Thermal diffusion

Thermal diffusion may refer to: See also:
 * A thermal force on a gas due to a temperature gradient, also called thermal diffusion or Thermal transpiration.
 * It is used to drive a gas pump with no moving parts called a Knudsen pump.
 * It is the currently accepted theory for the rotation of the Crookes radiometer.
 * Diffusion in a temperature gradient, also called thermodiffusion or thermophoresis.
 * It can be used as an obsolete method of making enriched uranium (see enriched uranium § thermal diffusion).
 * Thermal diffusion can be used to measure fluid flow, including perfusion and rCBF at one location over time.
 * Brownian motion (at a constant non-zero absolute temperature).
 * Molecular diffusion
 * Heat conduction (i.e., diffusion of heat)