Ionization cross-sections and ionization efficiency curves from polarizability volumes and ionization potentials

Electron induced ionization cross sections for astrophysical modelling

“…7 depicts the correlation plot between the maximum of total ionization cross section with the square root of the ratio of polarizability volume to ionization potential, (˛/IP) 1/2 for aldehyde, ketone, cycloalkane, methyl and ethyl acetate molecules reported previously [18,19]. It has been shown by simple electrostatic considerations and confirmed experimentally that there exists a strong correlation between the maximum electron impact ionization cross-section and the square root of the ratio of atomic or molecular polarizability volume to ionization potential [29]. Such empirical and semi-empirical correlations are useful in estimating cross sections theoretically, wherever values are not available.…”

Electron impact ionization cross-section of C2, C3, Si2, Si3, SiC, SiC2and Si2C

“…We have compared our results for C 2 and C 3 with available theoretical data. To find the consistency of our results, maximum ionization crosssection and square root of the ratio of polarizability to ionization potential [35] for each target investigated here is tabulated in Table 4 and the correlation between them is plotted in Figure 4.…”

Electron ionization time‐of‐flight mass spectrometry: Historical review and current applications

“…According to Harland and Vallance (1997), this correlation holds quite well for most atoms and molecules in general. For an atom, its position in the periodic table defines the proportionality constant (Fig.…”

“…However, when the incident electron energy and the electron affinity energy are shared among the various vibrational degrees of freedom, metastable dissociation on FIGURE 32. Correlation of molecular maximum electron ionization cross-sections with the quantity (a/E 0 ) 1/2 reproduced from the work of Harland and Vallance (1997) with permission from Elsevier Limited, Copyright 1997.…”