Effective collision strengths for 1s–2s and 1s–2p electron–hydrogen atom scattering

Extensive electron–hydrogen atom scattering calculations have recently been performed (Scott et al. ) using a hybrid model which employs intermediate energy R-matrix theory, pseudostate close-coupling and the second Born approximation. The resulting 1s–2s and 1s–2p cross-sections have been integrated over a Maxwellian electron energy distribution to yield effective collision strengths and rate coefficients for excitation to the n = 2 levels of the hydrogen atom. These parameters are reported for plasma temperatures ranging from |5 10^3\, to\, 5 10^5| K and are fitted to simple analytic formulae.