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Quasi-neutrality and Debye length

The distance over which quasi-neutrality becomes apparent depends on factors such as the density and temperature of a plasma. For example, the higher the density of a plasma, the smaller the region of quasi-neutrality because it will contain nearly equal numbers of negative and positively charged particle. This distance over which quasi-neutrality may break down, is often described by the Debye length (or Debye sphere), and varies according to the physical characteristics of the plasma. The Debye length is typically less than a millimeter (i.e., charged regions will not exceed a millimeter), in plasmas found in fluorescent light tubes, tokamaks (used in fusion research), and the ionosphere. However, the Debye length may reach about 10m in the interplanetary medium (solar wind) and interstellar medium (between the star), and up to 10,000m (10km) in intergalactic space. http://www.plasma-universe.com/index.php/Quasi-neutrality

Debye length, λD(m) (Min. neutrality distance) (Max charge separation)
Gas discharge tube 10−4m
Tokamak 10−4m
Ionosphere 10−3m
Magnetosphere 102m
Solar core 10−11m
Solar wind 10m
Interstellar medium 10m
Intergalactic medium 105m (10km)

After Chapter 19: The Particle Kinetics of Plasma[4]

Lars Block calculated that for an idealized space charge distribution model, if:

".. a double layer (DL) is made up of the rectangular charge distribution .. the thickness LD of a DL is at least of the order of 50 Debye lengths .. based on the assumption of a certain shape of the charge or potential distribution.

"It may be concluded that the thickness of a DL is generally large compared to the Debye length, but small compared to space plasmas and most laboratory plasmas.

"The satellite S3-3 (Mozer et al., 1977)[5] flew through, what appeared to be 'pairs' of double layers, with thickness d ~ 3-10 km"[6] http://www.plasma-universe.com/index.php/Quasi-neutrality

See Also


3.14 - Vortex Theory of Atomic Motions 13.04 - Atomic Subdivision Atomic Atomic Cluster X-Ray Emission Atomic Clusters Atomic Force atomic mass atomic number atomic theory atomic triplet atomic weight Debye Continuum Debye length Debye length in a plasma Debye length in an electrolyte diatomic Etheric Orbital Rotations Figure 13.06 - Atomic Subdivision Force-Atomic Formation of Atomic Clusters Inert Gas Interaction of Intense Laser Pulses with Atomic Clusters - Measurements of Ion Emission Simulations and Applications TD69.pdf InterAtomic Laser Cluster Interactions Law of Atomic Dissociation Law of Atomic Pitch Law of Oscillating Atomic Substances Law of Pitch of Atomic Oscillation Law of Variation of Atomic Oscillation by Electricity Law of Variation of Atomic Oscillation by Sono-thermism Law of Variation of Atomic Oscillation by Temperature Law of Variation of Atomic Pitch by Electricity and Magnetism Law of Variation of Atomic Pitch by Rad-energy Law of Variation of Atomic Pitch by Temperature Law of Variation of Pitch of Atomic Oscillation by Pressure Models of Laser Cluster Interactions monatomic Nanoplasma Plasma Plasma holes Quasi-neutrality Quasi-neutrality and Debye length Violation of quasi-neutrality

Created by Dale Pond. Last Modification: Wednesday June 5, 2013 03:29:44 MDT by Dale Pond.