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Series fault limiting resistors for Atlas Marx modules

Description: The proposed Atlas design provides a current pulse to the experiment chamber from a set of 20, 3-Marx-unit-wide modules radially positioned around a retangular disk transmission-line system (total of 60 Marxes in parallel){sup 1}. The Atlas circuit is designed to be near-critically-damped network with a total erected capacitance of 200 {mu}F at 600 KV. The justification for the necessary circuit resistance in this approach is based on reliability, fault tolerance and operational maintenance{sup 1}. Also the use of high energy- density capacitors that have lower tolerance to voltage reversal is a primary reason for the damping provided by significant series resistance. To obtain the damping there are two system resistors in the Atlas design. One resistor is a shunt element designed to damp the resonance caused by the relatively high-Q disk transmission-line capacitance and the Marx bank inductance. The second, more significant resistor is a series, fault-current limiting element that also performs the necessary damping for voltage reversal at the bank capacitors. The Series resistor is the subject of this paper.
Date: September 1, 1995
Creator: Thompson, C.; Bowman, D.; Gribble, R.F.; Griego, J.; Hinckley, W.B.; Kasik, R.J. et al.
Partner: UNT Libraries Government Documents Department

Butyl rubber O-ring seals: Revision of test procedures for stockpile materials

Description: Extensive testing showed little correlation between test slab and O-ring performance. New procedures, comparable to those used with the traditional test slabs, were defined for hardness, compression set, and tensile property testing on sacrificial O-ring specimens. Changes in target performance values were made as needed and were, in one case, tightened to reflect the O-ring performance data. An additional study was carried out on O-ring and slab performance vs cure cycle and showed little sensitivity of material performance to large changes in curing time. Aging and spectra of certain materials indicated that two sets of test slabs from current vendor were accidently made from EPDM rather than butyl rubber. Random testing found no O-rings made from EPDM. As a result, and additional spectroscope test will be added to the product acceptance procedures to verify the type of rubber compound used.
Date: December 1, 1996
Creator: Domeier, L.A. & Wagter, K.R.
Partner: UNT Libraries Government Documents Department

A Method for Achieving Constant Rotation Rates in a Micro-Orthogonal Linkage System

Description: Silicon micromachine designs include engines that consist of orthog- onally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small as 50 {micro}m in diameter and can be driven at rotation rates exceeding 300,000 rpm. Generally, these en- gines will run with non-uniform rotation rates if the drive signals are not properly designed and maintained over a range of system parameters. We present a method for producing constant rotation rates in a micro-engine driven by an orthogonal linkage system. We show that provided the val- ues of certain masses, springs, damping factors, and lever arms are in the right proportions, the system behaves as though it were symmetrical. We will refer to systems built in this way as being quasi-symmetrical. We show that if a system is built quasi-symmetrically , then it is possible to achieve constant rotation rates even if one does not know the form of the friction function, or the value of the friction. We analyze this case in some detail.
Date: May 12, 1999
Creator: Dickey, F.M.; Holswade, S.C. & Romero, L.A.
Partner: UNT Libraries Government Documents Department

Individual software plan for the programmable logic controller

Description: This document defines the software quality assurance plan (SQAP) as it shall be applied to the development of the monitor and control system for the Integrated Corrosion Facility (ICF). The purpose of this SQA plan is to provide guidance to the development team in software quality and associated documentation.
Date: July 28, 1997
Creator: Green, R
Partner: UNT Libraries Government Documents Department

Buoyancy-generated variable-density turbulence

Description: Both a one-point (engineering) and a two-point (spectral) model are tested against numerical data. Deficiencies in these variable-density models are disucssed and modifications are suggested. Attention is restricted to turbulent interactions of two miscible, incompressible Newtonian fluids of different densities. Departures from the limits of validity of the Boussinesq approximation are examined. Results of the buoyancy-generated turbulence are compared with variable-density model predictions. 3 figs, 6 refs.
Date: June 1, 1996
Creator: Sandoval, D.L.; Clark, T.T. & Riley, J.J.
Partner: UNT Libraries Government Documents Department

