Atomic and Nuclear Physics: An Introduction

After the death of Dr. Littlefield it was decided that I should undertake the revision ofthe whole of Atomic and Nuclear Physics: an Introduction for the third edition, and it was soon apparent that major changes were necessary. I am confident that these changes would have had Dr. Littlefield's approval. The prime consideration for the present edition has been to modernize at a minimum cost. As much as possible of the second edition has therefore been retained, but where changes have been made they have been fairly drastic. Thus the chapters on fine structure, wave mechanics, the vector model of the atom, Pauli's principle and the Zeeman effect have been completely restructured. The chapters on nuclear models, cosmic rays, fusion systems and fundamental particles have been brought up to date while a new chapter on charm and the latest ideas on quarks has been included. It is hoped that the presentation of the last named will give readers a feeling that physics research can be full of adventure and surprises.

1 Kinetic Theory.- 1.1 The Atom in History.- 1.2 Brownian Motion.- 1.3 Basic Assumptions of Kinetic Theory.- 1.4 Pressure of a Gas.- 1.5 Molecular Velocities.- 1.6 Temperature of a Gas: Avogadro’s Hypothesis.- 1.7 Mean Free Path.- 1.8 Thermal Conductivity and Viscosity.- 1.9 Specific Heat Capacities.- 1.10 Atomicity.- 1.11 Molar Heat Capacities.- 1.12 Van der Waals’ Equation.- 1.13 Molecular Sizes.- 1.14 Summary.- 2 The Electron.- 2.1 Electrical Conduction in Solutions.- 2.2 Conduction in Gases.- 2.3 Properties of Cathode Rays.- 2.4 Thomson’s Method for Measuring Charge per Unit Mass (e/m).- 2.5 Dunnington’s Method for e/m.- 2.6 Charge on the Electron.- 3 Natural Radioactivity.- 3.1 Introduction.- 3.2 e/m for ?-Rays.- 3.3 Bucherer’s Method for e/m of ?-Rays.- 3.4 The Charge-Mass Ratio (E/M) for ?-Rays.- 3.5 Charge on ?-Particles.- 3.6 Identification of ?-Particles.- 3.7 Early Models of the Atom.- 3.8 The Scattering of ?-Particles.- 3.9 Estimates of Nuclear Diameter and Charge.- 3.10 The Neutron.- 4 Radioactive Series and Isotopes.- 4.1 Introduction.- 4.2 Equation of Radioactive Decay.- 4.3 Mean Lifetime of Radioactive Substance.- 4.4 Half-Lives of Radioactive Substances.- 4.5 Radioactive Series.- 4.6 Radioactive Equilibrium.- 4.7 Isotopes.- 4.8 The Bainbridge Mass Spectrograph.- 5 The Electromagnetic Spectrum.- 5.1 Theories of Light.- 5.2 Interference.- 5.3 Diffraction.- 5.4 Spectra.- 5.5 The Electromagnetic Theory.- 5.6 Hertz’s Experiment.- 5.7 The Electromagnetic Spectrum.- 6 Quantum Theory.- 6.1 The Continuous Spectrum.- 6.2 Planck’s Quantum Theory.- 6.3 The Photoelectric Effect.- 6.4 Einstein’s Equation.- 6.5 The Discovery of X-Rays.- 6.6 Diffraction of X-Rays.- 6.7 X-Ray Wavelengths.- 6.8 Continuous Spectrum of X-Rays.- 6.9 Compton Effect.- 6.10 Summary.- 7 Spectra.- 7.1 The Hydrogen Spectrum.- 7.2 The Bohr Theory of the Hydrogen Atom.- 7.3 Isotope Effect.- 7.4 The Spectrum of Sodium.- 7.5 Quantum Defects — Interpretation.- 7.6 Selection Rules and the Correspondence Principle.- 7.7 Excitation Potentials.- 7.8 Controlled Excitation of Spectra.- 7.9 X-Ray Spectra.- 7.10 Moseley’s Work.- 7.11 The Interpretation of X-Ray Spectra.- 8 Fine Structure and Electron Spin.- 8.1 Fine Structure of Alkali-Metal Spectra.- 8.2 Electron Spin.- 8.3 Characteristic X-Rays and Absorption Spectra.- 8.4 Multiplicity of X-Ray Levels.