Convergence of energy-differential ionization cross sections obtained from a T-matrix approach with R-matrix wave functions

The T-matrix approach, as formulated by Pindzola et al. [Phys. Rev. A 62, 062718 (2000)] for calculating the single-differential ionization cross section (SDCS) has been further investigated. Using the “intermediate-energy R-matrix method” to obtain the full scattering wave function needed in the matrix element, we performed several case studies for the Temkin-Poet S-wave model of e-H scattering to study the dependence of the results on the box radius and the number of states included. Despite encouraging results before reaching convergence, we conclude that the method will ultimately not yield the correct form of the SDCS but instead will still suffer from unphysical oscillations.