The β decay of Hg208 into the one-proton hole, one neutron-particle Tl81208127 nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the ...proton-neutron interactions used, with implications for the whole of the N>126, Z
The average energy and multiplicity of prompt
γ
-rays from slow neutron-induced fission of
235
U have been measured using the STEFF spectrometer at the neutron time-of-flight facility n_TOF. The ...individual responses from 11 NaI scintillators were corrected for multiple
γ
-ray interactions, prompt fission neutrons and background counts before being deconvolved to estimate the emitted spectrum of prompt fission
γ
-rays. The results give an average
γ
-ray energy
E
¯
γ
of 1.71(5) MeV and multiplicity
ν
¯
γ
of 2.66(18) considering
γ
-rays emitted within the energy range 0.8–6.8 MeV. The n_TOF data has a slightly larger
E
¯
γ
and smaller
ν
¯
γ
than other recent measurements, however the product of the two is in agreement within quoted uncertainties.
The neutron time-of-flight facility n_TOF at CERN is a spallation source dedicated to measurements of neutron-induced reaction cross-sections of interest in nuclear technologies, astrophysics, and ...other applications. Since 2014, Experimental ARea 2 (EAR2) is operational and delivers a neutron fluence of ∼4⋅107 neutrons per nominal proton pulse, which is ∼50 times higher than the one of Experimental ARea 1 (EAR1) of ∼8⋅105 neutrons per pulse. The high neutron flux at EAR2 results in high counting rates in the detectors that challenged the previously existing capture detection systems. For this reason, a Segmented Total Energy Detector (sTED) has been developed to overcome the limitations in the detector’s response, by reducing the active volume per module and by using a photo-multiplier (PMT) optimized for high counting rates. This paper presents the main characteristics of the sTED, including energy and time resolution, response to γ-rays, and provides as well details of the use of the Pulse Height Weighting Technique (PHWT) with this detector. The sTED has been validated to perform neutron-capture cross-section measurements in EAR2 in the neutron energy range from thermal up to at least 400 keV. The detector has already been successfully used in several measurements at n_TOF EAR2.
•The previous detectors to do capture measurements at n_TOF EAR2 show disadvantages.•The sTED has been made with smaller active volumes and optimized photomultipliers.•The detector shows an excellent response to perform capture measurements at n_TOF EAR2.•In a large energy range, the sTED has been validated to do capture measurements.
The cross section of the
89
Y(n,
γ
) reaction has important implications in nuclear astrophysics and for advanced nuclear technology. Given its neutron magic number N = 50 and a consequent small ...neutron capture cross section,
89
Y represents one of the key nuclides for the stellar
s
-process. It acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier elements. Moreover, it is located at the overlapping region, where both the weak and main
s
-process components take place.
89
Y, the only stable yttrium isotope, is also used in innovative nuclear reactors. Neutron capture and transmission measurements were performed at the time-of-flight facilities n_TOF at CERN and GELINA at JRC-Geel. Resonance parameters of individual resonances were extracted from a resonance analysis of the experimental transmission and capture yields, up to a neutron incident energy of 95 keV. Even though a comparison with results reported in the literature shows differences in resonance parameters, the present data are consistent with the Maxwellian averaged cross section suggested by the astrophysical database
KADoNiS
.
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