- 9 Waves and Particles.- 9.1 The Radiation Dilemma.- 9.2 De Broglie’s Theory.- 9.3 Group Velocity.- 9.4 The Davisson and Germer Experiment.- 9.5 The Experiment of Thomson and Reid.- 9.6 The Electron Microscope.- 9.7 Heisenberg’s Uncertainty Principle.- 9.8 Born’s Statistical Interpretation of Waves and Particles.- 10 Wave Mechanics.- 10.1 Some Preliminaries.- 10.2 The Need for Change.- 10.3 The Schrödinger Wave Equation.- 10.4 An Alternative Approach.- 10.5 Solution of the Schrödinger Wave Equation.- 10.6 Simple One-Electron Atom Model.- 10.7 The Hydrogen Atom.- 10.8 Angular Momenta.- 10.9 Summary.- 11 The Vector Model of the Atom.- 11.1 Quantum Numbers and Angular Momenta: Summary of Symbols and Notation.- 11.2 Magnetic Moments — Orbital and Spin.- 11.3 The Stern-Gerlach Experiment.- 11.4 Spatial Quantization of Electron Spin.- 11.5 Spin-Orbit Coupling and the Total Angular Momentum j.- 12 Two-Electron Atoms — Pauli Principle.- 12.1 Wave Functions of Two-Electron Atoms.- 12.2 Vector Coupling for Two Electrons.- 12.3 The Helium Spectrum.- 12.4 jj Coupling.- 12.5 The Electronic Structure of the Elements and the Periodic Table.- 12.6 The Periodic Table — Some Empirical Rules.- 12.7 Hyperfine Structure and Nuclear Spin Angular Momentum.- 13 The Zeeman Effect.- 13.1 Introduction.- 13.2 The Normal Zeeman Effect.- 13.3 Explanation of Zeeman Effect in Terms of Vector Model.- 13.4 Zeeman Effect of Cadmium 643·8 nm Line.- 13.5 The Anomalous Zeeman Effect and the Landé Splitting Factor.- 13.6 Zeeman Splitting in a Strong Magnetic Field: the Paschen-Back Effect.- 13.7 Conclusion.- 14 The Structure of the Nucleus.- 14.1 Introduction.- 14.2 Nuclear Constituents: Isotopes and Isobars.- 14.3 The Size of the Nucleus.- 14.4 Exact Atomic Masses — Mass Excess ?M.- 14.5 Binding Energies of Nuclides — Mass Defect.- 14.6 Stable and Unstable Nuclides.- 14.7 Derivation of Practical Form of E = m0c2.- 15 Properties and Uses of Natural Radioactivity.- 15.1 The Nature of Radioactivity.- 15.2 ?-Particles and the Geiger-Nuttall Rule.- 15.3 The Theory of ?-Decay.- 15.4 ?-Rays and the Neutrino.- 15.5 The Absorption and Range of ?-Rays.- 15.6 The Properties of ?-Rays.- 15.7 Radioactivity as a Measurable Quantity.- 16 Nuclear Bombarding Experiments.- 16.1 Single ?-Particle Scattering.- 16.2 Nuclear Alchemy.- 16.3 Cockcroft-Walton Proton Experiments.- 16.4 The Neutron.- 16.5 Nuclear Reactions.- 16.6 Formation of Tritium.- 17 The Measurement and Detection of Charged Particles.- 17.1 The Wilson Cloud Chamber.- 17.2 The Bubble Chamber.- 17.3 Ionization Chambers.- 17.4 The Proportional Counter.- 17.5 The Geiger-Muller Counter.- 17.6 Scintillation Counters and Semiconductor Counters.- 17.7 The Spark Chamber.- 17.8 The Cerenkov Counter.- 17.9 Neutron Counting.- 17.10 The Photographic Plate.- 17.11 Summary.- 18 Accelerating Machines as Used in Nuclear Physics.- 18.1 Introduction.- 18.2 The Cockcroft-Walton Proton Accelerator.- 18.3 The Van de Graaff Electrostatic Generator.- 18.4 The Linear Accelerator.- 18.5 The Lawrence Cyclotron.- 18.6 The Synchrocyclotron.- 18.7 Electron Accelerating Machines. The Betatron.- 18.8 Electron Synchrotron.- 18.9 Proton Synchrotron.- 18.10 The Alternating-Gradient Synchrotron.- 18.11 Intersecting Beam Accelerators.- 18.12 The Growth and Future of Large Accelerating Machines.- 19 Nuclear Models and Magic Numbers.- 19.1 Introduction.- 19.2 Neutron Cross-Sections and Nuclear Radii.