Download or read book Atomic Structure and Lifetimes written by Lorenzo J. Curtis and published by Cambridge University Press. This book was released on 2003-10-30 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a new approach to introductory graduate courses on atomic structure. The author's approach utilizes conceptually powerful semiclassical modeling methods, and demonstrates the degree to which the Maslov-indexed EBK quantization elucidates the quantum mechanical formulation of level energies and lifetimes. It merges this with an update and extension of semiempirical data systematizations developed by Bengt Edlén to describe complex atoms, and adapts them to include the specification of lifetimes. The text emphasizes the historical basis of the nomenclature and methodologies of spectroscopy. However, interaction mechanisms are presented deductively, based on quantum mechanical and field theoretical models, rather than tracing their indirect paths of discovery. Many worked examples provide applications to areas such as astrophysics, hyperfine structure, and coherent anisotropic excitation. The book presents a firm foundation for specialists in atomic physics, as well as a capstone application for specialists in astrophysics, chemistry, condensed matter, and other related fields.
Download or read book Beam foil Spectroscopy written by and published by . This book was released on 1976 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Measurements of Atomic Lifetimes and Hyperfine Energies in Alkali Like Systems written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Financial support of this research project has lead to advances in the study of atomic structure through precision measurements of atomic lifetimes, energy splittings, and transitions energies. The interpretation of data from many areas of physics and chemistry requires an accurate understanding of atomic structure. For example, scientists in the fields of astrophysics, geophysics, and plasma fusion depend on transition strengths to determine the relative abundances of elements. Assessing the operation of discharges and atomic resonance line filters also depends on accurate knowledge of transition strengths. Often relative transition strengths are measured precisely, but accurate atomic lifetimes are needed to obtain absolute values. Precision measurements of atomic lifetimes and energy splittings also provide fundamentally important atomic structure information. Lifetimes of allowed transitions depend most strongly on the electronic wave function far from the nucleus. Alternatively, hyperfine splittings give important information about the electronic wave function in the vicinity of the nucleus as well as the structure of the nucleus. Our main focus throughout this project has been the structure of atomic cesium because of its connection to the study of atomic parity nonconservation (PNC). The interpretation of atomic PNC experiments in terms of weak interaction coupling constants requires accurate knowledge of the electronic wave function near the nucleus as well as far from the nucleus. It is possible to address some of these needs theoretically with sophisticated many-electron atomic structure calculations. However, this program has been able to address these needs experimentally with a precision that surpasses current theoretical accuracy. Our measurements also play the important role of providing a means for testing the accuracy of many-electron calculations and guiding further theoretical development, Atomic systems such as cesium, with a single electron outside of a closed shell, provide the simplest open shell systems for detailed comparisons between experiment and theory. This program initially focused on measurements of excited state atomic lifetimes in alkali atomic systems. Our first measurements of atomic lifetimes in cesium surpassed the precision and accuracy of previous measurements and sparked renewed interest in the need for greater precision in lifetime measurements throughout the atomic physics community. After enhancing the capabilities of the laser systems built for these initial measurements, we began a study hyperfine energy splittings in cesium using a thermal atomic beam. The results surpassed previous measurements by more than an order of magnitude and lead to the first observation of the nuclear magnetic octupole moment in cesium demonstrating the inadequacy of the nuclear shell model for predicting high order nuclear moments. The laser system and atomic beam apparatus developed for these endeavors turned out to be perfectly suited for exploring the possibility of making absolute optical frequency measurements of atomic transitions. We initiated collaboration with researchers at NIST so that the desired optical frequencies could be reference with respect to the primary microwave frequency standard (Cs atomic fountain NIST-FI) via a femtosecond laser frequency comb. Our first absolute optical frequency measurement, of the cesium D2 line, surpassed the accuracy of a previous measurement by more than an order of magnitude. An absolute optical frequency measurement of the cesium D1 line, now near completion, also surpasses previous results and places us in a position to be able to report a new value for the fine structure constant which is the fundamental dimensionless constant that underlies all electromagnetic interactions.
Download or read book Beam Foil Spectroscopy written by Ivan Sellin and published by Springer. This book was released on 2011-10-14 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: The appreciable evolution of the nearly teenaged branch of atomic and molecular physics called beam foil spectroscopy is clearly depicted in the present volumes, which are devoted to publication of presentations at the Fourth International Conference on Beam Foil Spectroscopy and Heavy Ion Atomic Physics Symposium. The transition from childhood to adolescence parallels human experience in that diffusion of interests and interactions beyond the confines of the original family has most certainly occurred. The pre-occupation with techniques and their develop ment has been largely replaced by interest in the physics of the widest possible array of atomic and molecular physics experiments, in which spectroscopic study (visible, UV, XUV, X-ray, electron) of collisional interactions of fast beams is the unifying theme. The description "accelerator-based atomic physics" is perhaps more representative of the subject today than is the original, beam-foil spectroscopy," since so many experiments have nothing to do with foils, and furthermore, employ spectroscopy mainly as an incidental tool. What, then distinguishes beam-foil spectro scopy from overlapping fields of atomic collisions physics? In an era where the boundaries are becoming ever more diffuse, there can be no clear definition. A good functional definition was recently conceived by Peter Erman, under the salubrious stimulus of a large Tennessee bourbon: it is the tribal experience of the community of scientists who have banded together to develop the discipline over the past dozen years, as shared at the triennial conferences devoted to it.
