1
|
de Urquijo J, Casey MJE, Serkovic-Loli LN, Cocks DG, Boyle GJ, Jones DB, Brunger MJ, White RD. Assessment of the self-consistency of electron-THF cross sections using electron swarm techniques: Mixtures of THF–Ar and THF–N2. J Chem Phys 2019. [DOI: 10.1063/1.5108619] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. de Urquijo
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62251, Cuernavaca, Morelos, Mexico
| | - M. J. E. Casey
- College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia
| | - L. N. Serkovic-Loli
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62251, Cuernavaca, Morelos, Mexico
| | - D. G. Cocks
- College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia
| | - G. J. Boyle
- College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia
| | - D. B. Jones
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia
| | - M. J. Brunger
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia
| | - R. D. White
- College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia
| |
Collapse
|
2
|
Casey MJE, de Urquijo J, Serkovic Loli LN, Cocks DG, Boyle GJ, Jones DB, Brunger MJ, White RD. Self-consistency of electron-THF cross sections using electron swarm techniques. J Chem Phys 2017; 147:195103. [DOI: 10.1063/1.5004717] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. J. E. Casey
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - J. de Urquijo
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de Mexico, 62251 Cuernavaca, Morelos, Mexico
| | - L. N. Serkovic Loli
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de Mexico, 62251 Cuernavaca, Morelos, Mexico
| | - D. G. Cocks
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - G. J. Boyle
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - D. B. Jones
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - M. J. Brunger
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - R. D. White
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| |
Collapse
|
3
|
Stokes PW, Philippa B, Cocks D, White RD. Generalized balance equations for charged particle transport via localized and delocalized states: Mobility, generalized Einstein relations, and fractional transport. Phys Rev E 2017; 95:042119. [PMID: 28505754 DOI: 10.1103/physreve.95.042119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Indexed: 11/07/2022]
Abstract
A generalized phase-space kinetic Boltzmann equation for highly nonequilibrium charged particle transport via localized and delocalized states is used to develop continuity, momentum, and energy balance equations, accounting explicitly for scattering, trapping and detrapping, and recombination loss processes. Analytic expressions detail the effect of these microscopic processes on mobility and diffusivity. Generalized Einstein relations (GER) are developed that enable the anisotropic nature of diffusion to be determined in terms of the measured field dependence of the mobility. Interesting phenomena such as negative differential conductivity and recombination heating and cooling are shown to arise from recombination loss processes and the localized and delocalized nature of transport. Fractional transport emerges naturally within this framework through the appropriate choice of divergent mean waiting time distributions for localized states, and fractional generalizations of the GER and mobility are presented. Signature impacts on time-of-flight current transients of recombination loss processes via both localized and delocalized states are presented.
Collapse
Affiliation(s)
- Peter W Stokes
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Bronson Philippa
- College of Science and Engineering, James Cook University, Cairns, QLD 4870, Australia
| | - Daniel Cocks
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Ronald D White
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| |
Collapse
|
4
|
Bruggeman PJ, Kushner MJ, Locke BR, Gardeniers JGE, Graham WG, Graves DB, Hofman-Caris RCHM, Maric D, Reid JP, Ceriani E, Fernandez Rivas D, Foster JE, Garrick SC, Gorbanev Y, Hamaguchi S, Iza F, Jablonowski H, Klimova E, Kolb J, Krcma F, Lukes P, Machala Z, Marinov I, Mariotti D, Mededovic Thagard S, Minakata D, Neyts EC, Pawlat J, Petrovic ZL, Pflieger R, Reuter S, Schram DC, Schröter S, Shiraiwa M, Tarabová B, Tsai PA, Verlet JRR, von Woedtke T, Wilson KR, Yasui K, Zvereva G. Plasma–liquid interactions: a review and roadmap. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/0963-0252/25/5/053002] [Citation(s) in RCA: 917] [Impact Index Per Article: 114.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
5
|
Abstract
The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the ‘gas-phase’ assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations.
Collapse
|
6
|
Boyle GJ, McEachran RP, Cocks DG, White RD. Electron scattering and transport in liquid argon. J Chem Phys 2015; 142:154507. [PMID: 25903897 DOI: 10.1063/1.4917258] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann's equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange, while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-sections with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies.
