Nuclear magnetic resonance study of metallic scandium chlorides (open access)

Nuclear magnetic resonance study of metallic scandium chlorides

The /sup 45/Sc nuclear magnetic resonance was studied in samples having the general composition CsSc/sub x/Cl/sub 3/ (0.67 less than or equal to x less than or equal to 1.0) in the CsCl-ScCl/sub 3/-Sc system. In particular the structure of CsScCl/sub 3/ suggests that it may be a one-dimensional conductor, and an attempt was therefore made to detect the occurrence of a metal-insulator transition of the type characteristic of one-dimensional conductors. Conventional crossed-coil (nuclear induction) techniques were employed. The /sup 45/Sc resonance was studied over a wide frequency range (4 to 24 MHz) at 300K, these measurements yielding the Knight shift and nuclear electric quadrupole coupling parameters. No significant variation in the spectra occurred from 4.2K to 450K, indicating the absence of a metal-insulator transition in this temperature range.
Date: April 1, 1978
Creator: McMullen, T.P.
Object Type: Report
System: The UNT Digital Library
Bibliography of reports on research sponsored by the NRC office of nuclear regulatory research, July--December 1977 (open access)

Bibliography of reports on research sponsored by the NRC office of nuclear regulatory research, July--December 1977

A bibliography of 198 reports published by contractors of the NRC Office of Nuclear Regulatory Research during the period July through December 1977 is presented along with abstracts from the Nuclear Safety Information Center computer file. The bibliography has been sorted into the subject categories used by NRC to organize the research program. Within the subject categories, the reports are arranged first by contractor organization and then chronologically. A brief description of the NRC research program precedes the bibliography.
Date: April 1, 1978
Creator: Buchanan, J.R.
Object Type: Report
System: The UNT Digital Library
Radially resolved measurements of ''q'' on the ATC tokamak (open access)

Radially resolved measurements of ''q'' on the ATC tokamak

This paper describes a new technique for directly measuring the safety factor, or q, profile in a tokamak. A tightly collimated neutral beam capable of injecting approximately 100 mA of 30 keV deuterium atoms was mounted on the ATC tokamak. By proper tangential aiming of the beam a strong concentration of circulating fast ions was created at a chosen plasma minor radius. By examining the orbits of these ions with a multi-sight-line charge exchange detector, it was possible to measure the shifts of the orbits off of magnetic surfaces, and thereby to make local measurements of q. This experiment showed that when q on axis reached unity, strong internal turbulence began, and further lowering of q at the outer edge of the plasma did not lower q(0). A second result was that the measured q(0) was approximately 1.8 times larger than the q(0) deduced from the T/sub e/(r) profile, assuming z/sub eff/ to be independent of minor radius. This suggests a significant peaking of z/sub eff/ on axis in ATC.
Date: April 1, 1978
Creator: Goldston, R.J.
Object Type: Report
System: The UNT Digital Library
Development of ultrafiltration and inorganic adsorbents for reducing volumes of low-level and intermediate-level liquid waste: January--March 1978 (open access)

Development of ultrafiltration and inorganic adsorbents for reducing volumes of low-level and intermediate-level liquid waste: January--March 1978

The exposure of noncellulosic ultrafiltration membranes to a radioactive environment simulating up to 24 months of exposure to a beta dose of 10 ..mu..Ci/cm/sup 3/ and a gamma dose of 10/sup -5/ ..mu..Ci/cm/sup 3/ did not show any conclusive evidence of membrane degradation. Viscosity measurements for control membranes and irradiated membranes indicate no changes in polymer molecular weight were caused by the radiation exposure. This, in turn, suggests no physical or mechanical degradation took place. A continuous run on the ultrafiltration pilot plant was completed. The run lasted 33.5 hr; during this period, the flux declined from 4 gal/min to 0.8 gal/min while rejection of alpha activity increased slightly. A total of 20,000 gal were processed through the ultrafiltration system. The small laboratory column tests were continued with uranium-233 and americium-241. Several new resins were being evaluated along with the same type of resin as used before with uranium-233 and plutonium-238. Tests were continued with the 2-in. Engineering Columns using ultrafiltration product spiked with uranium-233.
Date: April 27, 1978
Creator: Koenst, J. W.; Herald, W. R. & Roberts, R. C.
Object Type: Report
System: The UNT Digital Library
ORIS: the Oak Ridge Imaging System program listings. [Nuclear medicine imaging with rectilinear scanner and gamma camera] (open access)

