Atom, Molecule, and Cluster Beams I: Basic Theory, Production and Detection of Thermal Energy Beams

ISBN-13: 9783642086236 / Angielski / Miękka / 2010 / 344 str.

Hans Pauly

Opis

A consistent, up-to-date description of the extremely manifold and varied experimental techniques which nowadays enable work with neutral particles. Th book lays the physical foundations of the various experimental techniques, which utilize methods from most fields in physics.

Spis treści

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.