Generalized Oscillator Strengths of the Helium Atom. II. Transitions from the Metastable States

The generalized oscillator strengths for the transitions $2{}_{}{}^1{}_{}{}^{}S\to 2{}_{}{}^1{}_{}{}^{}P, 3{}_{}{}^1{}_{}{}^{}S, 3{}_{}{}^1{}_{}{}^{}P, 3{}_{}{}^1{}_{}{}^{}D, 4{}_{}{}^1{}_{}{}^{}P$, and $2{}_{}{}^3{}_{}{}^{}S\to 2{}_{}{}^3{}_{}{}^{}P, 3{}_{}{}^3{}_{}{}^{}S, 3{}_{}{}^3{}_{}{}^{}P, 3{}_{}{}^3{}_{}{}^{}D, 4{}_{}{}^3{}_{}{}^{}P$ of He are computed from the Weiss correlated wave functions of the Hylleraas type. The results from two alternative formulas, corresponding to the "length" and "velocity" formulas in the optical limit, agree with each other within a few percent for moderate values of the momentum transfer. The first Born excitation cross sections for the above-mentioned transitions by charged-particle impact are also presented.