ORIS: the Oak Ridge Imaging System program listings. [Nuclear medicine imaging with rectilinear scanner and gamma camera]

The Oak Ridge Imaging System (ORIS) is a general purpose access, storage, processing and display system for nuclear medicine imaging with rectilinear scanner and gamma camera. This volume contains listings of the PDP-8/E version of ORIS Version 2. The system is designed to run under the Digital Equipment Corporation's OS/8 monitor in 16K or more words of core. System and image file mass storage is on RK8E disk; longer-time image file storage is provided on DECtape. Another version of this program exists for use with the RF08 disk, and a more limited version is for DECtape only. This latter version is intended for non-medical imaging.
Date: April 1, 1978
Creator: Bell, P. R. & Dougherty, J. M.
Object Type: Report
System: The UNT Digital Library
Prediction of temperature increases in a salt repository expected from the storage of spent fuel or high-level waste (open access)

Prediction of temperature increases in a salt repository expected from the storage of spent fuel or high-level waste

Comparisons in temperature increases incurred from hypothetical storage of 133 MW of 10-year-old spent fuel (SF) or high-level waste (HLW) in underground salt formations have been made using the HEATING5 computer code. The comparisons are based on far-field homogenized models that cover areas of 65 and 25 sq miles for SF and HLW, respectively, and near-field unit-cell models covering respective areas of 610 ft/sup 2/ and 400 ft/sup 2/. Preliminary comparisons based on heat loads of 150 kW/acre and 3.5 kW/canister indicated near-field temperature increases about 20% higher for the storage of the spent fuel than for the high-level waste. In these comparisons, it was also found that the thermal energy deposited in the salt after 500 years is about twice the energy deposited by the high-level waste. The thermal load in a repository containing 10-year-old spent fuel was thus limited to 60 kW/acre to obtain comparable far-field thermal effects as obtained in a repository containing 10-year-old high-level waste loaded at 150 kW/acre. Detailed far-field and unit-cell comparisons of transient temperature increases have been made based on these loadings. Unit-cell comparisons were made between a canister containing high-level waste with an initial heat production rate of 2.1 kW and a …
Date: April 1, 1978
Creator: Llewellyn, G.H.
Object Type: Report
System: The UNT Digital Library
Recent Developments In The Horn Of Africa (open access)

Recent Developments In The Horn Of Africa

This report consists of recent developments in the horn of Africa and implications for american foreign policy.
Date: April 1978
Creator: Branaman, Brenda & Inglee, William
Object Type: Report
System: The UNT Digital Library
Kilowatt Isotope Power System: component test report for the Ground Demonstration System Alternator Stator (open access)

Kilowatt Isotope Power System: component test report for the Ground Demonstration System Alternator Stator

Results are presented of acceptance tests conducted on the Alternator Stator, S/N 002, for the Kilowatt Isotope Power System. These results show that the Alternator Stator, S/N 002 for the Kilowatt Isotope Power System has satisfactorily completed the testing set forth within Sundstrand Test Specification 2538. Test requirements of TS 2538 were extracted from the Kilowatt Isotope Power System, and Phase I Test Plan.
Date: April 25, 1978
Creator: Brainard, E.L.
Object Type: Report
System: The UNT Digital Library
Precipitation kinetics of a continuous precipitator, with application to the precipitation of ammonium polyuranate (open access)

Precipitation kinetics of a continuous precipitator, with application to the precipitation of ammonium polyuranate

A mathematical model describing the kinetics of continuous precipitation was developed which accounts for crystal nucleation, crystal growth, primary coagulation, and secondary coagulation. Population density distributions, average particle sizes, dominant particle sizes, and suspension density fractions of the crystallites, primary agglomerates, and secondary agglomerates leaving the continuous precipitator can be determined. This kinetic model was applied to the continuous precipitation of ammonium polyuranate, which consists of: (1) elementary crystals, (2) clusters or primary coagulated particles, and (3) agglomerates or secondary coagulated particles. The crystallites are thin, submicron, hexagonal platelets. The clusters had an upper size limit of about 7 ..mu.. in diameter and contained numerous small voids (less than 0.3 ..mu..m) due to the packing of the crystallites. The agglomerates had an upper size limit of about 40 ..mu..m in diameter and contained large voids (approximately 1 ..mu..m). The particle size distribution and particle structure of the ammonium polyuranate precipitate can be controlled through proper regulation of the precipitation conditions. The ratio of clusters to agglomerates can be best controlled through the uranium concentration, and the cohesiveness or internal bonding strength of the particles can be controlled with the ammonium to uranium reacting feed mole ratio. These two conditions, in …
Date: April 1, 1978
Creator: Hoyt, R.C.
Object Type: Report
System: The UNT Digital Library
Field procedures for the uranium hydrogeochemical and stream sediment reconnaissance as used by the Los Alamos Scientific Laboratory (open access)

