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Holographic and acoustic emission evaluation of pressure vessels (open access)

Holographic and acoustic emission evaluation of pressure vessels

Optical holographic interfereometry and acoustic emission monitoring were simultaneously used to evaluate two small, high pressure vessels during pressurization. The techniques provide pressure vessel designers with both quantitative information such as displacement/strain measurements and qualitative information such as flaw detection. The data from the holographic interferograms were analyzed for strain profiles. The acoustic emission signals were monitored for crack growth and vessel quality.
Date: March 5, 1980
Creator: Boyd, D.M.
System: The UNT Digital Library
Application of digital image analysis techniques to the Geyser's data and topography (open access)

Application of digital image analysis techniques to the Geyser's data and topography

This paper describes the results of digital image analysis and techniques applied to acoustic sounder data and topographic relief in the Geyser's region. The two dimensional fast Fourier transform (2DFFT) represents the spacial variability of a photographic image. The spacial variability of topography in complex terrain can be represented in this way and insight into degree of complexity and dominating spacial wavelengths can be gained. This was performed for a 16 km square digitized topographic map of the Geyser's region with 63.5 m resolution. It was also of interest to compare facsimile recordings of acoustic sounder data to optical turbulence measurements.
Date: May 5, 1980
Creator: Porch, W.M.
System: The UNT Digital Library
Low-temperature hydrothermal resource evaluation (open access)

Low-temperature hydrothermal resource evaluation

The objectives of testing low-temperature hydrothermal wells are to characterize well response to production (injection), determine resource characteristics and project reservoir longevity. Testing procedures and analysis techniques differ in some respects from proven procedures in the oil and gas and ground water fields. Some basic definitions and standard techniques necessary for the evaluation of a fluid resource in an intergranular permeable reservoir are presented. Problems particular to a non-ideal thermal resource are outlined and some analytical techniques are discussed.
Date: May 5, 1980
Creator: Goldman, D.
System: The UNT Digital Library
Recent developments in nuclear reaction theories and calculations (open access)

Recent developments in nuclear reaction theories and calculations

A brief review is given of some recent developments in the fields of optical model potentials; level densities; and statistical model, precompound, and direct reaction codes and calculations. Significant developments have occurred in all of these fields since the 1977 Conference on Neutron Cross Sections, which will greatly enhance the ability to calculate high-energy neutron-induced reaction cross sections in the next few years. 11 figures, 3 tables.
Date: May 5, 1980
Creator: Gardner, D. G.
System: The UNT Digital Library
Three-dimensional thermal analysis of a baseline spent fuel repository (open access)

Three-dimensional thermal analysis of a baseline spent fuel repository

A three-dimensional thermal analysis has been performed using finite difference techniques to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplaced to yield a 36 kw/acre (8.9 w/m/sup 2/) loading. A unit cell model in an infinite array is used to simplify the problem and provide upper-bound temperatures. Boundary conditions are imposed which allow simulations to 1000 years. Variations studied include a comparison of ventilated and unventilated storage room conditions, emplacement packages with and without air gaps surrounding the canister, and room cool-down scenarios with ventilation following an unventilated state for retrieval purposes. At this low power level ventilating the emplacement room has an immediate cooling influence on the canister and effectively maintains the emplacement room floor near the temperature of the ventilating air. The annular gap separating the canister and sleeve causes the peak temperature of the canister surface to rise by 10/sup 0/F (5.6/sup 0/C) over that from a …
Date: June 5, 1980
Creator: Altenbach, T.J. & Lowry, W.E.
System: The UNT Digital Library
Reliability of large superconducting magnets through design (open access)

Reliability of large superconducting magnets through design

As superconducting magnet systems grow larger and become the central component of major systems involving fusion, magnetohydrodynamics, and high-energy physics, their reliability must be commensurate with the enormous capital investment in the projects. Although the magnet may represent only 15% of the cost of a large system such as the Mirror Fusion Test Facility, its failure would be catastrophic to the entire investment. Effective quality control during construction is one method of ensuring success. However, if the design is unforgiving, even an inordinate amount of effort expended on quality control may be inadequate. Creative design is the most effective way of ensuring magnet reliability and providing a reasonable limit on the amount of quality control needed. For example, by subjecting the last drawing operation is superconductor manufacture to a stress larger than the magnet design stress, a 100% proof test is achieved; cabled conductors offer mechanical redundancy, as do some methods of conductor joining; ground-plane insulation should be multilayered to prevent arcs, and interturn and interlayer insulation spaced to be compatible with the self-extinguishing of arcs during quench voltages; electrical leads should be thermally protected; and guard vacuum spaces can be incorporated to control helium leaks. Many reliable design options …
Date: September 5, 1980
Creator: Henning, Carl D.
System: The UNT Digital Library
Shiva automatic pinhole alignment (open access)

