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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 109 records · Page 6

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NASA NTRS1978

Nuclear quadrupole resonance studies project

The participation of undergraduates in nuclear quadrupole resonance research at Grambling University was made possible by NASA grants. Expanded laboratory capabilities include (1) facilities for high and low temperature generation and measurement; (2) facilities for radio frequency generation and measurement with the modern spectrum analyzers, precision frequency counters and standard signal generators; (3) vacuum and glass blowing facilities; and (4) miscellaneous electronic and machine shop facilities. Experiments carried out over a five year period are described and their results analyzed. Theoretical studies on solid state crystalline electrostatic fields, field gradients, and antishielding factors are included.

Murty, A. N.↗

NASA NTRS1995

LET spectra measurements from the STS-35 CPDs

Linear energy transfer (LET) spectra derived form automated track analysis system (ATAS) track parameter measurements for crew passive dosimeters (CPD's) flown with the astronauts on STS-35 are plotted. The spread between the seven individual spectra is typical of past manual measurements of sets of CPD's. This difference is probably due to the cumulative net shielding variations experienced by the CPD's as the astronauts carrying them went about their activities on the Space Shuttle. The STS-35 mission was launched on Dec. 2, 1990, at 28.5 degrees inclination and 352-km altitude. This is somewhat higher than the nominal 300-km flights and the orbit intersects more of the high intensity trapped proton region in the South Atlantic Anomaly (SAA). However, in comparison with APD spectra measured on earlier lower altitude missions (STS-26, -29, -30, -32), the flux spectra are all roughly comparable. This may be due to the fact that the STS-35 mission took place close to solar maximum (Feb. 1990), or perhaps to shielding differences. The corresponding dose and dose equivalent spectra for this mission are shown. The effect of statistical fluctuations at the higher LET values, where track densities are small, is very noticeable. This results in an increased spread within the dose rate and dose equivalent rate spectra, as compared to the flux spectra. The contribution to dose and dose equivalent per measured track is much greater in the high LET region and the differences, though numerically small, are heavily weighted in the integral spectra. The optimum measurement and characterization of the high LET tails of the spectra represent an important part of the research into plastic nuclear track detector (PNTD) response. The integral flux, dose rate, dose equivalent rate and mission dose equivalent for the seven astronauts are also given.

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NASA NTRS2004

Non-nuclear Testing of Reactor Systems in the Early Flight Fission Test Facilities (EFF-TF)

The Early Flight Fission-Test Facility (EFF-TF) can assist in the &sign and development of systems through highly effective non-nuclear testing of nuclear systems when technical issues associated with near-term space fission systems are "non-nuclear" in nature (e.g. system s nuclear operations are understood). For many systems. thermal simulators can he used to closely mimic fission heat deposition. Axial power profile, radial power profile. and fuel pin thermal conductivity can be matched. In addition to component and subsystem testing, operational and lifetime issues associated with the steady state and transient performance of the integrated reactor module can be investigated. Instrumentation at the EFF-TF allows accurate measurement of temperature, pressure, strain, and bulk core deformation (useful for accurately simulating nuclear behavior). Ongoing research at the EFF-TF is geared towards facilitating research, development, system integration, and system utilization via cooperative efforts with DOE laboratories, industry, universities, and other NASA centers. This paper describes the current efforts for the latter portion of 2003 and beginning of 2004.

VanDyke, Melissa↗

NASA NTRS2021

Microstructural Observations on Advanced Multilayer Protective Coatings for Nuclear Thermal Propulsion