Experiments on planar plasma flow switches at Los Alamos

Description: The authors have performed a series of experiments on the Colt facility at Los Alamos to study the performance of plasma flow switches and to understand the important physics issues which affect that performance. These experiments were done in planar geometry on a small machine to allow for better diagnostic access and a higher repetition rate. The Colt facility is a capacitor bank which stores 300 kJ at maximum charge and produced a peak current of 1.1 MA in 2.0 microseconds for these experiments. The diagnostics used for these experiments included an array of b-dot probes, visible framing pictures, visible spectroscopy, and laser interferometry. Characteristics of the switch are determined from spatial and temporal profiles of the magnetic field and the spatial profile and temperature of the switch plasma. Here the authors present results from experiments for a variety of switch conditions.
Date: December 1997
Creator: Benage, J. F., Jr.; Wysocki, F. J.; Bowers, R. & Oona, H.
Partner: UNT Libraries Government Documents Department

Nonlinear simulation of a tetrode vacuum tube

Description: We have developed a variety of circuit models that may be used to simulate vacuum triodes and tetrodes in the extremes of nonlinear operation - from cutoff to saturation. These models, which run on Spectrum Software`s Microcap-IV{reg_sign} (MC4) electronic circuit analysis program, have been used to analyze radiofrequency (rf) amplifiers and high- voltage pulse modulators. In this preliminary report, we provide a single example of a high-power tetrode model and its use in a simple radio-frequency amplifier circuit. Within the next few months, we intend to produce a more exhaustive report that will provide a detailed explanation of the purpose of specific model elements, simulation of a variety of vacuum triodes and tetrodes, and additional circuit applications for these models.
Date: August 1, 1997
Creator: Doss, J.D.
Partner: UNT Libraries Government Documents Department

LCR bridge measurements at elevated operating levels

Description: A critical part in the design of high voltage systems is the selection of the appropriate discrete components The proper selection involves consideration to the basic equivalent electrical parameters of inductance, capacitance, and resistance. The typical approach to establish these parameters involves the use of low level measurements at reduce scale and extrapolate the results to the desired operating ranges. A test voltage level of one volt represents the typical low- level measurement system. The linearity of this process is always in question and may not represent the system operating parameters. The following technique involves the use of a standard Hewlett Packard LCR bridge to measure the electrical parameters of a selected component while it is at its operating level. This process not only provides discrete component values at operating stress but also provides limited information of frequency information at the internal frequency steps. Capacitance is the principal parameter of interest and is highly stress related The significance of a varying capacitance as a function of voltage is the direct relationship to the available stored energy Additional concerns of system frequency response depend on the application.
Date: December 1, 1997
Creator: Wilson, M.J., LLNL
Partner: UNT Libraries Government Documents Department

High power 2 {mu}m diode-pumped Tm:YAG laser

Description: Using a scaleable diode end-pumping technology developed at LLNL, we have demonstrated a compact Tm:YAG laser capable of generating more than 50 W of cw 2 {mu}m laser output power. The design and operational characteristics of this laser, which was built originally for use in assessing laser surgical techniques, are discussed.
Date: January 1, 1996
Creator: Beach, R.J.; Sutton, S.B.; Honea, E.C.; Skidmore, J.A. & Emanuel, M.A.
Partner: UNT Libraries Government Documents Department

High-power laser diodes at various wavelengths

Description: High power laser diodes at various wavelengths are described. First, performance and reliability of an optimized large transverse mode diode structure at 808 and 941 nm are presented. Next, data are presented on a 9.5 kW peak power array at 900 nm having a narrow emission bandwidth suitable for pumping Yb:S-FAP laser materials. Finally, results on a fiber-coupled laser diode array at {approx}730 nm are presented.
Date: February 19, 1997
Creator: Emanuel, M.A.
Partner: UNT Libraries Government Documents Department

