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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Test Report for the Qualification Testing of the ORNL-SFC-W-1 Special Form Capsule

Three prototypes the ORNL-SFC-W-1 special form capsules (SFCs) of the same design were evaluated to determine if the requirements of Title 49, Code of Federal Regulations (CFR), Part 173.469, Tests for Special Form Class 7 (Radioactive) Materials, were met. The results of the special form tests are documented in this test report. This report describes the special form testing activities performed on the three ORNL-SFC-W-1 capsules. The test units were designated as TU-1, TU-2 and TU-3. TU-1 was subjected to leak testing, impact testing and percussion testing. TU-1 was leak tested using the leak rate test specified in 49 CFR 173.469(a)(4)(i). The impact test was conducted according to the requirements in 49 CFR 173.469 (b)(1). The percussion test that was carried out on TU-1 was conducted in accordance with 49 CFR 173.469 (b)(2). Both TU-2 and TU-3 were subjected to a leak rate test as specified in 173.469(a)(4)(i) and a heat test as specified in 49 CFR 173.469(b)(4). Each test unit was leak tested before and after these respective tests. The leak rate tests performed were helium back-pressure tests and bubble tests as specified in American National Standards Institute (ANSI) N14.5-2014.The measured leak rates were converted to standard condition leak rates as specified in American Society for Testing and Measurement (ASTM) E 493. The determined standardized leak rates obtained from the test and the calculations for all the test units met the requirements for special form certification. The testing was performed under the direction of the Oak Ridge National Laboratory (ORNL) Package Testing Program (PTP).

42 ENGINEERING↗
DOE OSTI2022

Towards a combination of LHC and TeVatron W-boson mass measurements

In this note methodological and modelling considerations towards a combination of the ATLAS, CDF and D0 measurements of the W -boson mass are discussed. As they were performed at different moments in time, each measurement employed different assumptions for the modelling of W -boson production and decay, as well as different fits of the parton distribution functions of the proton (PDFs). Methods are presented to accurately evaluate the effect of PDFs and other modelling variations on existing measurements, allowing to extrapolate them to any PDF set and to evaluate the corresponding uncertainties. Based on this approach, the measurements can be corrected to a common modelling reference and to the same PDFs, and subsequently combined accounting for PDF correlations in a quantitative way.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Sputter deposition of Ta 1 W 1 Au 1 Bi 7 films for next generation hohlraums

Hohlraum simulation predicts a higher x-ray drive from Ta 1 W 1 Au 1 Bi 7 compared with our current Au hohlraum. Here, we study the effect of deposition process parameters including deposition rate, working pressure, target-to-substrate distance, substrate bias, and substrate temperature on the microstructure of Ta1W1Au1Bi7 films deposited by direct current magnetron sputtering onto planar substrates. We found that the substrate temperature has a pronounced effect on the film microstructure. This is attributed to the Bi low melting point (271°C) causing its adatom mobility to be strongly dependent on the substrate temperature. Additionally, we observed phase separation for films deposited with a high substrate bias. These results have important implications for the development of a robust Ta 1 W 1 Au 1 Bi 7 hohlraum fabrication process.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Test Report for the Regulatory Testing of the Welded Isotek-SFC-W-3 Special Form Capsule

Two prototypes the welded ISOTEK-SFC-W-3 special form capsules (SFCs) of the same design were evaluated to determine if the requirements of Title 49, Code of Federal Regulations (CFR), Part 173.469, Tests for Special Form Class 7 (Radioactive) Materials, were met. The results of the special form tests are documented in this test report. This report describes the special form testing activities performed on the two welded ISOTEK-SFC-W-3 capsules. The test units were designated as TU-1 and TU-2. TU-1 was subjected to leak testing, percussion testing, and impact testing. TU-1 was leak tested using the leak rate test specified in 49 CFR 173.469(a)(4)(i). The impact test on TU-1 was conducted according to the requirements in 49 CFR 173.469 (b)(1). The percussion test that was carried out on TU-1 was conducted in accordance with 49 CFR 173.469 (b)(2). TU-2 was subjected to a leak rate test as specified in 173.469(a)(4)(i) and a heat test as specified in 49 CFR 173.469(b)(4). Each test unit was leak tested before and after these respective tests. The leak rate tests performed were helium back-pressure tests and bubble tests, as specified in American National Standards Institute (ANSI) N14.5-2014. The measured leak rates were converted to standard condition leak rates as specified in American Society for Testing and Measurement (ASTM) E 493. The determined standardized leak rates obtained from the test and the calculations for all the test units met the requirements for special form certification. The testing was performed under the direction of the Oak Ridge National Laboratory (ORNL) Package Testing Program (PTP).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Autonomous Infrared and Small (Wide) Angle X-Ray Scattering (IR-S(W)AXS) Capability

