diamagnetic_drift

plasmapy.formulary.drifts.diamagnetic_drift( dp: Quantity, B: Quantity, n: Quantity, q: Quantity, ) → Quantity[source]

Calculate the diamagnetic fluid perpendicular drift.

Aliases: vd_

Parameters:

dp (Quantity) – Pressure gradient vector
B (Quantity) – Magnetic field vector
n (Quantity) – Number density
q (Quantity) – Particle charge

Returns:

v – Drift velocity, in m/s

Return type:

Quantity

Notes

The diamagnetic drift is given by

\[\vec{v} = -\frac{ ∇ p × \vec{B} }{ q n |B|^2 }\]

This is the velocity component of a fluid element perpendicular to the magnetic field.

Examples

>>> import astropy.units as u
>>> import numpy as np
>>> dp = np.array([0, -1, 0]) * u.Pa / u.m
>>> b = np.array([0, 0, 1]) * u.T
>>> n = 1 / u.m**3
>>> q = 1 * u.C
>>> diamagnetic_drift(dp, b, n, q)
<Quantity [ 1., -0., -0.] m / s>