Integral electronic excitation cross sections of hydrogen atom levels

Combined results on the integral electron impact excitation cross sections of the 1s -> 2s, 2p, 3s, 3p, and 3d transitions in the hydrogen atom obtained on the basis of the global approximation of all available data are presented. The parameters of a four-parameter approximation of the dependence of the excitation cross sections on the electron energy are calculated. Although the values of the cross sections reported in different papers differ by several times, the relative variance obtained by us for the 1s -> 2s and 2p transitions is about 25%, while that for the 1s -> 3s, 3p, and 3d transitions amounts to 30-40%, which corresponds to the real accuracy for these transitions reported to date. The data obtained on the basis of the global approximation seem to be more reliable than the data of any separate study.