A novel scheme to handle highly pulsed loads with a standard helium refrigerator (open access)

A novel scheme to handle highly pulsed loads with a standard helium refrigerator

Helium refrigerator performance degrades rapidly when it has to handle a varying or pulsed heat load. A novel scheme is presented to handle highly pulsed 4.5 K cryogenic loads with a standard helium refrigerator by isolating it from these pulses. The scheme uses a relatively simple arrangement of control valves, heat exchangers, and a storage dewar. Applications include pulsed tokamak machines such as TPX (Tokamak Physics Experiment) and ITER (International Thermonuclear Experimental Reactor). For example, the TPX (currently in the conceptual design phase in a DoE contract) requires an average 4.5 K refrigerator capacity of about 10 kW; however, pulsed loads caused by eddy current and nuclear heating will exceed 100 kW. The scheme presented here provides a method for handling these pulsed loads. Because of the simple and proven nature of the components involved and the thermodynamic properties of the helium, the system could be implemented for projects such as TPX or ITER with little or no development.
Date: June 30, 1993
Creator: Slack, D. S.
Object Type: Article
System: The UNT Digital Library
Restoring locality with faster-than-light velocities (open access)

Restoring locality with faster-than-light velocities

The idea of ``locality`` is a deep rooted concept. It does not have to be abandoned even if ``loophole free`` EPR experiments are performed and confirm the predictions of quantum theory. To satisfy locality, one can imagine that influences at a distance are exerted via mechanisms involving an ether and effects propagating in that ether a velocity V > c. Such model of physical phenomena is not Lorentz invariant but, with V large enough, the model can be made to reproduce the results of all experiments where quantum mechanics and Lorentz invariance have been verified.
Date: August 30, 1993
Creator: Eberhard, P. H.
Object Type: Article
System: The UNT Digital Library
Sound velocity estimation: A system theoretic approach (open access)

Sound velocity estimation: A system theoretic approach

A system-theoretic approach is proposed to investigate the feasibility of reconstructing a sound velocity profile (SVP) from acoustical hydrophone measurements. This problem is based on a state-space representation of the normal-mode propagation model. It is shown that this representation can be utilized to investigate the so-called observability of the SVP from noisy measurement data. A model-based processor is developed to extract this information and it is shown that even in cases where limited SVP information is available, the SVP can be estimated using this approach.
Date: July 30, 1993
Creator: Candy, J. V. & Sullivan, E. J.
Object Type: Article
System: The UNT Digital Library
Detector development and test facility. [Annual] technical report, [August 1, 1992--July 31, 1993] (open access)

Detector development and test facility. [Annual] technical report, [August 1, 1992--July 31, 1993]

Following the ideas presented in the proposal to the DoE, we have begun to acquire the equipment needed to design, develop, construct, and test the electronic and mechanical features of detectors used in High Energy Physics Experiments. A guiding principle for the effort is to achieve integrated electronic and mechanical designs which meet the demanding specifications of the modern hadron collider environment yet minimize costs. This requires state of the art simulation of signal processing as well as detailed calculations of heat transfer and finite element analysis of structural integrity.
Date: June 30, 1993
Creator: Reeder, D. D.
Object Type: Report
System: The UNT Digital Library
Hydrologic test plan for the Environmental Remediation Disposal Facility (open access)

Hydrologic test plan for the Environmental Remediation Disposal Facility

Hydrologic tests are planned at seven wells that will be drilled at the proposed Environmental Remediation Disposal Facility (ERDF). These wells are supporting hydrologic, geologic, and hydrochemical characterization at this new facility. Hydrologic testing will consist of instantaneous slug tests, slug interference tests, step-drawdown tests, and constant rate discharge tests (generally single-well). These test results and later groundwater monitoring data will be used to determine groundwater flow directions, flow rates, and the chemical makeup of the groundwater below the proposed ERDF. The seven wells will be drilled in two phases. In Phase I four wells will be drilled and tested: Two to the top of the uppermost aquifer (water table) and two as characterization boreholes to the top of basalt. The Phase I wells are located in the northern portion of the proposed ERDF site (699-32-72, 699-SDF-6, -7 and -8) (Figure 1). If Phase II drilling proceeds, the remaining three wells will be installed and tested (two deep and one shallow). A phased approach to drilling is warranted because of current uncertainty in the land use requirements at the proposed ERDF.
Date: September 30, 1993
Creator: Swanson, L. C.
Object Type: Report
System: The UNT Digital Library
Development of Rotating Shadowband Spectral Radiometers and GCM Radiation Code Test Data Sets in Support of ARM. Technical Progress Report, September 15, 1992--October 31, 1993 (open access)