Femtosecond laser materials processing

Description: Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area Applications ranging from drilling teeth to cutting explosives to making high-aspect ratio cuts in metals with no heat-affected zone are made possible by this technology For material removal at reasonable rates, we developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.
Date: June 2, 1998
Creator: Stuart, B. C., LLNL
Partner: UNT Libraries Government Documents Department

Extracting a Whisper from the DIN: A Bayesian-Inductive Approach to Learning an Anticipatory Model of Cavitation

Description: For several reasons, Bayesian parameter estimation is superior to other methods for inductively learning a model for an anticipatory system. Since it exploits prior knowledge, the analysis begins from a more advantageous starting point than other methods. Also, since "nuisance parameters" can be removed from the Bayesian analysis, the description of the model need not be as complete as is necessary for such methods as matched filtering. In the limit of perfectly random noise and a perfect description of the model, the signal-to-noise ratio improves as the square root of the number of samples in the data. Even with the imperfections of real-world data, Bayesian methods approach this ideal limit of performance more closely than other methods. These capabilities provide a strategy for addressing a major unsolved problem in pump operation: the identification of precursors of cavitation. Cavitation causes immediate degradation of pump performance and ultimate destruction of the pump. However, the most efficient point to operate a pump is just below the threshold of cavitation. It might be hoped that a straightforward method to minimize pump cavitation damage would be to simply adjust the operating point until the inception of cavitation is detected and then to slightly readjust the operating point to let the cavitation vanish. However, due to the continuously evolving state of the fluid moving through the pump, the threshold of cavitation tends to wander. What is needed is to anticipate cavitation, and this requires the detection and identification of precursor features that occur just before cavitation starts.
Date: November 7, 1999
Creator: Kercel, S.W.
Partner: UNT Libraries Government Documents Department

High energy density capacitors using nano-structure multilayer technology

Description: Today, many pulse power and industrial applications are limited by capacitor performance. While incremental improvements are anticipated from existing capacitor technologies, significant advances are needed in energy density to enable these applications for both the military and for American economic competitiveness. We propose a program to research and develop a novel technology for making high voltage, high energy density capacitors. Nano-structure multilayer technologies developed at LLNL may well provide a breakthrough in capacitor performance. Our controlled sputtering techniques are capable of laying down extraordinarily smooth sub-micron layers of dielectric and conductor materials. With this technology, high voltage capacitors with an order of magnitude improvement in energy density may be achievable. Well-understood dielectrics and new materials will be investigated for use with this technology. Capacitors developed by nano-structure multilayer technology are inherently solid state, exhibiting extraordinary mechanical and thermal properties. The conceptual design of a Notepad capacitor is discussed to illustrate capacitor and capacitor bank design and performance with this technology. We propose a two phase R&D program to address DNA`s capacitor needs for electro-thermal propulsion and similar pulse power programs. Phase 1 will prove the concept and further our understanding of dielectric materials and design tradeoffs with multilayers. Nano-structure multilayer capacitors will be developed and characterized. As our materials research and modeling prove successful, technology insertion in our capacitor designs will improve the possibility for dramatic performance improvements. In Phase 2, we will make Notepad capacitors, construct a capacitor bank and demonstrate its performance in a meaningful pulse power application. We will work with industrial partners to design full scale manufacturing and move this technology to industry for volume production.
Date: August 1, 1992
Creator: Barbee, T.W. Jr.; Johnson, G.W. & O`Brien, D.W.
Partner: UNT Libraries Government Documents Department

Role of nondestructive evaluation in life cycle management

Description: This paper provides an overview of some common NDE methods and several examples for the use of different NDE techniques throughout the life cycle of a product. NDE techniques are being used to help determine material properties, design new implants, extend the service life of aircraft, and help dispose of radioactive waste in a safe manner. It is the opinion of this author and others that the NDE community needs to work more closely with end users in the life cycle of a product to better incorporate NDE techniques. The NDE community needs to highlight the importance of NDE in the entire life-cycle process of a product by showing real costs savings to the manufacturing community.
Date: December 18, 1997
Creator: Martz, H.
Partner: UNT Libraries Government Documents Department

