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Electronic Engineering Design Problems in Fusion Research

Description: Abstract: "Design problems peculiar to fusion research are discussed. Particular emphasis is placed on the development of large energy storage systems, transfer of and utilization of this energy. In addition, design criteria for delay systems, data reduction systems, and other problems related to our fusion research program are discussed."
Date: August 1959
Creator: Smith, Vernon L.
Partner: UNT Libraries Government Documents Department

An Exploding Wire as a Fuse for the LASL Capacitor Bank--Zeus

Description: Abstract: "An exploding copper wire, one millimeter in diameter, 30 centimeters long, has been developed as a fuse component for a Los Alamos capacitor energy source to be employed in controlled thermonuclear research studies. The fuse allows the passage of the high normal duty "action" (13,700 ampere-coulombs per capacitor) at a 20-second repetition rate. However, it interrupts the circuit to a shorted capacitor in 12 microseconds, thereby protecting the faulted capacitor from explosive energy consumption. The initial phase of the development included observations of various metals (copper, silver, iron, and nickel) as well as various configurations (straight wires, helixes, foils, and tubes). Direct scaling of previous small exploding wire studies at Sandia Corporation was demonstrated with scaling factors up to 700,000."
Date: June 4, 1959
Creator: Cnare, Eugene C.
Partner: UNT Libraries Government Documents Department

Boron Nitride Capacitors for Advanced Power Electronic Devices

Description: This project fabricates long-life boron nitride/boron oxynitride thin film -based capacitors for advanced SiC power electronics with a broad operating temperature range using a physical vapor deposition (PVD) technique. The use of vapor deposition provides for precise control and quality material formation.
Date: November 1, 2010
Creator: Badi, N.; Starikov, D.; Boney, C.; Bensaoula, A. & Johnstone, D.
Partner: UNT Libraries Government Documents Department

Capacitor mismatch caused by oxide thickness variations in submicron I. C. processes

Description: Chip design in submicron processes will present new challenges and problems which were not present in designs with larger dimension processes. One effect in the newer processes is the field oxide thickness variation due to interconnect density variations. This effect becomes much more extreme for the smaller dimension processes. Large density discontinuities can cause lower yield and will also result in capacitor value mismatch over substantial distances from the edges of a large array when using poly/metal capacitors. If good matching in this type of large area capacitor array is required, the only way to achieve this is to guarantee nearly constant metal/ poly density for at least 1500 microns (this distance will likely depend on the process) around the edges of the array. If the array boundary is close to the chip edge, then dummy capacitors should be placed up to the chip edge, and another layout with similar density must be placed as close as possible to the relevant edges of the chip in the reticle. When using a standard MOSIS reticle size, this may entail placing dummy chip layouts around the chips of interest in order to guarantee that identical density exists for the required distance outside of any chip�s borders.
Date: May 4, 1999
Creator: Zimmerman, Tom
Partner: UNT Libraries Government Documents Department

Determination of Strength for Reliability Analysis of Multilayer Ceramic Capacitors

Description: A Nanoindenter<sup>TM</sup> equipped with a Vickers indenter was used to measure fracture toughness of Multilayer Capacitors (MLCs) and BaTiO<sub>3</sub> blanks. Strength of blanks of 6.3 x 4.7 x 1.1 mm<sup>3</sup> was measured by performing three-point flexure using a 4 mm support span. The size of the strength limiting pores in the flexure tests was compared to pore sizes measured on polished MLC cross sections, and it was found that much larger pores were present in the 3-point flexure specimens. Strength distributions for the MLCs were generated using the measured fracture toughness values, assuming the measured pores or second phase inclusions were strength limiting.
Date: January 25, 1999
Creator: Breder, K.; Bridge, R.J.; Kirkland, T.P.; Riester, L. & Wereszczak, A.A.
Partner: UNT Libraries Government Documents Department

Ultra-thin multilayer capacitors.

Description: The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.
Date: June 1, 2009
Creator: Renk, Timothy Jerome & Monson, Todd C.
Partner: UNT Libraries Government Documents Department

A least squares method for CVT calibration in a RLC capacitor discharge circuit.

