Download or read book Theoretical Calculations for Electron Impact Ionization of Atoms and Molecules written by Sadek Mohamed Fituri Amami and published by . This book was released on 2017 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In the last twenty years, significant progress has been made for the theoretical treatment of electron impact ionization (e,2e) of atoms and molecules and, for some cases, very nice agreement between experiment and theory has been achieved. In particular, excellent agreement between theory and experiment and theory has been achieved for ionization of hydrogen and helium. However, agreement between experiment and theory is not nearly as good for ionization of larger atoms and molecules. In the first part of this dissertation, different theoretical approaches will be employed to study the triply differential cross section (TDCS) for low and intermediate energy electron-impact ionization of Neon and Argon for different orbital states. There is a very recent interest in studying ionization of Laser aligned atoms in order to get a better understanding about electron impact ionization of molecules. In the next part of this dissertation, results will be presented for electron-impact ionization of three laser aligned atoms, Mg, Ca, and Na. The comparison between the theory and experiment showed that our three body distorted wave (3DW) model gave excellent agreement with experiment in the scattering plane but very poor agreement perpendicular to the scattering plane. An explanation for this poor agreement out of the scattering plane has been provided by comparing our theoretical results with those of the time depended close coupling (TDCC) model and this explanation is also provided in this dissertation. Recently, significant attention has been directed towards obtaining a better understanding of electron-impact ionization of molecules which are significantly more challenging than atoms. In the last part of this dissertation, results will be presented for electron-impact ionization of three different molecules (N2, H2O, and CH4) which have been studied comprehensively using different theoretical approximations for different types of geometries. The published papers in section two contain a detailed analysis and discussion for each of these topics"--Abstract, page iv.

Download or read book Electron Impact Ionization written by T.D. Märk and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is perhaps surprising that a process which was one of the first to be studied on an atomic scale, and a process which first received attention over seven decades ago, continues to be the object of diverse and intense research efforts. Such is the case with the (seemingly) conceptually simple and familiar mechanism of electron impact ionization of atoms, molecules, and ions. Not only has the multi-body nature of the collision given ground to theoretical effort only grudgingly, but also the variety and subtlety of processes contributing to ionization have helped insure that progress has come only with commensurate work: no pain - no gain. Modern experimental methods have made it possible to effectively measure and explore threshold laws, differential cross sections, partial cross sections, inner-shell ionization, and the ionization of unstable species such as radicals and ions. In most instances the availability of experimental data has provided impetus and guidance for further theoretical progress.

Download or read book Analysis of Excitation and Ionization of Atoms and Molecules by Electron Impact written by Afzal Chaudhry and published by Springer Science & Business Media. This book was released on 2010-10-17 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The content of this book describes in detail the results of the present measurements of the partial and total doubly differential cross sections for the multiple-ionization of rare gas atoms by electron impact. These measurements show, beside other trends, the role of Auger transitions in the production of multiply ionized atoms in the region where the incident electron energy is sufficient to produce inner shell ionization. Other processes like Coster-Kronig transitions and shake off also contribute towards increasing the charge of the ions. The incident electron having energy of 6 keV, for example, in a collision with xenon atom can remove up to nine electrons! (*) X-ray-ion coincidence spectroscopy of the electron xenon atom collisions is also described. The present measurements of doubly differential cross sections for the dissociative and non-dissociative ionization of hydrogen, sulfur dioxide and sulfur hexa fluoride molecular gases by electron impact are also described in the text of this book. The results of the measurements for sulfur dioxide molecule show how this major atmospheric pollutant can be removed from the atmosphere by electron impact dissociation of this molecule. The present results of the measurements for sulfur hexa fluoride give an insight into the dissociation properties of this molecular gas, which is being so widely used as a gaseous insulator in the electrical circuits. The book also describes the present measurements of the polarization parameters of the fluorescence radiation emitted by the electron-impact-excited atoms of sodium and potassium. In these investigations the target atoms are polarized, therefore, the measurements of the polarization parameters give information about the electron atom interaction in terms of the interference, direct and exchange interaction channels.

