Alfvén Speed

\[v_A=\frac{B}{\sqrt{\mu_0\rho}}\]

Variables

vA[vA]Alfvén speed (m/s)

Bmagnetic flux density (T)

mu0[μ0]vacuum permeability (H/m)

rho[ρ]mass density (kg/m³)

The Alfvén speed formula calculates the propagation speed of Alfvén waves in a magnetized plasma.

These waves are transverse magnetohydrodynamic waves where magnetic tension acts as the restoring force.

The Alfvén speed is one of the most important characteristic velocities in plasma physics and astrophysics.

Use this formula when studying:

- magnetohydrodynamics (MHD),

- plasma wave propagation,

- solar wind dynamics,

- fusion plasmas,

- astrophysical plasmas,

- and magnetic confinement systems.

A plasma has:

B = 0.02 T

ρ = 5×10^-7 kg/m³

μ0 = 4π×10^-7 H/m

Formula:

vA = B/√(μ0*ρ)

Substitution:

vA = 0.02/√((4π×10^-7)(5×10^-7))

Result:

vA ≈ 2.52×10^4 m/s

- Solar corona analysis

- Space plasma physics

- Fusion reactors

- Tokamak plasma modeling

- Astrophysical plasma studies

- Magnetohydrodynamic simulations

- Plasma wave propagation