Field procedures for the uranium hydrogeochemical and stream sediment reconnaissance as used by the Los Alamos Scientific Laboratory

This manual of field procedures is prepared to aid personnel involved in the field sampling of natural waters and waterborne sediment for the Los Alamos Scientific Laboratory (LASL) as part of the US Department of Energy (DOE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the National Uranium Resource Evaluation (NURE) program. It presents the procedural guidelines to be followed by all contractors, contractor employees, and others who collect, treat, or otherwise handle samples taken for the LASL as part of the HSSR program. Part I relates to all sampling in the conterminous states of the US for which the LASL is responsible to the DOE for carrying out the HSSR work. Part II describes procedures to be followed for HSSR work, using helicopter support, in the state of Alaska. The objective of the manual is to insure that consistent techniques are used throughout the survey. If any procedure is unclear or cannot be followed, telephone collect to Group G-5, LASL, (505) 667-7590, for further instructions. No variations in the specific procedures should be made without prior approval of the LASL.
Date: April 1, 1978
Creator: Sharp Jr., R. R. & Aamodt, P. L.
Object Type: Report
System: The UNT Digital Library
Safety analysis report for packaging (SARP) of the Oak Ridge National Laboratory Shipping Cask D-38 (open access)

Safety analysis report for packaging (SARP) of the Oak Ridge National Laboratory Shipping Cask D-38

An analytical evaluation of the Oak Ridge National Laboratory Shipping Cask D-38 (solids shipments) was made to demonstrate its compliance with the regulations governing off-site radioactive material shipping packages. The evaluation encompassed five primary categories: structural integrity, thermal resistance, radiation shielding, nuclear criticality safety, and quality assurance. The results of the evaluation show that the cask complies with the applicable regulations.
Date: April 1, 1978
Creator: Klima, B. B.; Shappert, L. B.; Seagren, R. D. & Box, W. D.
Object Type: Report
System: The UNT Digital Library
Literature review of the saturation state of seawater with respect to calcium carbonate and its possible significance for scale formation on OTEC heat exchangers (open access)

Literature review of the saturation state of seawater with respect to calcium carbonate and its possible significance for scale formation on OTEC heat exchangers

An investigation of available data on the saturation state of seawater with respect to calcium carbonate and its possible significance for scale formation on Ocean Thermal Energy Conversion (OTEC) heat exchangers has been carried out. Pertinent oceanographic data is lacking at or near potential OTEC sites for the calculation of the degree of saturation of seawater with respect to calcium carbonate. Consequently, only ''extrapolated'' saturation values can be used. These indicate that near surface seawater is probably supersaturated, with respect to the calcium carbonate phases calcite and aragonite, at all potential OTEC sites. The deep seawater that would be brought to the surface at the potential Atlantic Ocean sites is also likely to be supersaturated with respect to calcium carbonate. The deep seawater at the potential Pacific Ocean sites may be slightly undersaturated. The fact that OTEC heat exchangers will be operating in seawater, which is supersaturated with respect to calcium carbonate, means that if nucleation of calcite or aragonite occurs on the heat exchanger surfaces, significant growth rates of calcium carbonate scale may be expected. The potential for calcium carbonate nucleation is highest at cathodic metal surface locations, which are produced as the result of aluminum corrosion in seawater. …
Date: April 5, 1978
Creator: Morse, J. W.; de Kanel, J. & Craig, Jr., H. L.
Object Type: Report
System: The UNT Digital Library
Outlet plenum mixing for transient overpower conditions of a one-exit nozzle LMFBR (open access)

Outlet plenum mixing for transient overpower conditions of a one-exit nozzle LMFBR

