Results 31 to 40 of about 55,721 (192)

Calculation of Low-Energy Positron-Atom Scattering with Square-Integrable Wavefunctions

Atoms, 2022
The variational method is applied to the low-energy positron scattering and annihilation problem. The ultimate aim of the investigation is to find a computationally economical way of accounting for strong electron–positron correlations, including the ...
Sarah Gregg, Gleb Gribakin
doaj   +1 more source

Many-body theory of positron-atom interactions

, 2004
A many-body theory approach is developed for the problem of positron-atom scattering and annihilation. Strong electron-positron correlations are included non-perturbatively through the calculation of the electron-positron vertex function.
A. B. Migdal, A. L. Fetter, B. Barbiellini, C. de Boor, C. Schwartz, D. A. Varshalovich, G. F. Gribakin, G. F. Gribakin, G. F. Gribakin, J. Ludlow, J. Mitroy, J. Mitroy, J. W. Humberston, L. D. Landau, M. Charlton, M. T. McAlinden, M. Ya. Amusia, M. Ya. Amusia, M. Ya. Amusia, M. Ya. Amusia, M. Ya. Amus’ya, M. Ya. Amus’ya, P. A. Fraser   +22 more
core   +1 more source

Neutron irradiated tungsten bulk defect characterization by positron annihilation spectroscopy

Nuclear Materials and Energy, 2021
Positron annihilation spectroscopy was used to evaluate the defects in neutron irradiated tungsten exposed at five different irradiation conditions. The variables in neutron irradiation included temperature, displacements per atom (dpa), and neutron ...
Chase N. Taylor, Masashi Shimada, Joseph M. Watkins, Xunxiang Hu, Yasuhisa Oya   +4 more
doaj   +1 more source

Annihilation of positrons, emitted at β+-decay with electrons of the daughter's atom [PDF]

Ядерна фізика та енергетика, 2010
The processes of photon creation or atom ionization during annihilation of positron with other electron of daughter’s atom at β+-decay are considered.
S. M. Fedotkin
doaj  

Positron annihilation in liquid crystals

Nukleonika, 2015
Positron annihilation studies of liquid crystals are reviewed with particular reference to thermotropic liquid crystals with rod-like molecules. The studies of compounds exhibiting smectic A or smectic E phases indicate that local arrangement of dipole ...
Dryzek Ewa, Juszyńska-Gałązka Ewa
doaj   +1 more source

Ultrashort, MeV-scale laser-plasma positron source for positron annihilation lifetime spectroscopy

Physical Review Accelerators and Beams, 2021
Submicron defects represent a well-known fundamental problem in manufacturing since they can significantly affect performance and lifetime of virtually any high-value component. Positron annihilation lifetime spectroscopy is arguably the only established
Thomas L. Audet, Aaron Alejo, Luke Calvin, Mark Hugh Cunningham, Glenn Ross Frazer, Gagik Nersisyan, Michael Phipps, Jonathan Richard Warwick, Gianluca Sarri, Nasr A. M. Hafz, Christos Kamperidis, Song Li, Daniel Papp   +12 more
doaj   +1 more source

Effect of positron-atom interactions on the annihilation gamma spectra of molecules

, 2012
Calculations of gamma spectra for positron annihilation on a selection of molecules, including methane and its fluoro-substitutes, ethane, propane, butane and benzene are presented. The annihilation gamma spectra characterise the momentum distribution of
Akhiezer A I, Armour E A G, Armour E A G, Armour E A G, Berestetskii V B, C M Surko, Cooper J N, Cotton F A, D G Green, Dunlop L J M, Dunlop L J M, F Wang, G F Gribakin, Gaussian M J Frisch, Green D G, Green D G Gribakin G F, Green D G Gribakin G F, Gribakin G F, Laricchia G, McCarthy I E, Pomeranchuk I, Reeth P V, S Saha, Slater J C, Varshalovich D A, Wang F, Wang F, Wright G L, Zhang R   +28 more
core   +1 more source

In-flight annihilation correction for 511 keV photon spectrometry

EPJ Web of Conferences, 2017
Spectrometry based on the 511 keV annihilation photopeak requires the positron source to be surrounded by a suitable absorber material. While this method is well established in the literature, correction for in-flight annihilation losses from the 511 keV
Steyn G.F., Dolley S.G., Szelecsényi F., Kovács Z., Meulen N.P. van der, Vermeulen C.   +5 more
doaj   +1 more source

Defect Analysis of the β– to γ–Ga2O3 Phase Transition

Advanced Functional Materials, EarlyView.
The role of defects at all the relevant stages of the β$\beta$‐ to γ$\gamma$‐Ga2O3 polymorph transition is investigated using a multi method approach. The positron annihilation spectroscopy based results show that the defect density decreases after the transition, and that changes in defect configuration within the γ phase occur with increasing ...
Umutcan Bektas, Maciej O. Liedke, Huan Liu, Fabian Ganss, Maik Butterling, Nico Klingner, René Hübner, Ilja Makkonen, Andreas Wagner, Gregor Hlawacek   +9 more
wiley   +1 more source

Ion‐Selective Microporous Membranes via One‐Step Copolymerization Enable High‐Performance Redox Flow Batteries

Advanced Functional Materials, EarlyView.
A scalable one‐step copolymerization strategy is developed to produce low‐cost microporous ion exchange membranes that boost both the efficiency and lifespan of flow batteries. When combined with organic electrolytes in aqueous systems, these membranes enable safe and cheap flow battery energy storage, supporting the widespread integration of renewable
Jiaye Liu, Chunchun Ye, Ying Ma, Rui Tan, Xiangwen Wang, Huiting Zhang, Peng Song, Quan‐Fu An   +7 more
wiley   +1 more source