Development of Rotating Shadowband Spectral Radiometers and GCM Radiation Code Test Data Sets in Support of ARM. Technical Progress Report, September 15, 1992--October 31, 1993

The ARM goal is to help improve both longwave and shortwave models by providing improved radiometric shortwave data. These data can be used directly to test shortwave model predictions. As will be described below they can also provide inferred values for aerosol and cloud properties that are useful for longwave modeling efforts as well. The current ARM research program includes three tasks all related to the study of shortwave radiation transfer through clouds and aerosol. Two of the tasks involve the assembly of archived and new radiation and meteorological data sets; the third and dominant task has been the development and use of new shortwave radiometric sensors. Archived data from Golden, Colorado, and Albany, New York, were combined with National Weather Service ground and upper air data for testing radiation models for the era when the Earth Radiation Budget Experiment (ERBE) was operational. These data do not include optimum surface radiation measurements; consequently we are acquiring downwelling shortwave, including direct and diffuse irradiance, plus downwelling longwave, upwelling shortwave, and aerosol optical depth, at our own institution, as an additional dataset for ARM modelers.
Date: April 30, 1993
Creator: Michalsky, J. & Harrison, L.
Object Type: Report
System: The UNT Digital Library
Density functional studies: First principles and semi-emperical calculations of clusters and surfaces (open access)

Density functional studies: First principles and semi-emperical calculations of clusters and surfaces

Theoretical electronic structure techniques are used to analyze widely different systems from Si clusters to transition metal solids and surfaces. For the Si clusters, first principles density functional methods are used to investigate Si{sub N} for N=2-8. Goal is to understand the different types of bonding that can occur in such small clusters where the atomic coordination differs substantially from tetrahedral bonding; such uncoordinated structures can test approximate models of Si surfaces. For the transition metal systems, non-self-consistent electronic structure methods are used to understand the driving force for surface relaxations. In-depth analysis of results is presented and physical basis of surface relaxation within the theory is discussed. Limitations inherent in calculations of metal surface relaxation are addressed. Finally, in an effort to understand approximate methods, a novel non-self- consistent density functional electronic structure method is developed that is about 1000 times faster than more sophisticated methods; this method is tested for various systems including diatomics, mixed clusters, surfaces, and bulk lattices.
Date: April 30, 1993
Creator: Susan, S.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Applications and source development for high-repetition rate x-ray lasers (open access)

Applications and source development for high-repetition rate x-ray lasers

Many applications in material science, chemistry, and atomic physics require an x-ray source that has a repetition rate of 1 Hz to a few kHz. In these fields, a very wide range of photon energies is of interest. One application is time-resolved surface photoelectron spectroscopy and microscopy where low energy (< 1{mu}J) pulses are required to avoid space charge effects but high-repetition rates ({approx} kHz) provide the high average power which is needed to obtain the desired resolution. In pump-probe experiments, it is desirable to have the repetition rate of the x-ray source be comparable to the repetition rate of the corresponding IR, optical, or UV laser. We show that the very high-repetition rate of synchrotrons (1--1000 MHz) results in an inefficient use of x rays for these types of experiments and that a kHz repetition rate x-ray laser would be an excellent source for many experiments. For some applications, a slower repetition rate of order 1 Hz is adequate provide the energy per pulse is larger ({approx}1 mJ). For example, in photoelectron spectroscopy of free clusters, an x-ray laser can provide the required large number of nearly monoenergetic photons during the short time the clusters can be probed in …
Date: July 30, 1993
Creator: Eder, D. C.; Amendt, P. & Bolton, P. R.
Object Type: Article
System: The UNT Digital Library
A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1993--June 1993 (open access)

