Resonance Phenomena in Electron-Atom Collisions

Scattering of electrons by atoms and atomic ions probes one of the most ubiquitous interparticle interactions. The book is of interest to everyone working in rarefied media (plasma physics, quantum chemistry, astrophysics). It includes a detailed, graduate-level exposition of the theory and a comprehensive review of recent experimental results.

Texte du rabat

Depending on the energy of the collision, the scattering of electrons by atoms or atomic ions is the fundamental process in plasma physics, in laser cavities, nuclear fusion reactions, quantum chemistry, astrophysics and the physics of the upper atmosphere. The positions and intensities of resonances yield information on the formation of quasi-stationary autoionizing states. The first two-thirds of this text is devoted to a detailed exposition of the methods of calculating such scattering resonances, introducing a simplified Feshback diagonalization method. Comparisons to other calculational techniques are brought throughout. The final third is a comprehensive review of electron scattering experiments, with data on hydrogen, the alkalis, group II elements, and rare gases (both neutral atoms and atomic cations). The text is written for readers with graduate level experience.

Contenu

1. Introduction.- 1.1 General Overview.- 1.2 Scope of the Book.- 2. Scattering by a Potential Field.- 2.1 Formulation of the Problem.- 2.2 Solution of the Schrödinger Equation for Potential Scattering.- 2.3 The Radial Schrödinger Equation.- 2.4 Numerical Methods for the Solution of the Schrödinger Equation.- 2.5 Resonances.- 3. Collisions Between an Electron and a Composite Target.- 3.1 Static Potential Approximation.- 3.2 Radial Equation for Elastic Scattering.- 3.3 Inelastic Scattering. The Distorted-Wave Approximation.- 3.4 Close-Coupling Method.- 3.5 Total Angular Momentum Representation.- 3.6 Two-State Approximation Within the Close-Coupling Method.- 4. Single-Channel Theory of Resonance Scattering.- 4.1 Closed-Channel Resonances. Fano's Theory.- 4.2 Resonances in the Close-Coupling Method.- 4.3 Autoionizing States of Two-Electron Systems.- 5. Diagonalization Method.- 5.1 Basic Ansatz.- 5.2 Radial Equations.- 5.3 Example: Resonances in Elastic Electron Scattering by Helium Ions.- 6. Multichannel Resonance Scattering of Electrons by Complex Atoms.- 6.1 Complex-Atom Wave Functions.- 6.2 Initial System of Equations.- 6.3 Diagonalization Method Solution.- 6.4 Elastic Electron Scattering by Ions with Zero Orbital Angular Momentum in Their Ground State.- 6.5 Resonance Excitation of np 2P0 and Metastable ns 2S States of Ions with Ground State Zero Angular Momentum.- 7. Survey of the Experimental and Theoretical Results.- 7.1 Experimental Techniques.- 7.2 Hydrogen Atom.- 7.3 Helium Atom.- 7.4 Helium Ion.- 7.5 Alkali Metal Atoms.- 7.6 Alkaline-Earth and Alkali Ions.- 7.7 Group II Atoms.- 7.8 Polarization Effects in Scattering.- 8. Conclusion.- References.