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open access

Thermodynamics of mobile order theory

Description: Article on the thermodynamics of mobile order theory.
Date: 1997
Creator: Acree, William E. (William Eugene); Powell, Joyce R.; McHale, Mary E. R.; Pandey, Siddharth; Borders, Tammie L. & Campbell, Scott W.
Partner: UNT College of Arts and Sciences
open access

Magnetic core studies at LBNL and LLNL

Description: The objective of this work is to minimize the cost of the materials and maximize the performance of magnetic cores, a major cost component of a Heavy-Ion-Fusion, HIF, induction accelerator driver. This includes selection of the alloy for cost and performance, and maximizing the performance of each alloy evaluated. The two major performance parameters are the magnetic flux swing and the energy loss. The volt seconds of the cores, obtained from the flux swing with Faraday's Law, determines the be… more
Date: September 20, 1997
Creator: Molvik, A.W.; Faltens, A.; Reginato, L.; Blaszkiewicz, M.; Smith, C. & Wood, R.
Partner: UNT Libraries Government Documents Department
open access

PLASMA WINDOW FOR VACUUM - ATMOSPHERE INTERFACE AND FOCUSING LENS OF SOURCES FOR NON-VACUUM MATERIAL MODIFICATION.

Description: Material modifications by ion implantation, dry etching, and micro-fabrication are widely used technologies, all of which are performed in vacuum, since ion beams at energies used in these applications are completely attenuated by foils or by long differentially pumped sections, which ate currently used to interface between vacuum and atmosphere. A novel plasma window, which utilizes a short arc for vacuum-atmosphere interface has been developed. This window provides for sufficient vacuum atmos… more
Date: September 7, 1997
Creator: Hershcovitch, A.
Partner: UNT Libraries Government Documents Department
open access

Methods for fabricating arrays of holes using interference lithography

Description: Optical interference lithography offers a robust patterning technology capable of achieving high spatial resolution over extremely large field sizes ( {approx}1 m ). Here, we compare two different approaches for fabricating arrays of holes using interferometric techniques. We show that by applying an image reversal process to standard two-beam interference lithography, arrays of high aspect ratio holes can be generated. This process scales to submicron periods and allows holes as small as 0.1 m… more
Date: May 28, 1997
Creator: Fernandez, A.; Decker, J. Y.; Herman, S. M.; Phillion, D. W.; Sweeney, D. W. & Perry, M. D.
Partner: UNT Libraries Government Documents Department
open access

Hanford K Basins spent nuclear fuels project update

Description: Twenty one hundred metric tons of spent nuclear fuel are stored in two concrete pools on the Hanford Site, known as the K Basins, near the Columbia River. The deteriorating conditions of the fuel and the basins provide engineering and management challenges to assure safe current and future storage. DE and S Hanford, Inc., part of the Fluor Daniel Hanford, Inc. lead team on the Project Hanford Management Contract, is constructing facilities and systems to move the fuel from current wet pool stor… more
Date: October 17, 1997
Creator: Hudson, F. G.
Partner: UNT Libraries Government Documents Department
open access

Criticality parameters for tank waste evaluation

Description: Nuclear criticality parameters were developed as a basis for evaluating criticality safety for waste stored in the high-level waste tank farms on the Hanford Site in Washington State. The plutonium critical concentration and critical mass were calculated using a conservative waste model (CWM). The primary requirement of a CWM is that it have a lower neutron absorption than any actual waste. Graphs are provided of the critical mass as a function of plutonium concentration for spheres and for uni… more
Date: May 19, 1997
Creator: Rogers, C. A.
Partner: UNT Libraries Government Documents Department
open access

Operation of CEBAF With Heavy Beamloading

Description: CEBAF is a 4 GeV, 200 {micro}A five-pass recirculating superconducting electron accelerator that has been operating for nuclear physics research at full energy since November 95. The beam current has been increased to over 180 {micro}A at 4 GeV with the maximum current in the linac over 900 {micro}A. The superconducting cavities operate in a regime where the beam-induced voltage is comparable to the accelerating gradient. The operational limits and the issues required to maintain stable operati… more
Date: July 1, 1997
Creator: Hutton, A.
Partner: UNT Libraries Government Documents Department
open access

Jefferson Lab Personnel Safety Fast Beam Kicker System

Description: The CEBAF accelerator at Thomas Jefferson National Accelerator Facility (Jefferson Lab) uses a continuous electron beam with up to 800 kilowatts of average beam power. The laboratory beam containment policy requires that in the event of an errant beam striking a beam blocking device, the beam must be shut off by three methods in less than 1 millisecond. One method implemented is to shut off the beam at the gun. Two additional methods have been developed which use fast beam kickers to deflect th… more
Date: August 1, 1997
Creator: Mahoney, K.; Garza, O.; Stitts, E.; Areti, H. & O`Sullivan, M.
Partner: UNT Libraries Government Documents Department
open access

