Author: EUGENE.. DE PRUNELE
Publisher:
ISBN:
Category :
Languages : fr
Pages : 252
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Book Description
ANALYSE ET DISCUSSION DES PRINCIPALES APPROCHES THEORIQUES CONCERNANT LES COLLISIONS ENTRE ATOMES DE RYDBERG ET PARTICULES NEUTRES; ETUDE D'IMPLICATIONS IMPORTANTES DES HYPOTHESES FAITES, PAR EXEMPLE DANS LES TRANSFERTS D'ENERGIE EXTREMAUX SELON LA THEORIE DE FLANNERY. PROPOSITION D'UN MODELE SEMI-CLASSIQUE POUR CALCULER LA SECTION EFFICACE TOTALE DE DIFFUSION ENTRE UN ATOME DE RYDBERG A ET UNE PARTICULE NEUTRE B DANS L'HYPOTHESE QUE L'INTERACTION E-B EST A TRES COURTE PORTEE PAR RAPPORT AU RAYON MOYEN DE A. EXPRESSION DE LA PROBABILITE DE COLLISION EN FONCTION DE LA DENSITE DE PROBABILITE DE PRESENCE DE L'ELECTRON ET DE LA SECTION EFFICACE DE DIFFUSION ELECTRON LIBRE-B. ESTIMATION DE LA SECTION EFFICACE DE DIFFUSION ELASTIQUE ET COMPARAISON AUX EXPERIENCES DE DEPOPULATION COLLISION-NULLE TOTALE DE A. EN APPENDICES, 1) ETUDE DES VALEURS MOYENNES ET DISTRIBUTIONS DES VITESSES D'UN ELECTRON DE RYDBERG, ET 2) APPLICATION DU PRINCIPE DE CORRESPONDANTE AUX ETATS DE RYDBERG
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1454
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Book Description
Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1038
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Book Description
Author: S.P. Khare
Publisher: Springer Science & Business Media
ISBN: 1461506115
Category : Science
Languages : en
Pages : 362
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Book Description
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.
Author: Nicolas Sisourat
Publisher:
ISBN:
Category :
Languages : fr
Pages : 183
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Book Description
Au cours de cette thèse, nous avons mis au point des modèles et des programmes informatiques originaux pour étudier les processus électroniques au cours de collisions entres particules lourdes (ion, atome ou molécule) pour des énergies allant de quelques keV à plusieurs MeV. Nous avons utilisé une approche semi-classique non perturbative, consistant à résoudre l'équation de Schrödinger dépendante du temps (ESDT) pour les électrons du système dans le champ des noyaux en mouvement. Deux types de méthodes ont été développées pour résoudre l'ESDT. La première, totalement numérique, repose sur la méthode des différences finies. La seconde, semi-analytique, consiste à développer la fonction d'onde sur des bases analytiques. Nous avons appliqué ces programmes à l'étude de plusieurs systèmes, en particulier pour la description de l'ionisation d'atomes ou de molécules par impact d'ions, ainsi que pour l'examen des processus biélectroniques lors de collisions ion-atome et ion-molécule.
Author: Richard Barry Bernstein
Publisher: Springer Science & Business Media
ISBN: 1461329132
Category : Science
Languages : en
Pages : 785
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Book Description
The broad field of molecular collisions is one of considerable current interest, one in which there is a great deal of research activity, both experi mental and theoretical. This is probably because elastic, inelastic, and reactive intermolecular collisions are of central importance in many of the fundamental processes of chemistry and physics. One small area of this field, namely atom-molecule collisions, is now beginning to be "understood" from first principles. Although the more general subject of the collisions of polyatomic molecules is of great im portance and intrinsic interest, it is still too complex from the viewpoint of theoretical understanding. However, for atoms and simple molecules the essential theory is well developed, and computational methods are sufficiently advanced that calculations can now be favorably compared with experimental results. This "coming together" of the subject (and, incidentally, of physicists and chemists !), though still in an early stage, signals that the time is ripe for an appraisal and review of the theoretical basis of atom-molecule collisions. It is especially important for the experimentalist in the field to have a working knowledge of the theory and computational methods required to describe the experimentally observable behavior of the system. By now many of the alternative theoretical approaches and computational procedures have been tested and intercompared. More-or-Iess optimal methods for dealing with each aspect are emerging. In many cases working equations, even schematic algorithms, have been developed, with assumptions and caveats delineated.
