Atom, Molecule, and Cluster Beams I

1. The Role of Molecular Beams in the 20th Century.- 1.1 Historical Development.- 1.1.1 The Work of the School of Otto Stem.- 1.1.2 Molecular Beam Magnetic Resonance.- 1.1.3 Early Work with Fast Molecular Beams.- 1.1.4 Developments in the Second Half of the 20th Century.- 1.2 Main Applications of Molecular Beams.- 1.2.1 Elastic Scattering.- 1.2.2 Inelastic Scattering.- 1.2.3 Reactive Scattering.- 1.2.4 Investigation of Gas—Surface Interactions.- 1.2.5 Determination of Electrical Polarizabilities.- 1.2.6 Cluster Research.- 1.2.7 Slow Atom Beams and Cold Atoms.- 1.3 Thermal Energy Molecular Beam Applications in other Fields.- 1.3.1 Photon Experiments.- 1.3.2 Low Energy Electron and Ion Scattering.- 1.3.3 Plasma Diagnostics.- 1.3.4 Cluster and Nozzle Beams as Targets in High Energy Physics.- 1.3.5 Molecular Beam Epitaxy and Lithography.- 1.4 Fast Beam Applications.- 1.4.1 Plasma Diagnostics with Fast Beams.- 1.4.2 Ionization of Rydberg Atoms in Electric and Magnetic Fields.- 1.4.3 Merged Beams.- 1.5 Examples of Molecular Beam Machines.- 1.5.1 A Universal Scattering Apparatus.- 1.5.2 Requirements for a Scattering Experiment.- 1.5.3 Technical Realization.- 1.5.4 A Molecular Beam Apparatus for Surface Investigations.- 2. Fundamentals of Kinetic Gas Theory.- 2.1 Ideal Gases in Thermodynamic Equilibrium.- 2.1.1 The Maxwellian Velocity Distribution.- 2.1.2 Number of Wall Collisions, Pressure, and Equation of State.- 2.1.3 Mean Free Path, Collision Rates, and Collision Frequencies.- 2.1.4 Rotational State Distribution of Molecules.- 2.1.5 Vibrational State Distribution of Molecules.- 2.1.6 Total Distribution and Partition Function.- 2.1.7 Fraction of Dimers and Degree of Dissociation at Equilibrium.- 2.2 Quantum Statistics.- 2.2.1 Bose Statistics.- 2.2.2 Bose—Einstein Condensation.- 2.3 Molecular Flow Through an Ideal Aperture.- 2.3.1 Particle Flux.- 2.3.2 Particle Number Density.- 2.4 Molecular Flow Through Channels.- 2.4.1 Channels of Circular Cross Section.- 2.4.2 Channels of Noncircular Cross Section.- 2.4.3 Multichannel Arrays.- 3. Fundamental Principles of Gas Dynamics.- 3.1 Some Fundamentals of Thermodynamics.- 3.2 Governing Equations of Steady Flow.- 3.3 One-Dimensional Flow.- 3.3.1 Speed of Sound and Mach Number.- 3.3.2 Flow Through Passages with Changing Cross-Sectional Area.- 3.3.3 Flow Through a Converging—Diverging (Laval) Nozzle.- 3.3.4 Flow Through Converging Nozzles.- 3.3.5 Unsteady Flow, Normal Shock Waves.- 3.4 Two-Dimensional Flow.- 3.4.1 Oblique Shock Waves.- 3.4.2 Planar Supersonic Flow over a Symmetrical Wedge.- 3.4.3 Axisymmetric Supersonic Flow over a Cone.- 3.4.4 Prandtl—Meyer Expansion.- 3.4.5 Mach Waves.- 3.4.6 Numerical Techniques and Results.- 3.5 Free-Jet Expansion.- 3.6 The Transition to Nonequilibrium Conditions.- 3.6.1 Collision Cross Sections.- 3.6.2 Collision Rates.- 3.6.3 Terminal Temperature and Speed Ratio.- 3.6.4 Velocity Distribution in Nozzle Beams.- 3.6.5 Intensity of Nozzle Beams.- 3.7 Internal Energy Relaxation.- 3.7.1 Rotational Energy Relaxation.- 3.8 Binary Gas Mixtures.