Electron Impact Reaction
Use the Electron Impact Reaction node to add collisions to a model by entering a formula and some properties of the collision. The cross-section data can be entered manually or by loading it from a file.
Load in multiple cross sections from a file in the Boltzmann Equation, Two-Term Approximation settings. In this case, the collision features are automatically generated.
Collision
Enter a Formula for the collision.
Select a Collision type: Elastic (the default), Excitation, Attachment, or Ionization.
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For Elastic enter a value for the Electron mass ratio mr (dimensionless) (the ratio of the mass of the electron to the target species).
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Select Excitation for excitation reactions where the collision is inelastic. Enter the Energy loss Δε (SI unit: V) for the reaction. This is also known as threshold energy for the reaction. Select this option for electronic excitation, vibrational and rotational excitation, and superelastic collisions. For superelastic collisions, the energy loss is negative.
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Select Attachment for collisions which result in the electron attaching to the target species, forming a negative ion. No user input is required.
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Select Ionization for electron impact reactions which result in secondary electrons being formed. Enter the Energy loss Δε (SI unit: V) for the reaction. This is also known as threshold energy for the reaction.
Cross Section Data
Enter the cross section data in two columns. Enter the Electron energy (SI unit: eV) and the Collision cross section data (SI unit: m2). Also click the Load from file button () to import data from a text file. The file must contain the two columns of data (Electron energy (SI unit: eV) in the first column and Collision cross section data (SI unit: m2) in the second column).