Download or read book Accuracy of Theory for Calculating Electron Impact Ionization of Molecules written by Hari Chaluvadi and published by . This book was released on 2015 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The study of electron impact single ionization of atoms and molecules has provided valuable information about fundamental collisions. The most detailed information is obtained from triple differential cross sections (TDCS) in which the energy and momentum of all three final state particles are determined. These cross sections are much more difficult for theory since the detailed kinematics of the experiment become important. There are many theoretical approximations for ionization of molecules. One of the successful methods is the molecular 3-body distorted wave (M3DW) approximation. One of the strengths of the DW approximation is that it can be applied for any energy and any size molecule. One of the approximations that has been made to significantly reduce the required computer time is the OAMO (orientation averaged molecular orbital) approximation. In this dissertation, the accuracy of the M3DW-OAMO is tested for different molecules. Surprisingly, the M3DW-OAMO approximation yields reasonably good agreement with experiment for ionization of H2 and N2. On the other hand, the M3DW-OAMO results for ionization of CH4, NH3 and DNA derivative molecules did not agree very well with experiment. Consequently, we proposed the M3DW with a proper average (PA) calculation. In this dissertation, it is shown that the M3DW-PA calculations for CH4 and SF6 are in much better agreement with experimental data than the M3DW-OAMO results."--Abstract, page iv.

Download or read book Theoretical Study of Electron Impact ionization of Molecules written by Ola Ali Al-Hagan and published by . This book was released on 2010 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: "There has been impressive progress in the area of theoretical treatments of electron impact ionization (e,2e) of atoms and molecules in the last decade. Most recently, low to intermediate incident electron energies have been reported for molecular systems. In this dissertation, different theoretical models will be used to calculate the fully differential cross section (FDCS) for (e,2e) processes for low to intermediate incident electron energies for a variety of final state electron angles and energies for the diatomic molecules H2 and N2, the triatomic molecule H2O, and the boimolecule [sic] HCOOH. In addition, there has been a large amount of interest in diatomic molecules inspired by the possibility of observing an interference effect due to the two molecular centers playing the role of a double slit. In this dissertation, the interference effect for the diatomic molecules H2 and N2 will be examined. Finally, there is presently considerable experimental effort directed towards measuring the FDCS for a specific molecular orientation. Most recently, the FDCS for single ionization of aligned hydrogen molecules was measured by Alexander Dorn's experimental group in Heidelberg, Germany. These measurements were successful for the first time to observe features of the FDCS for different alignment of H2. Theoretical calculations for aligned H2 will be presented. These calculations were able to obtain good agreement with the experimental data especially in the binary peak region"--Abstract, leaf iv.

Download or read book Coincidence Studies of Electron and Photon Impact Ionization written by C.T. Whelan and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The great advantage of coincidence measurements is that by suitable choice of the kinematical and geometrical arrangement one may probe delicate physical effects which would be swamped in less differential experiments. The measurement of the triple dif ferential and higher-order cross sections presents enormous technical difficulties, but refined experiments of this type provide an insight into the subtleties of the scattering process and offer a welcome, if severe, test of the available theoretical models. The last few years have been an exciting time to work in the field and much has been learned. Profound insights have been gleaned into the basic Coulomb few body problem in atomic physics: the experimental study of the fundamental (e,2e) processes on hydrogen and helium targets continues to add to our knowledge and indeed to challenge the best of our theoretical models; significant advances have been made in the understanding of the "double excitation problem," that is the study of ionization processes with two active target electrons: important measurements of (e,3e), (,),,2e), excitation-ionization and excitation autoionization have been reported and strides have been made in their theoretical description; the longstanding discrepancies between theory and experiment for relativistic (e,2e) processes were resolved, spin dependent effects predicted and ob served and the first successful coincidence experiments on surfaces and thin films were announced. Theory and experiment have advanced in close consort. The papers pre sented here cover the whole gambit of research in the field. Much has been achieved but much remains to be done.

