Swarm Studies And Inelastic Electron Molecule Collisions

This volume presents the contributions of participants in the Symposium on Swarm Studies and Inelastic Electron-Molecule Collisions, held on July 19-23, 1985, in Tahoe City, California. This was a joint meeting of the Fourth International Swarm Seminar and the Electron-Molecule Collisions Symposium which have been traditionally separate satellite symposia to the International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC). In the early stages of planning for these two satellite symposia to the XIVth ICPEAC, a group of us recognized the significant scientific merit and advantages of having a joint symposium. This idea was particularly appealing due to a large mutual interest in important advances (theoretical, experimental, and modeling) in both fields, and because it provides a forum to bring together a single-collision point of view with a multiple-collision one. For example, studies of multiple-term solutions to Boltzmann's equation and their application to swarm systems are intrinsically coupled to the availability of both integral and differential cross-sections for electron-molecule collisions. In tum, experimental and theoretical studies of these electron-molecule scattering cross-sections are becoming quite sophisticated, accurate, and comprehensive. Furthermore, in swarm studies, computational and experimental methods have advanced to the point where detailed and meaningful comparison with, and use of, single-collision beam data is now possible. More over, recent experimental advances in the study of single-collision electron at tachment phenomena have provided a significant overlap with swarm data and extension to subthermal energies.

Electron–molecule collisions have been studied extensively by both experimentalists and theorists since the early years of this century. The past ten years have seen a remarkable renaissance in experimental and theoretical activities in the study of electron collision processes with molecules. This was stimulated (i) by the advent of more powerful computers and new theoretical concepts that allow the study of complex targets and collision processes with a multitude of final states (such as ionization and dissociation) and the investigation of collisions with oriented and aligned molecules, (ii) by advances in experimental instrumentation (improved electron spectrometers, intense sources of spin-polarized electrons, position-sensitive detectors), and (iii) by the discovery of a new class of species, e.g. large stable carbon clusters or “fullerenes”, which opened up a new field of theoretical and experimental research in which collisions involving fullerenes as targets or as projectiles constitute an important component. Lastly, electron–molecule collisions are a key component in efforts to characterize, diagnose, describe and model the complex processes in low-temperature plasmas, which are of ever-increasing importance in many rapidly developing high-tech applications (such as the fabrication of microelectronic chips), in the controlled deposition of thin films and in plasma-assisted surface-modification processes. This book covers the activities in all those areas. Contents:Positive and Negative Ion Formation in Electron Collisions with Fullerenes (S Matt et al.)The Scattering of Low-Energy Electrons and Positrons from Polar Targets: Experimental and Theoretical Difficulties (F A Gianturco & P Paioletti)Spin Effects in Electron Molecule Collisions (G F Hanne)Collisions with Oriented and Aligned Molecules (A Busalla & K Blum)Recent Developments in Electron Momentum Density Measurements of Polyatomics by Molecular (e,2e) Spectroscopy (K T Leung)Electron Impact Dissociative Excitation and Ionization of Molecular Ions (G H Dunn & N Djuric)Electron-Molecule Cross Sections for Plasma Applications: The Role of Internal Energy of the Target (M Capitelli & R Celiberto)Improvements to the “Standard” Complex Kohn Variational Method: Towards the Development of an “R-Matrix Theory without a Box” (T N Rescigno & C W McCurdy) Readership: Students and researchers in atomic and molecular physics. Keywords:

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.

Advances in Atomic and Molecular Physics

This is a comprehensive textbook designed for graduate and advanced undergraduate students. Both authors rely on more than 20 years of teaching experience in renowned Physics Engineering courses to write this book addressing the students’ needs. Kinetics and Spectroscopy of Low Temperature Plasmas derives in a full self-consistent way the electron kinetic theory used to describe low temperature plasmas created in the laboratory with an electrical discharge, and presents the main optical spectroscopic diagnostics used to characterize such plasmas. The chapters with the theoretical contents make use of a deductive approach in which the electron kinetic theory applied to plasmas with basis on the electron Boltzmann equation is derived from the basic concepts of Statistical and Plasma Physics. On the other hand, the main optical spectroscopy diagnostics used to characterize experimentally such plasmas are presented and justified from the point of view of the Atomic and Molecular Physics. Low temperature plasmas (LTP) are partially ionized gases with a broad use in many technological applications such as microelectronics, light sources, lasers, biology and medicine. LTPs lead to the production of atomic and molecular excited states, chemically reactive radicals, and activated surface sites, which are in the origin, among others, of the deposition of thin films, advanced nanotechnology products, solar cells, highly efficient combustion motors, and treatment of cancer cells.

This work studies the relaxation dynamics of molecules in both the gas and liquid phases after strong field ionization, using transient absorption in the soft X-rays. In particular, the thesis presents the first realization of time-resolved X-ray absorption spectroscopy in the spectral water window with a laser-based HHG source. These remarkable experiments were not only performed for isolated molecules, but also in liquids, for which the spectral coverage of the K-edges of C, N, and O are of primary importance for investigating biological molecules. The technique relies on the generation of high-order harmonics to further probe the electronic structure of molecules. Using the atomic selectivity of high energies and the temporal coherence of laser technology, we demonstrate the observation of the first stages of chemical transformation of matter in the gas and liquid phases.