The formation of surface films by electron bombardment Final report, Oct. 1968 - Sep. 1969
Determining mechanism of formation of thin polymeric films from organic materials by electron beam technique
Murphy, W. J.↗
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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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Rocket measurements of the lower ionosphere
Rocket measurement techniques for electron density profiles in D region, giving results from auroral zone disturbed and midlatitude quiet D region
Kane, J. A.↗
Electron-beam studies of low Reynolds-number flows inside a Delaval nozzle
Low Reynolds number flow inside Delaval nozzle, examining gas density and rotational temperatures by electron beam techniques
Rothe, D. E.↗
Mineralogy of the lunar clinopyroxenes, augite and pigeonite
Apollo 11 lunar rocks and fines, examining clinopyroxenes augite and pigeonite by single crystal X ray diffraction microprobe optical and electron optical techniques
Bence, A. E.↗
Development of a 25 - 50 watt high efficiency, X-band, traveling wave tube Quarterly report, Nov. 1970 - Jan. 1971
Computer design technique of electron gun for use in spacecraft transmitters
Knight, R. I.↗
Coadsorption of hydrogen and carbon monoxide on /111/ platinum
Hydrogen and carbon monoxide coadsorption on platinum single crystal surface, examining interactions and species formation by thermal flash and electron impact techniques in ultrahigh vacuum
Baldwin, V. H., Jr.↗
Lifetimes of metastable CO and N2 molecules
Metastable radiative lifetimes of molecular states of nitrogen and CO, using time of flight and high resolution electron gun techniques
Borst, W. L.↗
Electron-beam studies of viscous flow in supersonic nozzles
Viscous flow in supersonic de Laval nozzle, measuring gas density and rotational temperatures by electron beam techniques
Rothe, D. E.↗
Niobium hyperfine structure in crystal calcium tungstate
A study of the niobium hyperfine structure in single crystal calcium tungstate was made by the combination of the technique of electron paramagnetic resonance and electron nuclear double resonance (EPR/ENDOR). The microwave frequency was about 9.4 GHz and the radio frequency from 20MHz to 70 MHz. The rare earth ions Nd(3+), U(3+), or Tm(3+) were added as the charge compensator for Nb(5+). To create niobium paramagnetic centers, the sample was irradiated at 77 deg K with a 10 thousand curie Co-60 gamma source for 1 to 2 hours at a dose rate of 200 K rads per hour and then transferred quickly into the cavity. In a general direction of magnetic field, the spectra showed 4 sets of 10 main lines corresponding to 4 nonequivalent sites of niobium with I = 9/2. These 4 sets of lines coalesced into 2 sets of 10 in the ab-plane and into a single set of 10 along the c-axis. This symmetry suggested that the tungsten ions are substituted by the niobium ions in the crystal.
Tseng, D. L.↗
Absolute calibration of ultraviolet filter photometry
The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was determined by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was determined from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an absolute basis by the electron counting technique described earlier.
Bless, R. C.↗
Analog video magnetograms in real time.
Description of a video differential photometer which is the result of an attempt to adapt television technology to the task of producing an electronic equivalent of the photographic subtraction technique. Advantages of electronic subtraction are potentially greater field sensitivity, immediate availability of the subtracted magnetograms (virtually in real time), and greater versatility in combining and comparing image data. Commercial television equipment was used in construction of the apparatus. All video subtraction, averaging, and other processing is done in analog form. The final magnetogram is displayed on an ordinary television monitor.
Smithson, R. C.↗
Profiling with the electron microscope.
Discussion of a profiling technique using a scanning electron microscope for obtaining depth information on a single micrograph of a small specimen. A stationary electron beam is used to form a series of contamination spots in a line across the specimen. Micrographs obtained by this technique are useful as a means of projection and display where stereo viewers are not practical.
Vedder, J. F.↗
Examination of UC-ZrC after long term irradiation at thermionic temperature
Two fluoride tungsten clad UC-ZrC fueled capsules, designated as V-2C and V-2D, were examined a hot cell after irradiation in NASA Plum Brook Reactor at a maximum cladding temperature of 1930 K for 11,089 and 12,031 hours to burnups of 3.0 x 10 to the 20th power and 2.1 x 10 to the 20th power fission/c.c. respectively. Percentage of fission gas release from the fuel material was measured by radiochemical means. Cladding deformation, fuel-cladding interaction and microstructures of fuel, cladding, and fuel-cladding interface were studied metallographically. Compositions of dispersions in fuel, fuel matrix and fuel-cladding interaction layer were analyzed by electron microprobe techniques. Axial and radial distributions of burnup were determined by gamma-scan, autoradiography and isotopic burnup analysis. The results are presented and discussed in conjunction with the requirements of thermionic fuel elements for space power application.
