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Initial time-resolved particle beam profile measurements at the Advanced Photon Source (open access)

Initial time-resolved particle beam profile measurements at the Advanced Photon Source

The commissioning of the 7-GeV Advanced Photon Source (APS) storage ring began in early 1995. Characterization of the stored particle beam properties involved time-resolved transverse and longitudinal profile measurements using optical synchrotron radiation (OSR) monitors. Early results include the observation of the beam on a single turn, measurements of the transverse beam sizes after damping using a 100 {mu}s integration time ({sigma}{sub x} {approximately} 150 {plus_minus} 25 {mu}m, {sigma}{sub {gamma}} {approximately} 65 {plus_minus} 25 {mu}m, depending on vertical coupling), and measurement of the bunch length ({sigma}{sub {tau}} {approximately} 25 to 55 ps, depending on the charge per bunch). The results are consistent with specifications and predictions based on the 8.2 nm-rad natural emittance, the calculated lattice parameters, and vertical coupling less than 10%. The novel, single-element focusing mirror for the photon transport line and the dual-sweep streak camera techniques which allow turn-by-turn measurements will also be presented. The latter measurements are believed to be the first of their kind on a storage ring in the USA.
Date: October 19, 1995
Creator: Yang, B. X. & Lumpkin, A. H.
System: The UNT Digital Library
Performance of the beam position monitor for the Advanced Photon Source (open access)

Performance of the beam position monitor for the Advanced Photon Source

Performance measurement and analysis of the Advanced Photon Source (APS) beam position monitor (BPM) electronics are reported. The results indicate a BPM resolution of 0.16 {mu}m{center_dot}mA/{radical}Hz in terms of the single-bunch current and BPM bandwidth. For the miniature insertion device (ID) BPM, the result was 0.1 {mu}m{center_dot}mA/{radical}Hz. The improvement is due to the 3.6 times higher position sensitivity (in the vertical plane), which is partially canceled by the lower button signal by a factor of 2.3. The minimum single-bunch current required was roughly 0.03 mA. The long-term drift of the BPM electronics independent of the actual beam motion was measured at 2 {mu}m/hr, which settled after approximately 1.5 hours. This drift can be attributed mainly to the temperature effect. Implications of the BPM resolution limit on the global and local orbit feedback systems for the APS storage ring will also be discussed.
Date: October 19, 1995
Creator: Chung, Y. & Kahana, E.
System: The UNT Digital Library
ACLMPL: Portable and efficient message passing for MPPs (open access)

ACLMPL: Portable and efficient message passing for MPPs

This paper presents the Advanced Computing Lab Message Passing Library (ACLMPL). Modeled after Thinking Machines Corporation`s CMMD, ACLMPL is a high throughout, low latency communications library for building message passing applications. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM. On the Cray T3D, benchmarks show ACLMPL to be 4 to 7 times faster than MPI or PVM.
Date: September 19, 1995
Creator: Painter, J.; Krogh, M.; Hansen, C.; McCormick, P. & de Verdiere, G.C.
System: The UNT Digital Library
Evolutionary pattern search algorithms (open access)

Evolutionary pattern search algorithms

This paper defines a class of evolutionary algorithms called evolutionary pattern search algorithms (EPSAs) and analyzes their convergence properties. This class of algorithms is closely related to evolutionary programming, evolutionary strategie and real-coded genetic algorithms. EPSAs are self-adapting systems that modify the step size of the mutation operator in response to the success of previous optimization steps. The rule used to adapt the step size can be used to provide a stationary point convergence theory for EPSAs on any continuous function. This convergence theory is based on an extension of the convergence theory for generalized pattern search methods. An experimental analysis of the performance of EPSAs demonstrates that these algorithms can perform a level of global search that is comparable to that of canonical EAs. We also describe a stopping rule for EPSAs, which reliably terminated near stationary points in our experiments. This is the first stopping rule for any class of EAs that can terminate at a given distance from stationary points.
Date: September 19, 1995
Creator: Hart, W.E.
System: The UNT Digital Library
New aminating reagents forthe synthesis of 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB) and other insensitive energetic materials (open access)

New aminating reagents forthe synthesis of 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB) and other insensitive energetic materials

We are investigating the amination of electrophilic aromatic systems through the use of Vicarious Nucleophilic Substitution (VNS) chemistry. This research has led to a new synthesis of 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) and 1,3-diamino-2,4,6-trinitrobenzene (DATB) which uses 2,4,6-trinitroaniline (picramide) or 1,3,5-trinitrobenzene as starting materials. We also describe the development of a new class of VNS aminating reagents based on quarternary hydrazinium halides. 1,1,1-Trimethylhydrazinium iodide (TMHI), available from the methylation of the surplus propellant uns-dimethylhydrazine (UDMH), was used in a new synthesis of TATB. The advantages, scope and limitations of the VNS approach to the synthesis of TATB and other amino-substituted nitroarenes are discussed.
Date: September 19, 1995
Creator: Pagoria, P. F.; Mitchell, A. R. & Schmidt, R. D.
System: The UNT Digital Library
Price anderson nuclear safety rules: Impacts of implementation (open access)

