Multiple ionization of atoms including post-collisional contributions

Tables of experimental branching ratios of Auger-type post collisional ionization of rare gases

“…In tables 1, 2 and 3 we display the branching ratios used in this work for PCI of 0-6 electrons and all the shells of Ne, Ar, Kr and Xe. These values have already been employed with good results in previous calculations of multiple ionization of rare gases by protons, antiprotons and different positive ions [3,4,6,7,8,9,10,11]. A detailed discussion on the experimental branching ratios and the comparison of the different data available in the literature is included in [3].…”

“…This rearrangement gives rise to P P CI (n) , the probabilities of exactly n emitted electrons, part of them in direct ionization and part in PCI. This formalism has already been employed with good results in previous calculations of multiple ionization including direct and post-collsional contributions [3,4,6,7,8,9,10,11].…”

Multiple ionization of Ar by alpha particles

“…The comparison with the highly-charged ion production data requires the calculation of total ionization cross sections (direct plus PCI). We follow previous works [4] by employing the CDW-EIS [5], and including the PCI through the experimental branching ratios of single to multiple vacancy production.…”

Empirical formulas for direct double ionization by bare ions:Z=−1to 92

“…Note that it is also possible to use double-to single-ionization ratios, rather than cross sections, in Eqs. (2). For the cross-section version, σ 1st is obtained from R 1st (Ý)σ 1 .…”

“…Unlike the situation for double photoionization, for direct multiple ionization of outer-shell electrons by charged-particle impact the most common approach is to use an independent-electron model (IEM) where the projectile interacts with each target electron independently. In the independent-electron model, the single-and multipleionization cross sections scale as (Ze/v) 2n , where Z and v are the projectile charge and velocity, e is the electron charge, and n is the number of ionized electrons (see [1,2] and references therein). However, two aspects of the independent-electron model that are inconsistent with experimental data are that * Corresponding author: dubois@mst.edu (a) it predicts the relative amount of double ionization, i.e., R 2 = σ 2 /σ 1 , which corresponds to n = 2 and 1 in the scaling relationships, to steadily decrease and ultimately become negligible for very large v and (b) the double-to singleionization ratios should be the same for positive and negative values of Z, i.e., for electron and proton impact, positron and electron impact, and antiproton and proton impact.…”