Download or read book Electron and Photon Impact Ionization and Related Topics 2004 written by B Piraux and published by CRC Press. This book was released on 2005-02-01 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron and Photon Impact Ionization and Related Topics 2004 provides an overview of the latest advances in the field of ionization by electron and photon impact. The book contains 18 contributions of recent experimental, theoretical, and computational work on correlated processes that involve a wide range of targets, including atoms, molecules, clusters, and surfaces. It covers a broad range of current topics, such as multi-particle coincidence studies, in particular, (e,2e) and (e,3e) processes, photoionization with or without excitation, and multiphoton single and double ionization. Three chapters contain the following topics: anisotropy and polarization in Auger-electron emission, multiple ionization of atoms in strong fields, and theoretical and practical aspects of photoionization with excitation. Because of the extensive array of applications discussed, this book is an essential reference for chemists, biologists, and researchers working in atomic, molecular, cluster, and surface physics.

Download or read book Electron Scattering written by Colm T. Whelan and published by Springer Science & Business Media. This book was released on 2006-01-17 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a unity to physics; it is a discipline which provides the most fundamental understanding of the dynamics of matter and energy. To understand anything about a physical system you have to interact with it and one of the best ways to learn something is to use electrons as probes. This book is the result of a meeting, which took place in Magdalene College Cambridge in December 2001. Atomic, nuclear, cluster, soHd state, chemical and even bio- physicists got together to consider scattering electrons to explore matter in all its forms. Theory and experiment were represented in about equal measure. It was meeting marked by the most lively of discussions and the free exchange of ideas. We all learnt a lot. The Editors are grateful to EPSRC through its Collaborative Computational Project program (CCP2), lOPP, the Division of Atomic, Molecular, Optical and Plasma Physics (DAMOPP) and the Atomic Molecular Interactions group (AMIG) of the Institute of Physics for financial support. The smooth running of the meeting was enormously facilitated by the efficiency and helpfulness of the staff of Magdalene College, for which we are extremely grateful. This meeting marked the end for one of us (CTW) of a ten-year period as a fellow of the College and he would like to take this opportunity to thank the fellows and staff for the privilege of working with them.

Download or read book Introduction to the Theory of Collisions of Electrons with Atoms and Molecules written by S.P. Khare and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: An understanding of the collisions between micro particles is of great importance for the number of fields belonging to physics, chemistry, astrophysics, biophysics etc. The present book, a theory for electron-atom and molecule collisions is developed using non-relativistic quantum mechanics in a systematic and lucid manner. The scattering theory is an essential part of the quantum mechanics course of all universities. During the last 30 years, the author has lectured on the topics presented in this book (collisions physics, photon-atom collisions, electron-atom and electron-molecule collisions, "electron-photon delayed coincidence technique", etc.) at many institutions including Wayne State University, Detroit, MI, The University of Western Ontario, Canada, and The Meerut University, India. The present book is the outcome of those lectures and is written to serve as a textbook for post-graduate and pre-PhD students and as a reference book for researchers.

Download or read book Electron Atom and Electron Molecule Collisions written by Jürgen Hinze and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers collected in this volume have been presented during a workshop on "Electron-Atom and Molecule Collisions" held at the Centre for Interdisciplinary Studies of the University of Bielefeld in May 1980. This workshop, part of a larger program concerned with the "Properties and Reactions of Isolated Molecules and Atoms," focused on the theory and computational techniques for the quanti tative description of electron scattering phenomena. With the advances which have been made in the accurate quantum mechanical characterisation of bound states of atoms and molecules, the more complicated description of the unbound systems and resonances important in electron collision processes has matured too. As expli cated in detail in the articles of this volume, the theory for the quantitative explanation of elastic and inelastic electron molecule collisions, of photo- and multiple photon ionization and even for electron impact ionization is well developed in a form which lends itself to a complete quantitative ab initio interpretation and pre diction of the observable effects. Many of the experiences gained and the techniques which have evolved over the years in the com putational characterization of bound states have become an essential basis for this development. To be sure, much needs to be done before we have a complete and detailed theoretical understanding of the known collisional processes and of the phenomena and effects, which may still be un covered with the continuing refinement of the experimental tech niques.

Download or read book Photon and Electron Collisions with Atoms and Molecules written by Philip G. Burke and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on photon and electron collisions with atomic and molecular targets and their ions has seen a rapid increase in interest, both experimentally and theoretically, in recent years. This is partly because these processes provide an ideal means of investigating the dynamics of many particle systems at a fundamental level and partly because their detailed understanding is required in many other fields, particularly astrophysics, plasma physics and controlled thermonuclear fusion, laser physics, atmospheric processes, isotope separation, radiation physics and chemistry and surface science. In recent years a number of important advances have been made, both on the experimental side and on the theoretical side. On the experimental side these include absolute measurements of cross sections, experiments using coincidence techniques, the use of polarised beams and targets, the development of very high energy resolution electron beams, the use of synchrotron radiation sources and ion storage rings, the study of laser assisted atomic collisions, the interaction of super-intense lasers with atoms and molecules and the increasing number of studies using positron beams.

