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  • Essay / Single and double ionization

    Collision physics provides fundamental knowledge about the ionization process. The differential spectra of ionized electrons provide detailed information on the dynamics of the ionization process. The characteristic structure of the species may be associated with different collision mechanisms. The ionization of atoms and molecules is one of the fundamental processes of atomic physics. Single and multiple ionization of atoms by ions is one of the fundamental processes of atomic physics with important applications in plasma physics, fusion, studies of the upper atmosphere, astrophysics, nuclear astrophysics and many other technological areas. Because of this wide range of applications, great efforts have been made, both experimentally and theoretically, to improve our understanding of ionization processes resulting from the impact of ions with atoms. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay The description of multiple ionization is very tedious, mainly because of the complexity of the many possible paths leading to it. For example, the double ionization of atoms by fast ions is generally understood in terms of three mechanisms (McGuire, 1982). First, the shake off process, in which a fast electron is ejected upon direct ionization with the projectile, while the second electron is ionized by final state rearrangement, and second, a two-step process, in which the two electrons are simultaneously ejected by the direct projectile. interaction with the projectile and thirdly the ionization of the inner layer electron with post-collision Auger decay. The shake off process and inner shell ionization give double ionization cross sections and are essentially proportional to the single ionization. The two-step mechanism is based on the action of the projectile on the two active electrons. Multiple ionizations depend on the energy of the projectile and its charge state which is significantly different from those of a single ionization. In the case of different multiple ionization processes, the double ionization is the most important because the main contributions to the total ionization of the target are made by the single and double ionization processes. Theoretical calculations of double ionization cross sections are considered very important because the contribution of different physical processes, e.g. simultaneous ejection of two electrons, inner shell ionization followed by Auger emission, excitation by resonance, the double self-ionization process, etc., can be estimated separately at various impacts. energies. The independent particle model is a widely used approach for the multiple ionization process. In this approach, it is assumed that the ionization of one electron is independent of the other and that the associated probabilities are given by the binomial distribution (Sant-Anna et al., 1998; Kirchner et al., 1999). This method depends heavily on how well the probability of ionization of a single electron is calculated. Although some general qualitative estimates can be obtained through simple semi-classical calculations using the hydrogen wave function (Sant-Anna et al., 1998). An alternatively theoretical approach to IPM is the statistical energy distribution model. It was formulated by Russek and Thomas (1958) and developed by Cocke (1979) and Kabachnik et al. (1997). The hypothesis is based on the fact that the probability of multiple ionizations is directly linked to the energy deposited by the projectile on the target. The energy deposited is.