An Etymological Dictionary of Astronomy and Astrophysics

A characteristic length scale in a → plasma, determined by the temperature and number density of the charged particles. The Debye length (in cm) is given by the expression:
λ_D = 743(T_e/n_e)^1/2, where T_e is the electron temperature in → electron-volts
and n_e is the electron density in cm^-3. Particles which pass each other at distances smaller than the Debye length interact directly. Outside the Debye length particle interactions are dominated by collective effects. In typical laboratory plasmas the Debye length is small compared with the plasma dimension, so that collective effects are important.

See also: → debye (D); → length.