{\it K}-Shell Photoionization of B-like Atomic Nitrogen Ions: Experiment and Theory

Measurements of absolute cross sections for the {\it K}-shell photoionization of B-like atomic nitrogen ions were carried out utilizing the ion-photon merged-beam technique at the SOLEIL synchrotron radiation facility in Saint-Aubin, France. High-resolution spectroscopy with E/$\mathrm{\Delta }$E $\approx$ 13,500 was the maximum resolution achieved. We have investigated two photon energy regions: 404 eV – 409 eV and 439 eV – 442 eV. Resonance peaks found in the experimental measured cross sections are compared with theoretical estimates from the multi-configuration Dirac - Fock, R-matrix and empirical methods, allowing identification of the strong 1s $\to$ 2p and the weaker 1s $\to$ 3p resonances in the observed {\it K}-shell spectra of this B-like nitrogen ion.