Physics of Ion Impact Phenomena

This book offers a lucid and concise description of contemporary experimental and theoretical progress in the field of ion impact phenomena. New results are combined with a review of essential background material to yield a work that will be equally useful to established reseachers and newcomers to the field.

1. Introduction.- 1.1 The Need to Study Ion Impact Phenomena.- 1.2 Some Contemporary Ion Production Techniques.- 1.2.1 Electron Impact (EI) Sources.- 1.2.2 The Electron Bombardment Ion Source (EBIS).- 1.2.3 The Electron Cyclotron Resonance Ion Source (ECRIS).- 1.2.4 The ‘Ion Hammer’ Technique.- References.- 2. Ion Formation Processes: Ionization in Ion-Electron Collisions.- 2.1 Theoretical Methods.- 2.1.1 The Classical Approach of J. J. Thomson.- 2.1.2 Quantum Mechanical Approaches.- 2.1.3 Predictor Formulae.- 2.1.4 Threshold Behaviour.- 2.2 Ionization Mechanisms.- 2.2.1 Single Ionization.- 2.2.2 Multiple Ionization.- 2.2.3 Summation of Cross Section Contributions.- 2.3 Experimental Approaches.- 2.3.1 Plasma Rate Measurements.- 2.3.2 Trapped-Ion Methods.- 2.3.3 Ion Channeling.- 2.3.4 Crossed-Beams Method.- 2.4 Single Ionization Cross Section Data.- 2.4.1 Hydrogen-like Ions.- 2.4.2 Helium-like Ions.- 2.4.3 Lithium-like Ions.- 2.4.4 Sodium-like Ions.- 2.4.5 Heavy Alkali-like Ions.- 2.4.6 Magnesium-like Ions.- 2.4.7 Isonuclear Sequences.- 2.4.8 Ionization of Heavy Ions.- 2.5 Multiple Ionization Cross Section Data.- 2.5.1 Helium-like Ions.- 2.5.2 The Argon Isonuclear Sequence.- 2.5.3 The Xenon Isonuclear Sequence.- 2.6 A Unified Picture of Ionization.- 2.6.1 Single and Double Ionization of Sb and Bi Ions.- 2.6.2 Single and Multiple Ionization of Heavy Metal Ions.- 2.7 Conclusions.- References.- 3. Ion-Neutral Reactions: Collision Spectrometry of Multiply Charged Ions at Low Energies.- 3.1 Dynamics of Collisions.- 3.2 Theoretical Aspects.- 3.2.1 Landau-Zener Model.- 3.2.2 The Classical Over-Barrier Transition Model.- 3.2.3 Reaction Window.- 3.3 Experimental Techniques.- 3.4 Discussion of Translational Energy Spectrometry.- 3.4.1 State-Selective Single Electron Capture Processes by Ground and Metastable Doubly Charged Ions.- 3.4.2 State-Selective Single Electron Capture by Multiply Charged Ions.- 3.4.3 Multiple Electron Capture by Multiply Charged Ions.- 3.5 Discussion of State-Selective Differential Electron Capture Cross Sections.- References.- 4. Energy Spectrometry of Fine-Structure Transitions in Ion-Atom Collisions.- 4.1 High-Resolution Ion Translational Energy Spectrometry.- 4.1.1 Apparatus.- 4.1.2 Broadening of Line Shape.- 4.2 Fine-Structure Transitions in Ne+, Ar+ and Kr+.- 4.2.1 Translational Energy Spectra.- 4.2.2 Fractional Populations of 2P3/2 and 2P1/2 States.- 4.2.3 Cross Sections for Fine-Structure Transitions in Ne+, Ar+ and Kr+.- 4.3 Excitation and De-excitation Processes in Doubly Charged Rare Gas Ions.- 4.3.1 Translational Energy Spectra.- 4.3.2 Fractional Populations of 3PJ, 1D2 and 1S0.- 4.3.3 Cross Sections for Excitation and De-excitation Among 3P2, 3P1, 3Po, 1D2 and 1S0 States.- 4.4 The Role of Fine-Structure States in Electron Capture Reactions.- 4.4.1 Relative Cross Sections for Reactions in Kr2+(1D2)+Ne.- 4.4.2 Diabatic Potential Energy Curves.- 4.4.3 Landau-Zener Model for Single Crossing.- 4.4.4 Multichannel Landau-Zener Model.- 4.4.5 Landau-Zener Calculation with Weighted Transition Probability.- References.