145 research outputs found
Stellar and thermal neutron capture cross section of ⁹Be
The neutron capture cross section of ⁹Be for stellar energies was measured via the activation technique using the Karlsruhe Van de Graaff accelerator in combination with accelerator mass spectrometry at the Vienna Environmental Research Accelerator. To characterize the energy region of interest for astrophysical
applications, activations were performed in a quasistellar neutron spectrum of kT = 25 keV and for a spectrum
at En = 473 ± 53 keV. Despite the very small cross section, the method used provided the required sensitivity for
obtaining fairly accurate results of 10.4 ± 0.6 and 8.4 ± 1.0 μb, respectively. With these data it was possible to
constrain the cross section shape up to the first resonances at 622 and 812 keV, thus allowing for the determination
of Maxwellian-averaged cross sections at thermal energies between kT = 5 and 100 keV. In addition, we report
a new experimental cross section value at thermal energy of σth = 8.31 ± 0.52 mb.This work was partly funded by the Austrian Science
Fund (FWF), Projects No. P20434 and No. I428, and by
the Australian Research Council, Projects No. DP140100136
and No. DP180100496
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