UV-visible emission as a probe of core excitations applied to the furan and carbon dioxide molecules

O 1s excitation and ionization processes in the CO2molecule studied via detection of low-energy fluorescence emission

“…We have also remeasured with high photon energy resolution the excitation function of the 845-nm oxygen line in order to search for a possible correlation between fluorescence emission and the vibrational energy content of the core-to-Rydberg excited states. In the previous low-resolution study (∆hν ∼ 0.8 eV) [32], the yield of this oxygen line seemed to be systematically enhanced at photon energies slightly higher than in the total ion yield. In the new measurements, the incident photon energy resolution was improved to about 0.15 eV and the spectral resolution for fluorescence photons was slightly relaxed to ∼2.5 nm.…”

“…It was shown in Ref. [32] that the enhancement in 845-nm emission follows resonant Auger decay of the core-excited states. The emission weakens gradually just above the O 1s IP.…”

“…We followed the intensity of some selected emission lines across all core excitations up to about 40 eV above the O 1s IP. Preliminary results of a neutral oxygen emission line at 845 nm were reported in [32]. We also recorded a non-dispersed fluorescence yield using a PMT.…”

“…Preliminary results of a neutral oxygen emission line at 845 nm were reported in Ref. [32]. We also recorded a non-dispersed fluorescence yield using a photomultiplier tube (PMT).…”

“…Our total ion yield spectrum, shown as a solid line in figure 3, displays these features. Figure 3 also contains the excitation function of the 845-nm emission line, which is due to the 1s 2 2s 2 2p 3 3p 1 ( 3 P) → 1s 2 2s 2 2p 3 3s 1 ( 3 S) transitions in neutral oxygen (a dispersed fluorescence spectrum was reported in [32]), and the partial fluorescence yield measured with the PMT that is sensitive to the light at wavelengths 300-650 nm.…”