Thin water films are 2-D, nanoconfined layers that form on solid surfaces exposed to humid atmospheres—environments ubiquitous across catalysis, corrosion science, soil science, and subsurface geochemistry. At relative humidity (RH) values below saturation, these films are Å–nm thick and exhibit properties that differ sharply from bulk water, including disrupted H-bonding and impeded mass transport. Owing to their high surface-to-volume ratio, dissolution of the solid can rapidly drive strong supersaturation with respect to secondary phases. Reactivity in thin water films is highly sensitive to film thickness, and critically, thickness evolves during reaction because the hygroscopicity of the interfacial system changes as ions accumulate or diminish in the film and as reaction products transform. To accurately probe and control these dynamics, a capability is needed that can measure and automatically maintain a constant water-film thickness while simultaneously monitoring solid dissolution, nucleation, and growth. This project developed an autonomous Infrared/Small Angle X-ray Scattering-Wide Angle X-ray Scattering (IR/(W)SAXS) for investigating reactivity in thin water films on solid surfaces exposed to humidified gases. The capability consists of an IR spectrometer, a (W)SAXS instrument, and a mass flow controller system for generating variably humidified gas flows to a custom reaction cell. Progress on each of the major components of the capability are detailed below.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Carbide Formation in Refractory Mo 15 Nb 20 Re 15 Ta 30 W 20 Alloy under a Combined High-Pressure and High-Temperature Condition

In this work, the formation of carbide with the concertation of carbon at 0.1 at.% in refractory high-entropy alloy (RHEA) Mo 15 Nb 20 Re 15 Ta 30 W 20 was studied under both ambient and high-pressure high-temperature conditions. The x-ray diffraction of dilute carbon (C)-doped RHEA under ambient pressure showed that the phases and lattice constant of RHEA were not influenced by the addition of 0.1 at.% C. In contrast, C-doped RHEA showed unexpected phase formation and transformation under combined high-pressure and high-temperature conditions by resistively employing the heated diamond anvil cell (DAC) technique. The new FCC_L1 2 phase appeared at 6 GPa and 809 °C and preserved the ambient temperature and pressure. High-pressure and high-temperature promoted the formation of carbides Ta 3 C and Nb 3 C, which are stable and may further improve the mechanical performance of the dilute C-doped alloy Mo 15 Nb 20 Re 15 Ta 30 W 20 .

36 MATERIALS SCIENCE↗
DOE OSTI2023

Vibronic Relaxation Pathways in Molecular Spin Qubit Na 9 [Ho(W 5 O 18 ) 2 ]·35H 2 O under Pressure

In order to explore how spectral sparsity and vibronic decoherence pathways can be controlled in a model qubit system with atomic clock transitions, we combined diamond anvil cell techniques with synchrotron-based far infrared spectroscopy and first-principles calculations to reveal the vibrational response of Na 9 [Ho(W 5 O 18 ) 2 ]·35H 2 O under compression. Because the hole in the phonon density of states acts to reduce the overlap between the phonons and f manifold excitations in this system, we postulated that pressure might move the HoO 4 rocking, bending, and asymmetric stretching modes that couple with the M J = ±5, ±2, and ±7 levels out of resonance, reducing their interactions and minimizing decoherence processes, while a potentially beneficial strategy for some molecular qubits, pressure slightly hardens the phonons in Na 9 [Ho(W 5 O 18 ) 2 ]·35H 2 O and systematically fills in the transparency window in the phonon response. The net result is that the vibrational spectrum becomes less sparse and the overlap with the various M J levels of the Ho 3+ ion actually increases. These findings suggest that negative pressure, achieved using chemical means or elongational strain, could further open the transparency window in this rare earth-containing spin qubit system, thus paving the way for the use of device surfaces and interface elongational/compressive strains to better manage decoherence pathways.

36 MATERIALS SCIENCE↗
NASA NTRS1973

Water and the Martian W cloud.

The diurnal brightening of the W cloud region of Mars during the flyby of Mariners 6 and 7 is likely due to the formation of water ice clouds. The water required in the cloud and as vapor in the atmosphere to produce the observed brightening is estimated to be roughly between 0.1 and 10 microns. Either a qualified local source with this daily production over the W cloud area or a more probable daily uplift and saturation of existing atmosphere are compatible with observations.

Peale, S. J.↗
NASA NTRS1981

IUE ultraviolet observations of W UM a Stars

International Ultraviolet Explorer observations of four W UMa eclipsing binary systems (44 Boo, VW Cep, W UMa, and epsilon) are discussed. The stars generally show large surface fluxes of high temperature lines (C II, C IV, N V, Si IV) which may result from the high rotational velocities forced by synchronous rotation. High dispersion spectra of the 44 Boo system in the Mg II line enable the individual stellar components to be identified. The line widths and phase variations are consistent with the optically determined spectroscopic orbit. Circumstellar absorption of Mg II may be presented at selected phases.

