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Data Group [He]: M. Santos, C. Noel, T. Belmonte and L.L. Alves ''Microwave capillary plasmas in helium at atmospheric pressure'' 2014 J. Phys. D: Appl. Phys. 47 265201 1-18. Cross sections were defined for energies up to 1 keV and were adjusted as to yield good agreement between calculated and measured swarm parameters. The calculations use a two-term Boltzmann solver with the SST growth model. The cross sections are handled choosing a linear interpolation scheme with no extrapolation after the last energy point, within energy-grids with 1000 points and constant step-sizes comprised between 0.01 and 1 eV, according to the (low/high) reduced-field values considered.
The present cross section set updates its previous version, published in L.L. Alves et al ''Comparisons of sets of electron–neutral scattering cross sections and swarm parameters in noble gases: II. Helium and neon'' 2013 J. Phys. D: Appl. Phys. 46 334002 1-22.
The elastic momentum-transfer cross section corresponds to the one proposed by Crompton et al at low energies, Milloy and Crompton at intermediate energies, and Belmonte et al at high energies. The inelastic electron cross sections for transitions n(2s+1)S -> n’(2s’+1)l’ with n < 3, 1 < n’ < 5, l’ = S,P,D,F are obtained from Belmonte et al, by multiplying the excitation cross sections for the metastables and the n3P states by factors of 0.31 and 0.60, respectively, and by multiplying the excitation cross sections for the n1P states by a factor of 1.66.
For the rest of transitions, the cross sections are obtained from the analytical expressions proposed by Ralchenko et al.
The ionization cross section is taken from the measurements of Rapp and Englander-Golden, for electron energies below 100 eV, and from Belmonte et al, between 100–1000 eV.

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e / He