Two types of transient tests were employed to model a one-exit nozzle LMFBR outlet plenum. Water was used as a test fluid in the simulation of constant flowrates, Transient Overpower (TOP) conditions. In the first test, simulated fuel flow was 85% and blanket flow was 15%, whereas in the second test, the fuel flow was 100%. This allowed the assessment of the mitigating effects of blanket flow upon the exit nozzle temperature transient. The flow field was clearly three-dimensional, and a less active, though not stagnant, region was observed diametrically opposite the exit nozzle. During steady state, oscillations above the fuel-blanket interface were found to be small. This is attributed to the existence above the reactor core of a recirculating flow field, which served as an effective mixing agent. A simple lumped-parameter model, EXIT1, was developed to simulate TOP transient conditions for the test with both fuel and blanket flows. The predicted temperature profiles for various regions in the plenum were in good agreement with the experimental profiles, except for the region immediately above the reactor blanket. In devising the computer model, the temperature in this region was assumed to remain constant throughout the transient. However, this constant temperature did …
Date: April 1, 1978
Creator: Howard, P. A.
Object Type: Report
System: The UNT Digital Library
Stochastic ion heating by a lower hybrid wave (open access)

Stochastic ion heating by a lower hybrid wave

The motion of an ion in a lower hybrid wave in a tokamak type plasma is studied. For ions with ..nu../sub perpendicular to/ approximately greater than ..omega../k/sub perpendicular to/ the motion is stochastic for fields satisfying E/B/sub 0/ greater than /sup 1///sub 4/ (..cap omega../sub i//..omega..)/sup /sup 1///sub 3//(..omega../k/sub perpendicular to/). Provided the perpendicular phase velocity, ..omega../k/sub perpendicular to/, can be slowed down to a few times the ion thermal speed, this stochastic ion motion may be an important mechanism by which injected rf power near the lower hybrid frequency can directly heat the ions.
Date: April 1, 1978
Creator: Karney, C.F.F.
Object Type: Report
System: The UNT Digital Library
Thermal drawdown and recovery of singly and multiply fractured hot dry rock reservoirs (open access)

Thermal drawdown and recovery of singly and multiply fractured hot dry rock reservoirs

To calculate heat extraction and thermal recovery in hot dry rock geothermal reservoirs, a computer code was written to solve the differential equations for rock-water heat conduction and convection by finite differences. Temperature versus time functions for multiple fractures separated by various spacings are presented in dimensional and in nondimensional plots. The results were specialized for the limiting case of a single fracture in unbounded rock and for the other limiting case where the rock is so extensively fractured that thermal breakthrough phenomena can occur. Fracture temperatures were calculated during the thermal recovery following various extraction periods. For the single-fracture case these temperature recoveries could, with slight approximation, be represented as a single curve depending only upon the ratio of the total elapsed time and the extraction time.
Date: April 1, 1978
Creator: Wunder, R. & Murphy, H.
Object Type: Report
System: The UNT Digital Library
HMC-to-flatpack attachment (open access)

HMC-to-flatpack attachment

A method has been developed for attaching a completed hybrid microcircuit to a flatpack which can then be hermetically sealed. Ablefilm 517B and Epo-Tek H77 epoxies, in conjunction with an abraded flatpack and applied pressure during cure, were shown to provide HMC-to-flatpack bonds which meet all environmental and processing requirements of hybrid microcircuits in two recent programs.
Date: April 1, 1978
Creator: Zawicki, L.R.
Object Type: Report
System: The UNT Digital Library
Sensitivity and uncertainty analysis for functionals of the time-dependent nuclide density field. [ORIGEN-A] (open access)

Sensitivity and uncertainty analysis for functionals of the time-dependent nuclide density field. [ORIGEN-A]

An approach to extend the present ORNL sensitivity program to include functionals of the time-dependent nuclide density field is developed. An adjoint equation for the nuclide field was derived previously by using generalized perturbation theory; the present derivation makes use of a variational principle and results in the same equation. The physical significance of this equation is discussed and compared to that of the time-dependent neutron adjoint equation. Computational requirements for determining sensitivity profiles and uncertainties for functionals of the time-dependent nuclide density vector are developed within the framework of the existing FORSS system; in this way the current capability is significantly extended. The development, testing, and use of an adjoint version of the ORIGEN isotope generation and depletion code are documented. Finally, a sample calculation is given which estimates the uncertainty in the plutonium inventory at shutdown of a PWR due to assumed uncertainties in uranium and plutonium cross sections. 8 figures, 4 tables.
Date: April 1, 1978
Creator: Williams, M.L. & Weisbin, C.R.
Object Type: Report
System: The UNT Digital Library
Measurements of pressure for the TiH/sub x//KClO/sub 4/ system (open access)

