Precision spectroscopy and electron-ion scattering
Scientific research fields for future source of energy such as inertial confinement fusion research and astrophysics studies, especially with satellite observatories, advance into stages of precision physics. The relevant atomic data are not only enormous but also of accuracy according to requirements, especially for both energy levels and the collision data. We propose a scenario to provide such abundant atomic data with enough accuracy based on analytical continuation properties of the scattering matrices, which is a combination of indispensable theoretical computations and benchmark experimental measurements. Using our modified $R$-matrix method we can directly calculate the scattering matrices in the whole energy regions, from which we can obtain all energy levels and the related scattering cross sections with accuracies comparable with spectroscopic precision. The $e$+Kr${}^{+}$ system is used as an illustrative example; the degrees of accuracies of scattering matrices of each partial wave are calculated within about 6%, which should be much more accurate than state-of-the-art scattering experiments.