Low-cost solar array project. Task I. Silicon material. Investigation of the hydrogenation of SiCl/sub 4/ (open access)

Low-cost solar array project. Task I. Silicon material. Investigation of the hydrogenation of SiCl/sub 4/

Reaction kinetic measurements on the hydrochlorination of SiCl/sub 4/ and m.g. silicon metal were last reported as a function of reaction temperature, reactor pressure, H/sub 2//SiCl/sub 4/ ratio and silicon metal particle size distribution, 3 SiCl/sub 4/ + 2 H/sub 2/ + Si reversible 4 SiHCl/sub 3/. The effect of impurities in the m.g. silicon metal on the rate of this reaction has been investigated in this quarter. The m.g. silicon was replaced with high purity, electronic grade silicon metal in the hydrochlorination reaction. With electronic grade Si, the reaction rate was found to be about one order of magnitude slower than those obtained with m.g. silicon metal. These metallic impurities in the m.g. silicon appear to have a catalytic effect. Addition of 5 wt% cuprous chloride to the electronic grade Si mass bed increased the reaction rate to the same level as those obtained with m.g. silicon with 5% CuCl added. The effect of prolonged reaction time on the hydrochlorination reaction was studied. The plan is to run the reaction for long periods of time with the objective of studying the life of the Si mass bed. No significant change in the reaction rate was observed after about 80 …
Date: October 7, 1980
Creator: Mui, J. Y. P. & Seyferth, D.
Object Type: Report
System: The UNT Digital Library
Some Scoping Experiments for a Space Reactor (open access)

Some Scoping Experiments for a Space Reactor

Some scoping experiments were performed to evaluate fuel performance in a lithium heat pipe reactor operating at a nominal 1500K heat pipe temperature. Fuel-coolant and fuel-coolant-clad relationships showed that once a failed heat pipe occurs temperatures can rise high enough so that large concentrations of uranium can be transported by the vapor phase. Upon condensation this uranium would be capable of penetrating heat pipes adjacent to the failed pipe. The potential for propagation of failure exists with UO/sub 2/ and a lithium heat pipe. Changing the composition of the metal of the heat pipe would have only a second order effect on the kinetics of the failure mechanism. Uranium carbide and nitride were considered as potential fuels which are nonreactive in a lithium environment. At high temperatures the nitride would be favored because of its better compatibility with potential cladding materials. Compositions of UN with small additions of YN appear to offer very attractive properties for a compact high temperature high power density reactor.
Date: July 7, 1983
Creator: Alexander, C. A. & Ogden, J. S.
Object Type: Report
System: The UNT Digital Library
An MS-DOS-based program for analyzing plutonium gamma-ray spectra (open access)

An MS-DOS-based program for analyzing plutonium gamma-ray spectra

A plutonium gamma-ray analysis system that operates on MS-DOS-based computers has been developed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra for plutonium isotopics. The user interacts with the system by means of menus and screens that allow the user to select various applications and to enter information pertinent to a measurement. This information, along with the plutonium weight-percent-abundance results from the data analysis, is stored in dBASE III files. The spectral-data-analysis program, IAEAPU, determines the relative plutonium isotopic abundances from gamma-ray peaks in the 110- to 390-keV region of the spectral data. The program is compact so that it may be used on a portable, battery-operated, laptop, personal computer (PC) that uses a 3-1/2-in. floppy diskette. This is intended to be the final report on this work. We describe in detail the data-analysis methodology, the software, and the operation of the plutonium gamma-ray analysis system. 10 refs., 1 fig., 2 tabs.
Date: September 7, 1989
Creator: Ruhter, W. D. & Buckley, W. M.
Object Type: Report
System: The UNT Digital Library
Hyper filter-fluorescer spectrometer for x rays above 120 keV (open access)

Hyper filter-fluorescer spectrometer for x rays above 120 keV

An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E/sub PRF/ < E/sub F/, contrary to the prior art technique E/sub PRF/ > E/sub F/. In this way, the response function is virtually zero between E/sub PRF/ and E/sub F/ and well defined and enhanced in an energy band of less than 1000 keV above the 120 keV energy.
Date: July 7, 1981
Creator: Wang, C. L.
Object Type: Patent
System: The UNT Digital Library
Search for narrow states produced in the reaction. pi. /sup -/p. --&gt;. n +. gamma. &#x27;s at 13 GeV/c (open access)

Search for narrow states produced in the reaction. pi. /sup -/p. --&gt;. n +. gamma. &#x27;s at 13 GeV/c

