Download or read book Differential Cross Sections for Positronium Formation in Positron Hydrogen Scattering written by Mohd Zahurin Mohamed Kamali and published by . This book was released on 2008 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impressions militaires d un s jour Constantinople en octobre 1887 Par un officier allemand written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Physics with Positrons written by J.W. Humberston and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Research Workshop on Atomic Physics with Positrons, which was held at University College London during 15-18 July 1987, was the fourth meeting in a series devoted to the general theme of positron colli sions in gases. Previous meetings have been held at York University, Toronto (1981); Royal Holloway College, Egham (1983) and Wayne State Uni versity, Detroit (1985). Recent very significant improvements in positron beam currents, due to the development of more efficient moderators and the use of more intense positron sources, are making possible an increasingly sophisticated range of experiments in atomic collision physics. Whereas a few years ago only total scattering cross sections could be determined, measurements can now be made of various partial and differential cross sections. Intense positron beams are also being used to produce positronium beams and already, as reported here, preliminary investigations have been made of collisions of positronium with several target systems. These experimental developments have stimulated, and been stimulated by, steady, if somewhat less spectacu1ar,progress in associated theoretical studies. Both aspects of the field are well represented in these Proceed ings.
Download or read book Positron Cross Sections and Transport in Water written by Wade Tattersall and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed understanding of the behaviour of positrons and electrons as they pass through liquids is critical for a number of applications, from positron emission tomography and ion therapy to cosmic ray detectors and materials characterisation. In particular, transport in liquid water is vital for medical applications because of its similarity to human tissue, and is an area of continued research. This thesis presents newly measured experimental cross sections for positrons in water as well as several Monte Carlo simulation techniques aimed at improving our models of positron and electron transport. In particular, special efforts have been made to model the effects of elastic coherent scattering, which arise due to the position and velocity correlations between molecules in liquids and other dense media. The experimental scattering results include the first measurements of integral and differential elastic positron cross sections for water vapour, as well as detailed grand total and positronium formation cross sections for the same. Performed on the positron beamline apparatus at the Australian National University, this transmission experiment passed a high-resolution beam of positrons through a scattering cell containing water vapour. The parallel component of the energy of the positrons after scattering was analysed to determine the ratio between the scattered and unscattered portions of the beam, from which absolute total cross sections were calculated. The experiment further utilised a differentiated magnetic field to separate elastic scattering from the other scattering processes, and to distinguish between scattering angles in order to measure angle-differential cross sections. An original Monte Carlo track-structure simulation code has been written which aims to precisely model the transport behaviour of electrons and positrons in dilute gases, dense gases and liquids. This simulation incorporates several new features to improve its ability to model systems with high particle loss rates, varying electric fields and fully-differential ionisation interactions. Each feature has been rigorously tested against benchmark systems from the literature and, where necessary, against Boltzmann equation solutions of new benchmark systems. The simulation has also been applied to model elements of the positron trapping apparatus which is a critical component of the positron scattering experiment. The simulation's validity has been extended beyond dilute gases by including a treatment of the coherent elastic scattering that is caused by the structure of dense media. Following the theories of Van Hove, Cohen and Lekner, either a static or dynamic structure factor can be combined with gas-phase cross sections to form a modified scattering cross section that partially accounts for the temporal and spatial correlations of nearby molecules. The benchmarked Monte Carlo simulation techniques are then used to calculate transport profiles for positrons in liquid water, using the measured water cross sections. These profiles are estimates of the spatial distributions of positronium formation and energy deposition, from the positrons' emission until their first positronium formation event. Comparisons between simulations employing different cross section sets demonstrate the importance of a complete and accurate set of scattering cross sections for positrons in water.
Download or read book Measurements of Positronium Formation Cross Sections for Positrons Scattering with Atoms and Molecules written by Kostoula Pipinos and published by . This book was released on 2000 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Differential Cross Sections of Positron hydrogen Collisions Project Supported by the Nanyang Normal University Science Foundation of China Grant No ZX2013017 and the National Natural Science Foundation of China Grant Nos 11174066 61306007 and U1304114 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: We make a detailed study on the angular differential cross sections of positron–hydrogen collisions by using the momentum-space coupled-channels optical (CCO) method for incident energies below the H ionization threshold. The target continuum and the positronium (Ps) formation channels are included in the coupled-channels calculations via a complex equivalent-local optical potential. The critical points, which show minima in the differential cross sections, as a function of the scattering angle and the incident energy are investigated. The resonances in the angular differential cross sections are reported for the first time in this energy range. The effects of the target continuum and the Ps formation channels on the different cross sections are discussed.