Runtime Accelerator Configuration Tools at Jefferson Laboratory

Description: RF and magnet system configuration and monitoring tools are being implemented at Jefferson Lab to improve system reliability and reduce operating costs. They are prototype components of the Momentum Management System being developed. The RF is of special interest because it affects the momentum and momentum spread of the beam, and because of the immediate financial benefit of managing the klystron DC supply power. The authors describe present and planned monitoring of accelerating system parame… more
Date: July 1, 1997
Creator: Tiefenback, M. G.; Doolittle, L. & Benesch, J. F.
Partner: UNT Libraries Government Documents Department
open access

Automated Path Length and M{Sub 56} Measurements at Jefferson Lab

Description: Accurate measurement of path length and path length changes versus momentum (M{sub 56}) are critical for maintaining minimum beam energy spread in the CEBAF (Continuous Electron Beam Accelerator Facility) accelerator at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The relative path length for each circuit of the beam (1256m) must be equal within 1.5 degrees of 1497 MHz RF phase. A relative path length measurement is made by measuring the relative phases of RF signals from… more
Date: August 1, 1997
Creator: Hardy, D.; Tang, J. & Legg, R.
Partner: UNT Libraries Government Documents Department
open access

Investigation and deactivation of B Plant HEPA filters

Description: This paper describes the integrated approach used to manage environmental, safety, and health considerations related to the B Plant canyon exhaust air filters at the US Department of Energy (DOE) Hanford Site. The narrative illustrates the development and implementation of integrated safety management as applied to a facility and its systems undergoing deactivation. During their lifetime, the high efficiency particulate air (HEPA) filters prevented the release of significant quantities of radio… more
Date: May 12, 1997
Creator: Roege, P. E.
Partner: UNT Libraries Government Documents Department
open access

Over-the-road shock and vibration testing of the radioisotope thermoelectric generator transportation system

Description: Radioisotope Thermoelectric Generators (RTG) convert heat generated by radioactive decay into electricity through the use of thermocouples. The RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance, which make them particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title… more
Date: May 1, 1997
Creator: Becker, D. L.
Partner: UNT Libraries Government Documents Department
open access

Progress update on the US photovoltaic manufacturing technology project

Description: The Photovoltaic Manufacturing Technology (PVMaT) project is helping the U.S. photovoltaic (PV) industry extend its world leadership role in manufacturing and stimulate the commercial development of PV modules and systems. Initiated in 1990, PVMaT is being carried out in several directed and staggered phases to support industry`s continued progress. Thirteen subcontracts awarded in FY 1996 under Phase 4A emphasize improvement and cost reduction in the manufacture of full-system PV products. Are… more
Date: October 1, 1997
Creator: Mitchell, R. L.; Witt, C. E. & Thomas, H. P.
Partner: UNT Libraries Government Documents Department
open access

Analysis of the Performance Benefits of Short-Term Energy Storage in Wind-Diesel Hybrid Power Systems

Description: A variety of prototype high penetration wind-diesel hybrid power systems have been implemented with different amounts of energy storage. They range from systems with no energy storage to those with many hours worth of energy storage. There has been little consensus among wind-diesel system developers as to the appropriate role and amount of energy storage in such systems. Some researchers advocate providing only enough storage capacity to supply power during the time it takes the diesel genset … more
Date: April 1, 1997
Creator: Shirazi, M. & Drouilhet, S.
Partner: UNT Libraries Government Documents Department
open access

High Critical Current Densities in Nb3Sn Films with Engineered Microstructures--Artifical Pinning Microstructures

Description: Films with layers of Nb, Cu, and Sn have been fabricated to simulate a Nb{sub 3}Sn bronze-type process. These Nb{sub 3}Sn films have produced critical current densities greater than 1 x 10{sup 6} A/cm{sup 2} at 4.2 K and 7.5 T. Niobium films doped with Y, Sc, Dy, Al{sub 2}O{sub 3}, and Ti have been deposited with e-beam co-evaporation onto 75 mm diameter Si wafers with a 100 nm SiO{sub 2} buffer layer. The Nb layer was followed by a layer of Cu and a layer of Sn to complete the bronze-type proc… more
Date: July 1, 1997
Creator: Dietderich, D. R.; Kelman, M.; Litty, J. R. & Scanlan, R. M.
Partner: UNT Libraries Government Documents Department
open access

Techniques for Identifying and Measuring High Order Modes in RF Cavities

Description: We report on a number of techniques which can be used to unravel the higher-order-mode spectrum of an RF cavity. Most of these techniques involve the application of basic symmetry principles and require for their application only that the cavity exhibit some basic symmetry, possibly broken by the presence of couplers, apertures, etc., which permits a classification of these modes in terms of some property characterized by that symmetry, e.g., multipolarity for a cavity which is basically a figu… more
Date: May 1, 1997
Creator: Goldberg, D.A. & Rimmer, R.A.
Partner: UNT Libraries Government Documents Department
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