[1][2] The Spitzer resistivity of a plasma decreases in proportion to the electron temperature as
The inverse of the Spitzer resistivity
The Spitzer resistivity is a classical model of electrical resistivity based upon electron-ion collisions and it is commonly used in plasma physics.
[3][4][5][6][7] The Spitzer resistivity (in units of ohm-meter) is given by: where
is the electric permittivity of free space,
is the electron temperature (in Kelvin).
of a plasma column to its resistance is to multiply by the length of the column and divide by its area.
In CGS units, the expression is given by: This formulation assumes a Maxwellian distribution, and the prediction is more accurately determined by [5] where the factor
and the classical approximation (i.e. not including neoclassical effects) of the
dependence is: In the presence of a strong magnetic field (the collision rate is small compared to the gyrofrequency), there are two resistivities corresponding to the current perpendicular and parallel to the magnetic field.
The transverse Spitzer resistivity is given by
, where the rotation keeps the distribution Maxwellian, effectively removing the factor of
The parallel current is equivalent to the unmagnetized case,
Measurements in laboratory experiments and computer simulations have shown that under certain conditions, the resistivity of a plasma tends to be much higher than the Spitzer resistivity.
[11] It has been observed in space and effects of anomalous resistivity have been postulated to be associated with particle acceleration during magnetic reconnection.
[12][13][14] There are various theories and models that attempt to describe anomalous resistivity and they are frequently compared to the Spitzer resistivity.