- 3.8.1 Velocity and Temperature Slip.- 3.8.2 Velocity Slip due to Molecular Orientation.- 3.8.3 Gas Separation.- 3.9 Condensation and Cluster Formation.- 3.9.1 Survey and Concepts of Models.- 3.9.2 Scaling Laws for Cluster Formation.- 3.9.3 Cluster Temperature.- 4. Thermal Energy Molecular Beam Sources.- 4.1 Experimental Requirements.- 4.1.1 Production of Nozzles, Apertures, and Skimmers.- 4.1.2 Pumping Requirements.- 4.1.3 Beam Guidance and Beam Absorption.- 4.2 Gas Sources (4–600 K).- 4.3 Ovens for Gases and Solids.- 4.3.1 Temperature Range up to 1200 K.- 4.3.2 Temperatures up to 2800 K.- 4.3.3 Sources for Highly Refractory Materials.- 4.4 Laser Ablation.- 4.5 Sputtering Sources.- 4.6 Recirculating Sources and Sources for Special Applications.- 4.6.1 Sources with Internal Shutter.- 4.6.2 Internal Collimation.- 4.7 Sources for Beams of Radicals.- 4.7.1 Pyrolysis.- 4.7.2 Gas Discharges.- 4.7.3 Hollow-Anode Discharges.- 4.7.4 Radiofrequency and Microwave Discharges.- 4.7.5 Corona Discharges.- 4.7.6 Flow Tube Sources.- 4.7.7 Photolysis.- 4.8 Production of Metastable Particles.- 4.8.1 Electron Impact Excitation.- 4.8.2 Gas Discharges.- 4.8.3 Flow Tubes.- 4.8.4 Optical Excitation.- 4.9 Rydberg Atoms.- 4.9.1 Electron Impact Excitation.- 4.9.2 Optical Excitation.- 4.10 Pulsed Beam Sources.- 4.10.1 Comparison between Pulsed and Continuous Beam Sources.- 4.10.2 Production of Pulsed Beams.- 4.10.3 Properties of Pulsed Beams.- 4.11 Sources of Slow and Cold Atoms.- 5. Detection Methods.- 5.1 Accumulation Detectors.- 5.1.1 Condensation Targets.- 5.1.2 Microbalances.- 5.1.3 Chemical Targets.- 5.1.4 Radioactivity Detection.- 5.1.5 Semiconducting Detectors.- 5.2 Momentum Detectors.- 5.3 Special Vacuum Gauges.- 5.3.1 Ionization Gauges.- 5.3.2 Thermal Conductivity Gauges (Stern—Pirani Detector).- 5.3.3 Diaphragm Gauges.- 5.3.4 Space Charge and Electron Impact Excitation Detectors.- 5.4 Surface Ionization (Langmuir—Taylor Detector).- 5.4.1 Positive Ionization of Atoms.- 5.4.2 Negative Ionization of Atoms.- 5.4.3 Ionization of Molecules.- 5.4.4 Chemical Surface Ionization.- 5.4.5 Practical Design and Operation.- 5.4.6 Response Time of Surface Ionization.- 5.5 Field Ionization.- 5.5.1 Ground-State Particles.- 5.5.2 Rydberg Atoms.- 5.6 Universal Molecular Beam Detector.- 5.6.1 Detection Limits.- 5.6.2 Electron Impact Ion Sources.- 5.6.3 Mass Spectrometers.- 5.6.4 Ion Detection.- 5.6.5 Detection of Cluster Ions by Secondary Electron Emission.- 5.6.6 Examples of Universal Beam Detectors.- 5.7 Thermal Detectors.- 5.7.1 Time Constant and Responsivity of Semiconductor Bolometers.- 5.7.2 Noise Sources and Detection Limits.- 5.7.3 Cryogenic Bolometers.- 5.7.4 Application in Optothermal Spectroscopy.- 5.7.5 Superconducting Bolometers.- 5.7.6 Pyroelectric Detectors.- 5.8 Detection of Metastable Particles.- 5.8.1 Electron Emission from Surfaces.- 5.8.2 Gas-Phase Penning Ionization.- 5.8.3 Detection by Radiative Decay.- 5.8.4 Detection by Optical Methods.- 5.9 Spectroscopic Detection Methods.- 5.9.1 Conventional Absorption Spectroscopy.- 5.9.2 Laser-Induced Fluorescence.- 5.9.3 Photoionization.- References.