A coal-fired combustion system for industrial process heating applications. Quarterly technical progress report, April 1993--June 1993

Vortec Corporation`s Phase III development contract DE-AC22-91PC91161 for a ``Coal-Fired Combustion System for Industrial Process Heating Applications`` is project funded under the DOE/PETC advanced combustion program. This advanced combustion system research program is for the development of innovative coal-fired process heaters which can be used for high temperature melting, smelting and waste vitrification processes. The process heater systems to be developed have multiple use applications; however, the Phase III research effort is being focused on the development of a process heater system to be used for producing value added vitrified glass products from boiler/incinerator ashes and industrial wastes. The primary objective of the Phase III project is to develop and integrate all the system components, from fuel through total system controls, and then test the complete system in order to evaluate its potential marketability. During the past quarter, the designs of the remaining major components of the integrated system were completed and the equipment was ordered. DOE has elected to modify the scope of the existing R&D program being conducted under this contract to include testing of a simulated TSCA incinerator ash. The modification will be in the form of an additional Task (Task 8 -- TSCA Ash Testing) to …
Date: July 30, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Radar stimulator interface protocol, preliminary interface design and Doppler Beam Sharpening implementation (open access)

Radar stimulator interface protocol, preliminary interface design and Doppler Beam Sharpening implementation

This is the final report for a subcontract to supply a Doppler Beam Sharpening model to interface with the radar stimulation package running on the Cray supercomputers. The article describes the beam sharpening model, and the way beam sharpening is implemented by the model. Changes from previous work are emphasized in this report.
Date: June 30, 1993
Creator: Aldrich, C. H.
Object Type: Report
System: The UNT Digital Library
Body growth considerations in age-specific dosimetry. Final report (open access)

Body growth considerations in age-specific dosimetry. Final report

This report describes the manner in which the age-specific dosimetric calculations of the International Commission on Radiological Protection (ICRP) addressed changes in organ size that occur with age. The approach involves an interpolation of dosimetric information derived for six reference individuals using the inverse of the total body mass as the interpolation variable. An alternative formulation is investigated that employs a functional representation of the organ mass as a function of age in conjunction with an explicit formulation of the dosimetric factors in terms of organ mass. Using an exponential-logistic growth function as suggested by Walker, this report demonstrates, through application to the dosimetry of radioiodines in the thyroid, that the alternative formulation can be formulated and implemented. Although either approach provides a workable basis for age-specific dosimetry, it is clear that the functional representation of organ growth has some attractive features. However, without question, the major difficulty is the quality and quantity of data available to address the age- and gender-specific parameters in the dosimetric formulations.
Date: September 30, 1993
Creator: Eckerman, K. F.
Object Type: Report
System: The UNT Digital Library
Final report for confinement vessel analysis: Task 1, Correlation of new vessel data with finite element results (open access)

Final report for confinement vessel analysis: Task 1, Correlation of new vessel data with finite element results

Los Alamos performed tests of a modified confinement vessel in November 1992 to gain a better understanding of the response of the confinement vessel. The first test was meant to duplicate, with additional instrumentation, tests done previously for correlation with analysis. Task 1 of Subcontract Number 9-XH3-0607K-1 was the correlation of this new vessel test data with the results of finite element analyses. The authors also examined the data for the other test, which was for optical port development. The tests were numbered H-1573 and H-1562 and were fired on November 9 and 10, 1992, respectively. Test H-1573 was identical to the previous 40 lb tests except that a Burke tube was used to support the explosive charge while the explosive was freely suspended in the earlier tests. The second test, H-1562, was for development of the optical port. In addition to the Burke tube, this test also had additional components on the inside of the ports to protect the windows. The following are conclusions and recommendations drawn from assessment and correlation of tests H-1573 and H-1562: (1) yielding was measured at the bottom of the vessel for these tests; (2) the presence of a support tube in the vessel …
Date: November 30, 1993
Creator: Lewis, B. B.
Object Type: Report
System: The UNT Digital Library
Theoretical particle physics. Progress report, FY 1993 (open access)