Shiva automatic pinhole alignment

This paper describes a computer controlled closed loop alignment subsystem for Shiva, which represents the first use of video sensors for large laser alignment at LLNL. The techniques used on this now operational subsystem are serving as the basis for all closed loop alignment on Nova, the 200 terawatt successor to Shiva.
Date: September 5, 1980
Creator: Suski, G.J.
System: The UNT Digital Library
Agriculture, greenhouse, wetland and other beneficial uses of geothermal fluids and heat (open access)

Agriculture, greenhouse, wetland and other beneficial uses of geothermal fluids and heat

The status for related beneficial uses including agriculture, greenhousing, and geothermal wetlands is presented. Data published for the geothermal fluids found in areas of China have been examined and compared with the geothermal fluids used in the agriculture evaluations in the United States. This comparison indicates that the geothermal fluids found in parts of China are similar to those used in the US agriculture experiments. Greenhousing is addressed largely from the standpoint of hardware systems and technology being employed or being proposed in the United States.
Date: April 5, 1981
Creator: Schmitt, R. C.
System: The UNT Digital Library
Ambipolar potential formation in TMX (open access)

Ambipolar potential formation in TMX

TMX experimental data on ambipolar potential control and on the accompanying electrostatic confinement are reported. New results on the radial dependence of the central-cell confining potential are given. Radial and axial particle losses as well as scaling of the central-cell axial confinement are discussed.
Date: May 5, 1981
Creator: Correll, D. L.; Allen, S. L. & Casper, T. A.
System: The UNT Digital Library
Central cell confinement in MFTF-B (open access)

Central cell confinement in MFTF-B

The point code TANDEM has been used to survey the range of plasma parameters which can be attained in MFTF-B. The code solves for the electron and ion densities and temperatures in the central cell, yin-yang, barrier, and A-cell regions as well as the plasma potential in each region. In these studies, the A-cell sloshing ion beams were fixed while the neutral beams in the yin-yang and central cell, the gas feed in the central cell, and the applied ECRH power ..beta.., central cell ion density and temperature, and the confining potential are discussed.
Date: May 5, 1981
Creator: Jong, R.A.
System: The UNT Digital Library
Effects due to the large ambipolar potential in TMX (open access)

Effects due to the large ambipolar potential in TMX

The large potentials and potential gradients in tandem mirrors have several effects. Some of these are discussed, together with supporting data from TMX. These include: azimuthal averaging by the E x B rotation, reduction of radial outward drifts (from high order multipoles) by the rapid E x B azimuthal velocity, neoclassical-resonant diffusion, Joule heating of central cell ions due to non-ambipolar transport in the radial electric field, low frequency instabilities, and differences between the details of the electron behavior and theory.
Date: May 5, 1981
Creator: Hooper, E. B. Jr.; Allen, S. L. & Coakley, P.
System: The UNT Digital Library
Low energy x-ray spectrometer (open access)

Low energy x-ray spectrometer

A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni L..cap alpha../sub 1/ /sub 2/ lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy …
Date: June 5, 1981
Creator: Woodruff, W. R.
System: The UNT Digital Library
Psuedo-3D, isodensity and density profiles from fiber optic output of a MACH-130 air shock (open access)

Psuedo-3D, isodensity and density profiles from fiber optic output of a MACH-130 air shock

A modified Voitenko compressor generated a Mach-130 air shock in an outlet pipe open to the atmosphere. Fiber optics transmitted luminosity associated with propagation of the air shock to an external display board, which was scanned with a high-speed streaking camera. We describe the computerized microdensitometer scanning technique for converting the film records to pseudo-3D, isodensity, and density profiles. The isodensity contours can be displayed using different colors to facilitate analysis. This technique can achieve resolutions of 1 ns and 2 ..mu..m. We give examples of the pseudo-3D, isodensity, and density profile plots for the experiment. The microdensitometer output was digitized for input to data display programs run on a CDC 7600. These results were used to provide submicrosecond accuracy for shock propagation over a 5 m of the outlet pipes. In addition, we obtained information about gas flow behind the shock front. Other current or possible applications for the technique are measurement of: target implosion in laser fusion, flash x-ray data in hydrodynamic and ballistic experiments, temperature profiles for high energy (> 10/sup 5/ K) gas dynamics, and dynamic events in weapons testing.
Date: June 5, 1981
Creator: Dittmore, C.H. & Glenn, H.D.
System: The UNT Digital Library
Feasibility study of a fission supressed blanket for a tandem-mirror hybrid reactor (open access)

Feasibility study of a fission supressed blanket for a tandem-mirror hybrid reactor

