Absolute photoionization cross sections with ultra-high energy resolution for Ar, Kr, Xe and N 2 in inner-shell ionization regions

Abstract

The high-resolution absolute photoionization cross sections for Ar, Kr, Xe and N 2 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), N 2: 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 N 2 over the present energy ranges with the energy resolution of over 10,000. The natural lifetime widths of 2 p 3 / 2 − 1 4 s , 2 p 3 / 2 − 1 3 d , 2 p 3 / 2 − 1 4 d and 2 p 1 / 2 − 1 4 s resonances for Ar, 3 d 5 / 2 − 1 6 p resonance for Xe, and 1 s − 1 π g * ( v ′ = 0 ) resonance for N 2 have been obtained based on the cross sections determined. The ionization energies into the Ar + ( 2 p 3 / 2 − 1 ), Ar + ( 2 p 1 / 2 − 1 ) and Xe + ( 3 d 5 / 2 − 1 ) ionic states are also determined using the Rydberg formula.