Theoretical particle physics. Progress report, FY 1993

This report discusses the following topics: Heavy Quark Physics; Chiral Perturbation Theory; Skyrmions; Large-N Limit; Weak Scale Baryogenesis; Supersymmetry; Rare Decays; Technicolor; Chiral Lattice Fermions; Pauli-Villars Regulator and the Higgs Mass Bound; Higgs and Yukawa Interactions; Gauge Fixing; and Quantum Beables.
Date: September 30, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A data distributed, parallel algorithm for ray-traced volume rendering (open access)

A data distributed, parallel algorithm for ray-traced volume rendering

This paper presents a divide-and-conquer ray-traced volume rendering algorithm and its implementation on networked workstations and a massively parallel computer, the Connection Machine CM-5. This algorithm distributes the data and the computational load to individual processing units to achieve fast, high-quality rendering of high-resolution data, even when only a modest amount of memory is available on each machine. The volume data, once distributed, is left intact. The processing nodes perform local ray-tracing of their subvolume concurrently. No communication between processing units is needed during this locally ray-tracing process. A subimage is generated by each processing unit and the final image is obtained by compositing subimages in the proper order, which can be determined a priori. Implementations and tests on a group of networked workstations and on the Thinking Machines CM-5 demonstrate the practicality of our algorithm and expose different performance tuning issues for each platform. We use data sets from medical imaging and computational fluid dynamics simulations in the study of this algorithm.
Date: March 30, 1993
Creator: Ma, Kwan-Liu; Painter, J. S.; Hansen, C. D. & Krogh, M. F.
Object Type: Article
System: The UNT Digital Library
Economic efficiency, IRPs and long term contracts (open access)

Economic efficiency, IRPs and long term contracts

There is no market failure that warrants utility regulation of the construction of new generating plants, the supply of energy efficiency or the purchase of fuel under contract. The natural monopoly problem applies to the distribution of electricity and gas, not to generation, energy conservation, or gas purchases. Utility regulation magnifies a market failure, which is the principal agent problem. Regulatory allowance of utilities signing long term fixed price contracts and undertaking conservation measures result in costs and risks being shifted to ratepayers that would not occur under competitive market conditions. Economic efficiency would be enhanced if cost of service regulation of electric and gas utilities were replaced by a competitive market process for the construction of new power plants, utility conservation programs and contracts to purchase fuel. Conservation measures could be supplied by energy service companies. Gas merchants could provide gas and energy conservation directly to ultimate customers, if they had access to LDC pipelines. With a competitive market established to sell gas and energy services, contracts and conservation measures would not require cost-of- service regulation.
Date: April 30, 1993
Creator: Sutherland, R. J.
Object Type: Article
System: The UNT Digital Library
Spallation neutron source/proposed rf system (open access)

Spallation neutron source/proposed rf system

The rf system for the synchrotrons of the spallation neutron source is designed to accelerate 1.4 {times} 10{sup 14} protons/pulse to an energy of 3.6 GeV. Injection energy is 600 MeV. The synchrotron repetition frequency is 30 Hz, with a 50% duty factor. The choice of operating frequency is somewhat arbitrary. The authors propose a low frequency of 1.3 to 1.6 MHz, which is the second harmonic of the revolution frequency. The advantages of such a low frequency system are: (1) There will be two bunches in the machines and the time between bunches will be sufficiently long to allow for the rise time of the extraction kicker. No missing bunches will be necessary, which simplifies injection, and transient beam loading problems are avoided. (2) With only two bunches there are no unstable coupled-bunch modes of longitudinal instability. (3) In multi-gap low frequency cavities the transient time factor is essentially unity because the rf wavelength is much longer than the cavity dimensions. (4) Cavities in this low frequency range are basically lumped-element type structures, where the sources of the inductance and capacitance are clearly identified. This allows effective control of higher order mode impedances in such cavities. (5) Ferrite-loaded low-frequency …
Date: September 30, 1993
Creator: Meth, M. & Brennan, J. M.
Object Type: Report
System: The UNT Digital Library
Treatability studies on F/H Area ``hot spot`` groundwater composite. Revision 1 (open access)

