The triple-differential cross section for the single ionization of helium in the coplanar asymmetric geometry has been calculated by using a second Born approximation which employs an improved choice of the target continuum-state wave function. The contribution of still higher-order terms of the scattering amplitude is also considered via the usual Glauber approximation. The results are compared with the recent data of Jung et al. at an incident energy of 600 eV and are found to be in very good agreement with them.

• Received 19 June 1987

DOI:https://doi.org/10.1103/PhysRevA.37.628