Download or read book Positron Electron Gas Scattering Proceedings Of The 3rd International Workshop written by Walter E Kauppila and published by World Scientific. This book was released on 1986-04-01 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: This workshop discusses the current state and future directions of research in positron — gas scattering, particularly in the relationship between positron and electron scattering by the same atoms and molecules. The possible applications of positron — gas scattering to astrophysical phenomena have also been discussed.
Download or read book Positronium Formation in Positron helium Scattering written by Margaret Fulton Fels and published by . This book was released on 1968 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions of Positrons with Matter and Radiation written by Anand K. Bhatia and published by MDPI. This book was released on 2021-03-19 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Positrons can be used to study metallic defects. Positron annihilation experiments have been carried out to identify the defects in complex oxides. Positrons have also been used to study the Bose–Einstein condensation (BEC). Ps-BEC can be used to measure antigravity using atomic interferometers. This Special Issue hopes to bring awareness of the various aspects of positron interactions to the larger physics communities. We invite authors to submit articles from all areas of physics.
Download or read book Measurements of Total Cross Sections for Positron and Electron Alkali Atom Scattering and of Positronium Formation Cross Sections for Argon and Potassium Atoms written by Sonal P. Parikh and published by . This book was released on 1992 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 852 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Positron Physics written by M. Charlton and published by Cambridge University Press. This book was released on 2005-10-13 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and up-to-date account of the field of low energy positrons and positronium within atomic and molecular physics. Each chapter contains a blend of theory and experiment, giving a balanced treatment of all the topics. Useful for graduate students and researchers in physics and chemistry.
Download or read book Scattering Two Volume Set written by E. R. Pike and published by Elsevier. This book was released on 2001-10-09 with total page 1831 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scattering is the collision of two objects that results in a change of trajectory and energy. For example, in particle physics, such as electrons, photons, or neutrons are "scattered off" of a target specimen, resulting in a different energy and direction. In the field of electromagnetism, scattering is the random diffusion of electromagnetic radiation from air masses is an aid in the long-range sending of radio signals over geographic obstacles such as mountains. This type of scattering, applied to the field of acoustics, is the spreading of sound in many directions due to irregularities in the transmission medium. Volume I of Scattering will be devoted to basic theoretical ideas, approximation methods, numerical techniques and mathematical modeling. Volume II will be concerned with basic experimental techniques, technological practices, and comparisons with relevant theoretical work including seismology, medical applications, meteorological phenomena and astronomy. This reference will be used by researchers and graduate students in physics, applied physics, biophysics, chemical physics, medical physics, acoustics, geosciences, optics, mathematics, and engineering. This is the first encyclopedic-range work on the topic of scattering theory in quantum mechanics, elastodynamics, acoustics, and electromagnetics. It serves as a comprehensive interdisciplinary presentation of scattering and inverse scattering theory and applications in a wide range of scientific fields, with an emphasis, and details, up-to-date developments. Scattering also places an emphasis on the problems that are still in active current research. The first interdisciplinary reference source on scattering to gather all world expertise in this technique Covers the major aspects of scattering in a common language, helping to widening the knowledge of researchers across disciplines The list of editors, associate editors and contributors reads like an international Who's Who in the interdisciplinary field of scattering
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 1118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Atomic Molecular and Optical Physics written by and published by Academic Press. This book was released on 2008-10-28 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume continues the tradition of the Advances series. It contains contributions from experts in the field of atomic, molecular, and optical (AMO) physics. The articles contain some review material, but are intended to provide a comprehensive picture of recent important developments in AMO physics. Both theoretical and experimental articles are included in the volume. - International experts - Comprehensive articles - New developments
Download or read book NBS Special Publication written by and published by . This book was released on 1976 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
