<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi></mml:math>-Wave Resonances of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">U</mml:mi></mml:mrow><mml:mrow><mml:mn>238</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

Bollinger, L.M.; Thomas, George E.

doi:10.1103/physrev.171.1293

Cited by 84 publications

(16 citation statements)

References 5 publications

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“…Even though there is a potential danger of incorrect assignment of l [41], the Bayesian approach was used in several cases in the past. The first investigators to apply Bayes' conditional probability for the determination of parities of 238 U resonances were Bollinger and Thomas [42]. Subsequently, Perkins and Gyullassy [43] and Oh et al [29] extensively applied this procedure in the evaluation of resonance parameters.…”

Section: Neutron Resonances: Bnl Approachmentioning

confidence: 99%

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Chadwick

Obložinský

Herman

et al. 2006

Nuclear Data Sheets

1,961

908

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We describe the next generation general purpose Evaluated Nuclear Data File, ENDF/B-VII.0, of recommended nuclear data for advanced nuclear science and technology applications. The library, released by the U.S. Cross Section Evaluation Working Group (CSEWG) in December 2006, contains data primarily for reactions with incident neutrons, protons, and photons on almost 400 isotopes. The new evaluations are based on both experimental data and nuclear reaction theory predictions.The principal advances over the previous ENDF/B-VI library are the following: (1) New cross sections for U, Pu, Th, Np and Am actinide isotopes, with improved performance in integral validation criticality and neutron transmission benchmark tests; (2) More precise standard cross sections for neutron reactions on H, 6 Li, 10 B, Au and for 235,238 U fission, developed by a collaboration with the IAEA and the OECD/NEA Working Party on Evaluation Cooperation (WPEC); (3) Improved thermal neutron scattering; (4) An extensive set of neutron cross sections on fission products developed through a WPEC collaboration; (5) A large suite of photonuclear reactions; (6) Extension of many neutron-and proton-induced reactions up to an energy of 150 MeV; (7) Many new light nucleus neutron and proton reactions; (8) Post-fission beta-delayed photon decay spectra; (9) New radioactive decay data; and (10) New methods developed to provide uncertainties and covariances, together with covariance evaluations for some sample cases.The paper provides an overview of this library, consisting of 14 sublibraries in the same, ENDF-6 format, as the earlier ENDF/B-VI library. We describe each of the 14 sublibraries, focusing on neutron reactions. Extensive validation, using radiation transport codes to simulate measured critical assemblies, show major improvements: (a) The long-standing underprediction of low enriched U thermal assemblies is removed; (b) The 238 U, 208 Pb, and 9 Be reflector biases in fast systems are largely removed; (c) ENDF/B-VI.8 good agreement for simulations of highly enriched uranium assemblies is preserved; (d) The underprediction of fast criticality of 233,235 U and 239 Pu assemblies is removed; and (e) The intermediate spectrum critical assemblies are predicted more accurately.We anticipate that the new library will play an important role in nuclear technology applications, including transport simulations supporting national security, nonproliferation, advanced reactor and fuel cycle concepts, criticality safety, medicine, space applications, nuclear astrophysics, and nuclear physics facility design. The ENDF/B-VII.0 library is archived at the National Nuclear Data Center,

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Section: Neutron Resonances: Bnl Approachmentioning

confidence: 99%

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Chadwick

Obložinský

Herman

et al. 2006

Nuclear Data Sheets

1,961

908

View full text Add to dashboard Cite

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“…They also result from propagating only the uncorrelated uncertainties to counting statistics. The assignment of orbital angular momentum ( = 0 or 1) was based on the approach proposed by Bollinger and Thomas [69]. An upper level gΓ From the data in appendix A an average radiation width Γ γ = 22.5 meV was derived with a variation of 1 meV at one standard deviation.…”

Section: Energy Region Below 1200 Evmentioning

confidence: 99%

Neutron capture cross section measurements for 238U in the resonance region at GELINA

et al. 2016

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Abstract. Measurements were performed at the time-of-flight facility GELINA to determine the 238 U(n, γ) cross section in the resonance region. Experiments were carried out at a 12.5 and 60 m measurement station. The total energy detection principle in combination with the pulse height weighting technique was applied using C 6D6 liquid scintillators as prompt γ-ray detectors. The energy dependence of the neutron flux was measured with ionisation chambers based on the 10 B(n, α) reaction. The data were normalised to the isolated and saturated 238 U resonance at 6.67 eV. Special procedures were applied to reduce bias effects due to the weighting function, normalization, dead time and background corrections, and corrections related to the sample properties. The total uncertainty due to the weighting function, normalization, neutron flux and sample characteristics is about 1.5%. Resonance parameters were derived from a simultaneous resonance shape analysis of the GELINA capture data and transmission data obtained previously at a 42 m and 150 m station of ORELA. The parameters of resonances below 500 eV are in good agreement with those resulting from an evaluation that was adopted in the main data libraries. Between 500 eV and 1200 eV a systematic difference in the neutron width is observed. Average capture cross section data were derived from the experimental capture yield in the energy region between 3.5 keV and 90 keV. The results are in good agreement with an evaluated cross section resulting from a least squares fit to experimental data available in the literature prior to this work. The average cross section data derived in this work were parameterised in terms of average resonance parameters and included in a least squares analysis together with other experimental data reported in the literature.

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“…Resonances with values of > 1 have a very low expected average neutron width for 232 Th and are considered to be not observable. This technique, based on the difference in the penetrability factor for s and p waves, was already described by Bollinger and Thomas [70] and is explained in some detail in, for example, Ref. [11] and references therein, notably Gyulassy et al [71].…”

Section: A Orbital Momentum Assignmentmentioning

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

Phys. Rev. C

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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.

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p-Wave Resonances ofU238

Cited by 84 publications

References 5 publications

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology

Neutron capture cross section measurements for 238U in the resonance region at GELINA

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

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