Using HECTOR to Study Capture Reactions Relevant to the Astrophysical γ-Process

For studies of the γ-process, photodisintegration rates on the nuclei involved are crucial. One way to constrain these rates is to measure the inverse capture reactions. In this work six different capture reactions were studied using the High EfficienCy TOtal absorption spectrometeR.

Four (α,γ) reactions were studied in this work, 90Zr(α,γ)94Mo, 102Pd(α,γ)106Cd, 108Cd(α,γ)112Sn, and 110Cd(α,γ)114Sn. These reactions were identified in a sensitivity study as being potential branching points in the reaction flow during the γ-process. These reactions were studied at the University of Notre Dame’s Nuclear Science Laboratory using the FN accelerator. With the results from these measurements a theoretical model was found that predicted cross sections within a factor of 2 of all four measured reactions.

Additionally, two (p,γ) reactions, 94Mo(p,γ)95Tc and 92Mo(p,γ)93Tc, were studied. The (p,γ) cross-section measurements were performed at the University of Notre Dame’s Nuclear Science Laboratory using the 5U accelerator. For these measurements an offline filter was developed to remove contamination from the reaction 19F(p,αγ)16O. With the development of this filter the measurements could be performed over almost the entirety of the Gamow Window.