Bohm_diffusion¶

plasmapy.formulary.
Bohm_diffusion
(T_e: Unit(‘K’), B: Unit(‘T’))¶ Return the Bohm diffusion coefficient.
The Bohm diffusion coefficient was conjectured to follow Bohm model of the diffusion of plasma across a magnetic field and describe the diffusion of early fusion energy machines. The rate predicted by Bohm diffusion is much higher than classical diffusion, and if there were no exceptions, magnetically confined fusion would be impractical.
\[D_B = \frac{1}{16} \frac{k_B T}{e B}\]where \(k_B\) is the Boltzmann constant and \(e\) is the fundamental charge.
Aliases:
DB_
 Parameters
 Warns
UnitsWarning
– If units are not provided, SI units are assumed. Raises
TypeError –
T_e
is not aQuantity
and cannot be converted into one.UnitConversionError – If
T_e
is not in appropriate units.
Examples
>>> import astropy.units as u >>> T_e = 5000 * u.K >>> B = 10 * u.T >>> Bohm_diffusion(T_e, B) <Quantity 0.00269292 m2 / s> >>> T_e = 50 * u.eV >>> B = 10 * u.T >>> Bohm_diffusion(T_e, B) <Quantity 0.3125 m2 / s>
 Returns
D_B (
Quantity
)The Bohm diffusion coefficient in meters squared per second.