Plasma Frequency Calculator

Summary

Calculate the electron plasma frequency (ωp and fp) from electron number density, with wavelength output and presets for ionosphere, fusion plasma, and semiconductor contexts.

How it works

1. Enter the electron number density in m⁻³ (particles per cubic metre).
2. The calculator applies ωp = sqrt(ne × e² / (ε₀ × me)) using SI constants: e = 1.6×10⁻¹⁹ C, ε₀ = 8.854×10⁻¹² F/m, me = 9.109×10⁻³¹ kg.
3. The plasma frequency fp = ωp / (2π) is displayed in Hz and GHz.
4. The free-space wavelength λ = c / fp is computed from fp and the speed of light.
5. Use the preset buttons to load typical densities for the ionosphere, a fusion reactor, or a semiconductor.

Use cases

• Determine the cut-off frequency below which EM waves cannot propagate through an ionospheric layer.
• Check whether a given radar frequency will penetrate or be reflected by the ionosphere.
• Estimate the plasma frequency in a tokamak or ICF target for diagnostics.
• Calculate the plasma resonance in a semiconductor or thin-film optical stack.
• Validate numerical plasma simulation parameters against analytical benchmarks.

Frequently Asked Questions