Measurements of pressure for the TiH/sub x//KClO/sub 4/ system

An investigation was conducted to measure the pressure obtained when the pyrotechnic mixture TiH/sub x//KClO/sub 4/ was ignited in a confined variable-volume system. It was possible to derive an expression of the form PV/sup ..gamma../ = k for the pressure-volume relationship obtained. This expression is a polytropic expansion of the ideal gas equation that best fits the data generated. For this particular work, values of ..gamma.. = 0.53 and k = 69.3 were obtained where P is in megapascals and V is in cubic centimeters. In addition, estimates of the reaction rates were calculated based on the times to achieve maximum pressure for a given volume system. An explicit expression relating rate to pressure was derived by a simplified least-squares fit of the data obtained.
Date: April 10, 1978
Creator: Chong, C. H. H. & Glaub, J. E.
Object Type: Report
System: The UNT Digital Library
Performance potential of (Th,U) carbide and (Th,U) nitride fuel in 1200 MWe LMFBR's (open access)

Performance potential of (Th,U) carbide and (Th,U) nitride fuel in 1200 MWe LMFBR's

An evaluation of the performance potential of thorium-uranium carbide and nitride fuel in 1200 MW(e) homogeneous and heterogeneous LMFBR's has been completed. Comparisons were done with 9.40 mm outer diameter, 0.38 mm cladding fuel pins at a selected peak (3 sigma) linear power of 98.4 kW/m for all cores. Breeding ratios for the homogeneous (Th,U)C and (Th,U)N cores are 1.12 and 1.16, respectively. In the heterogeneous cores the breeding ratios are 0.08 to 0.09 greater. A comparative breeding ratio of 1.48 results for a sodium-bonded (U,Pu)C homogeneous LMFBR with similar design criteria. Compound inventory doubling times for the homogeneous and heterogeneous (Th,U)C cores are 82 and 53 years, respectively. Additional performance parameters have also been compared, including sodium void worths, specific inventories, fissile material gains, and equilibrium cycle reactivity losses.
Date: April 1, 1978
Creator: Caspersson, S. A. & Kulwich, M. R.
Object Type: Report
System: The UNT Digital Library
Semiconductor die attachment. Final report (open access)

Semiconductor die attachment. Final report

A technique was established for attaching non-beam lead semiconductor devices to metallized ceramic substrates for hybrid microcircuits (HMCs). Conductive and non-conductive epoxies were shown to be capable of high shear strengths after exposure to high temperatures (125 to 200/sup 0/C) for significant periods of time (48 to 168 h). Chip-on-tab devices attached to the substrate with Ablefilm 517 non-conductive epoxy was the technology chosen.
Date: April 1, 1978
Creator: Zawicki, L.R.
Object Type: Report
System: The UNT Digital Library
Determination of phase boundaries and diffusion parameters in tantalum hydrides in pulsed NMR (open access)

Determination of phase boundaries and diffusion parameters in tantalum hydrides in pulsed NMR

Proton spin-lattice relaxation times T/sub 1/ were measured over a wide range of temperature (77 K to 470 K) and compositions (H/Ta = 0.155 to 0.677) in the tantalum-hydrogen system at a frequency of 40,000 MHz. In the high temperature solid solution ..cap alpha.. phase, the activation energy for hydrogen diffusion was found to be 0.140 +- 0.002 eV/atom, and the value of the jump rate (or its corresponding correlation time) was found to be essentially constant throughout the range of compositions studied. The conduction electron contribution to T/sub 1/ measured in the ..cap alpha.. phase agreed qualitatively with the trend shown by previously published susceptibility data. The single phase epsilon region and the ..cap alpha.. + epsilon two-phase region were particularly noted. It could also be concluded from the measurements that the hydrogen jump rate decreased by a factor of approximately 7.2 from the ..cap alpha.. phase to the ordered phases at low temperatures and slightly decreased further in the epsilon phase. Anomalous relaxation times were found in the low temperature range (77 K less than or equal to T less than or equal to K). In this region, T/sub 1/ remains essentially constant, and does not follow the …
Date: April 1, 1978
Creator: Hornung, P. A.
Object Type: Report
System: The UNT Digital Library
Volume reduction system for solid and liquid TRU waste from the nuclear fuel cycle: October--December 1977 (open access)

