Sep 11 – 15, 2023
Durham Convention Center
America/New_York timezone

Experimental Studies of Gamma-Induced Reactions for the P-Process

Sep 13, 2023, 11:00 AM
35m
Junior Ballroom (Durham Convention Center)

Junior Ballroom

Durham Convention Center

301 W Morgan St, Durham, NC 27701

Speaker

Kelly Chipps (Oak Ridge National Laboratory)

Description

The source of a series of rare, proton-rich stable isotopes, known as the p nuclei, remains an open question in nuclear astrophysics. The p nuclei cannot be produced through the known neutron capture processes such as the s and r process, but instead are thought to be synthesized in astrophysical environments where a series of photodisintegration reactions on s-process seeds takes place. Various sites have been proposed for the production of p-process nuclei, such as type Ia supernovae or neutrino-driven winds from core collapse supernovae. A major source of uncertainty in understanding the production of p nuclei is the necessity to use cross sections and reaction rates derived from theoretical models, in particular the statistical Hauser-Feshbach approach. With very little experimental constraint, these cross section predictions can vary by orders of magnitude, preventing a careful assessment of the conditions needed to produce p nuclei in the abundances observed today.

To tackle the need for experimental constraint of the predicted cross sections, the HI$\gamma$S P-Process Collaboration has undertaken several measurements of gamma-induced charged-particle emission of p-process nuclei across the range of energies relevant to explosive supernova environments. By utilizing an array of highly-segmented, high resolution silicon detectors, the energy and angle of the outgoing protons and alphas produced via the photodisintegration reactions from monoenergetic beams of gamma rays at HI$\gamma$S can be measured, and the total and partial cross sections derived and compared to predictions. In this talk, the experimental setup, preliminary analysis, and future plans will be discussed.

This research is supported in part by the U.S. Department of Energy under grant nos. DE-AC05-00OR22725 and the Romanian Ministry of Research, Innovation and Digitalization under project no. PN-III-P4-PCE-2021- 1024 and PN 23 21 01 06.

Primary authors

Catalin Matei (Extreme Light infrastructure – Nuclear Physics (ELI-NP)) Kelly Chipps (Oak Ridge National Laboratory)

Presentation materials