Dielectronic and tri-electronic recombination strengths of low-lying resonances and plasma rate coefficients for beryllium-like argon ions

Experimental dielectronic recombination spectra of highly charged ions, measured at the storage ring using the electron-ion merged-beam technique, are known for their high resolutions at low collision energies. This resolutions is quite in contrast to the present computations of the low-lying resonances and plasma rate coefficients, which are still a challenge for modern atomic theory. In this study, we investigate the dielectronic and tri-electronic recombination strengths of low-lying resonances for beryllium-like argon ions in the low energy range (0–5 eV) by using the newly developed Jena Atomic Calculator (JAC). JAC is a relativistic computational code based on the multi-configuration Dirac–Hartree–Fock (MCDHF) method. Our calculated strengths are compared with both experimental data and recent theoretical calculations by Zhang et al. (Phys Rev A 108:022801, 2023), showing good agreement within experimental uncertainties. Furthermore, in combination with a dielectronic cascade model, we derive the plasma rate coefficients for the \(\Delta n = 0\) transition over a wide temperature range from \(10^3\) K to \(10^7\) K. These rapidly derived, reliable plasma rate coefficients have potential applications in astrophysics and plasma physics.