gammaspy 0.2.0

Gamma Spectroscopy analysis in PYthon

GammaSPY: Gamma Spectroscopy analysis in PYthon

Warning This package is in active development and may introduce breaking changes.

A suite of open-source tools for automated γ-ray spectroscopy analysis of fast neutron-induced nuclear reactions, developed for data collected with the EXOGAM clover detector array, but can be use for any HPGe detector arrays.

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Overview

This repository contains the analysis framework developed for processing and interpreting γ–γ coincidence data from the EXOGAM detector array at GANIL. The tools integrate experimental data processing, nuclear database cross-referencing, and reaction simulation predictions into a unified automated workflow.

The suite currently includes:

• 2D background subtraction — Native ROOT implementation of the Palameta–Waddington background subtraction algorithm for γ–γ matrices, eliminating the need to convert to legacy RadWare formats
• Coincident γ finder — Automated coincidence identification tool with recursive cascade mapping against ENSDF and XUNDL databases, to arbitrary cascade order
• Expected spectrum plotter — Quantitative prediction of gated γ-ray spectra based on TALYS cross-sections, detector efficiency, and experimental geometry

Planned features include:

• DCO and polarization asymmetry extraction — Angular correlation analysis tools for spin-parity assignments from oriented nuclear ensembles
• Custom TALYS modifications — Source code patches extending discrete level tracking, memory allocation, and output formatting in TALYS for level-by-level population cross-sections

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Installation

GammaSPY requires ROOT with PyROOT bindings. If you already have a setup with that, you can install simply with:

pip install gammaspy

Otherwise using pixi (installation instructions) is highly recommended since it can also install root. Then simply:

git clone https://gitlab.com/Hemantika1122/GammaSPY.git
pixi install

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Quick Start

Get projection with background subtraction

If running in jupyter notebook use %jsroot for interactable TCanvases

from gammaspy.hist2d import Hist2D

hgg = Hist2D("output_gg_addback.root", "hgg")
canvas = hgg.draw_projection(gate_energy=1454, gate_width=3, subtract_background=True)

Add coincidence finder

First download the adaptedLevels csv files for relevant isotopes from the nudat website.

from gammaspy.nudat import LevelSchemes

level_schemes = LevelSchemes(
    isotopes=["57Ni", "58Ni", "56Co", "57Co"],
)
canvas = hgg.draw_projection(
    gate_energy=1454, gate_width=3, level_schemes=level_schemes, coincidence_order=2
)

Expected gamma spectrum

First run Talys simulations with relevant target isotope and neutron energy range. Pass the output location of the simulation to

from gammaspy.simulation import (
    save_simulated_counts_1d,
    save_simulated_projection_spectrum,
)

save_simulated_counts_1d()

along with incident flux spectrum and other experimental parameters. This will save the expected 1D counts at different gamma energies as a csv file. Pass this csv file to save_simulated_projection_spectrum() along with the LevelScheme object created above and gate energy and widths. It will produce a root file with expected spectrum which can be overlaid with experimental spectrum.