Gamma activation analysis (GAA) is a powerful elemental analysis technique, particularly suitable for light elements and those insensitive to thermal neutron activation. The establishment of the Shanghai Laser Electron Gamma Source (SLEGS) beamline has provided a unique platform in China for conducting advanced gamma activation studies using quasi-monochromatic gamma beams and obtaining high-precision nuclear data. In this paper, the gamma activation data measurement method and experimental setup developed at the SLEGS beamline are systematically presented, while demonstrating its specific applications and significant achievements in beam diagnostics and nuclear astrophysics research. This study is conducted at the SLEGS beamline. The SLEGS generates tunable quasi-monochromatic gamma beams in an energy range of 0.66–21.7 MeV through the inverse Compton scattering mode of a 3.5 GeV electron beam and a 10.64 μm CO₂ laser. The experimental procedure begins with the online irradiation of target samples such as natural abundance Au, Zn and Ru/Ga, thereby generating radioactive nuclei through photonuclear reactions. During irradiation, beam monitoring is conducted using LaBr₃(Ce) or BGO detectors in conjunction with spectral unfolding. Subsequently, offline γ-ray spectroscopy is performed on the activated samples using shielded HPGe detectors. Based on these measurements, the reaction cross-sections are ultimately determined by analyzing characteristic gamma peaks, beam parameters, and detector efficiency data.

Absolute calibration of SLEGS gamma beam intensity is successfully achieved using ¹⁹⁷Au(γ, n)¹⁹⁶Au and ⁶⁴Zn(γ, n)⁶³Zn reactions. The measured results agree with online monitor data and Geant4 simulations within an uncertainty of 10% , thereby validating activation as a reliable beam diagnostic tool. Key photonuclear reaction cross-sections relevant to p-process nucleosynthesis are measured. Using natural abundance Ru targets, preliminary quasi-monoenergetic cross-section data are obtained for ⁹⁶Ru(γ, n)⁹⁵Ru, ⁹⁶Ru(γ, p)⁹⁵Tc and ⁹⁸Ru(γ, n)⁹⁷Ru reactions. Systematic measurements of the ⁶⁹Ga(γ, n)⁶⁸Ga monoenergetic reaction cross-section are performed . The experimental data constrain parameters in the TALYS nuclear reaction model, enabling the calculation of ⁶⁹Ga(γ, n), (γ, p), and (γ, α) reaction rates over 1.5–10 GK temperature range. REACLIB-format parameters are derived for astrophysical network calculations. These experimental results provide crucial constraints for understanding the origin of p-nuclei.

his study successfully establishes a comprehensive and reliable gamma activation data acquisition and analysis platform at the SLEGS beamline of Shanghai Synchrotron Radiation Facility. Experimental results show that this platform can not only accurately calibrate gamma beam parameters, but also conduct cutting-edge basic research in nuclear astrophysics, especially in measuring the critical yet challenging photonuclear reaction cross-sections of the p-process. The obtained datasets are crucial for nuclear databases and astrophysical models. Looking ahead, the SLEGS gamma activation platform will broaden its applications to a wider range of fields including characteristic nuclide identification, archaeometry, materials science, and medical isotope production. Low-background gamma data and partial gamma activation data are provided, which can be accessed in the dataset at https://doi.org/10.57760/sciencedb.j00213.00194.