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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Relativistic plasma effects and ion acceleration using Scarlet and ELI-NP

High energy density science (HEDS) explores the nature of matter under extreme conditions of temperature and pressure. It has wide ranging fundamental importance from understanding the physical structure of our planet to extreme phenomena in the cosmos. It also has many applications such as facilitating imaging with ions, neutrons, x-rays, gamma rays and more with new applications being developed, including materials processing and medical therapies.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

Enhancing the Design of Photocathodes with 90% polarization and QE > 1% for DOE NP (Final Report)

This project’s 3 major goals were the following: 1. Fabricate state-of-the-art spin-polarized photocathodes using MOCVD and develop knowledge of fabrication parameters. 2. Enhance the design of 2 structures of spin-polarized photocathodes (strained-superlattice and strained-superlattice with distributed Bragg reflector) to assess paths to the next generation of spin-polarized photocathodes. 3. Provide a supply of state-of-the-art spin-polarized photocathodes to both Brookhaven National Laboratory and the Thomas Jefferson National Accelerator Facility.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Measured Reaction Rate Ratios of 235 U, 238 U, 237 Np, 239 Pu Samples in the PFUNS 235 U Prompt Fission Neutron Spectrum Criticality Experiment

The Prompt Fission Uranium Neutron Spectrum experiment, an experiment to reduce uncertainties in the high energy tail of the 235 U prompt fission spectrum, achieved success by performing two separate irradiations measuring approximately 40 different IRDFF-II reactions total using over 20 different foil materials at the National Criticality Experiments Research Center in February 2024. The criticality experiment utilized a set of highly enriched uranium hemispherical shells of increasing diameters with a large void in the center where the samples were located. The focus of this work is the first of two PFUNS irradiations focused on irradiating two of each fission foils, one bare and one cadmium covered, along with metal activation foils containing reaction products with short half-lives, such as indium, iron, and gold along with nickel fluence monitors. This work focuses on presenting the initial reaction rate ratio results of the fission foils from the aforementioned first irradiation to assist in nuclear data validation of those species in a nearly pure 235 U prompt fission neutron spectrum and compares to the Lady Godiva and Flattop-25 historic experiments at the Los Alamos Critical Experiments Facility. Future work will combine fission foil and metallic activation foil reaction rate ratio results from both the first and second higher power irradiation and reaction rates for a final spectral adjustment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Regional Training Program: Promoting Undergraduate Minority Persistence in Nuclear Physics (RTP: PUMP-NP)

A total of two cohorts of research experience were conducted under this grant. The first year of the program in which a cohort of six students were recruited from three Historically Black Colleges and Universities (HBCUs). These students travelled to Durham, NC in summer to participate in this program. Prior to their arrival, the students participated in an orientation in which they selected from a choice of topics for summer research and were paired up with mentors from Triangle Universities Nuclear Laboratory (TUNL). The participants of the program were integrated with the larger cohort of summer students who had arrived at TUNL as part of other programs, such as the Research Experience for Undergraduates (REU).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1971

Measurement of the circular polarization of pulsar NP 0532.

The polarizer is briefly described. The polarization of the whole pulse is not significantly different from zero (-0.15 plus or minus 0.70 per cent). Polarization measurements of the leading edge and trailing edge of the main pulse are also given.

Angel, J. R. P.↗
NASA NTRS1988

1s2 1S-1s np 1P transitions of the helium isoelectronic sequence members up to z = 30

The radial integrals required to calculate oscillator strengths for the helium sequence ions have been obtained using a one-electron hydrogenic model. The present approach retains two different values of the effective charge parameter, one for the initial state, and one for the final state. The model is shown to be capable of reasonably reproducing the existing dipole oscillator strength values with minimal computational effort. Dipole oscillator strengths for certain ions are presented for the first time.