Description: In many applications, the ability to monitor the output of a capacitive discharge circuit is imperative to ensuring the reliability and accuracy of the unit. This monitoring is commonly accomplished with the use of a Current Viewing Transformer (CVT). In order to calibrate the CVT, the circuit is assembled with a Current Viewing Transformer (CVR) in addition to the CVT and the peak outputs compared. However, difficulties encountered with the use of CVRs make it desirable to eliminate the use of the CVR from the calibration process. This report describes a method for determining the calibration factor between the current throughput and the CVT voltage output in a capacitive discharge unit from the CVT ringdown data and values of initial voltage and capacitance of the circuit. Previous linear RLC fitting work for determining R, L, and C is adapted to return values of R, L, and the calibration factor, k. Separate solutions for underdamped and overdamped cases are presented and implemented on real circuit data using MathCad software with positive results. This technique may also offer a unique approach to self calibration of current measuring devices.
Date: November 1, 2003
Creator: Yao, Stephen E.; Dickey, Fred McCartney & Pecak, Sara North
Partner: UNT Libraries Government Documents Department

Some comments on manganin wire pressure gauges

Description: A standard manganin wire pressure gage was examined by comparing it with a recently developed 0.01% CaF/sub 2/ capacitive pressure gage. The effects of the Bridgman water kick'' and intrinsic time constant are clearly shown, and the results punctuate the usual assertion that manganin wire gages are extremely difficult to use approaching the 0.1% level. (auth)
Date: January 1, 1973
Creator: Andeen, C.; Schuele, D. & Fontanella, J.
Partner: UNT Libraries Government Documents Department

Comparison of Lumped and Distributed Inflector Magnets

Description: Desirable characteristics of pulsed magnets used as ejectors or inflectors for large accelerators can be obtained by loading the magnet with distributed capacitance or by using a capacitor in shunt with the load. Comparable field build-up tlmes are available with either arrangement. The lumped magnet system offers greater simplicity. (D.C.W.)
Date: March 18, 1963
Creator: Forsyth, E. B.
Partner: UNT Libraries Government Documents Department

Determination of the Shelf Life of Aluminum Electrolytic Capacitors.

Description: The aluminum electrolytic capacitor is used extensively in the electric utility industry. A factor limiting the storage of spare capacitors is the integrity of the aluminum oxide dielectric, which over time breaks down contributing to a shelf life currently estimated at one nuclear power electric generating station to be approximately five years. This project examined the electrical characteristics of naturally aged capacitors of several different styles to determine if design parameters were still within limits. Additionally, the effectiveness of a technique known as “Reforming” was examined to determine its impact on those characteristics.
Date: May 2002
Creator: Wynne, Edward McFaddin
Partner: UNT Libraries

Insitu-Impregnated Capacitor for Pulse-Discharge Applications

Description: Capacitor designs for DOE and/or DoD applications are now driven by two major factors; first, the need to reduce component volumes (attain higher energy density) to permit inclusion of additional components and/ or sensors in systems and second, the continuing budget constraints. The reduced volume and cost must be achieved with no sacrifices in functionality, reliability and safety. Since this study was initiated, we have seen a general, continuous increase in resulting short-time breakdown (STB) values, with particular improvements noted on thermal cycled capacitors. Process and results support our prediction that a 50Y0-650A volume reduction can be achieved with no reduction in performance and reliability.
Date: January 15, 1999
Creator: Brooks, R.A.; Harris, J.O. & Pollard, J.R.
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 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

Vacuum deposited polymer films: Past, present, and future applications

Description: Two extremely high rate processes have been developed for the vacuum deposition of polymer thin films. Dubbed the PML (for Polymer Multi-Layer) and LML (for Liquid Multi-Layer) processes, the PML technique was originally developed for the manufacture of polymer/aluminum surface mount capacitors while the LML method arose from a need to fabricate lithium polymer batteries. These processes have since been found to be compatible with most other vacuum deposition techniques in, integrated, in-line coating processes. Battelle has developed an extensive program, and a great deal of hardware, to pursue a wide variety of PML and LML applications which integrate these two process technologies with other, conventional, vacuum deposition methods. The historical development of the technologies is reviewed and the Battelle PML/LML facilities are described. Current Battelle work involving solar thermal control films, PML QWOTs, and polymer/metal high reflectors are also discussed. Battelle PML work that is just starting, involving non-linear optical materials/devices, lithium polymer battery fabrication, electrochromic devices, and polymer/oxide multilayers, is discussed as well.
Date: November 1, 1994
Creator: Affinito, J.; Martin, P.; Gross, M. & Bennett, W.
Partner: UNT Libraries Government Documents Department

