Search the Site
Printer-Friendly Version
Home
|
|
Photonuclear Physics : 9Be(γ,n)
 |
|
One intersection of photonuclear physics and nuclear astrophysics is the 9Be(γ,nα)α reaction.
Precise understanding of its cross section is key to understanding isotopic abundances of nuclei produced during the
r-process. The inverse reaction bridges the unstable mass gaps at A =5 and A = 8, connecting
α(αn,γ)9Be to 9Be(α,n)12C and so on in the explosive environment of
Type II Supernovae. This reaction produces seed nuclei for the r-process and determines the neutron-to-seed nucleus
ratio that drives universal isotopic abundance predictions. TUNL’s high intensity gamma ray source (HIγS)
provides a tunable gamma ray beam with the best available ΔE/E in the world (<1% to ~3%) necessary to make precision
measurements (± 5%) of the narrow resonant behavior of the 9Be(γ,nα)α reaction. Measurements in the
energy range of 1.50 to 5.20 MeV have been taken with beam energy resolutions between 14 and 150 keV as determined by high
purity Ge detector. Precise detector calibrations will make future studies of other (γ,n) cross sections possible.
|
|
|
