Search results
Results from the WOW.Com Content Network
Generally speaking, the F region has the highest concentration of free electrons and ions anywhere in the atmosphere. It may be thought of as comprising two layers, the F1 and F2 layers. The F-region is located directly above the E region (formerly the Kennelly-Heaviside layer) and below the protonosphere. It acts as a dependable reflector of ...
Relationship of the atmosphere and ionosphere. The ionosphere (/ aɪ ˈ ɒ n ə ˌ s f ɪər /) [1] [2] is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, [3] a region that includes the thermosphere and parts of the mesosphere and exosphere.
where is the current density, is the external electric field, is the electronic density (number of electrons/volume), is the mean free time and is the electron electric charge. Other quantities that remain the same under the free electron model as under Drude's are the AC susceptibility, the plasma frequency , the magnetoresistance , and the ...
As a result, it is the least-understood part of the atmosphere, resulting in the humorous moniker ignorosphere. [20] [21] The presence of red sprites and blue jets (electrical discharges or lightning within the lower mesosphere), noctilucent clouds, and density shears within this poorly understood layer are of current scientific interest.
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 ...
Such so-called seed electrons can be created by ionization by natural radioactivity or cosmic rays. The creation of further free electrons is only achieved by impact ionization. Thus Paschen's law is not valid if there are external electron sources. This can, for example, be a light source creating secondary electrons by the photoelectric ...
The existence of the critical frequency is the result of electron limitation, i.e., the inadequacy of the existing number of free electrons to support reflection at higher frequencies. In signal processing the critical frequency it is also another name for the Nyquist frequency.
Free electron in physics may refer to: Electron, as a free particle; Solvated electron; Charge carrier, as carriers of electric charge; Valence electron, as an outer shell electron that is associated with an atom; Valence and conduction bands, as a conduction band electron relative to the electronic band structure of a solid