The Effects of Nitrogen on the Interface State Density Near the Conduction Band Edge in 4H and 6H-SiC

Description: Results are reported for the passivation of interface states near the conduction band edge in SiO{sub 2}/SiC MOS capacitors using post-oxidation anneals in nitric oxide, ammonia and forming gas (N{sub 2}5%H{sub 2}). Anneals in nitric oxide and ammonia reduce the interface state density significantly for 4H-SiC, while forming gas anneals are largely ineffective. Results suggest that interface states in SiO{sub 2}/SiC and SiO{sub 2}/SiC have different origins, and a model is described for interface state passivation by nitrogen in the SiO{sub 2}/SiC system. The peak inversion channel mobility measured for lateral 4H-SiC MOSFETs increases following NO passivation.
Date: June 12, 2000
Creator: Chung, G.Y.; Tin, C.C.; Isaacs-Smith, T.; Williams, J.R.; McDonald, K.; DiVentra, M. et al.
Partner: UNT Libraries Government Documents Department

Lead zirconate titanate on base metal foils: An approach for embedded high-K passive components

Description: An approach for embedding high-K dielectric thin films into polymer packages has been developed. Pb{sub 0.85}La{sub 0.15}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.96}O{sub 3} thin films were prepared by chemical solution deposition on 50 {micro}m thick Ni-coated Cu foils. Sputter deposited Ni top electrodes completed the all base-metal capacitor stack. After high temperature N{sub 2} crystallization anneals, the PLZT composition showed reduction resistance while the base-metal foils remained flexible. Capacitance density and Loss tangent values range between 300 and 400 nF/cm{sup 2} and 0.01 and 0.02 from 1 to 1,000 kHz respectively. These properties represent a 2 to 3 order of magnitude improvement over available embedded capacitor technologies for polymeric packages.
Date: January 26, 2000
Creator: Maria, J.-P.; Cheek, K.; Streiffer, S. K.; Kim, S.-H.; Dunn, G. & Kingon, A. I.
Partner: UNT Libraries Government Documents Department

A Novel Non-Destructive Silicon-on-Insulator Nonvolatile Memory - LDRD 99-0750 Final Report

Description: Defects in silicon-on-insulator (SOI) buried oxides are normally considered deleterious to device operation. Similarly, exposing devices to hydrogen at elevated temperatures often can lead to radiation-induced charge buildup. However, in this work, we take advantage of as-processed defects in SOI buried oxides and moderate temperature hydrogen anneals to generate mobile protons in the buried oxide to form the basis of a ''protonic'' nonvolatile memory. Capacitors and fully-processed transistors were fabricated. SOI buried oxides are exposed to hydrogen at moderate temperatures using a variety of anneal conditions to optimize the density of mobile protons. A fast ramp cool down anneal was found to yield the maximum number of mobile protons. Unfortunately, we were unable to obtain uniform mobile proton concentrations across a wafer. Capacitors were irradiated to investigate the potential use of protonic memories for space and weapon applications. Irradiating under a negative top-gate bias or with no applied bias was observed to cause little degradation in the number of mobile protons. However, irradiating to a total dose of 100 krad(SiO{sub 2}) under a positive top-gate bias caused approximately a 100% reduction in the number of mobile protons. Cycling capacitors up to 10{sup 4} cycles had little effect on the switching characteristics. No change in the retention characteristics were observed for times up to 3 x 10{sup 4} s for capacitors stored unbiased at 200 C. These results show the proof-of-concept for a protonic nonvolatile memory. Two memory architectures are proposed for a protonic non-destructive, nonvolatile memory.
Date: November 1, 1999
Partner: UNT Libraries Government Documents Department

Characterization of a fused silica capacitance standard

Description: An ovenized 10 pF standard capacitor was constructed by the National Institute of Standards and Technology (NIST). The dielectric material used as Wuprasil II grade fused silica. This report discusses a temperature coefficient analysis of the capacitor performed at the Primary Standards Laboratory (PSL) of Sandia National Laboratories (SNL). The effects of temperature change on dielectric loss will also be discussed.
Date: January 1, 1995
Creator: Daniel, M.G.
Partner: UNT Libraries Government Documents Department