# Debye_length¶

plasmapy.formulary.parameters.Debye_length(T_e: Unit("K"), n_e: Unit("1 / m3")) -> Unit("m")
Calculate the characteristic decay length for electric fields,
due to charge screening.
Parameters: T_e (Quantity) – Electron temperature n_e (Quantity) – Electron number density lambda_D – The Debye length in meters Quantity TypeError – If either argument is not a Quantity UnitConversionError – If either argument is in incorrect units ValueError – If either argument contains invalid values ~astropy.units.UnitsWarning – If units are not provided, SI units are assumed

Notes

The Debye length is the exponential scale length for charge screening and is given by

$\lambda_D = \sqrt{\frac{\epsilon_0 k_b T_e}{n_e e^2}}$

for an electron plasma with nearly stationary ions.

The electrical potential will drop by a factor of 1/e every Debye length.

Plasmas will generally be quasineutral on length scales significantly larger than the Debye length.

Example

>>> from astropy import units as u
>>> Debye_length(5e6*u.K, 5e15*u.m**-3)
<Quantity 0.002182... m>