diamagnetic_drift

plasmapy.formulary.drifts.diamagnetic_drift(dp: Unit(‘Pa / m’), B: Unit(‘T’), n: Unit(‘1 / m3’), q: Unit(‘C’))

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

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>

Notes

The diamagnetic drift is given by

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

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

References

• Chen, Introduction to Plasma Physics and Controlled Fusion, 3.65