Dupree, A. K.↗
NASA NTRS1983

RW Tauri as a weak W Serpentis star

Observations of the short-period eclipsing binary RW Tau made with the LWR and SWP cameras of the IUE satellite and with the ITS scanner at the 3-m Shane telescope of the Lick Observatory in August and October, 1982, are reported and analyzed. At total eclipse, weak excess continuous radiation in the LWR range and emission lines at Si IV (1), C IV (1), Al III (1), Fe III (34), and Mg II (1) in the SWP range were detected. These findings are similar to those for W Ser-type binaries such as U Cep. The parameters of the system are estimated using a bilinearly interpolated atmospheric model of the type developed by Kurucz (1979): primary-star T(eff) = 11,750 K, log g = 4.2, cool-component spectral type = K0 III, E(B-V) color excess = 0.14 mag, system distance = 270 pc. The implications of these findings for proposed models of the W Ser binaries are discussed, and the observation of a possible distant optical companion star 45 arcsec from RW Tau is reported.

Plavec, M. J.↗
NASA NTRS1983

The effects of Cr, Al, Ti, Mo, W, Ta, and Cb on the cyclic oxidation behavior of cast Ni-base superalloys at 1100 and 1150 C

Fifty Ni-base superalloys with concentrations of Cr, Al, Ti, Mo, W, Ta, and Cb systematically varied between two nonzero levels, were tested for cyclic oxidation resistance at 1100 and 1150 C. Oxidation resistance was interpreted in terms of the rate of specific weight change and the types of oxides formed. It is found that the resistance of the alloys to cyclic oxidation is largely determined by Al content, with a sharp increase in the oxidation resistance observed in the Al concentration range 5-8 at. pct. The effects of the other elements studied were small compared with that of aluminum. Best oxidation resistance characteristics were predicted for high Al (13 at. pct), low Cr (10 at. pct), low Ti (2 at. pct), low Cb (1 at. pct), and high Mo, W, and Ta (3 at. pct each). The effects of the refractory metals, however, are somewhat ambiguous and should be investigated further. Higher boron contents, which were unintentionally varied, were clearly detrimental even for the most resistant compositions.

Barrett, C. A.↗
NASA NTRS1989

Stable 1.25-W CW Methanol Laser

Far-infrared (FIR) laser operating at 119-micrometer-wavelength transition of methanol achieves very low drift in frequency. Continuous-wave (CW) FIR output is 1.25 W when laser pumped by 125-W commercial CO2 laser. Rate of drift of output frequency less than plus or minus 100 kHz per hour because laser designed to have low thermal-expansion coefficients and because temperatures of input and output couplers held within 0.1 degree C of fixed values.

Farhoomand, Jam↗
NASA NTRS1989

W-band six-port network analyzer for two-port characterization of millimeter wave transistors

A W-band (75-100 GHz) six-port junction network analyzer was constructed from commercially available descrete waveguide components and was used for the direct two-port S-parameter measurement of active three-terminal devices. A comparison between the six-port and a down-converter-type frequency extender for a conventional network analyzer revealed the superior performance of the six-port. The application of the six-port to characterize a 0.1-micron gate-length HEMT at W-band is described, and representative results are presented.

Moeller, Karl J.↗
NASA NTRS1989

Estimates of equatorial upwelling between 140 deg and 110 deg W during 1984

The equation of continuity is used to estimate profiles of vertical velocity between 25 and 120 m from moored current measurements in arrays nested within the triangle with vertices located at 1 deg 30 arcmins S, 140 deg W and along the equator at 140 deg and 110 deg W during December 1983 through March 1984 and May-September 1984. All directions of the 4- to 5-month mean values were upward. The ensemble averaged mean vertical velocity was 0.000022 m/s. Upwelling speeds decreased eastward.

Halpern, David↗
NASA NTRS1990

W-band monolithic oscillator using InAlAs/InGaAs HEMT

A W-band monolithic integrated oscillator circuit was designed and fabricated using submicron HEMT technology. The oscillation frequency was around 81 GHz and the power was -7 dBm at the chip level. This is the first report of an InAlAs/InGaAs monolithic oscillator operating at the W-band.

Kwon, Y.↗
NASA NTRS1991

Optimal discrete-time dynamic output-feedback design - A w-domain approach

An alternative method for optimal digital control design is described in this paper. The method is based on the usage of the w-transform and has many attractive design features. One of these is its immediate connection with frequency loop-shaping techniques that are now popular and effective for multivariable control synthesis in continuous-time domain. Furthermore, any design algorithms originally developed for continuous-time systems can now be immediately extended to the discrete-time domain. The main results presented in this paper are the exact problem formulation and solution of an optimal discrete-time dynamic output-feedback design in the w-domain involving a quadratic performance index to random disturbances. In addition, necessary conditions for optimality are obtained for the numerical solution of the optimal output-feedback compensator design. A numerical example is presented illustrating its application to the design of a low-order dynamic compensator in a stability augmentation system of a commercial transport.

Ha, Cheolkeun↗
NASA NTRS1991

Low noise InP-based MMIC receivers for W-band

A program to develop a monolithic W-band low noise amplifier (a critical element in any W-band communications, sensors, or radar application) is described. Goals of the program include a completely monolithic low noise amplifier, less than a 3.5 dB noise figure, and a monolithic mixer suitable for integration with the LNA.

Leonard, Regis F.↗