Volume reduction system for solid and liquid TRU waste from the nuclear fuel cycle: October--December 1977

A bench-scale incinerator for the investigation of unusual particulate and gaseous radioactive material in the incinerator off-gas was assembled and equipment checkout was begun. Modifications to a glovebox to be used for the demonstration phase of incinerator-ash immobilization are approximately 80% completed with demonstration to begin next quarter. The curing time for ash-cement pressed pellets was optimized by periodic crush-strength testing of open-air and underwater cured samples. Leach tests were performed at 70 and 100/sup 0/C to simulate normal and extreme storage conditions. Long-term leach tests were initiated on plutonium-238 doped ash-cement pressed pellets in distilled water at ambient temperature. Pressed pellets of bone char, ash, and sludge-ash in several mixtures were fabricated and tested to establish pressing and curing parameters. Leach tests were also performed on bone char-cement pressed pellets. Curing studies have been conducted on the pressed pellet matrix to define differences between curing in the open atmosphere and under water. Leachability studies have been initiated on the pressed pellet ash/cement matrix in distilled water at ambient, 70 and 100/sup 0/C. Also, leachability studies on doped plutonium-238 pressed ash/cement pellets and pressed bone char/cement pellets in distilled water at ambient temperature have been conducted. Compressive strengths of bone …
Date: April 21, 1978
Creator: Luthy, D. F. & Bond, W.H.
Object Type: Report
System: The UNT Digital Library
Simultaneous analysis of uranium and nitrate (open access)

Simultaneous analysis of uranium and nitrate

A direct spectrophotometric method has been developed for the determination of 20 to 200 g/l of uranium in the presence of 3 to 5 M nitric acid. A dual-wavelength analysis is used to eliminate the enhancing effect of nitrate ion on the uranium visible spectra. The precision and accuracy of the simultaneous analysis of uranium and nitrate were compared using combinations of the four uranium wavelength maxima, occurring at 426, 416, 403 and 359 nm. Calculations based on 426 and 416 nm data yielded the most accurate results. The calculated relative standard deviation of uranium and nitrate concentrations was 5.4 percent and 15.5 percent, respectively. The photometric procedure is slightly affected by temperature; an increase of one degree centigrade results in a 0.2 g/l overestimation of uranium concentration. Because the method is non-destructive, it is directly applicable to the continuous in-line analysis of dissolved uranium in aqueous fuel reprocessing streams.
Date: April 1, 1978
Creator: Bostick, D.T.
Object Type: Report
System: The UNT Digital Library
Thin films of gallium arsenide on low-cost substrates. Quarterly technical progress report No. 6 and topical report No. 2, January 1, 1978-April 1, 1978 (open access)

Thin films of gallium arsenide on low-cost substrates. Quarterly technical progress report No. 6 and topical report No. 2, January 1, 1978-April 1, 1978

The metalorganic chemical vapor deposition (MO-CVD) technique has been applied to the growth of thin films of GaAs and GaAlAs on inexpensive polycrystalline or amorphous substrate materials (primarily glasses and metals) for use in fabrication of large-area low-cost photovoltaic device structures. Trimethylgallium (TMG), arsine (AsH/sub 3/), and trimethylaluminum (TMAl) are mixed in appropriate concentrations at room temperature in the gaseous state and pyrolyzed at the substrate, which is heated in a vertical reactor chamber to temperatures of 725 to 750/sup 0/C, to produce the desired film composition and properties. The substrate materials used for experimental studies during the quarter included several grades of graphite (from two different manufacturers), commercial-grade Al alloy sheet, large-grained annealed Mo sheet, sputtered Mo films on Corning Code 0317 glass, uncoated 0317 glass, large-grained polycrystalline alumina (Coors Vistal 5), and large-grained bulk polycrystalline GaAs. Results indicted graphite to be a suitable substrate for GaAs film growth by MO-CVD, although some adherence problems were uncountered with improperly prepared graphite surfaces. No major differences were observed for GaAs growth on the various graphites; films approx. 10 ..mu..m thick exhibited apparent grain sizes (indicated by dimensions of surface features) in the 2 to 5 ..mu..m range. Annealed Mo sheet …
Date: April 1, 1978
Creator: Ruth, R. P.; Dapkus, P. D.; Dupuis, R. D.; Campbell, A. G.; Johnson, R. E.; Manasevit, H. M. et al.
Object Type: Report
System: The UNT Digital Library