ISBN: 3540669450
Title: Atom, Molecule, and Cluster Beams I
Author: H. Pauly
TOC:

1. The Role of Molecular Beams in the 20th Century 1
1.1 Historical Development 5
1.1.1 The Work of the School of Otto Stern 5
1.1.2 Molecular Beam Magnetic Resonance 6
1.1.3 Early Work with Fast Molecular Beams 7
1.1.4 Developments in the Second Half of the 20th Century 8
1.2 Main Applications of Molecular Beams . 9
1.2.1 Elastic Scattering .. 10
1.2.2 Inelastic Scattering 11
1.2.3 Reactive Scattering 14
1.2.4 Investigation of Gas-Surface Interactions 14
1.2.5 Determination of Electrical Polarizabilities 16
1.2.6 Cluster Research 17
1.2.7 Slow Atom Beams and Cold Atoms 19
1.3 Thermal Energy Molecular Beam Applications in other Fields 20
1.3.1 Photon Experiments 20
1.3.2 Low Energy Electron and Ion Scattering 22
1.3.3 Plasma Diagnostics 22
1.3.4 Cluster and Nozzle Beams as Targets in High Energy Physics 22
1.3.5 Molecular Beam Epitaxy and Lithography 22
1.4 Fast Beam Applications 23
1.4.1 Plasma Diagnostics with Fast Beams 24
1.4.2 Ionization of Rydberg Atoms in Electric and Magnetic Fields 24
1.4.3 Merged Beams 24
1.5 Examples of Molecular Beam Machines 25
1.5.1 A Universal Scattering Apparatus 26
1.5.2 Requirements for a Scattering Experiment 26
1.5.3 Technical Realization 28
1.5.4 A Molecular Beam Apparatus for Surface Investigations 30
2. Fundamentals of Kinetic Gas Theory 35
2.1 Ideal Gases in Thermodynamic Equilibrium 35
2.1.1 The Maxwellian Velocity Distribution 36
2.1.2 Number of Wall Collisions, Pressure, and Equation of State 38
2.1.3 Mean Free Path, Collision Rates, and Collision Frequencies 40
2.1.4 Rotational State Distribution of Molecules 46
2.1.5 Vibrational State Distribution of Molecules 49
2.1.6 Total Distribution and Partition Function 50
2.1.7 Fraction of Dimers and Degree of Dissociation at Equilibrium 51
2.2 Quantum Statistics 54
2.2.1 Bose Statistics 55
2.2.2 Bose-Einstein Condensation 58
2.3 Molecular Flow Through an Ideal Aperture 60
2.3.1 Particle Flux 61
2.3.2 Particle Number Density 63
2.4 Molecular Flow Through Channels 66
2.4.1 Channels of Circular Cross Section 66
2.4.2 Channels of Noncircular Cross Section 75
2.4.3 Multichannel Arrays 76
3. Fundamental Principles of Gas Dynamics 77
3.1 Some Fundamentals of Thermodynamics 78
3.2 Governing Equations of Steady Flow 80
3.3 One-Dimensional Flow 81
3.3.1 Speed of Sound and Mach Number 81
3.3.2 Flow Through Passages with Changing Cross-Sectional Area 83
3.3.3 Flow Through a Converging-Diverging (Laval) Nozzle 85
3.3.4 Flow Through Converging Nozzles 89
3.3.5 Unsteady Flow, Normal Shock Waves 90
3.4 Two-Dimensional Flow 93
3.4.1 Oblique Shock Waves 93
3.4.2 Planar Supersonic Fltiw over a Symmetrical Wedge 96
3.4.3 Axisymmetric Supersonic Flow over a Cone 97
3.4.4 Prandtl-Meyer Expansion 99
3.4.5 Mach Waves 102
3.4.6 Numerical Techniques and Results 103
3.5 Free-Jet Expansion 105
3.6 The Transition to Nonequilibrium Conditions 111
3.6.1 Collision Cross Sections 111
3.6.2 Collision Rates 113
3.6.3 Terminal Temperature and Speed Ratio 117
3.6.4 Velocity Distribution in Nozzle Beams 120
3.6.5 Intensity of Nozzle Beams 125
3.7 Internal Energy Relaxation 129
3.7.1 Rotational Energy Relaxation 129
3.8 Binary Gas Mixtores 136
3.8.1 Velocity and Temperature Slip 136
