R-matrix evaluation · AZURE2
7Be R-matrix evaluation
Reactions fitted
- 3He(α,γ)7Be
- 6Li(p,γ)7Be
- 6Li(p,α)3He
- 3He(α,p)6Li
- 6Li(p,p)6Li
- 3He(α,α)3He
J. Skowronski, R. J. deBoer, T. Szücs, submitted to Phys. Rev. C (2026) · R-matrix analysis: J. Skowronski · About this evaluation
An alpha particle (a helium-4 nucleus) and a helium-3 nucleus can merge for an instant into beryllium-7 (3He(α,γ)7Be), which then sheds its extra energy as a γ-ray. The level scheme shows the energies at which beryllium-7 can exist (excited states, each with its spin-parity Jπ); in the plot the dots are measurements and the line is the R-matrix model, here as an S-factor. Open Plot & data, drag a slider and see whether the line still passes through the dots: the lower the χ², the better the fit.
What am I looking at?
An alpha particle (a helium-4 nucleus) and a helium-3 nucleus can merge for an instant into beryllium-7 (3He(α,γ)7Be), which then sheds its extra energy as a γ-ray. The level scheme shows the energies at which beryllium-7 can exist (excited states, each with its spin-parity Jπ); in the plot the dots are measurements and the line is the R-matrix model, here as an S-factor. Open Plot & data, drag a slider and see whether the line still passes through the dots: the lower the χ², the better the fit.
J. Skowronski, R. J. deBoer, T. Szücs, submitted to Phys. Rev. C (2026) · R-matrix analysis: J. Skowronski · About this evaluation
Starting the calculation for ⁷Be…
About this evaluation
What was fitted
120 data segments from 23 data files: 75 differential cross sections (c.m. angles), 32 differential cross sections, 9 total-capture cross sections, 4 angle-integrated cross sections. The Plot & data tab overlays the model on the measurements, lets you move any free level, and lists every segment with its normalization and χ2 in its table.
How to cite
Please cite the paper this evaluation belongs to:
- J. Skowronski, R. J. deBoer, T. Szücs, submitted to Phys. Rev. C (2026).
- R. E. Azuma et al., “AZURE: An R-matrix code for nuclear astrophysics”, Phys. Rev. C 81, 045805 (2010), doi:10.1103/PhysRevC.81.045805.
- E. Uberseder and R. J. deBoer, AZURE2 User Manual, version 1.0 (2015).
- J. Skowronski, 7Be R-matrix evaluation, https://jskowron.eu/evaluations/7Be.
Cite the paper for the evaluation, AZURE2 for the code, and this page (with its version) if you use the interactive calculation or its numbers. The measured data belong to their authors: cite the original papers listed in the table of the Plot & data tab.
This page and the model file are shared under CC BY 4.0. creativecommons.org/licenses/by/4.0/
- Paper
- J. Skowronski, R. J. deBoer, T. Szücs, submitted to Phys. Rev. C (2026)
- R-matrix analysis
- J. Skowronski
- Energies
- Centre-of-mass energies Ec.m. in MeV throughout; AZURE2 converts the laboratory beam energies of the data files. Level energies are excitation energies of the compound nucleus.
- Engine
- AZURE2, commit bc3bd57