Preface

Kenneth Krane's Introductory Nuclear Physics was published in 1987. It is still the standard textbook at nearly every university that teaches nuclear physics. It costs over $170. And it is almost forty years old.

Nuclear physics has not stood still since 1987. The periodic table now extends to oganesson (Z = 118), completing the seventh row. A neutron star merger has been observed through gravitational waves, confirming that the heaviest elements in the universe are forged when neutron stars collide. The National Ignition Facility achieved fusion ignition in 2022, producing more energy from fusion reactions than the laser energy delivered to the target. Small modular reactors are approved and under construction. Nuclear medicine has been transformed by targeted alpha therapy, theranostics, and proton beam therapy. Radioactive ion beam facilities — FRIB in Michigan, RIKEN in Japan, ISOLDE at CERN — have opened access to thousands of previously unstudied nuclei, revealing that the shell structure we thought was universal changes far from the valley of stability. And computational nuclear physics has advanced from phenomenological models to ab initio calculations that build nuclei from the underlying strong force using chiral effective field theory.

None of this appears in any current textbook. Students deserve better.

This book is written to be the nuclear physics textbook that Krane's book was in 1987: comprehensive, rigorous, pedagogically careful, and connected to the real experimental data that defines the field. But updated for the 2020s, free, and available to every student in the world.

What This Book Covers

The book is organized in eight parts that follow the natural logic of the field:

Part I builds the foundations: how the nucleus was discovered, what its properties are, what force holds it together, and how the semi-empirical mass formula captures the gross features of nuclear binding. A targeted quantum mechanics review ensures every reader has the mathematical tools needed for what follows.

Part II develops nuclear structure — the shell model, residual interactions, collective motion — and then pushes to the frontiers: exotic nuclei far from stability and the superheavy elements that stretch the periodic table to its limits.

Part III treats radioactive decay exhaustively: the exponential law and decay chains, then alpha decay (quantum tunneling), beta decay (the weak interaction), and gamma decay (electromagnetic transitions). A chapter on radiation interactions with matter connects decay physics to detection.

Part IV covers nuclear reactions: kinematics and cross sections, the compound nucleus, direct reactions, fission, and fusion. Each topic is developed from first principles with real derivations, not just results.

Part V takes nuclear physics to the cosmos: stellar nucleosynthesis (how stars build the elements), explosive nucleosynthesis (supernovae and neutron star mergers), Big Bang nucleosynthesis (the first three minutes), and the nuclear physics of neutron stars.

Part VI turns to applications: nuclear energy (including advanced reactors and SMRs), nuclear medicine (PET, proton therapy, targeted radionuclide therapy), nuclear security and forensics, radiation in the environment, and the accelerators and experimental techniques that make it all possible.

Part VII connects nuclear physics to particle physics and the frontiers: the Standard Model and QCD, fundamental symmetries tested with nuclei, and the open questions that define the field today.

Part VIII is a capstone: a synthesis project that pulls everything together, and a guide to reading the nuclear physics literature.

How to Use This Book

This textbook is designed for multiple audiences and course formats. The How to Use This Book section that follows provides detailed learning paths:

  • Fast Track for nuclear engineering students who need the physics foundations
  • Standard for the full two-semester nuclear physics sequence
  • Deep Dive for students heading to graduate research, including all advanced sidebars and computational projects

Every chapter includes a progressive project checkpoint that builds a Nuclear Data Analysis Toolkit in Python — a computational toolkit that, by the end of the book, can plot binding energy systematics, simulate decay chains, calculate reaction kinematics, access online nuclear databases, and perform Monte Carlo radiation transport simulations.

A Note on Rigor

This is a physics textbook, not a survey. Every important result is derived, not just stated. The derivations follow a consistent pattern: physical motivation, mathematical setup, key steps, result, interpretation, and a numerical example using real nuclear data. We use real measured values from the Atomic Mass Evaluation, the Evaluated Nuclear Structure Data File, and the Evaluated Nuclear Data File — not made-up numbers. Every theoretical prediction is compared to experiment. When models fail, we say so and explain why.

The mathematics is at the level of a junior/senior physics major: angular momentum coupling, perturbation theory, Fermi's golden rule, the WKB approximation. Appendix A provides a self-contained review for readers who need it.

Acknowledgments

This book was written to fill a gap that has persisted for far too long. Nuclear physics is one of the most consequential branches of science — it powers stars, treats cancer, generates electricity, and poses existential risks through weapons proliferation. Every citizen of the twenty-first century is affected by nuclear physics, and every physics student deserves a modern, free textbook to learn it.

We hope this book serves that purpose.