Neoclassical transport: Difference between revisions

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== Brief summary of the theory ==
== Brief summary of the theory ==


The theory starts from the (Markovian) [http://en.wikipedia.org/wiki/Fokker-planck Fokker-Planck Equation] for the particle distribution function <math>f_\alpha(x,v,t)</math>:
The theory starts from the Kinetic Equation for the mean particle distribution function <math>f_\alpha(x,v,t)</math>:


:<math>
:<math>
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where <math>\alpha</math> indicates the particle species, <math>v</math> is the velocity,  
where <math>\alpha</math> indicates the particle species, <math>v</math> is the velocity,  
<math>F</math> is a force (the [http://en.wikipedia.org/wiki/Lorentz_force Lorentz force] acting on the particle) and <math>C_\alpha</math> the Fokker-Planck [[Collision operator|collision operator]].
<math>F</math> is a force (the [http://en.wikipedia.org/wiki/Lorentz_force Lorentz force] acting on the particle) and <math>C_\alpha</math> the [[Collision operator|collision operator]].
If the chosen collision operator is the Fokker-Planck operator, the equation is called the [http://en.wikipedia.org/wiki/Fokker-planck Fokker-Planck Equation].
The derivation of this collision operator is highly non-trivial and requires making specific assumptions;
The derivation of this collision operator is highly non-trivial and requires making specific assumptions;
in particular it must be assumed that a single collision has a small random effect on the particle velocity,  
in particular it must be assumed that a single collision has a small random effect on the particle velocity,