K-shell photoabsorption spectra ofN2andN2O using synchrotron radiation

The total photoionization cross section of the $1s$ level of nitrogen in ${\mathrm{N}}_2$ and ${\mathrm{N}}_2$O molecules has been measured using monochromatized synchrotron radiation. High-resolution spectra in the range $390<\mathrm{}\hslash \omega <450\mathrm{}$ eV were recorded. A broadband in the continuum at 9.4 eV above the ionization threshold, due to the $f$-type shape resonance, has been measured with high resolution. The data are compared with theoretical calculations of photoionization cross section. Recent Hartree-Fock calculations in the static-exchange approximation agree better than earlier results, which employed the multiple-scattering method.