The Influence of Nuclear Reactions and Nuclear Structure in Astrophysics

K E Rehm,E.C Simpson,K.J Cook,C Simenel,I.P Carter

doi:10.1051/epjconf/201716300048

Abstract

Nuclear reactions play an important role for the energy production and the nucleosynthesis in stars. New facilities, able to accelerate radioactive nuclei or high-intensity stable beams have allowed us to measure in the laboratory reactions involving short-lived nuclei or processes with very small cross sections, which are crucial for stellar nucleosynthesis. I will discuss some of the recent experiments studying fusion and transfer reactions with radioactive beams which play a critical role in various quiescent and explosive stellar environments.

Highlights

Nuclear structure and nuclear reactions involving the whole range from light to heavy nuclei are crucial for determining the format of our universe from its beginning to the present day
For the subsequent alpha capture reaction, 16O(α, γ)20Ne, we find that the nuclear structure in 20Ne provides no level with the proper quantum numbers, which inhibits this channel and restricts the destruction of 16O
These are just a few examples among the 6000 nuclei and 60,000 nuclear reactions participating in stellar nucleosynthesis showing the critical influence of nuclear structure and reactions in stellar environments

Summary

Introduction

Nuclear structure and nuclear reactions involving the whole range from light to heavy nuclei are crucial for determining the format of our universe from its beginning to the present day. [8], fusion reactions involving mediummass nuclei with negative Q-values require a maximum in the astrophysical S-factor (S (E) = σEexp(2πη) where η = Z1Z2e2/( v) is the Sommerfeld parameter), since the fusion cross section has to reach zero at a c.m. energy of E=-Q. Several recent experiments involving lighter nuclei with positive Q- that reason so far only two sites are known where 44Ti has values have shown that an S-factor maximum is observed been detected.

Results

Conclusion