Download or read book Beam Foil Spectroscopy written by Ivan Sellin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: The appreciable evolution of the nearly teenaged branch of atomic and molecular physics called beam foil spectroscopy is clearly depicted in the present volumes, which are devoted to publication of presentations at the Fourth International Conference on Beam Foil Spectroscopy and Heavy Ion Atomic Physics Symposium. The transition from childhood to adolescence parallels human experience in that diffusion of interests and interactions beyond the confines of the original family has most certainly occurred. The pre-occupation with techniques and their develop ment has been largely replaced by interest in the physics of the widest possible array of atomic and molecular physics experiments, in which spectroscopic study (visible, UV, XUV, X-ray, electron) of collisional interactions of fast beams is the unifying theme. The description "accelerator-based atomic physics" is perhaps more representative of the subject today than is the original, beam-foil spectroscopy," since so many experiments have nothing to do with foils, and furthermore, employ spectroscopy mainly as an incidental tool. What, then distinguishes beam-foil spectro scopy from overlapping fields of atomic collisions physics? In an era where the boundaries are becoming ever more diffuse, there can be no clear definition. A good functional definition was recently conceived by Peter Erman, under the salubrious stimulus of a large Tennessee bourbon: it is the tribal experience of the community of scientists who have banded together to develop the discipline over the past dozen years, as shared at the triennial conferences devoted to it.
Download or read book Precision Measurements of Atomic Lifetimes in Alkali Like Systems Progress Report September 15 1995 January 15 1998 written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precision measurements of atomic lifetimes are important to the analysis of data from many areas of physics and provide fundamental atomic structure information. Scientists in the fields of astrophysics, geophysics, and plasma fusion all depend on oscillator strengths to determine the relative abundances of elements. Assessing the operation of discharge lamps and atomic resonance line filters also depends on knowing accurately atomic oscillator strengths. Often relative values of oscillator strengths are measured precisely, but accurate atomic lifetimes are needed to obtain absolute values. In addition, the interpretation of parity nonconservation (PNC) experiments requires accurate knowledge of the atomic structure including radial matrix elements. Many of these scientific needs are addressed theoretically with sophisticated many-electron atomic structure calculations. In this program they address these needs experimentally with a precision that surpasses current theoretical accuracy. The lifetime measurements also play the important roles of assessing the accuracy of many-electron atomic structure calculations and of guiding further theoretical development. Alkali like atoms, with a single electron outside of a closed shell, provide the simplest open shell systems for detailed comparisons between experiment and theory. To date, the research has focused on measurements of excited state lifetimes in neutral alkali systems along with the development of the necessary equipment and techniques for studying alkali-like ionic systems. The accomplishments of this program are summarized in Section 2 and are supported by the reprints and preprints that appear in the Appendix.
Download or read book Theoretical and experimental investigations of atomic structures and lifetimes written by Claes-Göran Wahlström and published by . This book was released on 1986 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Radiative Lifetimes and Hyperfine Structure in Excited Atomic States written by Lennarth G.S. Holmgren and published by . This book was released on 1975 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Measurements of Atomic Lifetimes written by Ake G. Danemar and published by . This book was released on 1968 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic and Electronic Structure of Solids written by Efthimios Kaxiras and published by Cambridge University Press. This book was released on 2003-01-09 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graduate-level textbook for physicists, chemists and materials scientists.
Download or read book Beam foil Spectroscopy written by and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Atomic Structure and Law written by Kunming Xu and published by Nova Science Publishers. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discovers four-dimensional space within a sphere with the instantiation of the 2s2p electron octet in a neon shell. Four space dimensions correspond to points, lines, planes, and solids geometrically. This book develops the idea of dynamic calculus that is implemented by circular functions instead of infinitesimal limits. As the law of nature, dynamic calculus of spherical quantities describes harmonic oscillations of electrons in atoms by dimension transformation rather than kinematic movement. In particular, electronic orbitals of 1s2s2p within a neon atom are defined in calculus, trigonometry, and geometry rigorously. A fresh theory of the atomic structure and law is established from scratch that eventually changes the traditional spacetime worldview. The theory derived from atomic spacetime may be extended to the description of molecules, cells, and organisms. For example, both electrons within a helium atom constitute a two-dimensional system, which provides a mathematical model for life phenomena. A husband and a wife are two dimensions of the family; plants and animals are two kingdoms of the advanced lives. The interplay and transformation between both dimensions are the eternal theme of nature. A DNA molecule, composed of space and time strands, is a stepwise LC oscillatory circuitry where each base pair is a capacitor, each phosphate bridge is an inductor, and each deoxyribose is a charge router directed by chiral carbons with anisotropic 2p electronic orbitals. All physical quantities are ordered into a periodic table according to their spacetime dimensions. This original approach provides sharp insight into the properties of and relationships between various physical quantities, paving the way toward the formulation of a grand unification theory. Spherical quantities in dynamic calculus complement physical quantities in linear algebra, comply with the Pythagorean theorem and the general Stokes' theorem, observe Maxwell's equations, and characterize the rhythms of entities and life essentially. The spherical view also endorses the core concepts of traditional Chinese medicine, such as yin and yang theory, five element theory, and eight trigram philosophy.
