Photoejection with excitation in H$^{-}$ and other systems

Lyman-alpha radiation, 1216Angstrom, has been seen from the sun and from various other sources. This radiation arises from the radiative transition from the 2p $^{2}$P state to 1s $^{2}$S state of the hydrogen atom. The $^{2}$P state can be excited from the 1s $^{2}$S state by electron impact. However, it is also possible to produce this excited state by photodetachment of the H$^{-}$ ion, leaving the H atom in the $^{2}$P state. We have calculated cross sections for this process using Hylleraas-type functions for the H$^{-}$ ion and using the exchange approximation for the photoelectron in the final states of angular momentum equal to 0 and 2. The photoabsorption cross sections in H$^{-}$ ions and He atoms leaving the hydrogen and helium in $^{2}$S are also calculated. Similar calculations have been carried out for the Li$^{+}$, Be$^{2+}$ and C$^{4+}$ ions.