Single and Double Photoionization from Dipole Response Function

Single and double photoionization of Ne8+

A direct solution of the time-dependent Dirac equation is used to calculate the single and double photoionization cross sections for Ne8+. Expansion of a two-electron wavefunction in coupled spin–orbit eigenfunctions yields time-dependent close-coupled equations for quad-spinor radial wavefunctions. The repulsive interaction between electrons includes both Coulomb and Gaunt interactions. The fu...

Single and double photoionization of Be and Mg

A new version of the time-dependent close-coupling method is used to calculate the single and double photoionization of the Be and Mg atoms. Total cross sections are calculated using an implicit time propagator with a core orthogonalization method on a variable radial mesh. The double to single photoionization cross section ratios are found to be in good agreement with experiment for both Be an...

Dipole and nondipole photoionization of molecular hydrogen

We describe a theoretical approach to molecular photoionization that includes first-order corrections to the dipole approximation. The theoretical formalism is presented and applied to photoionization of H2 over the 20to 180-eV photon energy range. The angle-integrated cross section σ , the electric dipole anisotropy parameter βe, the molecular alignment anisotropy parameter βm, and the first-o...

Double Photoionization of Atoms

Double photoionization of Helium