- 5. Probing Interaction Potentials: Small Angle Differential Scattering of H+ and H with He.- 5.1 Experimental Method.- 5.2 Theoretical Considerations.- 5.2.1 Molecular Orbital Expansion Method.- 5.2.2 Potential Scattering.- 5.3 Results and Discussion.- 5.3.1 H-He Direct Scattering.- 5.3.2 H+-He Charge Transfer and Direct Scattering.- 5.4 Summary.- References.- 6. High-Resolution Translational Energy Spectrometry of Molecular Ions.- 6.1 Some Typical Experimental Arrangements.- 6.1.1 Double-Focussing Arrangements.- 6.2 Results and Discussion.- 6.2.1 TES of keV Atomic Ions.- 6.2.2 TES and the Spin-Conservation Rule.- 6.2.3 Doubly Charged Diatomic Molecules.- References.- 7. Molecular Ionization Energies by Double Charge Transfer Spectrometry.- 7.1 Apparatus and Experimental Techniques.- 7.1.1 Double Charge Transfer Spectrometry Prior to 1977.- 7.1.2 Double Charge Transfer Spectrometer Used at Paris.- 7.1.3 Double Charge Transfer Spectrometry at Swansea.- 7.1.4 Double Charge Transfer Spectrometer Used at Bombay.- 7.2 Studies of Electronic States of Doubly Charged Ions.- 7.2.1 Spin Conservation.- 7.2.2 Studies of Small Molecules.- 7.3 Studies of Large Molecules.- 7.3.1 CH3OH.- 7.3.2 SF6.- 7.3.3 CH4.- 7.3.4 Fluoromethanes, Chloromethanes and Bromomethanes.- 7.3.5 Perhalomethanes.- 7.3.6 Fluoroethanes.- 7.4 Reaction Window for Double Electron Capture.- 7.4.1 Endoergicity of DEC Reactions.- 7.4.2 Theoretical Prediction of a Reaction Window.- 7.4.3 Relative Cross Sections for DEC Reactions Measured as a Function of Endoergicity.- 7.4.4 Evidence for a Reaction Window in Collisions Involving the Molecular Target CH3Br.- 7.5 Single Ionization Energies of Radical Species.- 7.5.1 CH3O and CH3S Radicals.- 7.5.2 Mercaptyl Radicals C2H5S and n-C3H7S.- 7.5.3 CF2C1 and CFC12 Radicals.- 7.5.4 The SF5 Radical.- References.- 8. Studies of Multiply Charged Molecules by Ion Collision Techniques and Ab Initio Theoretical Methods.- 8.1 Stability of Multiply Charged Molecular Ions.- 8.1.1 Potential Energy Functions.- 8.1.1 A Qualitative Molecular Orbital Picture of Stability.- 8.2 Contemporary Ion-Impact Methods of Studying Multiply Charged Molecules.- 8.2.1 Translational Energy Spectrometry.- 8.2.2 Transmission of Singly and Doubly Charged Ions Through Electrostatic and Magnetic Fields.- 8.2.3 Charge-Stripping Studies.- 8.2.4 Double Electron Capture.- 8.2.5 Dissociation Studies.- 8.2.6 Excitation (De-excitation) and Electron Capture Reactions.- 8.2.7 Studies Using Forward-Geometry Mass Spectrometers.- 8.2.8 Studies Using High-Energy Accelerators.- 8.2.9 Energy Calibration.- 8.3 Other Experimental Techniques.- 8.3.1 Auger Spectroscopy.- 8.3.2 Photoionization Methods.- 8.3.3 Optical Spectroscopy.- 8.3.4 Electron Impact Experiments.- 8.4 Theoretical Description of Molecular Ions.- 8.4.1 The Schrödinger Equation and the Born-Oppenheimer Approximation.- 8.4.2 Hartree-Fock Theory.- 8.4.3 Electron Correlation.- 8.4.4 Multiconfiguration SCF Method (MCSCF).- 8.4.5 Spin-Coupled Valence Bond Theory.- 8.5 A Glimpse into the Real World of Multiply Charged Molecules: Ambiguities and Controversies.- 8.5.1 Diatomic Ions.- 8.5.2 Triatomic Ions.- 8.5.3 Polyatomic Ions.- References.- 9. Dissociative Recombination in Ion-Electron Collisions: New Directions.- 9.1 New Developments in the Merged Beam Technique.- 9.2 Detection of Highly Excited States.- 9.3 Measurements of Branching Ratios.- 9.4 Recombination Studies at Storage Rings.- 9.5 Heavy Ions.- 9.6 Epilogue.- Ions Fare Ye Well.- References.