Electron and Positron Scattering Cross Sections from CO 2 : A Comparative Study over a Broad Energy Range (0.1–5000 eV)
[1];
[5];
[9];
[10]
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain, Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, Avenida Complutense, E-28040 Madrid, Spain
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States, Department of Physics and Astronomy, University of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- The Research School of Physics, Australian National University, Canberra, ACT 0200, Australia
- College of Science and Engineering, James Cook University, Townsville 4810, Australia
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia, Department of Actuarial Science and Applied Statistics, Faculty of Business and Management, UCSI University, Kuala Lumpur 56000, Malaysia
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
In this Review, we present a comparative study between electron and positron scattering cross sections from CO2 molecules over a broad impact energy range (0.1-5000 eV). For electron scattering, new total electron scattering cross sections (e-TCS) have been measured with a high resolution magnetically confined electron beam transmission system from 1 to 200 eV. Dissociative electron attachment processes for electron energies from 3 to 52 eV have been analyzed by measuring the relative O- anion production yield. In addition, elastic, inelastic, and total scattering cross section calculations have been carried out in the framework of the Independent Atom Model by using the Screening Corrected Additive Rule, including interference effects (IAM-SCARI). Based on the previous cross section compilation from Itikawa (J. Phys. Chem. Ref. Data, 2002, 31, 749-767) and the present measurements and calculations, an updated recommended e-TCS data set has been used as reference values to obtain a self-consistent integral cross section data set for the elastic and inelastic (vibrational excitation, electronic excitation, and ionization) scattering channels. A similar calculation has been carried out for positrons, which shows important differences between the electron scattering behavior: e.g., more relevance of the target polarization at the lower energies, more efficient excitation of the target at intermediate energies, but a lower total scattering cross section for increasing energies, even at 5000 eV. This result does not agree with the charge independence of the scattering cross section predicted by the first Born approximation (FBA). However, we have shown that the inelastic channels follow the FBA's predictions for energies above 500 eV while the elastic part, due to the different signs of the scattering potential constituent terms, remains lower for positrons even at the maximum impact energy considered here (5000 eV). As in the case of electrons, a self-consistent set of integral positron scattering cross sections, including elastic and inelastic (vibrational excitation, electronic excitation, positronium formation, and ionization) channels is provided. Again, to derive these data, positron scattering total cross sections based on a previous compilation from Brunger et al. (J. Phys. Chem. Ref. Data, 2017, 46, 023102) and the present calculation have been used as reference values. Data for the main inelastic channels, i.e. direct ionization and positronium formation, derived with this procedure, show excellent agreement with the experimental results available in the literature. Inconsistencies found between different model potential calculations, both for the elastic and inelastic collision processes, suggest that new calculations using more sophisticated methods are required.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division; Portuguese National Funding Agency (FCT)
- Grant/Contract Number:
- SC0019482; AC02-05CH11231; UIDB/00068/2020; PTDC/FIS-AQM/31281/2017
- OSTI ID:
- 1885863
- Alternate ID(s):
- OSTI ID: 1887206; OSTI ID: 1887961
- Journal Information:
- Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory Vol. 126 Journal Issue: 36; ISSN 1089-5639
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Elastic and rotational excitation of the hydrogen molecule by 1--200-eV positron impact
Positron-hydrogen atom S-wave coupled channel scattering at low energies