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We review some of the basic concepts and the possible pore structures associated with electroporation (EP) for times after electrical pulsing. We purposefully give only a short description of pore creation and subsequent evolution of pore…

Biological Physics · Physics 2017-08-25 James C. Weaver , P. Thomas Vernier

Mijnarends et al. [J. Phys. Condens. Matter {\bf 10}, 10383 (1998)] contested the best existing calculations of positron annihilation rates in jellium and crystal lattices, pointing in this way at deficiencies of existing theories of…

Soft Condensed Matter · Physics 2007-05-23 H. Stachowiak , E. Boronski

Rates of the two-, three-, four- and five-photon annihilations of the electron-positron pairs are determined numerically for the three-body positronium ion Ps$^-$ ($e^- e^+ e^-$) and four-body bi-positronium `molecule' Ps$_2$ ($e^- e^+ e^-…

High Energy Physics - Phenomenology · Physics 2015-05-13 Alexei M. Frolov

We present the results of processing of Age-Momentum Correlation (AMOC) spectra that were measured for glycerol by the Gamma-induced positron spectroscopy (GiPS) facility. Our research has shown that the shape of experimental s(t) curve…

Chemical Physics · Physics 2023-07-19 D. Zvezhinskiy , M. Butterling , A. Wagner , R. Krause-Rehberg , S. V. Stepanov

Combined positron and visible light irradiations in the photodynamical therapy (PDT) applications are analyzed. Objectives and goals of PDT are killing or irreversible oxidative damage of pathogenic cells, or rather their cell walls, cell…

Chemical Physics · Physics 2010-01-26 L. V. El'nikova

Bound state properties of the negatively charged Ps$^{-}$ ion (or $e^{-} e^{+} e^{-}$) are discussed. The expectation values of operators which correspond to these properties have been determined with the use of the highly accurate wave…

Atomic Physics · Physics 2015-06-23 Alexei M. Frolov

Positronium is an ideal system for the research of QED in the bound state. The hyperfine splitting of positronium (Ps-HFS: about 203 GHz) is a good tool to test QED and also sensitive to new physics beyond the Standard Model. Previous…

Instrumentation and Detectors · Physics 2010-12-01 Akira Miyazaki

We investigate the modeling of positronium (Ps) states and their pick-off annihilation trapped at open volumes pockets in condensed molecular matter. Our starting point is the interacting many-body system of Ps and a He atom because it is…

Atomic and Molecular Clusters · Physics 2014-10-20 A. Zubiaga , F. Tuomisto , M. Puska

The annihilation parameters of positrons with electrons in different shells of Argon, Iron and Copper atoms are calculated below the positronium (Ps) formation thresholds. Quite accurate ab initio calculations of the bound state…

Atomic Physics · Physics 2007-11-06 M. A. Abdel-Raouf , M. M. Abdel-Mageed , S. Y. El-Bakry

Studies based on imaging the annihilation of the electron (e$^{-}$) and its antiparticle positron (e$^{+}$) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the…

We report the first observation of the annihilation of positronium from the 2S state. Positronium (Ps) is excited with a two-photon transition from the 1S to the 2S state where its lifetime is increased by a factor of eight compared to the…

We report a measurement of the radium ion's $7p$ ${}^{2}P_{3/2}$ state lifetime, $\tau=4.78(3)$ ns. The measured lifetime is in good agreement with theoretical calculations, and will enable a determination of the differential scalar…

Atomic Physics · Physics 2024-02-16 M. Fan , C. A. Holliman , A. Contractor , C. Zhang , S. F. Gebretsadkan , A. M. Jayich

Periodontal diseases, reportedly affect 4 out of 10 adults in the USA. The standard of care for clinical assessments of these diseases is invasive, subjective and semi-qualitative. Thus, research on proposing alternate noninvasive…

Surface Plasmon Resonance (SPR) is an important bio-sensing technique for real-time label-free detection. However, it is pivotal to optimize various parameters of the sensor configuration for efficient and highly sensitive sensing. To that…

Biological Physics · Physics 2020-07-20 Ehsan Kabir , Syed Mohammad Ashab Uddin , Sayeed Shafayet Chowdhury

Various mesoporous materials were investigated to choose the best material for experiments requiring high yield of long-lived positronium. We found that the fraction of 3\gamma annihilation determined using \gamma-ray energy spectra and…

We make a gradient correction to a new local density approximation form of positron-electron correlation. Then the positron lifetimes and affinities are probed by using these two approximation forms based on three electronic-structure…

Materials Science · Physics 2015-09-25 Wen-Shuai Zhang , Bing-Chuan Gu , Xiao-Xi Han , Jian-Dang Liu , Bang-Jiao Ye

We establish irrational constants, that contribute to the positronium lifetime at $O(\alpha)$ and $O(\alpha^2)$ order. In particular we show, that a new type of constants appear, which are not related to Euler--Zagier sums or multiple…

High Energy Physics - Phenomenology · Physics 2009-11-13 B. A. Kniehl , A. V. Kotikov , O. L. Veretin

Several first-principles calculations of positron-annihilation characteristics in solids have added gradient corrections to the local-density approximation within the theory by Arponen and Pajanne [Ann. Phys. (N.Y.) 121, 343 (1979)] since…

Materials Science · Physics 2014-07-16 Jan Kuriplach , Bernardo Barbiellini

Positronium is the simplest bound state, built of an electron and a positron. Studies of positronium in vacuum and its decays in medium tell us about Quantum Electrodynamics, QED, and about the structure of matter and biological processes…

Medical Physics · Physics 2024-08-07 Steven D. Bass , Sebastiano Mariazzi , Pawel Moskal , Ewa Stepien

Single-shot positron annihilation lifetime spectroscopy (SSPALS) is an extremely useful tool for experiments involving the positronium atom (Ps). I examine some of the methods that are typically employed to analyze lifetime spectra, and use…

Atomic Physics · Physics 2019-01-23 Adam Deller
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