A study of fission suppressed blankets for the tandem mirror not only showed such blankets to be feasible but also to be safer than fissioning blankets. Such hybrids could produce enough fissile material to support up to 17 light water reactors of the same nuclear power rating. Beryllium was compared to /sup 7/Li for neutron multiplication; both were considered feasible but the blanket with Li produced 20% less fissile fuel per unit of nuclear power in the reactor. The beryllium resource, while possibly being too small for extensive pure fusion application, would be adequate (with carefully planned industrial expansion) for the hybrid because of the large support ratio, and hence few hybrids required. Radiation damage and coatings for beryllium remain issues to be resolved by further study and experimentation.
Date: October 5, 1981
Creator: Moir, R. W.; Lee, J. D. & Barr, W. L.
System: The UNT Digital Library
Heat-exchanger concepts for neutral-beam calorimeters (open access)

Heat-exchanger concepts for neutral-beam calorimeters

Advanced cooling concepts that permit the design of water cooled heat exchangers for use as calorimeters and beam dumps for advanced neutral beam injection systems were evaluated. Water cooling techniques ranging from pool boiling to high pressure, high velocity swirl flow were considered. Preliminary performance tests were carried out with copper, inconel and molybdenum tubes ranging in size from 0.19 to 0.50 in. diameter. Coolant flow configurations included (1) smooth tube/straight flow, (2) smooth tube with swirl flow created by tangential injection of the coolant, and (3) axial flow in internally finned tubes. Additionally, the effect of tube L/D was evaluated. A CO/sub 2/ laser was employed to irradiate a sector of the tube exterior wall; the laser power was incrementally increased until burnout (as evidenced by a coolant leak) occurred. Absorbed heat fluxes were calculated by dividing the measured coolant heat load by the area of the burn spot on the tube surface. Two six element thermopiles were used to accurately determine the coolant temperature rise. A maximum burnout heat flux near 14 kW/cm/sup 2/ was obtained for the molybdenum tube swirl flow configuration.
Date: October 5, 1981
Creator: Thompson, C.C.; Polk, D.H.; McFarlin, D.J. & Stone, R.
System: The UNT Digital Library
Notification of change in a data base (open access)

Notification of change in a data base

The Supervisory Control and Diagnostics System for the Mirror Fusion Test Facility is an event driven system; tasks that handle specific events are active only when those events occur. One method of monitoring and generating events is the data base notification facility; a task can request that it be loaded and started by the dbms if a data element is touched or goes outside of a specified range. The motivations for this facility (along with an example of its use and some specifics regarding how it is done) are presented.
Date: October 5, 1981
Creator: Nelson, B.C.
System: The UNT Digital Library
TMX-Upgrade neutral-beam injection system (open access)

TMX-Upgrade neutral-beam injection system

The TMX experiment proved that axial confinement of central-cell ions is improved ninefold by the electrostatic potential of end-cell plasmas. The TMX Upgrade task is to improve this confinement further. This paper discusses the injector system aspects of the TMX Upgrade.
Date: October 5, 1981
Creator: Felker, B.; Kane, R. J.; Wong, R. L.; Calderon, M. O. & Moore, T. L.
System: The UNT Digital Library
Assessment of some of the problems in the USA of superconducting magnets for fusion research (open access)

Assessment of some of the problems in the USA of superconducting magnets for fusion research

This paper discusses some of the general difficulties and problems encountered during the development of the technology of superconductors and superconducting magnets for fusion and expresses some personal concerns.
Date: November 5, 1981
Creator: Cornish, D.N.
System: The UNT Digital Library
Mechanical properties of highly irradiated 20 percent cold-worked Type 316 stainless steel (open access)

Mechanical properties of highly irradiated 20 percent cold-worked Type 316 stainless steel

Recent experiments have extended the mechanical properties data base of 20 percent cold worked 316 stainless steel to a fluence of 1.3 x 10/sup 23/ n/cm/sup 2/ (E > 0.1 MeV), the goal exposure of the Fast Flux Test Facility. Both uniaxial and biaxial tests were conducted on speciments of developmental cladding which were irradiated in the Experimental Breeder Reactor-II at temperatures ranging from 370/sup 0/C to 650/sup 0/C. Uniaxial tensile tests were conducted at strain rates ranging from 10/sup -5//s to 10/sup -//sub 3//s. Controlled Biaxial Strain Rate (CBSR) tests, recently developed at the Hanford Engineering Development Laboratory, were conducted only at a strain rate of 10/sup -5//s. CBSR specimens are gas-loaded to produce a constant diametral strain rate. These tests are otherwise analogous to uniaxial tensile tests. The tensile strength and ductility of the cladding were generally in good agreement with the predicted values.
Date: April 5, 1982
Creator: Hamilton, M. L.; Cannon, N. S. & Johnson, G. D.
System: The UNT Digital Library
Axicell MFTF-B superconducting-magnet system (open access)

