K-Shell Photoionization of Singly Ionized Atomic Nitrogen: Experiment   and Theory
  Absolute cross sections for the K-shell photoionization of C-like nitrogen ions were measured by employing the ion-photon merged-beam technique at the SOLEIL synchrotron radiation facility in Saint-Aubin, France. High-resolution spectroscopy with E/$\Delta$E $\approx$ 7,000 was achieved with the photon energy from 388 to 430 eV scanned with a band pass of 300 meV, and the 399.4 to 402 eV range with 60 meV.   Experimental results are compared with theoretical predictions made from the multi-configuration Dirac-Fock (MCDF) and R-matrix methods. The interplay between experiment and theory enabled the identification and characterization of the strong 1s $\rightarrow$ 2p resonances observed in the spectra. 
M. F. Gharaibeh, J. M. Bizau, D. Cubaynes, S. Guilbaud, N. El Hassan,   M. M. Al Shorman, C. Miron, C. Nicolas, E. Robert, C...
astro-ph.EP physics.atom-ph