A double arm lead-glass lead-scintillator calorimeter system was used to search for narrow states, such as the eta/sub c/, produced in the exclusive reactions ..pi../sup -/p ..--&gt;.. ..gamma gamma..n, ..pi../sup -/p ..--&gt;.. ..pi../sup 0/..gamma..n, and ..pi../sup -/p ..--&gt;.. ..pi../sup 0/..pi../sup 0/n at 13 GeV/c. A 90% c.l. upper limit sigma.BR &lt; 260 pb was found for ..gamma gamma.. states with masses from 2.6 to 3.1 GeV/c/sup 2/. Corresponding limits on narrow ..pi../sup 0/..gamma.. and ..pi../sup 0/..pi../sup 0/ states are also given.
Date: July 7, 1980
Creator: Chiang, I. H.; Johnson, R. A. & Kwan, B.
Object Type: Article
System: The UNT Digital Library
Geotomography applied at the Stripa Mine in Sweden (open access)

Geotomography applied at the Stripa Mine in Sweden

LLNL made ultrahigh-frequency (450-MHz) electromagnetic borehole-to-borehole transmissions in the Stripa Mine near Guldsmedshyttan, Sweden, in April 1979. Transmission loss measurements were made between four sets of 76-mm boreholes 30 m long, located at the end of a drift. Distances between the boreholes varied from 2 to 22 m. More than 25,000 data points were taken. A geotomograph was constructed to show the variation of attenuation between boreholes. The observed spatial variation of electromagnetic attenuation may be related to the expected stress relief created by the mine. Transmission loss measurements were also made between two converging boreholes drilled from the surface to points near the mine. Data taken at 21 MHz show a nearly uniform attenuation within this sampled region. These experiments demonstrate that geotomographic data collection/interpretation provides high-resolution images of the underground environment and can provide useful input to those charged with providing the detailed site characterizations needed for both short- and long-term monitoring of underground nuclear waste repositories.
Date: April 7, 1980
Creator: Okada, J.T.; Laine, E.F.; Lytle, R.J. & Daily,W.D.
Object Type: Report
System: The UNT Digital Library
MTX (Microwave Tokamak Experiment) facility and machine grounding plan (open access)

MTX (Microwave Tokamak Experiment) facility and machine grounding plan

A key issue in the design of fusion research experiments and their related facilities is the control of ground currents. Because of the large magnetic field, high voltages and high currents present in most of these installations, it is essential to avoid ground loops, and to control ground currents during both normal operations and fault conditions. This paper describes the grounding policy that was developed for MTX. The vault area was divided into zones, and each of the four walls was treated as a separate grounding area. Cable runs and magnet buss bars were run into the machine radially. The paper also describes the steps taken to isolate diagnostic signals and power for pumps and instruments. The paper outlines some of the field calculations used to predict problem areas, and to reveal voltage isolation levels that were required. The paper includes the active ground fault detection system used to insure the integrity of the ground system. 2 refs., 5 figs.
Date: October 7, 1987
Creator: Bell, H.H.; Rice, B.W.; Petersen, D.E. & Herrera, C.H.
Object Type: Article
System: The UNT Digital Library
Atomic and molecular science with synchrotron radiation (open access)

Atomic and molecular science with synchrotron radiation

This paper discusses the following topics: electron correlation in atoms; atomic innershell excitation and decay mechanisms; timing experiments; x-ray scattering; properties of ionized species; electronic properties of actinide atoms; total photon-interaction cross sections; and molecular physics. 66 refs. (LSP)
Date: November 7, 1989
Creator: unknown
Object Type: Report
System: The UNT Digital Library
MFTF-B quasi-optical ECRH transmission system (open access)

MFTF-B quasi-optical ECRH transmission system

The microwave transmission system for ERCH on MFTF-B will utilize quasi-optical transmission techniques. The system consists of ten gyrotron oscillators: two gyrotrons at 28 GHz, two at 35 GHz, and six at 56 GHz. The 28 and 35 GHz gyrotrons both heat the electrons in the end plug (potential peak) while the 56 GHz sources heat the minimum-B anchor region (potential minimum). Microwaves are launched into a pair of cylindrical mirrors that form a pseudo-cavity which directs the microwaves through the plasma numerous times before they are lost out of the cavity. The cavity allows the microwave beam to reach the resonance zone over a wide range of plasma densities and temperatures. The fundamental electron cyclotron resonance moves to higher axial positions as a result of beta-depression of the magnetic field, doppler shifting of the resonance, and relativistic mass corrections for the electrons. With this system the microwave beam will reach the resonance surface at the correct angle of incidence for any density or temperature without active aiming of the antennas. The cavity also allows the beam to make multiple passes through the plasma to increase the heating efficiency at low temperatures and densities when the single pass absorption is …
Date: November 7, 1983
Creator: Yugo, J. J.; Shearer, J. W. & Ziolkowski, R. W.
Object Type: Article
System: The UNT Digital Library
Superconducting (radiation hardened) magnets for mirror fusion devices (open access)