3.8.2 Vetocity Slip due to Molecular Orientation 138
3.8.3 Gas Separation 138
3.9 Condensation and Cluster Formation 139
3.9.1 Survey and Concepts of Models 140
3.9.2 Scaling Laws for Cluster Formation 143
3.9.3 Cluster Temperature 146
4. Thermal Energy Molecular Beam Sources 147
4.1 Experimental Requirements 149
4.1.1 Production of Nozzles, Apertures, and Skicomers 149
4.1.2 Pumping Requirements 154
4.1.3 Beam Guidance and Beam Absorption 158
4.2 Gas Sources(4-600 K) 160
4.3 Ovens for Gases and Solids 162
4.3.1 Temperature Range up to 1200 K 162
4.3.2 Temperatures up to 2800 K 165
4.3.3 Sources for Highly Refractory Materials 167
4.4 Laser Ablation 169
4.5 Sputtering Sources 171
4.6 Recirculating Sources and Sources for Special Applications 171
4.6.1 Sources with Internat Shutter 174
4.6.2 Internat Collimation 175
4.7 Sources for Beams of Radicals 176
4.7.1 Pyrolysis 177
4.7.2 Gas Discharges 181
4.7.3 Hollow-Anode Discharges 181
4.7.4 Radiofrequency and Microwave Discharges 182
4.7.5 Corona Discharges 186
4.7.6 Flow Tube Sources 187
4.7.7 Photolysis 189
4.8 Production of Metastable Particles 190
4.8.1 Electron Impact Excitation 190
4.8.2 Gas Discharges 192
4.8.3 Flow Tubes 196
4.8.4 Optical Excitation 197
4.9 Rydberg Atoms 198
4.9.1 Electron Impact Excitation 200
4.9.2 Optical Excitation 200
4.10 Pulsed Beam Sources 201
4.10.1 Comparison between Pulsed and Continuous Beam Sources 202
4.10.2 Production of Pulsed Beams 204
4.10.3 Properties of Pulsed Beams 211
4.11 Sources of Slow and Cold Atoms 213
5. Detection Method 215
5.1 Accumulation Detectors 216
5.1.1 Condensation Targets 216
5.1.2 Microbalances 217
5.1.3 Chemical Targets 219
5.1.4 Radioactivity Detection 219
5.1.5 Semiconducting Detectors 220
5.2 Momentum Detectors 221
5.3 Special Vacuum Gauges 222
5.3.1 Ionization Gauges 223
5.3.2 Thermal Conductivity Gauges (Stern-Pirani Detector) 223
5.3.3 Diaphragm Gauges 224
5.3.4 Space Charge and Electron Impact Excitation Detectors 224
5.4 Surface Ionization (Langmuir-Taylor Detector) 225
5.4.1 Positive Ionization of Atoms 227
5.4.2 Negative Ionization of Atoms 228
5.4.3 Ionization of Molecules 228
5.4.4 Chemical Surface Ionization 230
5.4.5 Practical Design and Operation 230
5.4.6 Response Time of Surfase Ionization 232
5.5 Field Ionization 233
5.5.1 Ground-State Particles 233
5.5.2 Rydberg Atoms 234
5.6 Universal Molecular Beam Detector 235
5.6.1 Detection Limits 236
5.6.2 Electron Impact Ion Sources 237
5.6.3 Mass Spectrometers 240
5.6.4 Ion Detection 256
5.6.5 Detection of Cluster Ions by Secondary Electron Emission 262
5.6.6 Examples of Universal Beam Detectors 265
5.7 Thermal Detectors 269
5.7.1 Time Constant and Responsivity of Semiconductor Bolometers 271
5.7.2 Noise Sources and Detection Limits 274
5.7.3 Cryogenic Bolometers 277
5.7.4 Application in Optothermal Spectroscopy 278
5.7.5 Superconducting Bolometers 279
5.7.6 Pyroelectric Detectors 279
5.8 Detection of Metastable Particles 281
5.8.1 Electron Emission from Surfaces 281
5.8.2 Gas-Phase Penning Ionization 283
5.8.3 Detection by Radiative Decay 283
5.8.4 Detection by Optical Methode 284
5.9 Spectroscopic Detection Methods 284
5.9.1 Conventional Absorption Spectroscopy 285
5.9.2 Laser-Induced Fluorescence 287
5.9.3 Photoionization 295
References 299
Subject Index 339
END