Download or read book Atomic Molecular Ionization by Electron Scattering written by K. N. Joshipura and published by Cambridge University Press. This book was released on 2019-01-24 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers quantum scattering theories, experimental and theoretical calculations and applications in a comprehensive manner.

Download or read book Theory of Ionization of Atoms by Electron Impact written by Raimonds Peterkops and published by . This book was released on 1977 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Impact Ionization of Atoms and Ions written by Ghanshyam Purohit and published by LAP Lambert Academic Publishing. This book was released on 2015-05-05 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents details of electron impact single ionization of atoms and ions. The ionization of atoms and molecules by photon or charged particle impact such as electrons is of great importance in physics. Over the past several years a great progress has been made to understand the physics of electron impact single ionization processes (i.e. (e, 2e) processes) on atoms and ions and its quantum mechanically complete studies have also been performed. Theoretical investigations of (e, 2e) processes on atoms provide a platform to understand the collision dynamics and the characteristics of the targets by studying triple differential cross section (TDCS). Study of TDCS using the (e, 2e) technique is an important method to probe the dynamics of the ionization process and such data are strongly needed in the fields of astrophysics, controlled nuclear fusion, plasma physics etc. Chapter 1 of this book gives introduction of the electron impact ionization and the details of research work done so far has been described. The theoretical formalism has been described in detail in Chapter 2. Results of TDCS for various atomic and ionic targets have been presented in Chapter 3 and 4.

Download or read book Electron and Photon Impact Ionisation and Related Topics 2002 written by L.U Ancarani and published by CRC Press. This book was released on 2003-05-01 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron and Photon Impact Ionisation and Related Topics 2002 provides an overview of recent international research in the field of ionization by electron and photon impact. Emphasizing multi-particle coincidence studies, such as (e,2e), (e,3e), ionization-excitation, and double photo-ionization, the book contains 18 contributions of recent experimental, theoretical, and computational achievements in the realization, interpretation, and modeling of correlated processes that involve a wide range of targets, including atoms, molecules, and surfaces. It also covers nuclear reactions and interaction of electrons, photons, and ions with biological matter. This book is an essential reference for researchers working in atomic and molecular physics, surface science, chemistry, and biophysics.

Download or read book Advances in Atomic Molecular and Optical Physics written by and published by Elsevier. This book was released on 1999-10-20 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material as well as detailed descriptions of important recent developments.

Download or read book Trends in Atomic and Molecular Physics written by Krishan K. Sud and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary research in atomic and molecular physics concerns itself with studies of interactions of electron, positron, photons, and ions with atoms, molecules, and clusters; interactions of intense ultrashort laser interaction with atoms, molecules, and solids; laser assisted atomic collisions, optical, and magnetic traps of neutral atoms to produce ultracold and dense samples; high resolution atomic spectroscopy and experiments by using synchrotron radiation sources and ion storage rings. In recent years, important advances have been made in the experimental as well as theoretical understanding of atomic and molecular physics. The advances in atomic and molecu lar physics have helped us to understand many other fields, like astrophyics, atmo spheric physics, environmental science, laser physics, surface physics, computational physics, photonics, and electronics. XII National Conference on Atomic and Molecular Physics was held at the Physics Department, M. 1. S. University, Udaipur from 29th Dec. 1998 to 2ndJan. 1999 under the auspices of the Indian Society of Atomic and Molecular Physics. This volume is an outcome of the contributions from the invited speakers at the conference. The volume contains 24 articles contributed by the distinguished scientists in the field. The contrib utors have covered a wide range of topics in the field in which current research is being done. This also reflects the trend of research in this field in Indian universities and research institutes. We are grateful to the national programme committee, national, and local organiz ing committees, and members of the Physics Department and Computer Centre, M. 1.