Axicell MFTF-B superconducting-magnet system

The Axicell MFTF-B magnet system will provide the field environment necessary for tandem mirror plasma physics investigation with thermal barriers. The performance of the device will stimulate DT to achieve energy break-even plasma conditions. Operation will be with deuterium only. There will be 24 superconducting coils consisting of 2 sets of yin-yang pairs, 14 central-cell solenoids, 2 sets of axicell mirror-coil pairs, and 2 transition coils between the axicell mirror coil-pairs and the yin-yang coils. This paper describes the progress in the design and construction of MFTF-B Superconducting-Magnet System.
Date: May 5, 1982
Creator: Wang, S. T.; Bulmer, R.; Hanson, C.; Hinkle, R.; Kozman, T.; Shimer, D. et al.
System: The UNT Digital Library
Testing of the MFTF magnets (open access)

Testing of the MFTF magnets

This paper describes the cooldown and testing of the first yin-yang magnet for the Mirror Fusion Test Facility. The introduction describes the superconducting magnet; the rest of the paper explains the tests prior to and including magnet cooldown and final acceptance testing. The MFTF (originally MX) was proposed in 1976 and the project was funded for construction start in October 1977. Construction of the first large superconducting magnet set was completed in May 1981 and testing started shortly thereafter. The acceptance test procedures were reviewed in May 1981 and the cooldown and final acceptance test were done by the end of February 1982. During this acceptance testing the magnet achieved its full design current and field.
Date: May 5, 1982
Creator: Kozman, T.A.; Chang, Y. & Dalder, E.N.C.
System: The UNT Digital Library
Low-noise wide-band amplifiers for stochastic beam cooling experiments (open access)

Low-noise wide-band amplifiers for stochastic beam cooling experiments

Noise characteristics of the continuous-wave wide-band amplifier systems for stochastic beam cooling experiments are presented. Also, the noise performance, bandwidth capability and gain stability of components used in these amplifiers are summarized and compared in the 100 MHz to 40 GHz frequency range. This includes bipolar and field-effect transistors, parametric amplifier, Schottky diode mixer and maser. Measurements of the noise characteristics and scattering parameters of variety GaAs FETs as a function of ambient temperature are also given. Performance data and design information are presented on a broadband 150-500 MHz preamplifier having noise temperature of approximately 35/sup 0/K at ambient temperature of 20/sup 0/K. An analysis of preamplifier stability based on scattering parameters concept is included.
Date: September 5, 1982
Creator: Leskovar, B. & Lo, C.C.
System: The UNT Digital Library
Effects of pulsed dual-ion irradiation on phase transformations and microstructure in Ti-modified austenitic alloy (open access)

Effects of pulsed dual-ion irradiation on phase transformations and microstructure in Ti-modified austenitic alloy

The influence of pulsed 4 MeV Ni ion bombardment, with and without simultaneous helium injection, has been explored in a low swelling, Ti-modified austenitic stainless steel. Irradiations were carried out to 70 dpa at 950/sup 0/K; the pulsing frequencies were either 60 s on/off or 1 s on/off. Compared to continuous irradiation, pulsing caused a decrease in the interstitial loop diameter at 1 dpa, although at higher doses the overall dislocation density was not affected. Pulsing and helium both promoted the stability of MC precipitates and retarded the subsequent G phase formation; in some cases G-phase was suppressed and eta phase formed instead. Small bubble-like cavities were observed to grow into large voids after steady dual beam irradiation to 70 dpa. However, this conversion was suppressed by pulse irradiation to 70 dpa and furthermore the sizes of the small cavities were somewhat reduced. The results are explained in terms of current mechanistic understanding of mean point defect kinetics and the evolution of microstructure and microcomposition during irradiation with superimposed annealing periods.
Date: January 5, 1983
Creator: Lee, E. H.; Packan, N. H. & Mansur, L. K.
System: The UNT Digital Library
Magnets for the Mirror Fusion Test Facility: testing of the first Yin-Yang and the design and development of other magnets (open access)

Magnets for the Mirror Fusion Test Facility: testing of the first Yin-Yang and the design and development of other magnets

Completed in May 1981, the first Yin-Yang magnet for the tandem Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory (LLNL) was successfully tested in February 1982 to its full design field (7.68 T) and current (5775 A). Since that time, the entire magnet array has been reconfigured - from the original A-cell to an axicell design. The MFTF-B magnet array now contains a total of 26 large superconducting coils: 2 sets of yin-yang pairs, 2 sets of transition magnets (each containing two coils), 2 sets of axicell magnets (each containing three coils), and 12 central-cell solenoids. This paper chronicles recent magnet history - from te testing of the initial yin-yang set, through the design of the axicell configuration, to the planned development of the system.
Date: January 5, 1983
Creator: Kozman, T. A.; Wang, S. T. & Chang, Y.
System: The UNT Digital Library