Full text
README for Zenodo Release (Code Only) Python Implementation of the SCS–Hill–Wheeler Statistical Fission Model December 16, 2025 1 Overview This archive provides a reproducible Python implementation of a statistical nuclear-fission model that combines the Selective Channel Scission (SCS) framework with Hill–Wheeler barrier penetrability. The code is designed to estimate and visualize the charge-yield distribution Y(Z), the effective scission (fission) distance Reff (Z), and the Fermi energy Ex(Z). Target nuclides (example set): 232Th, 233U, 235U, 238U, 237Np, 239Pu, 240Pu, 242Pu, 241Am. Incident neutron-energy conditions: thermal / 500 keV / 14 MeV (thermal fission is not applicable to some nuclides). 2 Repository Structure (Typical) •src/: core implementation (SCS–HW calculation and fitting) •cases/: run configurations (nuclide, energy, thresholds, etc.) •notebooks/: Jupyter notebooks for batch runs and figure/table generation •data/: input data directory (if not included, please prepare separately) •results/: outputs (CSV/PNG, generated by running the notebooks) 3 Requirements •Python: recommended 3.10–3.12 •Main dependencies: numpy,pandas,scipy,matplotlib,pyyaml •For notebook execution: jupyter (recommended) 4 Setup (Recommended: Virtual Environment) Windows (PowerShell) python -m venv .venv .venv\Scripts\Activate.ps1 python -m pip install -U pip pip install numpy pandas scipy matplotlib pyyaml jupyter 1
macOS / Linux python3 -m venv .venv source .venv/bin/activate python -m pip install -U pip pip install numpy pandas scipy matplotlib pyyaml jupyter 5 Input Data This codebase reads charge-yield data Y(Z) and related inputs from data/. If you do not include the input data in the Zenodo deposit, please clearly document the data sources (e.g., ENDF/B-VIII.0) and the pre-processing steps either in a separate README or in the Zenodo description. 6 Usage Example (Recommended: Jupyter Notebook) 6.1 Launch From the project root directory, run: jupyter lab 6.2 Notebook to Run Open the following notebook (example) under notebooks/ and execute Run All: •run all 9nuclides with fermi.ipynb 6.3 Outputs (Typical) After completion, results will be generated under results/ (output paths may vary depending on the selected case configuration): •Charge-yield comparison figures: Yz compare <nuclide> <energy>.png •Effective scission distance (points only; no smoothing curve): Reff <nuclide> overlay.png •Fermi energy: Ex <nuclide> overlay.png •Table-3-like summary (mean defined using thermal and 500 keV only; 14 MeV excluded): table3 like * thermal 500keV.csv 7 Configuration Notes (Important) 7.1 Low-yield cutoff (to stabilize Exat the tails) To mitigate numerical instability in Ex(Z) estimation near the distribution tails, the fitting stage may exclude low-yield points via a parameter such as ex min yield (e.g., 10−3). Adjust it as needed, possibly per nuclide or per energy case. 7.2 Z-range cutoff (“dataStart” equivalent) A lower bound such as z fit start may be available to exclude the very-low-yield tails, improving robustness of the fits. 2
8 Common Issues •No figures / empty outputs: verify that data/ contains the required inputs and that the selected case file is correct. •No thermal results for some nuclides: thermal-induced fission is not applicable for certain nuclides (e.g., 232Th and 238U), so thermal plots may not be produced by design. 9 How to Cite Once Zenodo assigns a DOI, please cite the repository as follows (example): H. Maruyama, “(Repository title),” Zenodo, DOI: https://doi.org/xx.xxxx/zenodo.xxxxxxx 10 License Please follow the license selected in the Zenodo deposit (e.g., MIT, CC BY 4.0). 3