Superconducting (radiation hardened) magnets for mirror fusion devices

Superconducting magnets for mirror fusion have evolved considerably since the Baseball II magnet in 1970. Recently, the Mirror Fusion Test Facility (MFTF-B) yin-yang has been tested to a full field of 7.7 T with radial dimensions representative of a full scale reactor. Now the emphasis has turned to the manufacture of very high field solenoids (choke coils) that are placed between the tandem mirror central cell and the yin-yang anchor-plug set. For MFTF-B the choke coil field reaches 12 T, while in future devices like the MFTF-Upgrade, Fusion Power Demonstration and Mirror Advanced Reactor Study (MARS) reactor the fields are doubled. Besides developing high fields, the magnets must be radiation hardened. Otherwise, thick neutron shields increase the magnet size to an unacceptable weight and cost. Neutron fluences in superconducting magnets must be increased by an order of magnitude or more. Insulators must withstand 10/sup 10/ to 10/sup 11/ rads, while magnet stability must be retained after the copper has been exposed to fluence above 10/sup 19/ neutrons/cm/sup 2/.
Date: December 7, 1983
Creator: Henning, C. D.; Dalder, E. N. C.; Miller, J. R. & Perkins, J. R.
Object Type: Article
System: The UNT Digital Library
Estimating and coping with public response to radioactive waste repository siting (open access)

Estimating and coping with public response to radioactive waste repository siting

The siting and construction of a radioactive waste disposal operation is likely to be controversial in the communities being considered, and at the state and national levels as well. Public response can be conceptualized at two levels: individual, and group or organizational. At the individual level, public response is the behavior of people motivated by their attitudes, knowledge, and perceptions of radioactive waste and its hazards and risks. On the group or organizational level, public response is the organized activity of individuals. Organizations provide the ability to pool resources and talents, set up a division of labor, hire experts, develop a skilled leadership, take legal action, and so on. A broad range of organizations is possible: ad hoc, existing community groups with an added purpose, nationally-recognized organizations, or government offices and agencies. Two cases of response to radioactive waste disposal sites illustrate these sources and kinds of response and lead to indicators to estimate the nature and level of response. Finally, drawing from the theoretical discussion of the sources and levels of public response, on the estimation techniques, and on the examples, specific coping strategies are developed. These strategies take different forms, based on the nature and level of response …
Date: February 7, 1984
Creator: Payne, B.A.
Object Type: Article
System: The UNT Digital Library
Spatial averaging algorithms for ultrasonic inspection of austenitic stainless steel welds (open access)

Spatial averaging algorithms for ultrasonic inspection of austenitic stainless steel welds

Interpretation of ultrasonic inspection data from stainless steel welds is difficult because the signal-to-noise ratio is very low. The three main reasons for this are the granular structure of the weld, the high attenuation of stainless steel, and electronic noise. Averaging in time at the same position in space reduces electronic noise, but does not reduce ultrasonic noise from grain boundary scattering. Averaging wave-forms from different spatial positions helps reduce grain noise, but desired signals can destructively interfere if they shift in time. If the defect geometry is known, the ultrasonic waveforms can be shifted before averaging, ensuring signal reinforcement. The simplest geometry results in a linear time shift. An averaging algorithm has been developed which finds the optimum shift. This algorithm computes the averaged, or composite waveform as a function of the time shift. The optimum occurs when signals from a reflector become aligned in time, producing a large amplitude composite waveform. This algorithm works very well, but requires significant computer time and storage. This paper discusses this linear shift averaging algorithm, and considers an implementation using frequency domain techniques. Also, data from several weld defects are presented and analyzed.
Date: April 7, 1980
Creator: Horn, J. E.; Cooper, C.S. & Michaels, T.E.
Object Type: Article
System: The UNT Digital Library
Magnet power system for the Microwave Tokamak Experiment (MTX) (open access)

Magnet power system for the Microwave Tokamak Experiment (MTX)

