Accessible from this website

Databases containing complete sets of cross sections for electron scattering from ground state neutral atoms and molecules.

The energy range of interest is from 0 to some 100's of eV and higher. A complete set of cross sections consists of elastic momentum transfer, and total cross sections for the processes of ionization, attachment and excitation. Complete sets of cross sections are needed as input to a Boltzmann equation solver to determine the electron or ion energy distribution function.

Databases containing partial sets of electron-neutral scattering cross sections.

Partial sets of electron neutral scattering cross sections are also included on this site. These include additional data concerning electron collisions with ground state molecules - such as total scattering, total elastic scattering - not used in the Boltzmann calculations. These also include cross sections for electron impact ionization of metastable or radicals, needed for the calculation of stepwise ionization, for example.

Databases containing ion-neutral scattering cross sections.

The limited ion-neutral cross section data available on this site were derived assuming that the differential scattering can be reasonably well approximated as the sum of an isotropic part and a backscatter part. These two components are provided as functions of the center or mass energy.

Databases containing differential scattering cross sections.

Databases containing interaction potentials

Ion neutral interaction potentials can be used to calculate differential cross sections for ion-neutral scattering.

Databases containing oscillator strengths

Oscillator strength is a quantity that expresses the probability of absorption or emission of electromagnetic radiation in transitions between energy levels of an atom or molecule. These data, combined with a suitable model such as BEF scaling (Y-K Kim, Phys Rev A, 2001), can be used to infer the energy dependance and magnitude of electron-neutral scattering cross sections for specific processes for energies greater than several times the threshold energy.

Databases containing electron and ion swarm data

Swarm data consist of electron and ion transport and rate coefficients as functions of reduced electric field strength, E/N, the ratio of the electric field to the neutral density. At present, we have excluded swarm data measured in the presence of magnetic fields, where a large body of data exist. This may be included in the future if users are interested.