Yang, L.↗
Correlation of creep rate with microstructural changes during high temperature creep
The techniques of electron microscopy were used to examine the microstructural changes which occur during primary creep for two important types of engineering alloys: (1) alloys strengthened by solid-solution additions, and (2) dispersion-strengthened alloys. The metals chosen for study are unalloyed titanium, Ti-6Al-4V, and the cobalt-base alloy, Haynes 188. Results to date on NGR 47-004-108 show that development of prior dislocation substructure in Haynes 188 by 10% prestrain and annealing for one hour at 1800 F increases the time to reach 0.5% creep strain at 1600 F by more than an order of magnitude for creep stresses from 3 to 20 ksi. For creep at 1800 F, similar results were obtaind for stresses above 7 ksi, but the prior substructure decreases creep resistance below 7 ksi. This effect appears to be related to instability of grain structure at 1800 F in prestrained material.
Young, C. T.↗
An Exploratory Study of the Microstructure of Mullite Fibers
The microstructures of mullite composition fibers were examined by transmission electron microscopic techniques and by X-ray diffraction analyses. Both spun and monofilament fiber structures contained little porosity, nor did the degree of porosity change after heating the monofilament to 1205 C for one half hour. Thermal exposure produced crystallite growth and nucleation from the amorphous phase in all three of the spun fibers. After 116 hours at 1426 C, the crystallites of the standard spun fibers became contiguous. In addition, the surface crystallites of these fibers were found to be more than twice as large as the interior crystallites.
Santoro, G.↗
Petrographic and electron microprobe study of the Monturaqui impactite.
Study of Monturaqui-crater impactite specimens attempting to determine the type of shock features present, shock intensities, type of meteorite projectile, and environmental conditions of impactite formation, by means of petrographic and electron microprobe techniques. The specimens were found to contain shocked and unshocked mineral and rock fragments together with Ni-Fe-Co-P spherules tightly bound in a partly devitrified matrix of clear, green or brown glass. Shock effects range from lightly shocked to intensely shocked. Observed and simulated shock effects are discussed.
Bunch, T. E.↗
Major element composition of Luna 20 glasses.
Ten per cent of the 50 to 150-micron size fraction of Luna 20 soil is glass. A random suite of 270 of these glasses has been analyzed by electron microprobe techniques. The major glass type forms a strong cluster around a mean value corresponding to Highland basalt (anorthositic gabbro) with 70% normative feldspar. Minor glass groups have the compositions of mare basalts and of low-K Fra Mauro type basalts. The glass data indicate that Highland basalt is the major rock type in the highlands north of Mare Fecunditatis.
Warner, J.↗
Metallic particles of high cobalt content in Apollo 15 soil samples.
Single phase alpha-kamacite containing more than 3.2 wt % Co and gamma-taenite containing from 30 to 60 wt % Ni from the Apollo 15 soils - 15031, 15071, 15081, 15261, and 15271 - have been examined by metallographic and electron microprobe techniques. In addition two phase alpha + gamma particles from soils 14003, 15071, 15261, and 15271 with Ni and Co contents well outside the meteoritic range have also been examined. Two distinct types of alpha-gamma structure occur, one analogous to 'clear taenite' in ordinary chondrites, and the other analogous to a 'Widmanstaetten' structure in Ni-rich ataxites. The measured Ni gradients in the two-phase particles are very similar to those meteorites having the same structure. However the Co content is much higher than the meteoritic samples, up to 12 wt % in the alpha phase. Approximate phase equilibria data for the Fe-Ni-Co system indicate equilibration of the two-phase particles during cooling to approximately 350 C. Estimates of cooling rates and second-phase growth times indicate that the maximum time necessary for the development of the high-Co two-phase structures is roughly 25 to 100 m.y. These estimates argue for the development of the two-phase structures during formation of the lunar crust, at a depth of 10 to 20 km beneath the moon's surface.
Axon, H. J.↗