Abstract
We calculate the differential and the total cross sections for the direct excitation of the state of helium from the metastable state by electron impact using the Glauber and Born methods. For the Glauber cross-section calculation we use the analytic method of Thomas and Chan to reduce the Glauber amplitude for charged-particle-neutral-atom collisions to a one-dimensional integral representation involving modified Lommel functions. The calculations are made for incident electron energies between 3 and 1000 eV, and for two different sets of wave functions. The results of the differential and the total excitation cross sections are compared with all other available theoretical calculations.
- Received 28 September 1977
DOI:https://doi.org/10.1103/PhysRevA.17.513
©1978 American Physical Society