Download or read book Recombination of Molecular Positive Ions with Electrons written by M. A. Biondi and published by . This book was released on 1964 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of studies of the recombination of electrons with molecular positive ions are presented. Theoretical arguments indicate that the dissociative process -- in which a molecular ion captures an electron without change of energy, forming an unstable excited molecule which then dissociates -- provides a highly efficient recombination mechanism. The nature of the process responsible for the large recombination rates observed in Laboratory afterglow studies is investigated using combined microwave, optical spectrometric and interferometric, and mass spectrographic techniques. Dissociative recombination is shown to be the process operative in the laboratory studies, since it is found that (a) molecular positive ions must be present to observe a large recombination rate, (b) when diatomic ions are present, excited atoms are formed in the recombination process, and (c) these excited atoms have kinetic energy of dissociation substantially in excess of thermal energy. (Author).
Download or read book ELECTRON ION AND ION ION RECOMBINATION written by Manfred A. Biondi and published by . This book was released on 1963 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information obtained from laboratory experiments and theoretical calculations concerning electron ion and ion-ion recombination processes is re viewed. It is concluded that the two-boc esses of dissociative recombination and radia tive recombination between electrons and positive ions and of mutual neutralization of positive and negative ions are of importance for the iono sphere. Laboratory aferglow measurements on ions of ionospheric interest yield values for the dissociative recombination coefficients. Theoretical calculations yield radiative recom bination values for H(), He(), O() ions and electrons of 4-5 x 10 to the -12th power cc/sec at 250 K and a T(sub e) sup-0.5 dependence on electron temperature. Auxiliary processes affect ing ionospheric recombination, such as electron attachment to O2 molecules, charge transfer both for positive ions and negative ions, and ion conversion, are briefly considered. (Author).
Download or read book The Mobility and Recombination of Positive Rare Gas Ions written by J. M. Madison and published by . This book was released on 1963 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report describes briefly (a) a microwave system for measuring the electron density in decaying plasmas over t density range of about five thousand, (b) an experimental tube for measuring the value of the mobility of positive ions by means of the transit-time method, and (c) the results obtained during the period of the contract. The studies were confined to the rare gas ions and excellent agreement was found between the value of the mobility of atomic and molecular ions as determined from ambipolar diffusion coefficient measurements and those found by means of the ion transit-time method. The influence of the presence of negative ions on the ambipolar diffusion coefficient of electrons was demonstrated. The recombination coefficients of molecular neon and molecular argon ions were found to be independent of pressure and the values were in excellent agreement with previous studies. (Author).
Download or read book Dissociative Recombination written by D. R. Bates and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monte Carlo Calculations of Cross Sections of Electron positive Molecular Ion Dissociative Recombination written by Roger L. Wilkins and published by . This book was released on 1965 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a recent paper, Bauer and Wu proposed a self-consistent model for the application of perturbation theory to calculating the general order of magnitude of cross sections of electron-positive molecular ion dissociative recombination. In applying their model to the calculation on a hypothetical system of electron capture by molecular hydrogen ions, it was necessary to make several approximations, without which it would have been exceedingly difficult to evaluate certain matrix elements. It is shown that Monte Carlo methods can be used for evaluating these matrix elements without restoring to approximations other than the model itself. The Monte Carlo method of stratified sampling has been tested successfully on the capture of electrons by molecular hydrogen ions. The dissociative recombination coefficient is found to be of the order of 3 x 10 to the -8th power cu cm/sec at room temperature, which is in agreement with reported experimental results. (Author).
Download or read book Physics of Ion Ion and Electron Ion Collisions written by F. Brouillard and published by Springer Science & Business Media. This book was released on 2013-11-21 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some of the earliest civilizations regarded the universe as organized around four principles, the four "elements" earth. water, air, and fire. Fire, which was the source of light and as such possessed an immaterial quality related to the spiritual world. was clearly the most impressive of these elements, although its quanti tative importance could not have been properly discerned. M- ern science has changed the names, but macroscopic matter is still divided into four states. The solid, liquid, and gaseous states are ordinary states, but the fourth state of matter, the plasma state, has retained a somewhat extraordinary character. It is now recognized that most of the matter of the universe is in the ionized state. but on the earth. the plasma state is still the exception. Hence the importance and also the difficulty of investigations dealing with ionized matter, which have been greatly furthered by the development of thermonuclear fusion research. The study of matter in the ionized state comprises a large diversity of problems belonging to many different branches of phys ics. A number of them relate to the microscopic properties of plasmas and concern the structure and the collisional behavior of atomic constituents. Although they are clearly of basic importance, their relevance to thermonuclear research was at first overlooked, at a time when most of the effort was concentrated on designing fusion devices and understanding macroscopic phenomena, mostly of an electromagnetic nature. At present.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1970 with total page 1532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissociative Recombination written by Bertrand R. Rowe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a NATO ARW held in Saint Jacut de la Mer, Brittany, France, May 3-8, 1992
Download or read book Electron Molecule Interactions and Their Applications written by L Christophorou and published by Elsevier. This book was released on 2012-12-02 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron-Molecule Interactions and Their Applications, Volume 1 presents a comprehensive account of electron-molecule interactions in high- and ultra-high-pressure gases and liquids. Topics covered include elastic scattering of electrons by molecules; excitation, ionization, and dissociation of molecules by electron impact; electron-molecule resonances; and electron attachment and detachment processes. This volume is comprised of seven chapters and begins with a discussion on non-resonant elastic scattering and rotational excitation of molecules by electrons, followed by a review of non-resonant vibrational and electronic excitation. The reader is then introduced to resonance effects in electron scattering; electron-induced ionization and dissociation of molecules; and electron-molecule resonances. The ionization mechanisms and types of ions produced are highlighted, along with differential ionization cross sections. The final two chapters focus on electron attachment and detachment processes, paying particular attention to modes of electron capture by molecules such as via negative-ion resonant states. The collisional dynamics for a few selected atomic reactants are also described. Physicists will find this book extremely helpful.
