CONTRIBUTION OF THE IONIZATION CONTINUUM TO THE ELECTRON-HYDROGEN RESONANCES

Two independent calculations have been carried out to obtain the integ ral cross sections for the excitation of n = 2 and 3 states from the g roundstate of hydrogen at electron impact energies lying between n = 3 and n = 4 thresholds. The first is the 15-state R-matrix calculation of Fon er al and the second is the algebraic variation method of Wang and Callaway. It is shown that in this energy range the contribution o f the ionization continuum to the excitation cross sections is estimat ed to range from 12 to 15%, and that the convergent J-matrix results o f Konovalov and McCarthy have not yet completely converged.