The system configuration, layout, and general philosophy for the MTX magnet power system is described. The vast majority of the magnet power equipment was quite successfully used on the ALCATOR-C experiment at the Massachusetts Institute of Technology. The AC power for the magnet system at MIT was obtained from a 225MVA alternator. The power for the system at LLNL is obtained directly from the local utility's 230 kV line. This installation, therefore, necessitates the addition of a great deal of equipment in ranges from new switchgear in the substation to using existing switchgear obtained from MIT as contractors for intershop electrical isolation as well as safety isolation for personnel entry into the experimental area. Additionally, some discussion is made of the unique layout of this facility and the tradeoffs made to accommodate them. 2 refs., 6 figs.
Date: October 7, 1987
Creator: Jackson, M.C. & Musslewhite, R.C.
Object Type: Article
System: The UNT Digital Library
Specific heat loading in Nd:glass lasers (open access)

Specific heat loading in Nd:glass lasers

The specific thermal load parameter, chi, for xenon flashlamp-pumped Nd:glass gain media is written as a function of neodymium concentration, pump pulse duration, and energy extraction efficiency. The currently available data on radiative and nonradiative decay probabilities of several commercial Nd:glasses are used to calculate and graph specific thermal load parameter values. By factoring these results into performance scaling relationships for zig-zag and disk lasers, specific Nd:glasses can be selected for optimized laser performance.
Date: August 7, 1985
Creator: Krupke, W. F.
Object Type: Report
System: The UNT Digital Library
Thin-thick quadrature frequency conversion (open access)

Thin-thick quadrature frequency conversion

The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle.
Date: February 7, 1985
Creator: Eimerl, D.
Object Type: Article
System: The UNT Digital Library
Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators (open access)

Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators

The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.
Date: April 7, 1988
Creator: MacLachlan, J.A.
Object Type: Report
System: The UNT Digital Library
Magnetic testing probe (open access)

Magnetic testing probe

A cylindrical eddy current tube testing probe is disclosed. Current flow in dual electromagnetic coils separated by an eddy current sensing coil is so directed that magnetic fields of the electromagnet coils have components extending in opposite directions axially of the tested tube and components extending radially of the tube which add in the region of the eddy current sensing coil.
Date: July 7, 1981
Creator: Scott, G.W. & Chitwood, L.D.
Object Type: Patent
System: The UNT Digital Library
Difficulties with inferring neutron cross sections from charged-particle reactions (open access)

Difficulties with inferring neutron cross sections from charged-particle reactions

We have investigated problems associated with inferring cross sections for neutron reactions on unstable nuclei in the mass-90 region from charged-particle reactions on nearby stable targets. We conclude that effects due to precompound evaporation, isospin, and multiple reaction paths severely limit the circumstances under which charged-particle studies may be directly and easily converted to neutron cross sections of useful accuracy. 4 refs., 2 figs.
Date: May 7, 1985
Creator: Gardner, D. G. & Gardner, M. A.
Object Type: Article
System: The UNT Digital Library
Procedure for matching synfuel users with potential suppliers. Appendix B. Proposed and ongoing synthetic fuel production projects (open access)

Procedure for matching synfuel users with potential suppliers. Appendix B. Proposed and ongoing synthetic fuel production projects

To assist the Department of Energy, Office of Fuels Conversion (OFC), in implementing the synthetic fuel exemption under the Powerplant and Industrial Fuel Use Act (FUA) of 1978, Resource Consulting Group, Inc. (RCG), has developed a procedure for matching prospective users and producers of synthetic fuel. The matching procedure, which involves a hierarchical screening process, is designed to assist OFC in: locating a supplier for a firm that wishes to obtain a synthetic fuel exemption; determining whether the fuel supplier proposed by a petitioner is technically and economically capable of meeting the petitioner&#x27;s needs; and assisting the Synthetic Fuels Corporation or a synthetic fuel supplier in evaluating potential markets for synthetic fuel production. A data base is provided in this appendix on proposed and ongoing synthetic fuel production projects to be used in applying the screening procedure. The data base encompasses a total of 212 projects in the seven production technologies.
Date: August 7, 1981
Creator: unknown
Object Type: Report
System: The UNT Digital Library
High pressure gas metering project (open access)