Semi-analytic computation of the driven fields in right circular cylindrical microwave applicators

Description: A semi-analytic technique for computing the driven fields in a pillbox microwave applicator composed of concentric right circular cylinders (e.g., load, tube and air regions) is described. The fields are driven by idealized apertures on the cavity wall. A modal expansion of the driven fields provides insight about thermal energy deposition in the load.
Date: May 1, 1995
Creator: Nelson, E.M.; Kares, R.J. & Stringfield, R.M.
Partner: UNT Libraries Government Documents Department

SNF shipping cask shielding analysis

Description: The Waste Management and Remedial Action Division has planned a modification sequence for storage facility 7827 in the Solid Waste Storage Area (SWSA). The modification cycle is: (1) modify an empty caisson, (2) transfer the spent nuclear fuel (SNF) of an occupied caisson to a hot cell in building 3525 for inspection and possible repackaging, and (3) return the package to the modified caisson in the SWSA. Although the SNF to be moved is in the solid form, it has different levels of activity. Thus, the following 5 shipping casks will be available for the task: the Loop Transport Carrier, the In- Pile Loop LITR HB-2 Carrier, the 6.5-inch HRLEL Carrier, the HFIR Hot Scrap Carrier, and the 10-inch ORR Experiment Removal Shield Cask. This report describes the shielding tasks for the 5 casks: determination of shielding characteristics, any streaming avenues, estimation of thermal limits, and shielding calculational uncertainty for use in the transportation plan.
Date: January 1, 1996
Creator: Johnson, J.O. & Pace, J.V. III
Partner: UNT Libraries Government Documents Department

The road to proactive maintenance: The ideal philosophy and the pain of implementation

Description: The alphabet soups of maintenance, monitoring, diagnostic, and scheduling programs that are out there to help maintenance personnel perform their tasks in a planned and cost-efficient manner are many and varied. The optimum choice is out there somewhere. How do you read between the lines to select the methodology that helps you do your job and gets you where you want to be in the shortest amount of time and effort? The trick appears to be in how your organization is structured and what hoops and hurdles you have to overcome in that nasty phase called implementation. This paper will present some lessons learned in the school of hard knocks and some of what all maintenance organizations either have learned or will find out when they wade into the proactive maintenance philosophies that abound in the commercial world.
Date: April 1, 1997
Creator: Van Hoy, B. & Bracher, B.
Partner: UNT Libraries Government Documents Department

Reliability review of the remote tool delivery system locomotor

Description: The locomotor being built by RedZone Robotics is designed to serve as a remote tool delivery (RID) system for waste retrieval, tank cleaning, viewing, and inspection inside the high-level waste tanks 8D-1 and 8D-2 at West Valley Nuclear Services (WVNS). The RTD systm is to be deployed through a tank riser. The locomotor portion of the RTD system is designed to be inserted into the tank and is to be capable of moving around the tank by supporting itself and moving on the tank internal structural columns. The locomotor will serve as a mounting platform for a dexterous manipulator arm. The complete RTD system consists of the locomotor, dexterous manipulator arm, cameras, lights, cables, hoses, cable/hose management system, power supply, and operator control station.
Date: April 1, 1999
Creator: Chesser, J.B.
Partner: UNT Libraries Government Documents Department

Laser Programs Highlight 1995

Description: Our contributions to laser science and technology and corresponding applications range from concept to design of the National Ignition Facility, transfer of Atomic Vapor Laser Isotope Separation technology to the private sector, and from new initiatives in industry and defense to micro-optics for improving human vision.
Date: January 31, 1997
Creator: Jacobs, R.R.
Partner: UNT Libraries Government Documents Department

