The molecular and dissociative photoionization of ethane, propane, and n-butane: absolute oscillator strengths (10–80 eV) and breakdown pathways

Cross-section and asymmetry-parameter calculations for the outer- and inner-valence photoionization of ethane

“…The total cross section computed in the mixed form lies below the experimental points of Au et al [11,12], suggesting that the SE interaction potential is somewhat too attractive therefore causing a shift of intensity to lower energy, as discussed above.…”

“…1. In the figure, the most recent experimental data of Kameta et al [14,15] (the stated resolution is 29 meV at 20 eV of photon energy) and the absolute photoionization oscillator strengths measurements of Au et al [11,12] (1 eV of full width at half-maximum) are compared with our SCFCHF results. Both the computed partial cross sections for individual orbital ionizations (mixed form) and the summed profiles (in the three gauges of the dipole operator) are reported.…”

“…Above the ionization threshold the experimental profiles display a steep rise toward a maximum at about 16 eV, followed by a monotonic decreasing behavior at higher energies. In the low energy range, below the peak maximum, the experimental profiles show some irregularities, due to the opening of ionic thresholds and to the formation of super excited states that partially autoionize [14,15] giving irregularities in the vibrational spacing due to the Jahn-Teller effect [11,12]. In the energy interval 17-24 eV some vibrational progression are also discernible, which have been attribuited to Rydberg states converging to the ͑2a 2u ͒ −1 and ͑2a 1g ͒ −1 ionic thresholds [12].…”

“…Ionization and dissociative ionization channels of ethane cations have been further investigated both with electronimpact techniques, such as the ͑e ,2e͒ spectroscopy [10] and the ͑e , e͒ and ͑e , e + ion͒ coincidence spectroscopy [11][12][13], and with synchrotron radiation (SR) [14][15][16][17][18]. Furthermore, core ionization studies have also recently appeared [19,20].…”

Hydrocarbon Collision Cross Sections for Magnetic Fusion: The Methane, Ethane and Propane Families

“…In a second step we apply a common normalizing function α(E) which is the same for all channels j, and which will be determined from the cross section unitarity relation (23). Hence the normalizing function α(E) is defined as:…”