The Physics of the Manhattan Project

Preface to the Fourth Edition
Preamble
Fundamental Data on Little Boy and Fat Man
P.1 Little Boy
P.2 Fat Man
Contents
About the Author
1 Energy Release in Nuclear Reactions, Neutrons, Fission, and Characteristics of Fission
1.1 Notational Conventions for Mass Excess and Q-Values
1.2 Rutherford and the Energy Release in Radium Decay
1.3 Rutherford’s First Artificial Nuclear Transmutation
1.4 Discovery of the Neutron
1.5 Artificially-Induced Radioactivity and the Path to Fission
1.6 Energy Release in Fission
1.7 The Bohr-Wheeler Theory of Fission: The Z2/A Limit Against Spontaneous Fission
1.8 Energy Spectrum of Fission Neutrons
1.9 Leaping the Fission Barrier
1.10 A Semi-empirical Look at the Fission Barrier
1.11 A Numerical Model of the Fission Process
1.12 Results
References
2 Critical Mass, Efficiency, and Yield
2.1 Cross-Sections, Mean Free Path, and the Diffusion Equation
2.2 Critical Mass: Bare Core
2.3 Critical Mass: Tamped Core
2.4 Critical Mass: Tamped Composite Core
2.5 Estimating Yield—Analytic
2.6 Estimating Yield—Numerical
2.6.1 A Simulation of the Hiroshima Little Boy Bomb
2.7 History Lesson: Criticality Considered in 1939
2.8 Criticality and Yield: Approximate Methods
2.8.1 Bare Critical Mass: Simplified Boundary Condition
2.8.2 Bare Critical Mass: An Even Simpler Approach
2.8.3 Estimating the Yield of the Trinity Test by Examining the Rate of Growth of the Fireball
2.8.4 A Simplified Model of Tamped-Core Yield
2.9 Critical Mass of a Cylindrical Core (Optional)
References
3 Producing Fissile Material
3.1 Reactor Criticality
3.2 Neutron Thermalization
3.3 Plutonium Production
3.4 Electromagnetic Separation of Isotopes
3.5 Gaseous (Barrier) Diffusion
References
4 Complicating Factors
4.1 Boron Contamination in Graphite
4.2 Spontaneous Fission of 240Pu, Predetonation, and Implosion
4.2.1 Little Boy Predetonation Probability
4.2.2 Fat Man Predetonation Probability
4.3 Predetonation Yield
4.4 Tolerable Limits for Light-Element Impurities
4.5 Neutron Initiators
4.6 Estimating the Contribution of 238U to the Trinity Yield
References
5 Miscellaneous Calculations
5.1 How Warm Is It?
5.2 Brightness of the Trinity Explosion
5.3 A Model for Trace Isotope Production in a Reactor
5.4 Can Fission Make a Grain of Sand Visibly Jump?
References
6 Appendices
6.1 Appendix A: Selected Δ-Values and Fission Barriers
6.2 Appendix B: Densities, Cross-Sections, Secondary Neutron Numbers, and Spontaneous-Fission Half-Lives
6.2.1 Thermal Neutrons (0.0253 eV)
6.2.2 Fast Neutrons (Fission-Spectrum Averages)
6.3 Appendix C: Energy and Momentum Conservation in a Two-Body Collision
6.4 Appendix D: Energy and Momentum Conservation in a Two-Body Collision that Produces a Gamma-Ray
6.5 Appendix E: Formal Derivation of the Bohr-Wheeler Spontaneous Fission Limit
6.5.1 Introduction
6.5.2 Nuclear Surface Profile and Volume
6.5.3 The Area Integral
6.5.4 The Coulomb Integral and the SF Limit
6.6 Appendix F: Average Neutron Escape Probability from Within a Sphere
6.7 Appendix G: The Neutron Diffusion Equation
6.8 Appendix H: Exercises and Answers
6.9 Appendix I: Glossary of Symbols
6.10 Appendix J: Further Reading
6.10.1 General Works
6.10.2 Biographical and Autobiographical Works
6.10.3 Technical Works
6.10.4 Websites
6.11 Appendix K: Useful Constants and Rest Masses
References
Index