The present research discusses the microstructures of a new multilayered coating concept proposed to solve the “midrange corrosion” problem observed in NbC and ZrC-coated graphite (Gr) nuclear fuels during the NERVA/Rover programs. The concept envisions designing a compliant multilayered coatings architecture to accommodate the thermal expansion mismatch strains between the ZrC outer coating and the Gr/(U,Zr)C fuel matrix along with using a diffusion barrier to minimize carbon and hydrogen diffusion, respectively. Multilayered coatings were deposited on Gr substrates by chemical vapor deposition (CVD). Graphite disks, as well as the inner channels of a 19-hole hexagonal rod 152.4 mm long, were coated by CVD in proof-of concept process demonstration studies. Coated disk specimens were thermally-cycled between ambient and 1900 K for as long as 20 cycles with a 1h hold time at the temperature using both stepped and non-interrupted thermal cycling methods. Detailed cross-sectional microstructural analyses were conducted on the thermally-cycled coated disks. These results showed that the coatings were intact after 20 thermal cycles at 1900 K although the bonding of the overlay Mo coating appeared to be influenced by the oxygen content in the layer. Seven transverse sections were cut along the length from the coated hexagonal rod for microstructural studies. All the nineteen channels were observed to have been coated in all the sections. This paper reports the results of detailed microstructural analyses, compositional line scans and x-ray dot maps conducted on three coated channels from a mid-section of the rod. The measured values of carbon (C) were observed to be exceptionally high in all the specimens, which were attributed to hydrocarbon contamination of the specimen surfaces. It was observed that the oxygen (O) levels were high in all the coating layers even after approximately correcting for the observed high values of C. The source of O contamination of the CVD reactor system was attributed to either the presence of oxychloride impurities in the precursor salts or a pin hole leak in the coating system. It is concluded that high values of O result in poor bonding of the Mo overlay to the ZrC layer. These trials have established that it is possible to deposit multilayered coatings by CVD in 19-hole hexagonal rods 152.4 mm long similar to the NERVA fuel rod design although the quality of the coatings and the uniformity of their thicknesses require further improvement.

Nuclear thermal propulsion, multilayer coatings, m↗

NASA NTRS2013

A Potential NASA Research Reactor to Support NTR Development

In support of efforts for research into the design and development of a man rated Nuclear Thermal Rocket (NTR) engine, the National Aeronautics and Space Administration (NASA), Marshall Space Flight Center (MSFC), is evaluating the potential for building a Nuclear Regulatory Commission (NRC) licensed research reactor. The proposed reactor would be licensed by NASA and operated jointly by NASA and university partners. The purpose of this reactor would be to perform further research into the technologies and systems needed for a successful NTR project and promote nuclear training and education.

Eades, Michael↗

NASA NTRS1974

Research on fission fragment excitation of gases and nuclear pumping of lasers

Experimental investigations of fission fragment excited gases are reported along with a theoretical analysis of population inversions in fission fragment excited helium. Other studies reported include: nuclear augmentation of gas lasers, direct nuclear pumping of a helium-xenon laser, measurements of a repetitively pulsed high-power CO2 laser, thermodynamic properties of UF6 and UF6/He mixtures, and nuclear waste disposal utilizing a gaseous core reactor.

Schneider, R. T.↗

NASA NTRS1972

Space Nuclear Propulsion Systems and Applications

The basic principles of the operation of a nuclear rocket engine are reviewed along with a summary of the early history. In addition, the technology status in the nuclear rocket program for development of the flight-rated NERVA engine is described, and applications for this 75,000-pound thrust engine and the results of nuclear stage studies are presented. Advanced research and supporting technology activities in the nuclear rocket program are also summarized.

Schwenk, F. C.↗

NASA NTRS1979

Volume-pumped nuclear lasers

A summary is given to experimental results on volume-pumped nuclear lasers obtained at the Langley Research Center. The first volume-pumped nuclear laser was achieved in 1976 using the He-3(n, p)H-3 reaction. Since that time laser output has increased by more than a factor of 1000 (from mW to W). Lasing has been demonstrated in He-3-Ar (1.27 and 1.79 micron), He-3-Xe (2.027, 3.5, and 3.65 microns), He-3-Kr (2.19 and 2.52 microns), and He-3-Cl (1.587 micron). Pressures of the lasing mixture range from 300 torr to 4 atm with a peak power output of 26 W were achieved in a He-3-Ar mixture with a multiple-pass laser configuration.

Hohl, F.↗

NASA NTRS1979

Nuclear-pumped lasers 2

The two main research objectives of the contract were to demonstrate high power nuclear lasering (similar to kWatt) and demonstrate nuclear pumping with fission fragments from (U-235)F6. The progress made towards these objectives is discussed.

Wells, W.↗

NASA NTRS1993

Space Nuclear Thermal Propulsion (SNTP) tests

Viewgraphs on the space nuclear thermal propulsion (SNTP) program are presented. The objective of the research is to develop advanced nuclear thermal propulsion (NTP) technology based on the particle bed reactor concept. A strong philosophical commitment exists in the industry/national laboratory team to emphasize testing in development activities. Nuclear testing currently underway to support development of SNTP technology is addressed.

