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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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DOE OSTI2025

Tables of Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections, Astrophysical Reaction Rates, and r-process Abundances Calculated from the ENDF/B-VIII.1, JEFF-3.3, JENDL-5.0, BROND-3.1, and CENDL-3.2 Evaluated Data Libraries

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections, astrophysical reaction rates, and solar system r-process abundances using the latest data from the major evaluated nuclear libraries for 849 ENDF target materials. The recent release of ENDF/B-VIII.1 library, progress in 252 Cf(SF) evaluation, extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate the nuclear industry and neutron physics parameters, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, extract r-process abundances, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Neutrino Physics and Astrophysics at Colliders

Nonzero neutrino masses guarantee new physics and neutrinos are excellent probes of extreme environments in the Universe. The recent collider neutrino experimental program, including FASER$ν$ and SND@LHC, along with the planned Forward Physics Facility at the High-Luminosity Large Hadron Collider, is opening a new window into neutrino physics and astrophysics. In this article, we review recent achievements and prospects of collider neutrino experiments, including key achievements such as the first measurements of collider neutrino interactions at unprecedented energies and the exploration of new physics scenarios, like dark matter candidates, sterile neutrinos, and non-standard neutrino interactions. For concreteness, we will focus on the significant scientific opportunities presented by the Forward Physics Facility, which will enable precision measurements of neutrino cross sections and proton structure at low parton momentum fraction. Furthermore, collider neutrino studies will substantially reduce systematic uncertainties in calculating atmospheric neutrino fluxes, thereby improving astrophysical neutrino observations as well as advancing our understanding of cosmic-ray interactions.

Machado, Pedro [Fermilab] (ORCID:0000000291187354)↗
NASA NTRS1971

The shock tube in spectroscopy and astrophysics.

The role of shock-tube spectroscopy in laboratory astrophysics is discussed, with special emphasis on the effectiveness of the hook method for quantitative analyses on shock-heated gases in the determination of solar abundances. Oscillator strengths of Fe I obtained by the hook method are compared with f-values which have been measured by different experimental techniques. Although the hook values tend to be somewhat higher, they are in agreement with those obtained by wall-stabilized arc and shock-tube emission, the beamfoil techniques, and delayed coincidence measurements. Examples are given of other applications of shock-tube spectroscopy to solar and astrophysical studies such as comparisons of solar EUV spectra and laboratory observations of neutral iron, once-ionized iron, and the diatomic Fourth Positive system of CO.

Parkinson, W. H.↗
NASA NTRS1977

Symposium on Recent Results in Infrared Astrophysics

Abstracts of papers presented at a symposium titled Recent Results in Infrared Astrophysics are set forth. The abstracts emphasize photometric, spectroscopic, polarization, and theoretical results on a broad range of current topics in infrared astrophysics.

Dyal, P.↗
NASA NTRS1977

Recognition of compact astrophysical objects

NASA's Laboratory for High Energy Astrophysics and the Dept. of Physics and Astrophysics at the Univ. of Md. collaberated on a graduate level course with this title. This publication is an edited version of notes used as the course text. Topics include stellar evolution, pulsars, binary stars, X-ray signatures, gamma ray sources, and temporal analysis of X-ray data.

Ogelman, H.↗
NASA NTRS1978

Gamma-ray astrophysics - A new look at the universe

Gamma-ray astronomy, which may be defined to include the spectral region from above 100 keV to about 1000 GeV, permits investigation of the most energetic photons originating in the Galaxy and beyond. These observations provide the most direct means of studying the largest transfers of energy occurring in astrophysical processes, including the dynamic effects of the energetic charged cosmic-ray particles, element synthesis, and particle acceleration. Further, gamma-rays suffer negligible absorption or scattering as they travel in straight paths. Hence they may survive billions of years. Studies of the spatial, temporal, and energy distribution of cosmic gamma-rays will, therefore, provide fundamental new information for resolving some of the major problems in astrophysics today. Attention is given to the gamma-ray observations of the solar system, stellar objects, diffuse gamma-ray emission from the Galaxy, other galaxies and cosmology, and future prospects.

Trombka, J.↗
NASA NTRS1979

Workshop on the Physics of Planetary and Astrophysical Magnetospheres, Snowmass, Colo., July 30-August 4, 1978, Proceedings

The paper presents theoretical and observational works in the field of planetary and astrophysical magnetospheres. The magnetospheres of earth and Jupiter are analyzed along with pulsar magnetospheres and X-ray source magnetospheres. Consideration is given to coherent radio emissions in space and astrophysics and collective radio emissions from plasmas. Theories of magnetospheres around accreting compact objects are also presented.

Kennel, C. F.↗
NASA NTRS1981

Radiative decay of massious neutrinos: Implications for physics and astrophysics

The radiative lifetime tau for the decay of massious neutrinos is calculated using various physical models for neutrino decay. The results are related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data are used to place lower limits on tau. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models. It is considered that this may be an important test for substructure in leptons and quarks.

Stecker, F. W.↗
NASA NTRS1981

Astrophysical tests for radiative decay of neutrinos and fundamental physics implications

The radiative lifetime tau for the decay of massious neutrinos was calculated using various physical models for neutrino decay. The results were then related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data were used to place lower limits on tau. These limits are all well below predicted values. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models or other new physics. Thus an important test for substructure in leptons and quarks or other physics beyond the standard electroweak model may have been found.

