Vacuum Pump
Use the Vacuum Pump node to represent a vacuum pump such as a turbomolecular pump or a diffusion pump.
Vacuum Pump
Select how to Specify pump flux: Fraction of incident molecules (the default), Directly, or Pump speed. The emitted flux J is given by J = G − Jpump.
The Fraction of incident molecules fG, is specified either directly, or through a Pump speed, SG, such that f=√(2πMn/RT)S/A (here Mn is the molar mass of the species, R is the universal gas constant, T is the temperature, and A is the area of the pump). This condition applies pointwise across the surface of the pump.
Care should be taken with the specification of Jpump,G to ensure that the value is never negative.
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For Directly, and for each species, enter a value for  Jpump,G (SI unit: mol/(m2⋅s)).
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For Fraction of incident molecules, and for each species, enter a value for fG (dimensionless). The default is 0.8.
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For Pump speed, and for each species, enter a value or expression for SG (SI unit: m3/s). The default is 500 l/s.
For 2D components, also enter a Channel thickness dbc (SI unit: m). This specifies the out-of-plane thickness of the pump, which is required in order to compute its area.