The formulation of the time-dependent close-coupling method is extended to allow the calculation of electron-impact triple-differential cross sections for atoms. The fully quantal method is applied to the electron-impact ionization of hydrogen at an incident energy of 54.4 eV for various scattering geometries. The time-dependent close-coupling results are found to be in very good agreement with those obtained by a time-independent exterior complex-scaling method. On the other hand, even though the incident energy is relatively large, significant differences are found between the two nonperturbative cross-section results and those obtained using perturbative distorted-wave methods. Large differences are found for those geometries that require an accurate knowledge of the correlation between two outgoing continuum electrons in the presence of a Coulomb nuclear field.

• Received 30 November 2001

DOI:https://doi.org/10.1103/PhysRevA.65.042721