Investigation of γ-multiplicity spectra and neutron capture cross-sections of 232Th in the energy region 21.5–215 eV

We have measured the neutron capture reaction yield of 232 Th at the neutron time-of-flight facility n TOF at CERN in the energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves = 0, 1, and 2.

Section: B Comparison With Existing Datamentioning

confidence: 99%

“…Most of them have been performed using the neutron time-of-flight technique. Baek et al [24] investigated γ -ray multiplicity and capture cross section in the energy region between 21.5 and 215 eV. Grigoriev et al [25] measured the average cross section in the energy region between 10 eV and 10 keV.…”

Section: Introductionmentioning

confidence: 99%

Neutron capture cross section ofTh232measured at the n_TOF facility at CERN in the unresolved resonance region up to 1 MeV

Aerts¹,

Fujii²,

Vlastou³

et al. 2006

“…Experimental data are taken from Refs. [34][35][36] for 27 Al(n,γ ) 28 Al, [34,37] for 37 Cl(n,γ ) 38 Cl, [13] for 48 Ca(n,γ ) 49 Ca, [38] for 61 Ni(n,γ ) 62 Ni, [39,40] for 97 Mo(n,γ ) 98 Mo, [41,42] for 122 Sn(n,γ ) 123 Sn, [43][44][45] for 176 Lu(n,γ ) 177 Lu, [46,47] for 208 Pb(n,γ ) 209 Pb, and [48][49][50][51][52] for 232 Th(n,γ ) 233 Th.…”

Section: Figmentioning

confidence: 99%

Systematic study of neutron capture including the compound, pre-equilibrium, and direct mechanisms

Goriely

Koning

et al. 2014

The neutron capture reaction is investigated. The three major reaction mechanisms, namely, compound-nucleus capture (CNC), pre-equilibrium capture (PEC), and direct capture (DIC), are considered on the basis of the Hauser-Feshbach model, the exciton model, and potential model, respectively. The three mechanisms are treated simultaneously and consistently, i.e, they are obtained on the basis of the same nuclear ingredients, such as the optical potential and nuclear-level densities. In this framework, the three components are calculated on the same footing and represent partial fluxes of the same total reaction cross section. The total neutron-capture cross sections and astrophysical reaction rates are calculated within the updated modern reaction code TALYS for about 8000 nuclei with 8 Z 110 lying between the proton and neutron drip lines. The nuclear-structure ingredients involved in the calculation are determined from experimental data whenever available and, if not, from global microscopic nuclear models. For the targets with mass number A > 26, a fair agreement between the computed total-capture cross sections and experimental data is found but, for the lightest nuclei, only the predicted DIC cross sections reproduce the experimental results satisfactorily. Significant and even dominant contribution to the total reaction rate comes from the DIC component for neutron-rich nuclei, especially in the Z = 50-70 region. The impact of the newly determined reaction rates on the r process abundances resulting from the ejection of matter in neutrino-driven winds or the decompression of neutron star matter is investigated.

“…The 232 Th(n, γ ) cross sections in most of the evaluated data libraries [13] or data compilations [14,15] are based on a rather limited set of experiments [16][17][18][19][20][21][22][23][24][25][26] for which discrepancies have been pointed out to exist. A recent evaluation by Sirakov et al [27] for neutron-induced reactions of 232 Th in the unresolved resonance region included in addition several recent capture measurements [28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Publisher's Note: Measurement of resolved resonances of232Th(n,γ) at the n_TOF facility at CERN [Phys. Rev. C85, 064601 (2012)]

Gunsing¹,

Berthoumieux²,

Aerts³

et al. 2012

The yield of the neutron capture reaction 232 Th(n, γ ) has been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The reduction of the acquired data to the capture yield for resolved resonances from 1 eV to 4 keV is described and compared to a recent evaluated data set. The resonance parameters were used to assign an orbital momentum to each resonance. A missing level estimator was used to extract the s-wave level spacing of D 0 = 17.2 ± 0.9 eV.