Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-06-12
Astronomy and Astrophysics
Astrophysics
Proceedings "Nuclei in the Cosmos" NIC- IX, June 25-30 2006, CERN, Geneva/ Switzerland, published with Proccedings of Science,
Scientific paper
Although $^{79}$Se represents an important branching in the weak s process, the stellar neutron capture cross sections to this isotope have not yet been measured experimentally. In this case, experimental data is essential for evaluating the important branching in the s-process reaction path at $^{79}$Se. The total cross section of $^{78}$Se at a stellar energy of kT = 25 keV has been investigated with a combination of the activation technique and accelerator mass spectrometry (AMS), since offline decay counting is prohibitive due to the long terrestrial half life of $^{79}$Se (2.80$\pm$0.36 $\times10^5$ y) as well as the absence of suitable $\gamma$-ray transitions. The preliminary result for the total Maxwellian averaged cross section is $<\sigma>_{30 keV}$= 60.1$\pm$9.6 mbarn, significantly lower than the previous recommended value. In a second measurement, also the partial cross section to the 3.92 min-isomer was determined via $\gamma$-spectroscopy and yielded $<\sigma>_{30 keV}$(part.)= 42.0$\pm$2.0 mbarn.
Dillmann Iris
Faestermann Th.
Heil Matthias
Käppeler Franz
Knie Klaus
No associations
LandOfFree
First measurements of the total and partial stellar cross section to the $s$-process branching-point $^{79}$Se does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with First measurements of the total and partial stellar cross section to the $s$-process branching-point $^{79}$Se, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First measurements of the total and partial stellar cross section to the $s$-process branching-point $^{79}$Se will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-690863