Speaker
Dr
Steven Pain
(ORNL)
Description
The long-lived radioactive nuclide $^{26}$Al is a predominant target for
γ-ray astronomy, including the first all-sky survey of an individual
γ-ray line. Massive stars have been highlighted as a dominant source
of ongoing synthesis of $^{26}$Al [1]. At these stellar temperatures, the
$^{26}$Al(p,γ)27Si reaction is expected to be the main reaction destroying
$^{26}$Al, thus impacting the net $^{26}$Al production [2]. However, the strengths
of low-lying resonances in $^{27}$Si wihch determine this rate are not well-constrained experimentally, and are the subject of recently renewed interest [3].
In order to determine spectroscopic information for the mirror states
to astrophysically-important resonances in $^{27}$Si, and thereby constrain
the reaction rate via these resonances, the $^{26}$Al(d,p)$^{27}$Al reaction has
been measured [4]. The experiment was performed at the Holifield
Radioactive Ion Beam Facility at Oak Ridge National Laboratory, using
a beam of ~5 million $^{26}$Al per second. The SIDAR and ORRUBA silicon
detector arrays were used to measure proton ejectiles backwards of 90
degrees in the laboratory. Spectroscopic information was determined for
mirrors to the astrophysically-relevant resonances, which were
found to differ significantly from previously adpoted values. Details of the
astrophysical motivation, experiment, and results will be presented.
Work supported in part by the US Department of Energy and the National
Science Foundation
[1] J. Knödlseder, Astrophys. Lett. Commun. 38, 379 (1999)
[2] C. Iliadis, A. Champagne, A. Chieffi, and M. Limongi,
Astrophys. J. Suppl. Ser. 193, 16 (2011)
[3] A. Parikh, J. José, A. Karakas, C. Ruiz, and K. Wimmer, Phys. Rev. C 90 038801 (2014)
[4] S.D. Pain et al., Phys. Rev. Lett. 114, 212501 (2015)
Primary author
Dr
Steven Pain
(ORNL)
