Absolute photoionization cross sections with ultra-high energy resolution for Ar, Kr, Xe and N2 in inner-shell ionization regions

The high-resolution absolute photoionization cross sections for Ar, Kr, Xe and N2 in the inner-shell ionization region have been measured using a multi-electrode ion chamber and monochromatized synchrotron radiation. The energy ranges of the incident photons for the target gases were as follows: Ar: 242-252 eV (2p Rydberg excitation), Kr: 1650-1770 eV (near the 2p ionization thresholds), Xe: 665-720 eV (near the 3d ionization thresholds) and 880-1010 eV (near the 3p ionization thresholds), N2: 400-425 eV (N 1s excitation and ionization). It is the first time to measure the absolute ionization cross sections of Ar, Kr, Xe and N2 over the present energy ranges with the energy resolution of over 10,000. The natural lifetime widths of 2p3/2−14s, 2p3/2−13d, 2p3/2−14d and 2p1/2−14s resonances for Ar, 3d5/2−16p resonance for Xe, and 1s−1πg*(v′=0) resonance for N2 have been obtained based on the cross sections determined. The ionization energies into the Ar+ (2p3/2−1), Ar+ (2p1/2−1) and Xe+ (3d5/2−1) ionic states are also determined using the Rydberg formula.