Astronomy with Radioactivities: Chapter 9, Nuclear Reactions

TL;DR

This chapter reviews how nuclear reaction rates influence isotope abundances in stars, highlighting experimental and theoretical methods used to determine these rates, including statistical models and various laboratory techniques.

Contribution

It provides a comprehensive overview of experimental and theoretical approaches for determining stellar nuclear reaction rates, emphasizing recent facilities and methods.

Findings

Reaction rates are crucial for isotope abundance predictions.

Statistical models are widely used for complex reactions.

Multiple experimental techniques support reaction rate measurements.

Abstract

Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are determined by laboratory experiments supplemented by nuclear reaction and structure theory. We will discuss the experimental approach as well as the theoretical tools for obtaining the stellar reaction rates. A detailed analysis of a reaction is only possible for a few selected cases which will be highlighted in this section. The bulk of nuclear reaction processes is however described in terms of a statistical model approach, which relies on global nuclear structure and reaction parameters such as level density and mass and barrier penetration, respectively. We will discuss a variety of experimental facilities and techniques used in the field, this includes low energy stable beam experiments, measurements at radioactive beam accelerators, and neutron beam facilities.