- 19.3 The Liquid-Drop Model.- 19.4 Nuclear Shells and Magic Numbers.- 19.5 The Theory of the Nuclear Shell Model.- 19.6 The Collective Model.- 19.7 Superheavy Elements: Experimental and Theoretical.- 19.8 Latest Developments.- 19.9 The Melting of the Moon.- 20 Artificial Radioactivity.- 20.1 The Discovery of the Positron.- 20.2 K-Electron Capture.- 20.3 The Origin of Electrons and Positrons within the Nucleus.- 20.4 Nuclear Isomerism.- 20.5 The Production of Radioisotopes.- 20.6 Some Uses of Radioisotopes.- 21 Neutron Physics.- 21.1 Introduction.- 21.2 Properties of the Neutron.- 21.3 Neutron Bombardment Reactions.- 21.4 Archaeological Dating by the 14C Method.- 21.5 Tree-Ring Calibration of 14C Dates.- 22 Nuclear Fission and Its Implications.- 22.1 Introduction.- 22.2 The Theory of Nuclear Fission.- 22.3 The Energy of Nuclear Fission.- 22.4 The Distribution of Fission Products.- 22.5 Characteristics of Fission Neutrons.- 22.6 The ?-Decay Chains of Fission.- 22.7 Controlled Fission-Nuclear Reactors.- 22.8 Nuclear Power Reactors.- 22.9 Nuclear Power Prospects.- 23 The Transuranic Elements.- 23.1 Neptunium (Z = 93) to ?.- 23.2 Formation of Transuranic Elements.- 23.3 Neptunium, Np (Z = 93).- 23.4 Plutonium, Pu (Z = 94).- 23.5 Americium, Am (Z = 95), and Curium, Cm (Z = 96).- 23.6 Berkelium, Bk (Z = 97), and Californium, Cf (Z = 98).- 23.7 Einstein, Es (Z = 99), and Fermium, Fm (Z = 100).- 23.8 Mendelevium, Md (Z = 101), and Nobelium (Z = 102).- 23.9 Lawrencium, Lw (Z = 103).- 23.10 Elements with Z = 104, 105, 106 and 107.- 23.11 The Actinide Series.- 24 Thermonuclear Reactions and Nuclear Fusion.- 24.1 Introduction.- 24.2 The Source of Stellar Energy.- 24.3 The Plasma.- 24.4 Nuclear Fusion Reactions in the Plasma.- 24.5 Conditions for a Maintained Fusion Reaction.- 24.6 The Possibility of a Fusion Reactor.- 24.7 Tokomak Fusion Systems.- 24.8 Energy in the Future.- 25 Cosmic Rays.- 25.1 Discovery.- 25.2 Nature of Cosmic Rays.- 25.3 The Origin of Cosmic Rays.- 25.4 Geomagnetic Effects.- 25.5 Cosmic Rays at Sea-Level.- 25.6 Extensive Air Showers.- 25.7 The Detection of Cosmic Ray Particles.- 25.8 The Future of Cosmic Ray Research.- 26 Stable and Semi-Stable Particles.- 26.1 Introduction.- 26.2 The Positron: Particles and Antiparticles.- 26.3 Pions, Muons and Kaons.- 26.4 Hyperons.- 26.5 Classification of the Elementary Particles.- 26.6 Mesic Atoms: The Muonium Atom.- 27 Short-Lived Resonance States.- 27.1 Forces and Fields.- 27.2 What is an Elementary Particle?.- 27.3 Short-Lived or Resonance Particles.- 27.4 Conservation Laws: Baryon and Lepton Conservation.- 27.5 Multiplet Structure — Isospin and Hypercharges.- 27.6 Classification of Elementary Particles.- 27.7 Particle Symmetries.- 27.8 Quarks.- 27.9 Conclusions.- 28 Charm and All That.- 28.1 The Forces of Nature.- 28.2 The Three-Quirk Trick.- 28.3 The New Quark — Charm.- 28.4 The November Revolution — the J/? Particle.- 28.5 Quark Multiplet Representation.- 28.6 Gluons and Colour.- 28.7 The Confinement of Quarks.- 28.8 The Hunting of the Quark.- 28.9 Latest News: New Quarks.- 28.10 Conclusions.- Appendix A Relativity Theory.- Appendix B The Dangers of Atomic Radiations.- B.1 Introduction.- B.2 Biological Effects of Nuclear and Electromagnetic Radiations.- B.3 Maximum Permissible Radiation Levels for Safety.- B.4 Precautions against Radiation Hazards.- Appendix C Complete List of Nuclides of the Elements.