Positron-electron correlation-polarization potentials for the calculation of positron collisions with atoms and molecules*

Abstract

Abstract. We present correlation-polarization potentials for the calculation of scattering cross sections of positrons with atoms and molecules. The potentials are constructed from a short-range correlation term and a long-range polarization term. For the short-range correlation term we present four different potentials that are derived from multi-component density functionals. For the long-range polarization term we employ a multi-term expansion. Quantum scattering calculations are presented for low energy collisions of positrons with two atomic targets (argon and krypton) and two molecular targets (nitrogen and methane). For collision energies below the threshold for Positronium formation our calculations of scattering cross sections are in good agreement with recent data sets from experiments and theory.

The POCOBIO Database for Computed Scattering Cross-Sections for Positron Collisions with Biomolecular Systems

“…We have generalized our scattering codes to include complex absorbing potentials (CAPs) [23] and new correlation-polarization potentials [24]. CAPs can be used to efficiently describe channels like ionization and Positronium formation, as shown by Staszewska et al [25], Reid and Wadehra [26,27], and Blanco and Garcia [28,29].…”

Low-energy interactions related to atmospheric and extreme conditions

“…-low-energy interactions of charged particles (electrons [1][2][3][4][5][6][7], protons [8], positrons [9]), and photons [10] with atoms and molecules of biological [1][2][3][4]7,8], astrochemical [10], industrial, and environmental [5,6,9] interest; -molecular evolution of astrochemical ices [11][12][13]; -planetary atmospheric physics [14]; -atmospheric pressure photoionization and fragmentation of organic and inorganic aerosols [15]; -processes and applications of atmospheric pressure plasmas in astrochemical [16,17] and biomedical fields [17,18].…”

“…This issue also contains three theoretical articles about electron impact excitation of several highly-charged tungsten (W) ions [5], tin (Sn) [6], and positron scattering with two atomic targets (argon and krypton) and two molecular targets (nitrogen and methane) [9]. The electron impact excitation of W and Sn are particularly important to the field of plasma, in which data on excited atoms and ions are needed to develop realistic plasma models.…”

“…Moreover, Priti et al also attempted to use analytical formulas to fit the cross sections they obtained, which can be applied directly in plasma modeling [5]. In Franz' article, the author recommended using correlation-polarization potentials with the quantum Monte Carlo method to calculate scattering cross sections of positrons with atoms and molecules [9]. These potentials can be represented using simple analytical formulas and can be implemented easily in existing computer programs.…”

“…These potentials can be represented using simple analytical formulas and can be implemented easily in existing computer programs. To validate the suggested quantum Monte Carlo method of obtaining positron-electron correlation-polarization potentials, this approach also was used for positron scattering from Ar, Kr, N 2 , and CH 4 as examples [9].…”