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Cheong Z, Moreira GM, Bettega MHF, Blanco F, Garcia G, Brunger MJ, White RD, Sullivan JP. A comparison of experimental and theoretical low energy positron scattering from furan. J Chem Phys 2020; 153:244303. [PMID: 33380099 DOI: 10.1063/5.0027874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
This paper presents a joint experimental and theoretical study of positron scattering from furan. Experimental data were measured using the low energy positron beamline located at the Australian National University and cover an energy range from 1 eV to 30 eV. Cross sections were measured for total scattering, total elastic and inelastic scattering, positronium formation, and differential elastic scattering. Two theoretical approaches are presented: the Schwinger multichannel method and the independent atom method with screening corrected additivity rule. In addition, our data are compared to corresponding electron scattering results from the same target with a number of significant differences observed and discussed.
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Affiliation(s)
- Z Cheong
- Laser Physics Centre, Research School of Physics, Australian National University, Canberra, Australia
| | - G M Moreira
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - M H F Bettega
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - F Blanco
- Departamento de Fısica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - G Garcia
- Instituto de Fısica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 113-bis, 28006 Madrid, Spain
| | - M J Brunger
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - R D White
- College of Science and Engineering, James Cook University, Townsville, Qld., Australia
| | - J P Sullivan
- Laser Physics Centre, Research School of Physics, Australian National University, Canberra, Australia
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Abstract
A review on the positron scattering from atoms and molecules is presented in this article. The focus on positron scattering studies is on the rise due to their presence in various fields and application of cross section data in such environments. Positron scattering is usually investigated using theoretical approaches that are similar to those for electron scattering, being its anti-particle. However, most experimental or theoretical studies are limited to the investigation of electron and positron scattering from inert gases, single electron systems and simple or symmetric molecules. Optical potential and polarized orbital approaches are the widely used methods for investigating positron scattering from atoms. Close coupling approach has also been used for scattering from atoms, but for lighter targets with low energy projectiles. The theoretical approaches have been quite successful in predicting cross sections and agree reasonably well with experimental measurements. The comparison is generally good for electrons for both elastic and inelastic scatterings cross sections, while spin polarization has been critical due to its sensitive perturbing interaction. Positron scattering cross sections show relatively less features than that of electron scattering. The features of positron impact elastic scattering have been consistent with experiment, while total cross section requires significant improvement. For scattering from molecules, utilization of both spherical complex optical potential and R-matrix methods have proved to be efficient in predicting cross sections in their respective energy ranges. The results obtained shows reasonable comparison with most of the existing data, wherever available. In the present article we illustrate these findings with a list of comprehensive references to data sources, albeit not exhaustive.
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Aouina NY, Chaoui ZEA. Electrons and positrons elastic collisions with pyrimidine and tetrahydrofuran. Appl Radiat Isot 2018; 140:347-354. [DOI: 10.1016/j.apradiso.2018.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 07/04/2018] [Accepted: 08/08/2018] [Indexed: 10/28/2022]
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Stevens D, Babij TJ, Machacek JR, Buckman SJ, Brunger MJ, White RD, García G, Blanco F, Ellis-Gibbings L, Sullivan JP. Positron scattering from pyridine. J Chem Phys 2018; 148:144308. [DOI: 10.1063/1.5024246] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- D. Stevens
- Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Acton, Canberra 2601, Australia
| | - T. J. Babij
- Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Acton, Canberra 2601, Australia
| | - J. R. Machacek
- Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Acton, Canberra 2601, Australia
| | - S. J. Buckman
- Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Acton, Canberra 2601, Australia
| | - M. J. Brunger
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - R. D. White
- College of Science and Engineering, James Cook University, Townsville, Qld., Australia
| | - G. García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain
| | - F. Blanco
- Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - L. Ellis-Gibbings
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain
| | - J. P. Sullivan
- Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Acton, Canberra 2601, Australia
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Chiari L, Zecca A, Blanco F, García G, Brunger MJ. Experimental and theoretical cross sections for positron scattering from the pentane isomers. J Chem Phys 2016; 144:084301. [PMID: 26931696 DOI: 10.1063/1.4942472] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Isomerism is ubiquitous in chemistry, physics, and biology. In atomic and molecular physics, in particular, isomer effects are well known in electron-impact phenomena; however, very little is known for positron collisions. Here we report on a set of experimental and theoretical cross sections for low-energy positron scattering from the three structural isomers of pentane: normal-pentane, isopentane, and neopentane. Total cross sections for positron scattering from normal-pentane and isopentane were measured at the University of Trento at incident energies between 0.1 and 50 eV. Calculations of the total cross sections, integral cross sections for elastic scattering, positronium formation, and electronic excitations plus direct ionization, as well as elastic differential cross sections were computed for all three isomers between 1 and 1000 eV using the independent atom model with screening corrected additivity rule. No definitive evidence of a significant isomer effect in positron scattering from the pentane isomers appears to be present.
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Affiliation(s)
- L Chiari
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - A Zecca
- Department of Physics, University of Trento, Via Sommarive 14, Povo, Trento 38123, Italy
| | - F Blanco
- Departamento de Física Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - G García
- Instituto de Física Fundamental, Consejo Superior de Investigationes Científicas (CSIC), Serrano 113-bis, 28006 Madrid, Spain
| | - M J Brunger
- School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
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