons per ion, for which Drude used the valence number, A is the atomic mass per mole, [Ashcroft & Mermin 10] is the mass density (mass per unit volume) [Ashcroft & Mermin 10] of the "ions", and N A is the Avogadro constant.

  7. Mean free path - Wikipedia

    en.wikipedia.org/wiki/Mean_free_path

    where ℓ is the mean free path, n is the number of target particles per unit volume, and σ is the effective cross-sectional area for collision. The area of the slab is L 2, and its volume is L 2 dx. The typical number of stopping atoms in the slab is the concentration n times the volume, i.e., n L 2 dx. The probability that a beam particle ...

  8. Electron mobility - Wikipedia

    en.wikipedia.org/wiki/Electron_mobility

    The electron mobility is defined by the equation: =. where: E is the magnitude of the electric field applied to a material,; v d is the magnitude of the electron drift velocity (in other words, the electron drift speed) caused by the electric field, and

  9. Total electron content - Wikipedia

    en.wikipedia.org/wiki/Total_electron_content

    TEC is the total number of electrons integrated between two points, along a tube of one meter squared cross section, i.e., the electron columnar number density. It is often reported in multiples of the so-called TEC unit, defined as TECU=10 16 el/m 2 ≈ 1.66 × 10 −8 mol⋅m −2. [1]