Variables
Description
What is this formula?
The Debye length formula calculates the characteristic distance over which electric fields are screened inside a plasma.
Beyond the Debye length, electric potentials produced by charged particles become strongly reduced due to collective shielding effects from surrounding plasma particles.
It is one of the most fundamental parameters in plasma physics.
When to use it
Use this formula when studying plasma shielding, electrostatic interactions, plasma diagnostics, fusion plasmas, ionospheric plasmas, and laboratory plasma behavior.
Example
A plasma has:
Te = 2×10^5 K
ne = 8×10^17 m⁻³
Using:
ε0 = 8.854×10^-12 F/m
kB = 1.381×10^-23 J/K
e = 1.602×10^-19 C
Formula:
λD = √((ε0*kB*Te)/(ne*e²))
Substitution:
λD = √((8.854×10^-12 × 1.381×10^-23 × 2×10^5)/(8×10^17 × (1.602×10^-19)²))
Result:
λD ≈ 3.45×10^-5 m
Applications
- Plasma shielding analysis
- Fusion plasma diagnostics
- Space plasma physics
- Electrostatic plasma modeling
- Semiconductor plasmas
- Plasma sheath studies
- Laboratory plasma characterization