Nonlinear MHD Waves and Turbulence (Lecture Notes in Physics 636)

chap-01.pdf......Page 1
chap-07.pdf......Page 0
1 Introduction......Page 6
1.1 Noble Gas Solids......Page 7
1.2 Motivations for Phonon and Defect Studies in Solid He......Page 10
1.3 Theoretical Models......Page 11
2 Coherent Scattering Studies......Page 12
2.1 Debye–Waller Measurements......Page 14
2.2 Comparison to PIMC Computations......Page 17
3 Inelastic Scattering......Page 20
3.1 Neutron Studies of Phonons in Helium......Page 23
3.2 High–Resolution X–Ray Inelastic Studies......Page 25
4 Equilibrium Defects......Page 30
4.1 Some Definitions and Relations......Page 31
4.2 Direct Measurement of Net Vacancy Content......Page 33
4.3 Inferred Activation Energies and Volumes for Vacancies......Page 34
4.4 Defects and Isotopic Mixtures Are a Zoological Garden......Page 36
References......Page 38
1 Introduction......Page 42
2 Theory of Bragg and Diffuse Scattering of a Double-Beam of Neutrons from Condensed Matter......Page 46
3 The Bragg and Diffuse Scattering Structure Functions......Page 53
4 Crystallographic Symmetries in the Bragg and Diffuse Scattering Structure Functions......Page 59
5 Bragg and Diffuse Scattering in X-Ray Difraction of a Double-Beam from Condensed Matter......Page 63
6 Summary and Future Prospects......Page 69
References......Page 71
1 Introduction......Page 73
2 Molecular Dynamics Simulations of Crystals......Page 74
2.1 MD for Arbitrary Parallelepiped Simulation Cells......Page 75
2.2 MD Below the Debye Temperature......Page 76
3 Quantum E.ects in alpha-Quartz......Page 77
4 The Structure of beta-Quartz......Page 80
4.1 Non-gaussian Disorder in beta-Quartz......Page 81
4.2 Implications for Quasi-harmonic Treatments......Page 87
4.3 Nature of the alpha-beta Phase Transition......Page 88
5 Mechanical Stability of Quartz-I and Quartz-II......Page 94
References......Page 96
1 Introduction......Page 99
2 Simulation Models......Page 100
3 Theoretical Approaches......Page 101
4 Surface Anchoring Coeffcient......Page 102
5 Nematic-Isotropic Interface......Page 106
5.1 Orientational Order and Density Profiles......Page 107
5.2 Surface Tension......Page 109
5.3 Capillary Waves......Page 112
6 Disclination in Cylindrical Pores......Page 113
7 Defects near a Colloid Particle......Page 117
7.1 Saturn Ring Defect......Page 118
7.2 Satellite Defect......Page 120
7.4 Non-spherical Colloidal Particle......Page 122
8 Conclusions......Page 125
References......Page 127
1 Disorder......Page 130
2 Basic Diffraction Theory......Page 135
2.1 Elementary Formulae......Page 136
2.2 Average Structure, Structural Fluctuations......Page 137
2.3 Disorder Without Average Structure (Disorder of 2nd Kind)......Page 139
3.1 Domains......Page 140
3.2 Diffraction by Domains......Page 142
3.3 Basic Domain Structures......Page 143
4.1 General Remarks......Page 146
4.2 Qualitative Consideration......Page 147
4.3 Quantitative Treatments......Page 150
5.1 Aperiodic Order......Page 154
5.2 Disordered Aperiodic Structures......Page 156
5.3 Diffraction of Disordered Quasicrystals......Page 158
References......Page 162
1 Why Neutrons?......Page 164
2 Scattering and Correlation......Page 165
4 Applications......Page 170
4.1 Collective Excitations, Phonons – The THz-Regime......Page 172
4.2 Diffusion – Between GHz and THz......Page 178
4.3 Molecular Rotations, Tunnelling – The GHz-Regime......Page 183
4.4 Polymer Dynamics – Between MHz and GHz......Page 186
4.5 Kinetic Studies – Real-Time Experiments......Page 189
References......Page 192