Analysis of Gamma-Induced Reactions on Natural Copper and Zinc*

The p-process, responsible for the synthesis of several rare, heavy, neutron-deficient isotopes, is a critical component of nucleosynthesis in stellar environments. Understanding the p-process is essential for accurately modeling stellar evolution and the elemental abundances observed in the universe.  

At the High Intensity gamma Source (HIgS) facility, an experiment to measure the photodisintegration (γ, p) and (γ, α) reaction cross sections on the p-process nucleus 102Pd, at gamma-ray energies ranging from 10 to 19 MeV, was conducted. The target was a 750 μg isotopically-enriched 102Pd foil, with emitted protons and alphas detected using the Oak Ridge National Laboratory Silicon Detector Array (SIDAR).

During the experiment, backgrounds from trace contaminants in the 102Pd target were identified. To address this, we used measurements of natural Pd, Cu, and Zn targets to find and isolate the 102Pd signal. Protons and alphas from the reactions on these background targets were identified using standard energy loss techniques. Total yields, as well as spectroscopic information, were extracted. The Cu and Zn cross-section values could then be subtracted from the 102Pd data.