Treatability studies on F/H Area ``hot spot`` groundwater composite. Revision 1

The data found in this report were collected from laboratory experiments that were conducted to characterize the ``hot spot`` groundwater before and after pH adjustment, to describe the settling behavior and particle size of the precipitates resulting from pH adjustment, and to compare several methods of pH adjustment. Although Decontamination Factors (DFs) for all precipitating agents are similar, the best settling characteristics and most manageable precipitate were produced when 25 ppM Al{sup 3+} was introduced as Al{sub 2}(SO{sub 4}){sub 3} and pH adjustment was made from 6--8 with NaOH. The resulting precipitate will not be a hazardous secondary waste.
Date: August 30, 1993
Creator: Bibler, J. P.
Object Type: Report
System: The UNT Digital Library
Static ultra-high pressure study of lanthanide and actinide metals using a diamond-anvil cell (open access)

Static ultra-high pressure study of lanthanide and actinide metals using a diamond-anvil cell

Structural phase transformation in lanthanides and actinides were investigated as a function of pressure up to 300 GPa at room temperature. Except in Ce and Pr, no large volume changes were noticed for these metals as thy went through several phase changes. The appearance of a bct ultra-high pressure phase in Ce, Sm, Th, and possibly in Np, raises the possibility that the ultimate high pressure structure for the 4f and 5f metals may be the bct structure. On the other hand, it is also possible that this is a precursor to another close-packed structure at even higher pressure.
Date: June 30, 1993
Creator: Akella, J.; Smith, G. S. & Weir, S. T.
Object Type: Article
System: The UNT Digital Library
Bench-scale testing of the Multi-Gravity separator in combination with Microcel. Third quarterly report, April 1, 1993--June 30, 1993 (open access)

Bench-scale testing of the Multi-Gravity separator in combination with Microcel. Third quarterly report, April 1, 1993--June 30, 1993

The primary objective of the proposed work is to design, install, and operate an advanced fine coal processing circuit combining the Microcel and Multi-Gravity-Separator (MGS) technologies. Both of these processes have specific advantages as stand-alone units. For example, the Microcel column effectively removes ash-bearing mineral matter, while the MGS efficiently removes coal-pyrite composites. By combining both unit operations into a single processing circuit, synergistic advantages can be gained. As a result, this circuit arrangement has the potential to improve coal quality beyond that achieved using the individual technologies. Work this quarter primarily focused on procurement and fabrication of the required process equipment. All fabrication work is underway and is expected to be completed prior to the installation deadline. Delays in the existing project within the Pittsburgh Energy Technology Center`s Coal Preparations Process Research Facility have resulted in a shift in the original project schedule. A new installation date (June 28, 1993) has been established by DOE/PETC. The overall project schedule has been adjusted accordingly. Revisions to ESH subject plans were also completed during this quarter. Based on these plans, the ESH permitting procedure has been initiated by the contracting officer`s representative. The subject plans and circuit will be modified, if …
Date: July 30, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Production of mild gasification co-products project. First quarterly technical progress report, January 1, 1993--March 31, 1993 (open access)

Production of mild gasification co-products project. First quarterly technical progress report, January 1, 1993--March 31, 1993

Progress continued on production of co-product samples for four coals from three coal regions: Buckskin Mine coal (Wyoming, Powder River Basin, Coal), Knife River Mine Lignite (Beulah Zap, North Dakota Lignite), Sarpy Creek Mine Coal (Montana Rosebud, Powder River Basin Coal), Usibelli Mine Coal (Alaska Coal).
Date: April 30, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Inverse Cerenkov experiment. Final report (open access)

