plasma_frequency

hack.formulary.frequencies.plasma_frequency(n: Quantity, particle: str | int | integer | Particle | CustomParticle | Quantity, *, mass_numb: int | None = None, Z: float | None = None) → Quantity[source]

Calculate the particle plasma frequency.

Parameters:

  • n (~astropy.units.Quantity) – Particle number density in units convertible to m-3.

  • particle (str) – Representation of the particle species.

  • Z (int, optional) – The charge number of an ion or neutral atom, if not provided in particle.

  • mass_numb (int, optional) – The mass number of an isotope, if not provided in particle.

Returns:

The particle plasma frequency in radians per second.

Return type:

~astropy.units.Quantity

Notes

The particle plasma frequency is

\[ω_p = \sqrt{\frac{n |q|}{ε_0 m}}\]

where \(n\) is the number density, \(q\) is the particle charge, and \(m\) is the particle mass.

Examples

>>> import astropy.units as u
>>> plasma_frequency(1e19 * u.m**-3, particle="p+")
<Quantity 4.16329...e+09 rad / s>