High pressure gas metering project

The initial research and development of a system that uses high pressure helium gas to pressurize vessels over a wide range of pressurization rates, vessel volumes, and maximum test pressures are described. A method of controlling the mass flow rate in a test vessel was developed by using the pressure difference across a capillary tube. The mass flow rate is related to the pressurization rate through a real gas equation of state. The resulting mass flow equation is then used in a control algorithm. Plots of two typical pressurization tests run on a manually operated system are included.
Date: July 7, 1980
Creator: Tripp, L.R.
Object Type: Report
System: The UNT Digital Library
Advanced direct coal liquefaction. Quarterly technical progress report No. 1, September-November 1983 (open access)

Advanced direct coal liquefaction. Quarterly technical progress report No. 1, September-November 1983

Wyoming subbituminous coal was liquefied using three different two-stage process configurations in bench-scale tests. These process configurations differed in the type of fractionated deashing resid being recycled to the individual stages. The objective of these runs was to determine whether, by recycle of specific resid streams to the thermal stage, the second stage catalyst life could be improved without detrimentally affecting distillate yield or hydrogen consumption. The results indicate that the two-stage process configuration consisting of hydrotreating the Light Deashed Resid and direct recycle of heavy Deashed Resid to the thermal stage produced the best results. This process configuration resulted in a distillate yield of 54 wt % (MAF coal basis) and overall coal conversion in the 93 to 95% range, as measured by pyridine-soluble analytical test while operating in a total distillate mode. These results are very encouraging from the lower rank Wyoming subbituminous coal. Among the three two-stage process configurations tested, the particular process configuration of hydrotreating Light Deashed Resid resulted in the least amount of catalyst deactivation. As a part of this research effort, a test procedure for quick evaluation of various resids and catalysts in terms of coke precursors was also developed. This procedure utilizing as-produced …
Date: February 7, 1984
Creator: Paranjape, A.S.
Object Type: Report
System: The UNT Digital Library
Development of magnetic mirror systems for nuclear testing applications (open access)

Development of magnetic mirror systems for nuclear testing applications

Several system studies have concluded that the small size and steady state nature of magnetic mirror systems provide attractive features for nuclear-testing applications. The principle shortcoming of mirror systems is their small data base relative to that of tokamaks. This paper summarizes the present data base and describes experiments that could be carried out with small modifications of existing facilities to explore plasma physics issues associated with the production of high neutron fluxes in magnetic mirror configurations. The experiments would demonstrate physics principles important to such future applications of fusion power neutrons as blanket testing, tritium production, fissile fuel production, or decontamination of high-level radioactive nuclear-reactor wastes.
Date: August 7, 1986
Creator: Simonen, T. C.; Futch, A. H. & Kaiser, T. B.
Object Type: Report
System: The UNT Digital Library
Suppression of transverse beam breakup modes in an induction accelerator by gas focusing (open access)

Suppression of transverse beam breakup modes in an induction accelerator by gas focusing

The effect of beam-generated positive ions on the beam-breakup instability in linear electron accelerators is calculated using simple models. The strongly nonlinear dependence of the ion focusing force on radius makes a complete suppression of the mode growth possible, in contrast to solenoidal focusing. The predicted gas pressures for significant stabilization of the mode growth in a machine configuration like ATA is relatively low (10/sup -5/ to 10/sup -4/ torr), even for high-Q modes.
Date: April 7, 1980
Creator: Briggs, R. J.
Object Type: Report
System: The UNT Digital Library
Role of human- and animal-sperm studies in the evaluation of male reproductive hazards (open access)

Role of human- and animal-sperm studies in the evaluation of male reproductive hazards

Human sperm tests provide a direct means of assessing chemically induced spermatogenic dysfunction in man. Available tests include sperm count, motility, morphology (seminal cytology), and Y-body analyses. Over 70 different human exposures have been monitored in various groups of exposed men. The majority of exposures studied showed a significant change from control in one or more sperm tests. When carefully controlled, the sperm morphology test is statistically the most sensitive of these human sperm tests. Several sperm tests have been developed in nonhuman mammals for the study of chemical spermatotoxins. The sperm morphology test in mice has been the most widely used. Results with this test seem to be related to germ-cell mutagenicity. In general, animal sperm tests should play an important role in the identification and assessment of potential human reproductive hazards. Exposure to spermatotoxins may lead to infertility, and more importantly, to heritable genetic damage. While there are considerable animal and human data suggesting that sperm tests may be used to detect agents causing infertility, the extent to which these tests detect heritable genetic damage remains unclear. (ERB)
Date: April 7, 1982
Creator: Wyrobek, A.J.; Gordon, L. & Watchmaker, G.
Object Type: Article
System: The UNT Digital Library