Inverse Cerenkov experiment. Final report

The final report describes work performed to investigate inverse Cherenkov acceleration (ICA) as a promising method for laser particle acceleration. In particular, an improved configuration of ICA is being tested in a experiment presently underway on the Accelerator Test Facility (ATF). In the experiment, the high peak power ({approximately} 10 GW) linearly polarized ATF CO{sub 2} laser beam is converted to a radially polarized beam. This is beam is focused with an axicon at the Cherenkov angle onto the ATF 50-MeV e-beam inside a hydrogen gas cell, where the gas acts as the phase matching medium of the interaction. An energy gain of {approximately}12 MeV is predicted assuming a delivered laser peak power of 5 GW. The experiment is divided into two phases. The Phase I experiments, which were completed in the spring of 1992, were conducted before the ATF e-beam was available and involved several successful tests of the optical systems. Phase II experiments are with the e-beam and laser beam, and are still in progress. The ATF demonstrated delivery of the e-beam to the experiment in Dec. 1992. A preliminary ``debugging`` run with the e-beam and laser beam occurred in May 1993. This revealed the need for some …
Date: September 30, 1993
Creator: Kimura, W. D.
Object Type: Report
System: The UNT Digital Library
Assist in the Recovery of Bypassed Oil From Reservoirs in the Gulf of Mexico. Quarterly Status Report, April 1, 1993--June 30, 1993 (open access)

Assist in the Recovery of Bypassed Oil From Reservoirs in the Gulf of Mexico. Quarterly Status Report, April 1, 1993--June 30, 1993

Much of the remaining oil offshore is trapped in formations that are extremely complex due to intrusions of salt domes. Conventional seismic processing techniques cannot clearly image either these traps or the full extent of oil-bearing segments near the salt domes; therefore, substantial volumes of oil may have remained uncontacted by previous drilling. Recently, however, significant innovations have been made in seismic processing and mathematical migration of seismic signal. In addition, significant advances have been made in deviated and horizontal drilling technologies and applications. These technology advances make it possible to reprocess existing seismic data to identify non-contacted portions of the reservoirs, which can then be contacted using advanced drilling technologies to kick out new wells from existing wells. Effective application of these technologies, along with improved recovery methods, offers opportunities to significantly increase Gulf of Mexico production, delay platform abandonments, and preserve access to a substantial remaining oil target for enhanced recovery and other advanced recovery processes. During this reporting period, data collection continued from the Minerals Management Service (MMS) and several operators. Modifications to BOAST II and MASTER reservoir simulators for the integration of radial grid systems and for use in simulating miscible gas injection processes in steeply …
Date: July 30, 1993
Creator: Schenewerk, P. A.
Object Type: Report
System: The UNT Digital Library
Case studies of sewage treatment with recovery of energy from methane (open access)

Case studies of sewage treatment with recovery of energy from methane

In the Southeast, there are about 3,000 wastewater plants with a capacity of over one million gallons per day. Under this study, operating data and available financial information on a variety of technologies for large and small plans was documented for ten facilities. Studies were done on wastewater treatment plants (WWTPs) with design capacities ranging from 9.5--120 million gallons per day. All of these WWTPs recover the gas produced in their anaerobic digesters and use at least part of it as fuel for boilers and/or internal combustion engines. The engines power generators, blowers, or pumps, and most are equipped with heat recovery systems. Based on the historical data provided by the participants in this study and from the authors` own technical analysis, methane recovery and utilization systems appear to be cost effective, although the degree of cost effectiveness varies widely. The types of energy recovery systems are not uniform among all the participants so that the cases in this limited survey are not precisely comparable to each other. Also, reliance on historical data and cost information generated from portions of total plant operations and estimates makes it difficult to complete analysis of specific variables. The fact remains, however, that regardless …
Date: June 30, 1993
Creator: Phillips, C. A.; Webster, N. & Wander, J.
Object Type: Report
System: The UNT Digital Library
Time evolution of the quark-gluon plasma (open access)

Time evolution of the quark-gluon plasma

This report discusses the time evolution of the quark-gluon plasma.
Date: August 30, 1993
Creator: Cooper, F.; Kluger, Y.; Dawson, J. & Shepard, H.
Object Type: Article
System: The UNT Digital Library