For instructors
Inside a Nuclear Reaction explains, one picture at a time, how a modern reaction code computes what happens when a neutron hits a nucleus. Every picture answers to sliders, so it works projected in a lecture, as reading before class, or on students' phones. It is free and open, in many languages (the language menu at the top of every page), with nothing to install.
Using this in a course? I'd like to hear how it works with students and what would make it more useful: open a GitHub issue.
The INCOGNITA engine is a port of TALYS-2 (A. J. Koning, S. Hilaire, S. Goriely) and uses the TALYS nuclear-structure database. What INCOGNITA adds is listed, switch by switch, at the end of the teaching page.
Three levels
It starts simple and ends in detail, on purpose. Each chapter carries one of three tags, shown beside its number on the teaching page.
No physics needed. Ideas, pictures and orders of magnitude; suits a first-year or general audience.
The standard models of reaction theory, at the level of an undergraduate or first graduate nuclear physics course.
Research level: the details that decide a modern evaluation, and how this project builds its data on the engine.
The chapters
Times are for reading a chapter and trying its controls; presenting one in class takes about as long. Each chapter stands on its own, but they build on each other in order.
Suggested courses
Bar lengths are minutes; colours are levels. Tap a segment to open that chapter.
One lecture (about an hour)
Three lectures
For a general audience, the Intro chapters (1–3) and chapter 11 make a self-contained session. Chapters 9, 10 and 12 can each be dropped or swapped without breaking the rest.
Linking to a chapter or a step
Every chapter and every step has a stable address. A chapter is #omp; a step adds its number, counted from 1: #omp-3 is the third step of chapter 2. Add a language code such as ?lang=es before the # for that language. On the teaching page, the link mark beside each step copies its address.
The data explorer links the same way: data.html#Au-197 opens gold-197, data.html#Fe-56 iron-56.
Data for exercises
On Every nuclide, any nuclide's predicted curves and its curated measurements download as CSV or JSON, with units, sources and EXFOR ids in the file. The whole library is in the repository under library/v0.1. Exercises that work well: compare the prediction with the measurements for a nuclide the class chooses; find where the 68 % band is widest and ask why; follow capture at 30 keV across an isotope chain.
Credit and feedback
Code is Apache-2.0 and the data CC-BY-4.0. If you use the site or its data in teaching material, please cite the project (CITATION.cff) and TALYS (A. Koning, S. Hilaire, S. Goriely, Eur. Phys. J. A 59 (2023) 131). Corrections and classroom experience are welcome as GitHub issues.