Allen, George C.↗

NASA NTRS1979

Large volume multiple-pass nuclear pumped laser

The paper describes research efforts at the Langley Research Center to study large volume, volumetric pumped laser systems and methods to extract lasing energy from these systems. Nuclear lasing has been achieved for a mixture of 800 torr He-3-Ar (1% Ar) with a peak thermal flux of 2.9 x 10 to the 16th n/sq cm-sec. Attention is given to the scaling of the multiple-pass box laser with increasing number of multiple passes and the scaling of laser output with path length.

Deyoung, R. J.↗

NASA NTRS2012

NASA Glenn Research Center Experience with "LENR Phenomenon"

Since 1989 NASA Glenn Research Center (GRC) has performed some small-scale limited experiments that show evidence of effects claimed by some to be evidence of Low Energy Nuclear Reactions (LENR). The research at GRC has involved observations and work on measurement techniques for observing the temperature effects in reactions of isotopes of hydrogen with palladium hydrides. The various experiments performed involved loading Pd with gaseous H2 and D2, and exposing Pd thin films to multi-bubble sonoluminescence in regular and deuterated water. An overview of these experiments and their results will be presented.

Wrbanek, Susan Y.↗

NASA NTRS2012

NASA Glenn Research Center Experience with LENR Phenomenon

hydrogen↗

NASA NTRS1961

Research Summary No. 36-9

Nuclear physics, materials science, propulsion, telecommunication, guidance, and systems analysis

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NASA NTRS1982

Annual Conference on Nuclear and Space Radiation Effects, 19th, Las Vegas, NV, July 20-22, 1982, Proceedings

The results of research concerning the effects of nuclear and space radiation are presented. Topics discussed include the basic mechanisms of nuclear and space radiation effects, radiation effects in devices, and radiation effects in microcircuits, including studies of radiation-induced paramagnetic defects in MOS structures, silicon solar cell damage from electrical overstress, radiation-induced charge dynamics in dielectrics, and the enhanced radiation effects on submicron narrow-channel NMOS. Also examined are topics in SGEMP/IEMP phenomena, hardness assurance and testing, energy deposition, desometry, and radiation transport, and single event phenomena. Among others, studies are presented concerning the limits to hardening electronic boxes to IEMP coupling, transient radiation screening of silicon devices using backside laser irradiation, the damage equivalence of electrons, protons, and gamma rays in MOS devices, and the single event upset sensitivity of low power Schottky devices.

Long, D. M.↗

NASA NTRS1972

Conceptual design studies and experiments related to cavity exhaust systems for nuclear light bulb configurations

Investigations of various phases of gaseous nuclear rocket technology have been conducted. The principal research efforts have recently been directed toward the closed-cycle, vortex-stabilized nuclear light bulb engine and toward a small-scale fissioning uranium plasma experiment that could be conducted in the Los Alamos Scientific Laboratory's Nuclear Furnace. The engine concept is based on the transfer of energy by thermal radiation from gaseous fissioning uranium, through a transparent wall, to hydrogen propellant. The reference engine configuration is comprised of seven unit cavities, each having its own fuel transparent wall and propellant duct. The basic design of the engine is described. Subsequent studies performed to supplement and investigate the basic design are reported. Summaries of other nuclear light bulb research programs are included.

Kendall, J. S.↗

NASA NTRS1986

Physics through the 1990s: Nuclear physics

The volume begins with a non-mathematical introduction to nuclear physics. A description of the major advances in the field follows, with chapters on nuclear structure and dynamics, fundamental forces in the nucleus, and nuclei under extreme conditions of temperature, density, and spin. Impacts of nuclear physics on astrophysics and the scientific and societal benefits of nuclear physics are then discussed. Another section deals with scientific frontiers, describing research into the realm of the quark-gluon plasma; the changing description of nuclear matter, specifically the use of the quark model; and the implications of the standard model and grand unified theories of elementary-particle physics; and finishes with recommendations and priorities for nuclear physics research facilities, instrumentation, accelerators, theory, education, and data bases. Appended are a list of national accelerator facilities, a list of reviewers, a bibliography, and a glossary.

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NASA NTRS2014

A Research Reactor Concept to Support NTP Development

In support of efforts for research into the design and development of man rated Nuclear Thermal Propulsion (NTP), the National Aeronautics and Space Administration (NASA), Marshall Space Flight Center (MSFC), is evaluating the potential for building a Nuclear Regulatory Commission (NRC) licensed NTP based research reactor (NTPRR). The proposed NTPRR would be licensed by NASA and operated jointly by NASA and university partners. The purpose of the NTPRR would be used to perform further research into the technologies and systems needed for a successful NTP project and promote nuclear training and education.

Eades, Michael J.↗