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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Nuclear Data Sheets for A=38☆

All available experimental data of nuclear structure and decay are evaluated for the known nuclides of mass 38 (Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti). Detailed results of this evaluation are presented with the best values recommended for level energies, half-lives, γ-ray energies and intensities, decay properties (energies, intensities and placement of radiations), and other spectroscopic information. The {sup 38}Ar nuclide remains as the most extensively studied via various reactions and decays; no excited states are known in {sup 38}Al except for that an isomeric state is tentatively proposed from a recent β-decay measurement (2015St14); the {sup 38}Sc and {sup 38}Ti nuclides remain unidentified, with no experimental references reported for {sup 38}Sc and with a measurement of fragmentation cross sections reported for {sup 38}Ti but finding no evidence of its presence (1996Bl21). This work supersedes the earlier full evaluation of A=38 by J.A. Cameron and B. Singh (2008Ca01).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Nuclear Data Sheets for A=82☆

The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reactions studies for all isobars, Z=28(Ni) to Z=42(Mo), with mass number A=82. For {sup 82}Ni not much is known other than its identification. Most of the new data, i.e., after the last NDS (2003Tu03), are based on compilations included in XUNDL. Contributions of the various compilers in XUNDL are gratefully acknowledged.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2014

Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel

Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.

multilayer mirrors↗
DOE OSTI2021

Daejeon16 interaction with contact-term corrections for heavy nuclear systems

The Daejeon16 two-nucleon interaction is employed in many-body approaches based on the mean-field approximation. The perturbative character of Daejeon16 is verified by comparing results for 16 O from the Hartree–Fock (HF) approximation and from the no-core shell model and by examining the magnitude of perturbative corrections to the HF energy in light and heavy nuclei. Here, in order to approximately describe energies and radii across the nuclear chart, a phenomenological correction in the form of a two-plus-three-nucleon contact interaction is introduced. With fitted parameters we achieve a very good description of medium-mass nuclei in terms of energy and size and also in terms of the centroid energy of the giant monopole resonance and the dipole polarizability calculated within the random-phase approximation. Our results provide further justification for the use of Daejeon16 augmented with phenomenological corrections as an effective interaction of perturbative character in a variety of applications.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2010

International Nuclear Energy Research Initiative Development of Computational Models for Pyrochemical Electrorefiners of Nuclear Waste Transmutation Systems

In support of closing the nuclear fuel cycle using non-aqueous separations technology, this project aims to develop computational models of electrorefiners based on fundamental chemical and physical processes. Spent driver fuel from Experimental Breeder Reactor-II (EBR-II) is currently being electrorefined in the Fuel Conditioning Facility (FCF) at Idaho National Laboratory (INL). And Korea Atomic Energy Research Institute (KAERI) is developing electrorefining technology for future application to spent fuel treatment and management in the Republic of Korea (ROK). Electrorefining is a critical component of pyroprocessing, a non-aqueous chemical process which separates spent fuel into four streams: (1) uranium metal, (2) U/TRU metal, (3) metallic high-level waste containing cladding hulls and noble metal fission products, and (4) ceramic high-level waste containing sodium and active metal fission products. Having rigorous yet flexible electrorefiner models will facilitate process optimization and assist in trouble-shooting as necessary. To attain such models, INL/UI has focused on approaches to develop a computationally-light and portable two-dimensional (2D) model, while KAERI/SNU has investigated approaches to develop a computationally intensive three-dimensional (3D) model for detailed and fine-tuned simulation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2011

Nuclear Nonproliferation and Arms Control Primer Prepared for the Blue Ribbon Commission on America’s Nuclear Future

To provide a brief overview of key arms control and nonproliferation arrangements for the layperson that may be relevant to the Commission's comprehensive review of policies for managing the back end of the nuclear fuel cycle. Primer would be published by the Commission and made publicly available, probably as an appendix to a larger Commission report.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

J/ψ production and nuclear effects in p-Pb collisions at $ \sqrt{{{{\mathrm{s}}_{\mathrm{NN}}}}} $ = 5.02 TeV

We studied inclusive J/ψ production with the ALICE detector in p-Pb collisions at the nucleon-nucleon center of mass energy √s NN = 5.02 TeV at the CERN LHC. The measurement is performed in the center of mass rapidity domains 2.03 < y cms < 3.53 and -4.46 < y cms < -2.96, down to zero transverse momentum, studying the μ + μ - decay mode. In this paper, the J/ψ production cross section and the nuclear modification factor R pPb for the rapidities under study are presented. Moreover, while at forward rapidity, corresponding to the proton direction, a suppression of the J/ψ yield with respect to binary-scaled pp collisions is observed, in the backward region no suppression is present. Finally, the ratio of the forward and backward yields is also measured differentially in rapidity and transverse momentum. Theoretical predictions based on nuclear shadowing, as well as on models including, in addition, a contribution from partonic energy loss, are in fair agreement with the experimental results.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Measurement of D s + production and nuclear modification factor in Pb-Pb collisions at $ \sqrt{{\mathrm{s}}_{\mathrm{NN}}}=2.76 $

Here, the production of prompt D s + mesons was measured for the first time in collisions of heavy nuclei with the ALICE detector at the LHC. The analysis was performed on a data sample of Pb-Pb collisions at a centre-of-mass energy per nucleon pair, √s NN , of 2.76 TeV in two different centrality classes, namely 0–10% and 20–50%. Ds+ mesons and their antiparticles were reconstructed at mid-rapidity from their hadronic decay channel D s + → Φπ + , with Φ → K – K + , in the transverse momentum intervals 4 < pT < 12GeV/c and 6 < pT < 12 GeV/c for the 0–10% and 20–50% centrality classes, respectively. The nuclear modification factor RAA was computed by comparing the pT-differential production yields in Pb-Pb collisions to those in proton-proton (pp) collisions at the same energy. This pp reference was obtained using the cross section measured at √s = 7 TeV and scaled to √s = 2.76 TeV. The RAA of D s + mesons was compared to that of non-strange D mesons in the 10% most central Pb-Pb collisions. At high p T (8 < p T < 12 GeV/c) a suppression of the D s + -meson yield by a factor of about three, compatible within uncertainties with that of non-strange D mesons, is observed. At lower p T (4 < p T < 8 GeV/c) the values of the D s + -meson R AA are larger than those of non-strange D mesons, although compatible within uncertainties. The production ratios D s + /D 0 and D s + /D + were also measured in Pb-Pb collisions and compared to their values in proton-proton collisions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

The Sporadic History of Rubidium and its Role in Corrosion of Steel Related to Nuclear Material Storage

The influence of rubidium (Rb), both in its metallic and oxidized states, on the corrosion resistance of steels has direct relevance to the storage of radioactive Kr-85 containing nuclear materials. Kr-85 undergoes a ß-decay to generate stable, metallic Rb. The literature to date is sparse, contained primarily in company reports and divisive as to whether Rb metal, or its oxides, can lead to corrosion of steel materials. In both the direct storage of Kr-85 and used nuclear fuel that will contain Kr-85, if Rb is corrosive then continual decay of the Kr-85 will generate an increasingly corrosive environment for the steel canister it is stored in. This review was written to consolidate the known data to date on Rb corrosion of steels to identify consistencies, contradictions and remaining gaps in our understanding of the Rb : steel system.

krypton, corrosion, steel, Rubidium↗