Atom, Molecule, and Cluster Beams

A reference and graduate level textbook presenting an up-to-date review of the indespensible equipment in molecular beam experiments. Discusses hyperthermal and subthermal techniques, as well as outlining the theoretical foundations of the various experimental techniques. Part two of a two volume set.

1. Fast Beams, Production and Detection 1
1.1 Charge Exchange 4
1.1.1 Ground-State Particles 6
1.1.2 Metastable Particles 13
1.1.3 Rydberg Atoms 17
1.2 Neutralization of Negative Ions by Electron Detachment 18
1.2.1 Photodetachment 18
1.2.2 Collisional Detachment 21
1.2.3 Autodetachment 21
1.3 Neutralization of Ions by Collisions with Metal Surfaces 22
1.4 Aerodynamic Acceleration 24
1.5 Plasma and Gas Discharge Sources 29
1.5.1 Arc-Heated Jet Sources 29
1.5.2 Radiofrequency Discharges 34
1.5.3 Laser-Sustained Plasmas 34
1.5.4 Hollow Cathode Discharges 37
1.5.5 Corona Discharges 37
1.5.6 Glow Discharges 37
1.6 Laser Ablation 39
1.7 Sputtering 42
1.8 Photolysis 48
1.8.1 Beam Experiments 48
1.8.2 Gas-Phase Measurements 49
1.8.3 Oriented Reactants 49
1.9 Electron-Stimulated Resorption 50
1.10 Other Methods 51
1.10.1 Mechanical Acceleration 51
1.10.2 Shock Waves 52
1.10.3 Recoil Nuclei of Radioactive Decays 52
1.11 Some Examples of Fast Beam Applications 53
1.11.1 Coaxial Laser Spectroscopy with Fast Teams 53
1.11.2 Photofragment Translational Spectroscopy 56
1.11.3 Precision Measurements of Lifetimes 57
1.11.4 Merged Beams 59
1.11.5 Injection of Fast Beams into Fusion Plasmas 62
1.11.6 Fast Beam Methods for Plasma Diagnostics 63
1.12 Fast Beam Detection 65
1.12.1 Surface Ionization (Langmuir-Taylor Detector) 65
1.12.2 Solometer and Pyroelectric Detectors 67
1.12.3 Laser-Induced Fluorescence 68
1.12.4 Secondary Electron Emission 68
1.12.5 Collision-Induced Fluorescence 69
2. Production and Diagnostics of Cluster Beams 71
2.1 Survey of Methods for Cluster Formation 75
2.2 Supersonic Jets 77
2.2.1 Influence of Nozzle Shape 78
2.2.2 Influence of Carrier Gases 80
2.2.3 Technical Realization of Cluster Sources 81
2.3 Gas Aggregation 82
2.4 Surface Erosion 85
2.4.1 Sputtering 6
2.4.2 Laser Ablation 87
2.4.3 Pulsed Arc Discharges 89
2.4.4 Liquid Metal Ion Sources (LMIS) 91
2.5 Laser-Induced Pyrolysis 92
2.5.1 Multiphoton Infrared Dissociation and Photosensitization 93
2.5.2 Source Design and Applications 95
2.6 Doping of Clusters and Production of Mixed Clusters 96
2.6.1 Formation of Mixed Clusters by Coexpansion 97
2.6.2 Gas Aggregation 97
2.6.3 Particle Capture ("Pick-up" Sources) 97
2.6.4 Cluster Aggregation 99
2.6.5 Laser Ablation 100
2.6.6 Pulsed Arc Discharges 101
2.7 Generation of Excited Clusters 101
2.8 Determination of Size Distributions in Cluster Beams 102
2.8.1 Electron Diffraction 102
2.8.2 Light Scattering 105
2.8.3 Gas Scattering 107
2.8.4 Atom Diffraction 120
2.8.5 Mass Spectrometric Methods 122
2.8.6 Other Methods 125
2.9 Some Cluster Applications 132
2.9.1 Cluster Beam Deposition 132
2.9.2 Cluster Impact Lithography 133
2.9.3 Examples of Experimental Results 134
2.9.4 Cluster Beams in High Energy Physics 136
3. Velocity Measurement and Selection 137
3.1 Mechanical Selectors 138
3.1.1 Slotted Disk Velocity Selector (Fizeau Principle) 139
3.1.2 Calibration 150
3.1.3 Special Designs 152