Khan, F.↗
NASA NTRS1993

Excitation cross sections for the ns 2S yields np 2P resonance transitions in Mg(+) (n = 3) and Zn(+) (n = 4) using electron-energy-loss and merged-beams methods

Electron-excitation cross sections are reported for the 3s 2S yields 3p 2P(h, k) resonance transition in Mg(+) at energies from threshold (4.43 eV) to approximately 9 times threshold (40.0 eV). The electron-energy-loss merged-beams technique used in these measurements is described in detail. In addition, the method of separating contributions of the elastically scattered (Coulomb) and the inelastically scattered electrons in the present Mg(+) case and previously reported Zn(+) results is described. Comparisons in the experimental energy range are made for Mg(+) with the two five-state close-coupling theoretical calculations carried out herein, and with other published close-coupling, distorted-wave, and semiempirical calculations. The present Mg(+) cross sections and Zn(+) cross sections from earlier measurements are tabulated.

Smith, Steven J.↗
NASA NTRS1988

1s2 1S-1s np 1P transitions of the helium isoelectronic sequence members up to Z = 30

Radial integrals have been calculated under the one-electron hydrogenic model. Two different values of the effective charge parameter, one for the initial state and the other for the final state, are retained in these formulae. The model is able to reasonably reproduce the existing dipole oscillator strength values with little effort. The dipole oscillator strength values are given for many ions for the first time.

NASA Discipline Number 22-70↗
DOE OSTI2025

PHOTOPRODUCTION OF np^0 BY DOUBLE-REGGE EXCHANGE

The GlueX experiment is a photoproduction experiment based at Jeferson Lab in Newport News, Virginia. A major aim of GlueX is to look for hybrid mesons, which are a quark and an anti-quark bound by an excited gluonic field that contributes to the quantum numbers. The reaction ¿p ¿ ¿e0p is of particular interest since ¿e is a potential decay mode of states with exotic quantum numbers JPC =1¿+, which are forbidden in the constituent quark model. Finding such a resonance would be a clear sign of non-quark model physics. In concert with the Joint Physics Analysis Center we have developed a model for double-Regge interactions in this channel. These non-resonant processes generate asymmetries in the distributions of decay angles, which could be falsely attributed to the interference between exotic odd partial waves and even partial waves. In previous searches for light exotics we have seen evidence for the necessity of accounting for the presence of these non-resonant productions. We present a double-Regge model for photoproduction of ¿e0 and the application of it by measuring the asymmetry of ¿e0 production in the double Regge limit, as well as a comparison of the measured results to current theoretical predictions.

Barsotti, Rebecca [Indiana Univ. Southeast, New Al↗
DOE OSTI2020

Materials Data on NaNp3FeF15 by Materials Project

NaNp3FeF15 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to twelve F1- atoms to form NaF12 cuboctahedra that share faces with two equivalent FeF6 octahedra. There are a spread of Na–F bond distances ranging from 2.63–2.69 Å. In the second Na1+ site, Na1+ is bonded in a distorted octahedral geometry to six F1- atoms. There are a spread of Na–F bond distances ranging from 2.34–2.41 Å. There are six inequivalent Np+3.67+ sites. In the first Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.20–2.53 Å. In the second Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.21–2.53 Å. In the third Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.20–2.52 Å. In the fourth Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.21–2.54 Å. In the fifth Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.21–2.53 Å. In the sixth Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.20–2.56 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six F1- atoms to form FeF6 octahedra that share faces with two equivalent NaF12 cuboctahedra. There are five shorter (2.01 Å) and one longer (2.02 Å) Fe–F bond lengths. In the second Fe3+ site, Fe3+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of Fe–F bond distances ranging from 2.08–2.14 Å. There are thirty inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the third F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the seventh F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the eighth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the ninth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the tenth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the eleventh F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the twelfth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+ and two Np+3.67+ atoms. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the fourteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the fifteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the sixteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the seventeenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the eighteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Np+3.67+, and one Fe3+ atom. In the nineteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the twentieth F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the twenty-first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Na1+ and two Np+3.67+ atoms. In the twenty-second F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the twenty-third F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the twenty-fourth F1- site, F1- is bonded in a 3-coordinate geometry to two Np+3.67+ and one Fe3+ atom. In the twenty-fifth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-sixth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-seventh F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-eighth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-ninth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the thirtieth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms.

36 MATERIALS SCIENCE↗