Seminar Details

Studies of the α; p-process waiting points in X-Ray Bursts using Radioactive Ion Beams at ATLAS

Catherine Deibel, Louisiana State University
Wednesday, December 5, 4:00 PM - Nuclear Science Seminar
NSCL Lecture Hall

Type I X-ray bursts (XRBs) are thermonuclear explosions that occur in binary systems consisting of a neutron star accreting hydrogen-rich matter onto its surface from a main sequence companion star. Nucleosynthesis in XRBs is driven up the proton-rich side of the chart of nuclides by the rp and α, p processes to the SnSbTe region. Several intermediate mass nuclei, 22Mg, 26Si, 30S, and 34Ar, have been identified as possible candidates for waiting points in this α,p process. When such a nucleus is reached, the flow stalls due to a (p, γ)-(γ, p) equilibrium and must await β decay unless the (α, p) reaction is fast enough to break out of the waiting point first. Therefore, these waiting points may have significant effects on the final elemental abundances, energy output and luminosity profiles of XRBs. These α, p-process reactions have been studied via the time-inverse (p, α) reactions in inverse kinematics using radioactive ion beams produced by the in-flight method at the Argonne National Laboratory ATLAS facility. The results and possible implications for nucleosynthesis in XRBs will be discussed. This work was supported under JINA NSF grant No. PHY0822648 and U.S. DOE contract DE-AC02-06CH11357.