# Plasma parameters (plasmapy.physics.parameters)¶

This module gathers basic and general plasma parameters such as the plasma frequency or Debye length.

## Functions¶

 mass_density(density[, particle, z_mean]) Utility function to merge two possible inputs for particle charge. Alfven_speed(B, density[, ion, z_mean]) Return the Alfvén speed. ion_sound_speed(T_e, T_i[, gamma_e, …]) Return the ion sound speed for an electron-ion plasma. thermal_speed(T[, particle, method, mass]) Return the most probable speed for a particle within a Maxwellian distribution. Return the thermal pressure for a Maxwellian distribution. kappa_thermal_speed(T, kappa[, particle, method]) Return the most probable speed for a particle within a Kappa distribution. Hall_parameter(n, T, B, ion_particle[, …]) Calculate the ratio between the particle gyrofrequency and the particle-ion particle collision rate. gyrofrequency(B[, particle, signed, Z]) Calculate the particle gyrofrequency in units of radians per second. gyroradius(B[, particle, Vperp, T_i]) Return the particle gyroradius. plasma_frequency(n[, particle, z_mean]) Calculate the particle plasma frequency. Debye_length(T_e, n_e) Calculate the characteristic decay length for electric fields, Debye_number(T_e, n_e) Return the number of electrons within a sphere with a radius of the Debye length. inertial_length(n, particle) Calculate a charged particle’s inertial length. Calculate the magnetic pressure. Calculate the magnetic energy density. upper_hybrid_frequency(B, n_e) Return the upper hybrid frequency. lower_hybrid_frequency(B, n_i[, ion]) Return the lower hybrid frequency.

Examples: