The Iron Project and the RmaX Project: R-Matrix Data for Astrophysical and Fusion Applications

The R-Matrix method has long been employed to compute fundamental atomic parameters with high precision for large scale applications to astrophysical sources and magnetic and inertial fusion devices. Ongoing work is part of two projects: The Iron Project that focuses on Fe-peak elements, and the RmaX Project aimed at spectral diagnostics of laboratory and astrophysical X-ray plasmas. The primary atomic processes include electron impact excitation, photoionization, (e + ion) recombination, and spectral transitions. These data are employed in numerical simulations of high-temperature plasmas under stationary and transient conditions. The calculated parameters have been benchmarked against sophisticated experiments on electron-beam-ion-traps for excitation, synchrotron based light sources for photoionization, and heavy ion storage rings for (e + ion) recombination. Extensions of the two projects include a self-consistent and unified theoretical treatment of (e + ion) recombination that subsumes both the radiative and the dielectronic recombination processes. Cross sections are computed using an identical (e + ion) wavefunction expansion for both the photoionization and the recombination processes, thereby considering the resonant and non-resonant phenomena in an ab initio manner. Comparison with experiments ascertain an accuracy of 10-20%, within the uncertainties in experiment and theory, indicating that there are no significant shortcomings in the R-matrix method. We compare the close coupling R-matrix data with the Distorted Wave approximation and the effect on X-ray spectral analysis. Finally, we describe the electronic database TIPTOPbase, which will also make available new stellar opacities and radiative accelerations from the Opacity Project