Combination free-electron and gaseous laser (open access)

Combination free-electron and gaseous laser

A multiple laser having one or more gaseous laser stages and one or more free electron stages is described. Each of the free electron laser stages is sequentially pumped by a microwave linear accelerator. Subsequently, the electron beam is directed through a gaseous laser, in the preferred embodiment, and in an alternative embodiment, through a microwave accelerator to lower the energy level of the electron beam to pump one or more gaseous lasers. The combination laser provides high pulse repetition frequencies, on the order of 1 kHz or greater, high power capability, high efficiency, and tunability in the synchronous production of multiple beams of coherent optical radiation.
Date: June 8, 1981
Creator: Brau, C. A.; Rockwood, S. D. & Stein, W. E.
Object Type: Patent
System: The UNT Digital Library
Fast transient digitizer (open access)

Fast transient digitizer

Method and apparatus are presented for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display.
Date: July 8, 1981
Creator: Villa, F.
Object Type: Patent
System: The UNT Digital Library
Electromagnetic velocity gauge: use of multiple gauges, time response, and flow perturbations (open access)

Electromagnetic velocity gauge: use of multiple gauges, time response, and flow perturbations

We have developed an in-situ electromagnetic velocity (EMV) gauge system for use in multiple-gauge studies of initiating and detonating explosives. We have also investigated the risetime of the gauge and the manner in which it perturbs a reactive flow. We report on the special precautions that are necessary in multiple gauge experiments to reduce lead spreading, simplify target fabrication problems and minimize cross talk through the conducting explosive. Agreement between measured stress records and calculations from multiple velocity gauge data give us confidence that our velocity gauges are recording properly. We have used laser velocity interferometry to measure the gauge risetime in polymethyl methacrylate (PMMA). To resolve the difference in the two methods, we have examined hydrodynamic and material rate effects. In addition, we considered the effects of shock tilt, electronic response and magntic diffusion on the gauge's response time.
Date: April 8, 1981
Creator: Erickson, L. M.; Johnson, C. B.; Parker, N. L.; Vantine, H. C.; Weingart, R. C. & Lee, R. S.
Object Type: Article
System: The UNT Digital Library
Automatic gas-levitation system for vacuum deposition of laser-fusion targets (open access)

Automatic gas-levitation system for vacuum deposition of laser-fusion targets

An improved simple system has been developed to gas-levitate microspheres during vacuum-deposition processes. The automatic operation relies on two effects: a lateral stabilizing force provided by a centering-ring; and an automatically incremented gas metering system to offset weight increases during coating.
Date: September 8, 1981
Creator: Jordan, C. W.; Cameron, G. R.; Krenik, R. M. & Crane, J. K.
Object Type: Article
System: The UNT Digital Library
Low-level-signal data acquisition for the MFTF superconducting-magnet system (open access)

Low-level-signal data acquisition for the MFTF superconducting-magnet system

Acquisition of low level signals from sensors mounted on the superconducting yin-yang magnet in the Mirror Fusion Test Facility (MFTF) imposes very strict requirements on the magnet signal conditioning and data acquisition system. Of the various types of sensors required, thermocouples, strain gages, and voltage taps produce very low level outputs. These low level outputs must be accurately measured in the harsh environment of slowly varying magnetic fields, cryogenic temperatures, high vacuum, pulse power and 60 Hz electrical noise, possible neutron radiation, and high common mode voltage resulting from superconducting magnet quench. Successful measurements require careful attention to grounding, shielding, signal handling and processing in the data acquisition system. The magnet instrumentation system provides a means of effectively measuring both low level signals and high level signals from all types of sensors.
Date: October 8, 1981
Creator: Montoya, C.R.
Object Type: Article
System: The UNT Digital Library
Formulas for one-dimensional local properties for molecular-dynamics simulations of shock waves (open access)

Formulas for one-dimensional local properties for molecular-dynamics simulations of shock waves

Formulas are derived for the mass, momentum, and energy densities, the xx component of the pressure tensor P/sup xx/, and the x component of the heat flux Q/sup x/. The formulas relate these local properties to the masses, positions, and velocities of the constituent particles making up the system and are in a usable form for molecular-dynamics simulations without approximation. The formulas for P/sup xx/ and Q/sup x/ avoid the infinite series found in the formulas of Irving and Kirkwood.
Date: January 8, 1981
Creator: Hardy, R.J.
Object Type: Report
System: The UNT Digital Library
Copper-coated laser-fusion targets using molecular-beam levitation (open access)