3.1.4 Slotted Cylinder Velocity Selector 153
3.1.5 Other Designs 154
3.2 Time-of-Flight Methods 156
3.2.1 Resolution and Methods of Deconvolution 157
3.2.2 Cross-Correlation Method 161
3.2.3 Experimental Details 164
3.2.4 Calibration 169
3.3 Doppler Shift Measurements 171
3.3.1 Experimental Technique and Resolution 172
3.3.2 Measurements of Differential Scattering Cross Sections 175
3.4 Deflection in Inhomogeneous Magnetic Fields 177
3.4.1 Two-Wire Field 178
3.4.2 Magnetic Hexapole Fields 184
3.5 Deflection by Gravity 191
3.6 Determination of the de Broglie Wavelength 193
3.6.1 Diffraction from Crystal Surfaces 193
3.6.2 Diffraction from Transmission Gratings 195
3.7 Beam Deflection by Photon Recoil 195
4. State Selection 197
4.1 Potentials of Cylinder-Symmetric and Planar Fields 199
4.1.1 Monopole Field 200
4.1.2 Multipole Fields 201
4.1.3 Two-Dimensional, Periodic Fields 202
4.2 Deflection in Inhomogeneous Magnetic Fields 204
4.2.1 Effective Magnetic Dipole Moment of Atoms 204
4.2.2 Two-Wire Field (Rabi Field) 206
4.2.3 Quadrupole Sector Field 211
4.2.4 Two-Pole Field 213
4.2.5 Multipole Fields 213
4.3 Deflection in Inhomogeneous Electrostatic Fields 220
4.3.1 Effective Electric Dipole Moment of Molecules 221
4.3.2 Rabi and Two-Pole Fields 222
4.3.3 Electrostatic Multipole Fields 224
4.3.4 Other Fields 230
4.4 Magnetostatic and Electrostatic Traps 230
4.4.1 Three-Dimensional Quadrupole Fields 232
4.4.2 Ioffe Trap 233
4.5 Nonadiabatic (Majorana) Transitions 234
4.6 Technical Details 235
4.7 Applications of State Selection by Inhomogeneous Fields 240
4.7.1 Molecular Beam Magnetic and Electric Resonance Method 240
4.7.2 Cesium Frequency and Time Standard 242
4.7.3 Atomic and Molecular Collisions 244
4.7.4 Cluster Investigations 247
4.7.5 Atomic Polarizabilities 248
4.7.6 State Analysis 249
4.7.7 Gas-Surface Interaction 249
4.7.8 Miscellaneous Applications 250
4.8 Optical Methods for State Selection 251
4.8.1 Optical Pumping 252
4.8.2 Selective State Depopulation 252
4.8.3 Selective Population of an Atomic State 254
4.8.4 Selective Population of a Molecular State 255
4.8.5 Two-Photon Processes 257
4.8.6 Photodissociation 260
4.8.7 State Selection m Excited States 260
4.8.8 Stimulated Raman Adiabatic Passage (STIRAP) 263
5. Slow Atom Beams, Traps, and Atom Optics 267
5.1 Radiation Pressure Forces 268
5.1.1 Photon Recoil Force 269
5.1.2 Optical Dipole Force 271
5.1.3 Optical Beam Slowing by Photon Recoil 273
5.1.4 Atomic Beam Deflection by Photon Recoil 278
5.2 Trapping and Cooling of Atoms 282
5.2.1 Optical Molasses and Cooling Mechanisms 282
5.2.2 Atom Traps 284
5.2.3 Atom Traps as Sources for Slow and Cold Atoms 287
5.2.4 Methods of Beam Compression 289
5.3 Examples of Applications 291
5.3.1 Precision Spectroscopy and Frequency Standards 291
5.3.2 Atomic Collision Processes 292
5.3.3 Bose-Einstein Condensation 293
5.3.4 Photoassociative Spectroscopy 295
5.3.5 Atom Lithography 297
5.4 Atom Optics 298
5.4.1 Atom-Optical Elements 299
5.4.2 Lenses 300
5.4.3 Mirrors 303
5.4.4 Atom Waveguides 308
5.4.5 Diffraction Gratings 309
5.4.6 Prisms 315
5.5 Atom Interferometry 316
5.5.1 A Mach-Zehnder Interferometer 317
5.5.2 Some Experimental Results 318
References 323
Subject Index 369
Conversion Factors for Pressure and Energy Units 375