Download or read book Advances in Atomic and Molecular Physics written by and published by Academic Press. This book was released on 1970-09-30 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Atomic and Molecular Physics
Download or read book Atomic Physics of Highly Charged Ions written by Erhard Salzborn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the invited lectures and contributed papers presented at the V International Conference on the Physics of Highly Charged Ions, which was held at the lustus-Liebig-Universi tat Giessen, 10-14 September 1990. This conference was the ftfth in a series -after Stockholm (1982), Oxford (1984), Groningen (1986) and Grenoble (1988) -to deal with a rapidly growing fteld, which comprises the spectroscopy of highly charged ions and their interactions with photons, electrons, atoms, ions, and solids. Most of the matter of the universe is in the ionized state. Investigations dealing with hot plasmas on earth have been greatly furthered by thermonuclear-fusion research. The increasing maturity of this programme has revealed the fundamental role of highly charged ions in fusion plasmas. Today, it is clear that a detailed knowledge of the production mechanisms of highly charged ions and their interactions with other plasma constituents is an important prerequisite for a better understanding of the microscopic and macroscopic plasma properties. The study of highly charged ions involves various branches of physics. It was the aim of the conference to bring together physicists working in atomic collisions and spectroscopy, in plasma physics and astrophysics, as well as in solid-state and ion-source physics. About 220 scientists from 20 nations attended the conference, indicating the strong worldwide interest and the vital ity of research in this fteld.
Download or read book Instrumentation for the Detection and Determination of Pesticides and their Residues in Foods written by Los Angeles Meetings of the American Chemical Society and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The object of "Residue Reviews" is to provide concise, critical reviews of timely advances, philosophy, and significant areas of accomplished or needed endeavor in the total field of residues of pesticide and certain other chemicals in foods, feeds, and in transformed food products. During the 144th National Meetings of the American Chemical Society in Los Angeles, California the Pesticides Subdivision of the A. C. S. Division of Agricultural and Food Chemistry on April 1, 1963 sponsored a symposium "Instrumen tation for the Detection and Determination of Pesticides and Their Residues in Foods". With special permission from R. N. HADER and his associates in the American Chemical Society, that symposium is reproduced in this volume of "Residue Reviews" because of its timeliness and significance to pesticide residue analysts everywhere. Without exception the symposium authors accepted my invitation to utilize "Residue Reviews" as their publication medium, and their coopera tion in the extra chore of providing manuscripts conforming to the style requirements of "Residue Reviews" is gratefully acknowledged. Presiding over the two sessions of the symposium were CHARLES L. DUNN and MILTON S. SCHECHTER, whose introductory remarks at that time comprise the foreword to this volume; their enthusiastic assistance both in organizing the symposium and in achieving this final product is warmly appreciated. F. A. G.
Download or read book Electron Molecule Interactions and Their Applications written by L. G. Christophorou and published by Academic Press. This book was released on 2013-10-22 with total page 695 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron-Molecule Interactions and Their Applications, Volume 2 provides a balanced and comprehensive account of electron-molecule interactions in dilute and dense gases and liquid media. This book consists of six chapters. Chapter 1 deals with electron transfer reactions, while Chapter 2 discusses electron-molecular positive-ion recombination. The electron motion in high-pressure gases and electron-molecule interactions from single- to multiple-collision conditions is deliberated in Chapter 3. In Chapter 4, knowledge on electron-molecule interactions in gases is linked to that on similar processes in the liquid state. Selected examples on the translation of the results of basic research on electron-molecule interactions to application are reviewed in Chapter 5. The last chapter covers the electron affinity of molecules, atoms, and radicals. This volume is a good reference for students and researchers conducting work on the intricate ways electrons and molecules interact in their encounters.
Download or read book Atomic And Molecular Physics Proceedings Of The 3rd Us mexico Symposium written by C Cisneros and published by World Scientific. This book was released on 1991-12-31 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Third US/Mexico Symposium on Atomic and Molecular Physics brought together forty-five leading investigators in many fields. Both theory and experiment were well represented. The papers in this volume are based on the participants' invited talks at the symposium and represent an important collection reviewing the most up-to-date work in the different fields. The diversity of research areas represented, coupled to a common local point, revealed different perspectives on such questions as: How do particles depend on one another? Correlation provides a good starting point, but are there other useful conceptual approaches which will yield a new view of the phenomena and a more complete understanding?The contributions in this volume provide different perspectives and bring together a collection of papers which serve as a basis for further progress in this field.
Download or read book Physics of Microwave Discharges written by A Gurevich and published by Routledge. This book was released on 2018-12-19 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and unique account of the creation of artificially ionized layers in the middle and upper atmosphere, using powerful radio waves. Major physical mechanisms associated with the formation of the ionized region are studied in detail. The main part of the author's research is devoted to problems associated with the breakdown mechanisms for radio frequency discharges in air. A special chapter deals with breakdown in intersecting pulsed beams and the effects of recombination, diffusion and atmospheric winds on the stability of the structure. The kinetics of the plasma produced are also described. The authors examine possibilities of inducing changes in the chemical composition of the upper atmosphere by means of radio frequence heating, with promising effects on the concentration of constituents such as ozone. The feasibility of using this phenomenon for; ozone healing - in connection with the ozone holes in the polar regions is investigated. The text is a timely treatment of key topics in the field of ionospheric modification.
Download or read book Advances in Electronics and Electron Physics written by and published by Academic Press. This book was released on 1963-01-01 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Electronics and Electron Physics