Copper-coated laser-fusion targets using molecular-beam levitation

A series of diagnostic experiments at the Shiva laser fusion facility required targets of glass microspheres coated with 1.5 to 3.0 ..mu..m of copper. Previous batch coating efforts using vibration techniques gave poor results due to microsphere sticking and vacuum welding. Molecular Beam Levitation (MBL) represented a noncontact method to produce a sputtered copper coating on a single glassmicrosphere. The coating specifications that were achieved resulted in a copper layer up to 3 ..mu..m thick with the allowance of a maximum variation of 10 nm in surface finish and thickness. These techniques developed with the MBL may be applied to sputter coat many soft metals for fusion target applications.
Date: September 8, 1981
Creator: Rocke, M. J.
Object Type: Article
System: The UNT Digital Library
Incorporation of chemical kinetic models into process control (open access)

Incorporation of chemical kinetic models into process control

An important consideration in chemical process control is to determine the precise rationing of reactant streams, particularly when a large time delay exists between the mixing of the reactants and the measurement of the product. In this paper, a method is described for incorporating chemical kinetic models into the control strategy in order to achieve optimum operating conditions. The system is first characterized by determining a reaction rate surface as a function of all input reactant concentrations over a feasible range. A nonlinear constrained optimization program is then used to determine the combination of reactants which produces the specified yield at minimum cost. This operating condition is then used to establish the nominal concentrations of the reactants. The actual operation is determined through a feedback control system employing a Smith predictor. The method is demonstrated on a laboratory bench scale enzyme reactor.
Date: July 8, 1981
Creator: Herget, C.J. & Frazer, J.W.
Object Type: Article
System: The UNT Digital Library
Evaluated nuclear data library (open access)

Evaluated nuclear data library

The Lawrence Livermore National Laboratory (LLNL) collection of evaluated data for neutron-, photon-, and charged-particle-induced reactions is maintained in a computer-oriented system. In this report we recount the history of Evaluated Nuclear Data Library, describe the methods of evaluation, and give examples of input and output representation of the data.
Date: October 8, 1981
Creator: Howerton, R.J.; Dye, R.E. & Perkins, S.T.
Object Type: Report
System: The UNT Digital Library
Plasma effects in high frequency radiative transfer (open access)

Plasma effects in high frequency radiative transfer

This paper is intended as a survey of collective plasma processes which can affect the transfer of high frequency radiation in a hot dense plasma. We are rapidly approaching an era when this subject will become important in the laboratory. For pedagogical reasons we have chosen to examine plasma processes by relating them to a particular reference plasma which will consist of fully ionized carbon at a temperature kT=1 KeV (10/sup 70/K) and an electron density N = 3 x 10/sup 23/cm/sup -3/, (which corresponds to a mass density rho = 1 gm/cm/sup 3/ and an ion density N/sub i/ = 5 x 10/sup 22/ cm/sup -3/). We will consider the transport in such a plasma of photons ranging from 1 eV to 1 KeV in energy. Such photons will probably be frequently used as diagnostic probes of hot dense laboratory plasmas.
Date: February 8, 1981
Creator: Alonso, C.T.
Object Type: Report
System: The UNT Digital Library
Bio-Oxidation of Thiocyanates Typical of Coal Conversion Effluents. Final Report (open access)

Bio-Oxidation of Thiocyanates Typical of Coal Conversion Effluents. Final Report

Thiocyanates have been found in most coal conversion and coke plant effluents. The objectives of this study were to develop data for the biological degradation fate kinetics of thiocyanate removal, and to develop material balance information for the fate of sulfur and nitrogen resulting from such bio-decomposition of aqueous thiocyanates. A literature review of thiocyanate bio-degradation indicates that while much biochemistry information is available, little information in the biological processing arena is known. Based on both batch and continuous culture experiments utilizing an activated sludge type of system with strictly thiocyanate degradating organisms, the specific utilization rate for SCN degradation was found to follow a substrate inhibition biokinetic relationship as: d(SCN)/dt-X = 2.24/(1 + (5/SCN) + (SCN/1340)/sup 6/) where; d(SCN)/dt-X = lb SCN used/lb biomass-day, SCN = mg/L SCN in effluent. The observed biomass sludge production rate was quantified as a function of sludge age in the bio-reactor. The major metabolic by-products of SCN aerobic biodegradation are ammonia and sulfate, with such formation being stochiometric with SCN. High levels of SCN in coal conversion and Stretford system effluents may lead to biological nitrification process requirements to be added to the wastetreatment scheme for compliance with BAT effluent ammonia discharge restrictions.
Date: January 8, 1981
Creator: Neufeld, R. D.; Mattson, L. & Lubon, P.
Object Type: Report
System: The UNT Digital Library
Geothermal heating from Pinkerton Hot Springs at Colorado Timberline Academy, Durango, Colorado. Final technical report (open access)

