hyrr 0.1.3

Hierarchical Yield and Radionuclide Rates — isotope production in stacked target assemblies

HYRR

Hierarchical Yield and Radionuclide Rates

A pure Python package for predicting radio-isotope production in stacked target assemblies, using TENDL cross-section data and NIST stopping power tables.

Web App | Documentation

Try it now — full simulation runs in the browser, no install, no data leaves your machine.

What it does

• Stopping power via PSTAR/ASTAR table lookup (replaces Bethe-Bloch)
• Energy-integrated production rates for any projectile (p, d, t, ³He, α)
• Bateman equations for activity, yield, and decay chains
• Compound materials with natural or enriched isotopic composition
• Stacked layer geometries (windows, targets, degraders, backings)
• Depth-resolved heat and activity profiles

Performance

HYRR is designed for interactive use — simulations are fast enough for real-time parameter sweeps:

Operation	Time
Single isotope production rate	~56 µs
Full layer simulation (all isotopes)	~1.6 ms

Compared to tools like Isotopia, HYRR is significantly faster and lighter: pure NumPy/SciPy with Parquet-backed nuclear data (no heavy ORM, no database server). The browser frontend achieves similar performance with a pure TypeScript compute engine.

Installation

uv add git+https://github.com/exoma-ch/hyrr.git

Quick start

from hyrr import TargetStack, Layer, Beam

stack = TargetStack(
    beam=Beam(projectile="p", energy_MeV=30.0, current_mA=0.15),
    layers=[
        Layer(material=havar, thickness_cm=0.0025),
        Layer(material=enriched_mo100, energy_out_MeV=12.0),
        Layer(material=copper, thickness_cm=0.5),
    ],
)

result = stack.run(irradiation_time_s=86400, cooling_time_s=86400)
result.summary()

Frontend

exoma-ch.github.io/hyrr — hosted on GitHub Pages, zero backend.

The browser frontend (frontend/) is a standalone Svelte 5 + TypeScript app with a pure-TS physics engine (no Python/WASM). Nuclear data is lazy-loaded from Parquet files via hyparquet. All computation runs locally — no server, no data upload.

Development

git clone --recurse-submodules https://github.com/exoma-ch/hyrr.git
cd hyrr
uv sync --all-extras
uv run pytest

Frontend:

cd frontend
npm ci
npm run dev
npm test          # vitest
npm run check     # svelte-check (TypeScript)

Contributing

1. Fork and create a feature branch
2. Python: uv sync --all-extras, then uv run pytest and uv run ruff check src/
3. Frontend: cd frontend && npm ci, then npm test and npm run check
4. Commit format: type(scope): description
5. Open a PR against main

Dependencies

• numpy, scipy — numerics
• polars — data access (Parquet backend)
• matplotlib — plotting
• py-mat — material definitions
• nucl-parquet — evaluated nuclear data (TENDL, ENDF/B, JENDL, JEFF, EXFOR)

About eXoma

eXoma — Exotic Matter Applications — is a research group at ETH Zürich focused on novel radioisotope production methods and targetry.

License

MIT