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The nucleus23Na has been investigated by studying the primary γ-rays emitted from 53 keV neutron capture in it using a high resolution and high efficiency (100%) HPGe detector and NaI(T1) detector for anti-Compton. 24 primary γ-rays were placed in the24Na, in which 3 primary γ-rays were new ones from a (n, γ) reaction, and reported for the first time. In order to obtain an exact energy calibration within 7 MeV,56Fe(n,γ)57Fe reaction was used at thermal neutron energy. Intensity calibration was obtained from the27Al(p,γ)28Si reaction atEp=2046 keV. The neutron binding energy of24Na was determined to be 6959.75 keV.

Abstract: The cross sections of the neutron capture reaction on light nuclei, protons,12C and16O, were measured at astrophysically relevant energies between 10 and 300 keV. They are not only important for estimating yields of elements in the primordial nucleosynthesis, stellar nucleosynthesis of s-, r-, and p-processes, but also to study the role of meson exchange currents, the nuclear structure and the reaction mechanism. In the measurement, we used a prompt γ-ray detection method, combined with a pulsed neutron beam, and a recently developed Monte-Carlo code, TIME-MULTI, to correct for neutron multiple-scattering effects in a sample.

We have measured γ-ray spectra from the 434 keV p32-waveneutron resonance capture and from the off-resonance capture at 280 keV with an anti-Compton NaI(Tl) detector, employing a time-of-flight technique. Partial radiative widths and partial off-resonance capture cross sections were obtained for the transitions to the ground (52+)and 871 keV (12+)states in 17O. The radiative widths are well predicted by the valence capture formula of Lane and Mughabghab. Moreover, we found that the potential-capture theory substantially reproduces the partial off-resonance capture cross sections.