Geothermal heating from Pinkerton Hot Springs at Colorado Timberline Academy, Durango, Colorado. Final technical report

The efforts to establish a greater pool of knowledge in the field of low temperature heat transfer for the application of geothermal spring waters to space heating are described. A comprehensive set of heat loss experiments involving passive radiant heating panels is conducted and the results presented in an easily interpretable form. Among the conclusions are the facts that heating a 65 to 70 F/sup 0/ space with 90 to 100 F/sup 0/ liquids is a practical aim. The results are compared with the much lower rates published in the American Society of Heating Refrigeration and Air Conditioning Engineers SYSTEMS, 1976. A heat exchange chamber consisting of a 1000 gallon three compartment, insulated and buried tank is constructed and a control and pumping building erected over the tank. The tank is intended to handle the flow of geothermal waters from Pinkerton Hot Springs at 50 GPM prior to the wasting of the spring water at a disposal location. Approximately 375,000 Btu per hour should be available for heating assuming a 15 F/sup 0/ drop in water temperature. A combination of the panel heat loss experiments, construction of the heat exchange devices and ongoing collection of heat loss numbers adds to …
Date: November 8, 1981
Creator: Allen, C. C.; Allen, R. W. & Beldock, J.
Object Type: Report
System: The UNT Digital Library
Methodology for Comparing the Health Effects of Electricity Generation From Uranium and Coal Fuels (open access)

Methodology for Comparing the Health Effects of Electricity Generation From Uranium and Coal Fuels

A methodology was developed for comparing the health risks of electricity generation from uranium and coal fuels. The health effects attributable to the construction, operation, and decommissioning of each facility in the two fuel cycle were considered. The methodology is based on defining (1) requirement variables for the materials, energy, etc., (2) effluent variables associated with the requirement variables as well as with the fuel cycle facility operation, and (3) health impact variables for effluents and accidents. The materials, energy, etc., required for construction, operation, and decommissioning of each fuel cycle facility are defined as primary variables. The materials, energy, etc., needed to produce the primary variable are defined as secondary requirement variables. Each requirement variable (primary, secondary, etc.) has associated effluent variables and health impact variables. A diverging chain or tree is formed for each primary variable. Fortunately, most elements reoccur frequently to reduce the level of analysis complexity. 6 references, 11 figures, 6 tables.
Date: December 8, 1981
Creator: Rhyne, W. R. & El-Bassioni, A. A.
Object Type: Article
System: The UNT Digital Library
Some proposed disk-heating and beam-transport experiments for heavy-ion inertial-fusion test facilities (open access)

Some proposed disk-heating and beam-transport experiments for heavy-ion inertial-fusion test facilities

Calculations suggest that experiments relating to beam deposition, focusing and transport can be performed within the context of current design proposals for accelerator test-facilities. Since the test-facilities have lower ion kinetic energy and beam pulse power as compared to reactor drivers, we achieve high-beam intensities at the focal spot by using short focal distance and properly designed beam optics. In this regard, the low beam emittance of suggested multi-beam designs are very useful. Preliminary results suggest that intensities close to 10/sup 14/ W/cm/sup 2/ are achievable. Given these intensities, deposition experiments with heating of disks to greater than a million degrees Kelvin (100 eV) are expected. We could also expect as much as 1 to 3 kA of incident ion current on these disks with beam intensities almost comparable to that of reactor targets.
Date: June 8, 1981
Creator: Mark, J. W. K.; Bangerter, R. O.; Fawley, W. M.; Yu, S. & Wang, T. S. F.
Object Type: Article
System: The UNT Digital Library