Author: G.F. Drukarev
Publisher: Springer Science & Business Media
ISBN: 1461317797
Category : Science
Languages : en
Pages : 252
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Book Description
This book is a short outline of the present state of the theory of electron collisions with atomic particles - atoms, molecules and ions. It is addressed to those who by nature of their work need detailed information about the cross sections of various processes of electron collisions with atomic particles: experimentalists working in plasma physics, optics, quantum electronics, atmospheric and space physics, 'etc. Some of the cross sections have been measured. But in many important cases the only source of information is theoretical calcu lation. The numerous theoretical papers dealing with electronic collision processes contain various approximations. The inter relation between them and the level of their accuracy is often diffi cult to understand without a systematic study of the theory of atomic collisions, not to mention that theoretical considerations are necessary for the consistent interpretation of experimental results. The main constituents of the book are: 1. General theory with special emphasis on the topics most impor tant for understanding and discussing electron collisions with atomic particles.
Author: Philip G. Burke
Publisher: Springer Science & Business Media
ISBN: 9780306445460
Category : Science
Languages : en
Pages : 280
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Book Description
The authors aim to hone the theory of electron-atom and electron-ion collisions by developing mathematical equations and comparing their results to the wealth of recent experimental data. This first of three parts focuses on potential scattering, and will serve as an introduction to many of the concepts covered in Parts II and III. As these processes occur in so many of the physical sciences, researchers in astrophysics, atmospheric physics, plasma physics, and laser physics will all benefit from the monograph.
Author: Hicham Agueny
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0
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Book Description
Deux domaines différents de la physique des collisions ont fait l'objet de mes travaux de thèse réalisés dans le cadre d'une cotutelle entre l'Université Moulay Ismail, Meknes-Maroc et l'Université Pierre et Marie Curie, Paris-France: le premier concerne les collisions ion-atome/molécule dans le régime des énergies intermédiaires (keV), alors que le second vise le domaine des collisions électron-atome assistées par un champ laser intense. Bien que distincts, les deux thèmes sont interconnectés puisqu'il s'agit principalement d'étudier, dans des approches non-perturbatives, les phénomènes de diffusion et la dynamique électronique des collisions de cibles atomiques et moléculaires soumis à de fortes et très courtes perturbations. La première partie porte spécifiquement sur la modélisation des processus de transfert électronique et d'ionisation induits lors de collisions d'ions et de cibles atomiques et moléculaires. L'étude porte particulièrement sur les phénomènes d'interférences de type Young, de multi-diffusion et de diffraction Fraunhofer observés au cours de ces processus. La deuxième partie de thèse repose sur une étude des processus de diffusion élastiques et inélastiques induits lors de collisions assistées par un champ laser intense. L'étude s'appuie sur l'analyse spécifique des transitions "libre-libre" au cours lesquelles la cible reste dans son état fondamental après la collision, et des phénomènes de résonance dans le processus d'excitation simultanée électron-photon de la cible.
Author: Alexander Voitkiv
Publisher: Springer Science & Business Media
ISBN: 3540784217
Category : Science
Languages : en
Pages : 289
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Book Description
During the last two decades the explorations of di?erent processes accom- nyingion–atom collisions athigh-impactenergieshavebeenasubjectofmuch interest. This interest was generated not only by the advent of accelerators of relativistic heavy ions which enabled one to investigate these collisions in an experiment and possible applications of obtained results in other ?elds of physics, but also by the variety of physical mechanisms underlying the atomic collisional phenomena at high impact energies. Often highly charged projectiles produced at accelerators of heavy ions are not fully stripped ions but carry one or more very tightly bound el- trons. In collisions with atomic targets, these electrons can be excited or lost and this may occur simultaneously with electronic transitions in the target. The present book concentrates on, and may serve as an introduction to, th- retical methods which are used to describe the projectile–electron transitions occurringinhigh-energycollisionsbetweenionsandneutralatoms.Special- tention is given to relativistic impact energies and highly charged projectiles. Experimental results are used merely as illustrations and tests for theory. This book will be useful to graduate students and professional scientists who are interested in studying atomic collisions occurring at high-impact - ergies. It assumes that the reader possesses the basic knowledge in classical electrodynamics and nonrelativistic and relativistic quantum mechanics.