Download or read book The Basics of Atoms and Molecules written by Tom Jackson and published by The Rosen Publishing Group, Inc. This book was released on 2013-12-15 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the basic concepts of atoms and molecules.
Download or read book In Pursuit of Highly Accurate Atomic Lifetime Measurements of Multiply Charged Ions written by and published by . This book was released on 2009 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate atomic lifetime data are useful for terrestrial and astrophysical plasma diagnostics. At accuracies higher than those required for these applications, lifetime measurements test atomic structure theory in ways complementary to spectroscopic energy determinations. At the highest level of accuracy, the question arises whether such tests reach the limits of modern theory, a combination of quantum mechanics and QED, adn possibly point to physics beyond the Standard Model. If high-precision atomic lifetime measurements, especially on multiply charged ions, have not quite reached this high accuracy yet, then what is necessary to attain this goal?
Download or read book Atomic Structure 2nd Edition written by Rebecca L. Johnson and published by Twenty-First Century Books. This book was released on 2013-01-01 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is matter made of? Scientists have been trying to answer this question for thousands of years. The concept of the atom—the tiniest fragment of a substance that still retains the characteristics of that substance—goes back to the Greek philosopher Leucippus, who lived in about 450 b.c. In the mid-1600s, Robert Boyle provided experimental evidence that atoms did, indeed, exist. And in 1897, British physicist Joseph John Thomson discovered the first subatomic particle: the electron. Yet even the tiny components of the atom—protons, electrons, and neutrons—are not the smallest things in the universe. Subatomic particles are made up of still tinier objects called quarks and leptons. This book tells the story of how scientists unlocked the secrets of the atom and revolutionized the way we look at the world around us.
Download or read book Measurement of Short Lifetimes in Highly charged Ions Using a Two foil Target written by and published by . This book was released on 1995 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the frontiers in the study of the atomic physics of highly-charged ions is the measurement of lifetimes in the 100 fs to 10 ps regime. The standard technique for measuring lifetimes of states in highly-charged ions is the beam-foil time-of-flight method in which the intensity of an emission line is monitored as a function of the separation between the exciting foil and the portion of the beam being viewed by the detector. This method becomes increasingly difficult as the decay lengths of the states of interest become shorter. At a typical beam velocity of 10% of the speed of light, the beam travels 30 microns in a picosecond. The standard beam-foil time-of-flight method necessitates observation of the decay radiation within one or two decay lengths from the foil while preventing the detectors from observing the beam spot at the foil. For short-lived states this requires tight collimation of the detector with a resulting loss in solid angle. We are developing a method for measuring ultrashort atomic lifetimes utilizing a two-foil target. As a specific case to demonstrate the feasibility of our method, we are studying the decay of the 2 3P2 level in helium-like Kr{sup 34+}. This level has a calculated lifetime of 9.5 ps which corresponds to a decay length of 380 [mu]m. For krypton, theory predicts that 90% of the 2 3P2 states decay via M2 radiation to the ground state. A measurement of the lifetime of this state would contribute to an important current problem which concerns the understanding of atomic structure when both electron correlations and relativistic effects are simultaneously important.
Download or read book Structure and Collisions of Ions and Atoms written by I.A. Sellin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central subject of this volume is the atomic and molecular physics of heavy par ticles as investigated with charged particle accelerators. The natural division be tween atomic structure and ion-atom collision studies, and the similar division be tween the theoretical and experimental branches of these subjects, are reflected in a parallel subdivision into corresponding chapters. In addition, one chapter is de voted to the important interface between atomic and molecular physics with condensed matter physics. A principal aim of the present volume is to provide a compact de scription of a number of current interests and trends within the heavy particle structure and collisions field in a sufficiently general, non-specialized way that interested scientists who wish to become acquainted with such interests and trends can do so without becoming bogged down in excessive archival detail. It is, therefore, hoped that the book will be of some use to advanced students who seek a general in troduction to these subjects. Numerous, more specialized, archival review articles are frequently referred to in each chapter for the benefit of those who seek more detailed knowledge about particular topics discussed. The editor wishes to acknowledge the support of two U. S. government agencies: the Office of Naval Research and the National Science Foundation, during the preparation of this volume. Sincere thanks are due Mrs. Betty Thoe for her excellent editorial work on the various manuscripts and Mrs.