Stecker, F. W.↗
NASA NTRS1981

Relativistic astrophysics - The view from Texas in Baltimore /Review/

Recent observational and theoretical work presented at the Tenth Texas Symposium on Relativistic Astrophysics held in Baltimore, Maryland from December 15-19, 1980, is outlined. Areas covered include the theoretical foundations of relativistic astrophysics in general relativity, quantum gravitational theory and the association of grand unification with astronomical and cosmological issues, the cosmic microwave, X-ray, gamma-ray, UV, cosmic ray and gravitational wave backgrounds, the current expansion rate and average mass-energy density of the universe, and mechanisms of galaxy formation. Also discussed are the characteristics of active galaxies and clusters emitting in the gamma-ray and X-ray regions, and compact objects formed from supernova explosions, including pulsars, X-ray-emitting neutron stars, Sco X-1 and SS 433, gamma-ray sources, and X-ray and gamma-ray bursters.

Trimble, V. L.↗
NASA NTRS1982

Astronomy and astrophysics for the 1980's, volume 1

The programs recommended address the most significant questions that confront contemporary astronomy and fall into three general categories: prerequisites for research initiatives, including instrumentation and detectors, theory and data analysis, computational facilities, laboratory astrophysics, and technical support at ground-based observatories; programs including an Advanced X-ray Astrophysics Facility, a Very-Long Baseline Array, a Technology Telescope and a Large Deployable Reflector; and programs for study and development, including X-ray observatories in space, instruments for the detection of gravitational waves from astronomical objects, and long duration spaceflights of infrared telescopes. Estimated costs of these programs are provided.

Source record↗
NASA NTRS1983

Formation of standing shocks in stellar winds and related astrophysical flows

Stellar winds and other analogous astrophysical flows can be described, to lowest order, by the familiar one dimensional hydrodynamic equations which, being nonlinear, admit in some instances discontinuous as well as continuous transonic solutions for identical inner boundary conditions. The characteristics of the time dependent differential equations of motion are described to show how a perturbation changes profile in time and, under well defined conditions, develops into a stationary shock discontinuity. The formation of standing shocks in wind type astrophysical flows depends on the fulfillment of appropriate necessary conditions, which are determined by the conservation of mass, momentum and energy across the discontinuity, and certain sufficient conditions, which are determined by the flow's history.

Tsinganos, K.↗
NASA NTRS1982

Millimeter and submillimeter laboratory spectroscopy - Recent results of astrophysical interest

Recent laboratory spectroscopic results on the transient neutral species CCH, NH2, and NaH, the molecular ions HCO(+), N2H(+), and CO(+), and the light asymmetric internal rotor HOOH are reviewed. It is shown that the shorter millimeter and submillimeter spectral region offers a number of advantages, even in the laboratory. Attention is also given to the requirements for theoretical models capable of the accurate spectral predictions required for many astrophysical applications. The results presented here are seen as demonstrating that millimeter and submillimeter microwave spectroscopy provides a sensitive and flexible means of studying short-lived species in the laboratory. It is believed that, in combination with the appropriate theoretical approach, studies of this type are capable of providing accurate spectral maps over wide spectral regions for most species of astrophysical importance.

De Lucia, F. C.↗
NASA NTRS1984

Measurements of transition probabilities for spin-changing lines of atomic ions used in diagnostics of astrophysical plasmas

The intensities of ultraviolet, spin-changing, 'intersystem' lines of low-Z atomic ions are frequently used in determinations of electron densities and temperatures in astrophysical plasmas as well as in measurements of element abundances in the interstellar gas. The transition probabilities (A-values) of these lines, which are about five orders of magnitude weaker than allowed lines, have not been measured heretofore and various calculations produce A-values for these lines that differ by as much as 50 percent A radio-frequency ion trap has been used for the first measurements of transition probabilities for intersystem lines seen in astronomical spectra. The measurement procedure is discussed and results for Si III, O III, N II, and C III are reviewed and compared to calculated values. Discrepancies exist; these indicate that some of the calculated A-values may be less reliable than has been beleived and that revisions to the electron densities determined for some astrophysical plasmas may be required.

Smith, P. L.↗
NASA NTRS1985

Study of the potential usefulness of superfine holographic x-ray gratings in AXAF and astrophysics in general

Present day high energy electron storage rings and insertion devices (wigglers and undulators) provide the necessary technology to manufacture superfile (line density or=100,00/mm) holographic X-ray gratings. The usefulness in future astrophysical research of such gratings is determined, as a function of the grating size and line density. A model design is given for an instrument which would fit within the (presently specified) constraints of the planned Advanced X-ray Astrophysics Facility (AXAF).

Csonka, P. L.↗
NASA NTRS1985

Astrophysical payload accommodation on the space station

Surveys of potential space station astrophysics payload requirements and existing point mount design concepts were performed to identify potential design approaches for accommodating astrophysics instruments from space station. Most existing instrument pointing systems were designed for operation from the space shuttle and it is unlikely that they will sustain their performance requirements when exposed to the space station disturbance environment. The technology exists or is becoming available so that precision pointing can be provided from the space station manned core. Development of a disturbance insensitive pointing mount is the key to providing a generic system for space station. It is recommended that the MSFC Suspended Experiment Mount concept be investigated for use as part of a generic pointing mount for space station. Availability of a shirtsleeve module for instrument change out, maintenance and repair is desirable from the user's point of view. Addition of a shirtsleeve module on space station would require a major program commitment.

Woods, B. P.↗