Gasket and snap ring installation tool

Description: This invention is comprised of a tool for installing a gasket and a snap ring including a shaft, a first plate attached to the forward end of the shaft, a second plate slidably carried by the shaft, a spring disposed about the shaft between the first and second plates, and a sleeve that is free to slide over the shaft and engage the second plate. The first plate has a loading surface with a loading groove for receiving a snap ring and a shoulder for holding a gasket. A plurality of openings are formed through the first plate, communicating with the loading groove and approximately equally spaced about the groove. A plurality of rods are attached to the second plate, each rod slidable in one of the openings. In use, the loaded tool is inserted into a hollow pipe or pipe fitting having an internal flange and an internal seating groove, such that the gasket is positioned against the flange and the ring is in the approximate plane of the seating groove. The sleeve is pushed against the second plate, sliding the second plate towards the first plate, compressing the spring and sliding the rods forwards in the openings. The rods engage the snap ring and urge the ring from the loading groove into the seating groove.
Date: August 23, 1993
Creator: Southerland, J. M., Sr. & Barringer, C.N., Sr.
Partner: UNT Libraries Government Documents Department

Alternating-Z tripler with high dynamic range

Description: A KD*P alternating-Z tripler suitable for NIF consists of two detuned Type I doublers and one aligned Type II mixer. The dynamic range for efficient tripling is predicted to be larger for this arrangement than for a standard 2-crystal tripler. We tested an alternating-Z tripler that had doublers with thicknesses of 13 and 10 mm, and a 10-mm-thick mixer. All of the crystals were 80% deuterated. The model of this tripler provided an excellent description of the efficiencies that were measured using pulses with duration of 1 or 6 ns. We confirmed the importance for alternating-Z triplers of controlling the phase differences arising from wavelength dispersion in the air gap between the doublers. The confirmed wide dynamic range of this arrangement is of interest for conversion of the 21-ns Haan pulse, or for conversion of beams with significant intensity fluctuations. Compensation for wavelength dispersion in the gap between the crystals is not an issue if the crystals are in vacuum.
Date: October 10, 1996
Creator: Eimerl, D. & Milam, D.
Partner: UNT Libraries Government Documents Department

Wire brush fastening device

Description: A fastening device is provided which is a variation on the conventional nut and bolt. The bolt has a longitudinal axis and threading helically affixed thereon along the longitudinal axis. A nut having a bore extending therethrough is provided. The bore of the nut has a greater diameter than the diameter of the bolt so the bolt can extend through the bore. An array of wire bristles are affixed within the bore so as to form a brush. The wire bristles extend inwardly from the bore and are constructed and arranged of the correct size, length and stiffness to guide the bolt within the bore and to restrain the bolt within the bore as required. A variety of applications of the wire brush nut are disclosed, including a bolt capture device and a test rig apparatus.
Date: August 31, 1993
Creator: Meigs, R.A.
Partner: UNT Libraries Government Documents Department

Evaluation of concrete masonry unit walls for lateral natural phenomena hazards loads

Description: Older single-story facilities (Pre-1985 vintage) are commonly constructed of structural steel framing with concrete masonry unit (CMU) walls connected to columns and roof girders of the steel framing system. The CMU walls are designed for lateral wind and seismic loads (perpendicular to the wall) and transmit shear loads from the roof diaphragm to the foundation footings. The lateral loads normally govern their design. The structural framing system and the roof diaphragm system are straight forward when analyzing or upgrading the structure for NPH loads. Because of a buildings design vintage, probable use of empirical methodology, and poor design basis documentation (and record retention); it is difficult to qualify or upgrade CMU walls for lateral Natural Phenomena Hazards (NPH) loads in accordance with References 1, 2 and 3. This paper discusses three analytical approaches and/or techniques (empirical, working stress and yield line) to determine the collapse capacity of a laterally loaded CMU wall, and compares their results
Date: March 8, 1996
Creator: Faires, W.E. Jr.
Partner: UNT Libraries Government Documents Department