Atomic Library Linking Evaluated Nuclear-data
Teaching-focused σ(E) plots from ENDF/B-VIII.0 and JEFF-3.3 (processed with OpenMC 0.15.3). Overlay nuclides, MT channels, temperatures, and evaluated libraries; hover for readout; share deep links for courses. For production evaluated data, covariances, and 843+ materials, use NNDC Sigma.
How ALLEN differs from NNDC Sigma
ALLEN is a teaching companion on ReactorMC — not a replacement for Brookhaven's authoritative Sigma portal. Sigma hosts experimental cross sections, covariances, and hundreds of materials from ENDF/B and related libraries; ALLEN curates a smaller bundle (~45 nuclides from ENDF/B-VIII.0 and JEFF-3.3) processed for fast, linkable classroom use.
- Curated teaching presets — e.g. U-235 fission vs U-238 capture, H/O elastic, B-10 capture.
- 1/v reference line, thermal marker, and contextual education cards tied to your plot selection.
- Deep-linkable URLs — share exact nuclide/reaction/temperature views in slides or assignments.
- Modern, responsive UI integrated with NRDP and OWEN; temperature sweeps (294–1200 K) across the reactor-important nuclide set.
- Library comparison — overlay ENDF/B-VIII.0 and JEFF-3.3 evaluations of the same reaction with a Δ readout at the cursor.
Data lineage: evaluated files (ENDF/B-VIII.0 from NNDC; JEFF-3.3 from the OECD/NEA Data Bank) → official OpenMC HDF5 libraries → ALLEN JSON (peak-preserving downsample). Curves are read at the libraries' tabulated temperature grid points (no Doppler interpolation); JEFF-3.3's room-temperature point is 293.6 K, filed under 294 K.
Value | -- |
|---|---|
U-235 σ(fission) | -- |
U-235 σ(capture) | -- |
1/v reference | -- |
Data provenance & attribution
- ENDF/B-VIII.0 — D.A. Brown et al., "ENDF/B-VIII.0: The 8th Major Release of the Nuclear Reaction Data Library," Nuclear Data Sheets 148 (2018) 1–142. Evaluated files courtesy of the National Nuclear Data Center (NNDC), Brookhaven National Laboratory; HDF5 processing by the OpenMC development team.
- JEFF-3.3 — A.J.M. Plompen et al., "The joint evaluated fission and fusion nuclear data library, JEFF-3.3," Eur. Phys. J. A 56, 181 (2020). Distributed by the OECD Nuclear Energy Agency (NEA) Data Bank, free for use with attribution; HDF5 processing by the OpenMC development team (NJOY 2016.68). JEFF-3.3's room-temperature grid point is 293.6 K and is filed under ALLEN's 294 K bucket.
- Curves are extracted at each library's tabulated temperatures (294/600/900/1200 K where available) with peak-preserving downsampling for the browser; no Doppler interpolation between grid points is performed. ALLEN is for teaching — use the source libraries for production work.