Collapse
Affiliation(s)
- G J Boyle
- College of Science, Technology & Engineering, James Cook University, Townsville 4810, Australia
| | - R P McEachran
- Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200, Australia
| | - D G Cocks
- College of Science, Technology & Engineering, James Cook University, Townsville 4810, Australia
| | - R D White
- College of Science, Technology & Engineering, James Cook University, Townsville 4810, Australia
| |
Collapse
|
7
|
Tattersall WJ, Cocks DG, Boyle GJ, Buckman SJ, White RD. Monte Carlo study of coherent scattering effects of low-energy charged particle transport in Percus-Yevick liquids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:043304. [PMID: 25974609 DOI: 10.1103/physreve.91.043304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Indexed: 06/04/2023]
Abstract
We generalize a simple Monte Carlo (MC) model for dilute gases to consider the transport behavior of positrons and electrons in Percus-Yevick model liquids under highly nonequilibrium conditions, accounting rigorously for coherent scattering processes. The procedure extends an existing technique [Wojcik and Tachiya, Chem. Phys. Lett. 363, 381 (2002)], using the static structure factor to account for the altered anisotropy of coherent scattering in structured material. We identify the effects of the approximation used in the original method, and we develop a modified method that does not require that approximation. We also present an enhanced MC technique that has been designed to improve the accuracy and flexibility of simulations in spatially varying electric fields. All of the results are found to be in excellent agreement with an independent multiterm Boltzmann equation solution, providing benchmarks for future transport models in liquids and structured systems.
Collapse
Affiliation(s)
- W J Tattersall
- Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200, Australia
- College of Science, Technology and Engineering, James Cook University, Townsville 4810, Australia
| | - D G Cocks
- College of Science, Technology and Engineering, James Cook University, Townsville 4810, Australia
| | - G J Boyle
- College of Science, Technology and Engineering, James Cook University, Townsville 4810, Australia
| | - S J Buckman
- Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200, Australia
- Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - R D White
- College of Science, Technology and Engineering, James Cook University, Townsville 4810, Australia
| |
Collapse
|
8
|
de Urquijo J, Basurto E, Juárez AM, Ness KF, Robson RE, Brunger MJ, White RD. Electron drift velocities in He and water mixtures: Measurements and an assessment of the water vapour cross-section sets. J Chem Phys 2014; 141:014308. [DOI: 10.1063/1.4885357] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. de Urquijo
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62251, Cuernavaca, Mor., Mexico
| | - E. Basurto
- División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana, Av. San Pablo 180, 02200, México, D.F
| | - A. M. Juárez
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62251, Cuernavaca, Mor., Mexico
| | - K. F. Ness
- School of Engineering and Physical Sciences, James Cook University, Townsville 4810, Australia
| | - R. E. Robson
- School of Engineering and Physical Sciences, James Cook University, Townsville 4810, Australia
| | - M. J. Brunger
- School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
- Institute of Mathematical Sciences, University of Malaya, 5063 Kuala Lumpur, Malaysia
| | - R. D. White
- School of Engineering and Physical Sciences, James Cook University, Townsville 4810, Australia
| |
Collapse
|
9
|
Petrović ZL, Marjanović S, Dujko S, Banković A, Malović G, Buckman S, Garcia G, White R, Brunger M. On the use of Monte Carlo simulations to model transport of positrons in gases and liquids. Appl Radiat Isot 2014; 83 Pt B:148-54. [DOI: 10.1016/j.apradiso.2013.01.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 12/29/2012] [Accepted: 01/02/2013] [Indexed: 10/27/2022]
|
10
|
Ness KF, Robson RE, Brunger MJ, White RD. Transport coefficients and cross sections for electrons in water vapour: comparison of cross section sets using an improved Boltzmann equation solution. J Chem Phys 2012; 136:024318. [PMID: 22260590 DOI: 10.1063/1.3675921] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper revisits the issues surrounding computation of electron transport properties in water vapour as a function of E/n(0) (the ratio of the applied electric field to the water vapour number density) up to 1200 Td. We solve the Boltzmann equation using an improved version of the code of Ness and Robson [Phys. Rev. A 38, 1446 (1988)], facilitating the calculation of transport coefficients to a considerably higher degree of accuracy. This allows a correspondingly more discriminating test of the various electron-water vapour cross section sets proposed by a number of authors, which has become an important issue as such sets are now being applied to study electron driven processes in atmospheric phenomena [P. Thorn, L. Campbell, and M. Brunger, PMC Physics B 2, 1 (2009)] and in modeling charged particle tracks in matter [A. Munoz, F. Blanco, G. Garcia, P. A. Thorn, M. J. Brunger, J. P. Sullivan, and S. J. Buckman, Int. J. Mass Spectrom. 277, 175 (2008)].
Collapse
Affiliation(s)
- K F Ness
- ARC Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville 4810, Australia
| | | | | | | |
Collapse
|