Price anderson nuclear safety rules: Impacts of implementation

New nuclear safety rules are being implemented at Department of Energy sites. This paper examines the impacts of these rules as each site decides where rules will be implemented, whether implementation activities will be centralized, and how the site management and staff will be introduced to the new rules.
Date: September 19, 1995
Creator: Varchol, B.D. & Alhadeff, N.
System: The UNT Digital Library
Adaptive ocean acoustic processing for a shallow ocean experiment (open access)

Adaptive ocean acoustic processing for a shallow ocean experiment

A model-based approach is developed to solve an adaptive ocean acoustic signal processing problem. Here we investigate the design of model-based identifier (MBID) for a normal-mode model developed from a shallow water ocean experiment and then apply it to a set of experimental data demonstrating the feasibility of this approach. In this problem we show how the processor can be structured to estimate the horizontal wave numbers directly from measured pressure sound speed thereby eliminating the need for synthetic aperture processing or a propagation model solution. Ocean acoustic signal processing has made great strides over the past decade necessitated by the development of quieter submarines and the recent proliferation of diesel powered vessels.
Date: July 19, 1995
Creator: Candy, J. V. & Sullivan, E. J.
System: The UNT Digital Library
Model-based localization for a shallow ocean experiment (open access)

Model-based localization for a shallow ocean experiment

In this paper a modern approach was developed to solve the passive localization problem in ocean acoustics using the state-space formulation. It is shown that the inherent structure of the resulting processor consists of a parameter estimator coupled to a nonlinear optimization scheme. The parameter estimator is design using an acoustic propagation model in developing the modern identifier required for localization. The detection and localization of an acoustic source has long been the motivation of early sonar systems. With the advent of quieter and quieter submarines due to new manufacturing technologies and the next proliferation of diesel powered vessels, the need for more sophisticated processing techniques has been apparent for quite some time.
Date: July 19, 1995
Creator: Candy, J. V. & Sullivan, E. J.
System: The UNT Digital Library
On-site disposal of decontaminated and dismantled (D and D) materials: A management approach (open access)

On-site disposal of decontaminated and dismantled (D and D) materials: A management approach

The Fernald Environmental Management Project (FEMP) is a federal facility located near Cincinnati, Ohio that is being remediated. Operable Unit 3 (OU3) of the FEMP consists of 232 buildings and other structures that formerly housed various uranium and thorium metallurgical and chemical processes. The buildings are constructed primarily of steel and concrete, with transite siding. The structures are being decontaminated and dismantled using an interim remedial action approach. The disposition of the debris and other waste materials generated by the interim action is being addressed by the final remedial action for the operable unit. The preferred alternative is disposal of most of the material in an engineered disposal cell located on the FEMP property. This is complicated by the fact that the FEMP is located in an environmentally sensitive area and by the complex nature of the materials. The principal aquifer located beneath the site, the Great Miami Aquifer, is designated as a sole-source aquifer under the Safe Drinking Water Act. Disposal of any wastes at the FEMP must be protective of the aquifer. Dismantlement of OU3 structures will result in a very heterogeneous waste stream, both in terms of types of materials and levels of contamination. Wastes to be …
Date: July 19, 1995
Creator: Hall, J.S.; Clark, T.R.; Davis, M.J. & Picel, K.C.
System: The UNT Digital Library
Search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV (open access)

Search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV

The results of a search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV with subsequent decay to dilepton (e{mu}, ee, and {mu}{mu}) channels are presented. One event is observed with an expected background of 0.56 {plus_minus} 0.13 events with an integrated luminosity of approximately 14 pb{sup {minus}1}. Assuming equal strengths for the WWZ and WW{gamma} gauge boson coupling parameters {kappa} and {lambda}, limits on the CP-conserving anomalous coupling constants are {minus}2.6 < {delta}{kappa} < 2.8 and {minus}2.1 {lambda} < 2.1 at the 95% confidence level.
Date: July 19, 1995
Creator: Abachi, S.
System: The UNT Digital Library
Shock initiation of 1,3,3-trinitroazetidine (TNAZ) (open access)

Shock initiation of 1,3,3-trinitroazetidine (TNAZ)

The shock sensitivity of the pressed solid explosive 1,3,3-trinitroazetidine (TNAZ) was determined using the embedded manganin pressure gauge technique. At an initial pressure of 1.3 GPa, pressure buildup (exothermic reaction) was observed after ten {mu}s. At 2 GPa, TNAZ reacted rapidly and transitioned to detonation in approximately 13 mm. At 3.6 GPa, detonation occurred in less than 6 mm of shock propagation. Thus, pure TNAZ is more shock sensitive than HMX-based explosives but less shock sensitive than PETN-based explosives. The shocked TNAZ exhibited little reaction directly behind the shock front, followed by an extremely rapid reaction. This reaction caused both a detonation wave and a retonation wave in the partially decomposed TNAZ. An Ignition and Growth reactive model for TNAZ was developed to help understand this complex initiation phenomenon.
Date: July 19, 1995
Creator: Simpson, R. L.; Urtiew, P. A. & Tarver, C. M.
System: The UNT Digital Library
Shock initiation of 2,4-dinitroimidazole (2,4-DNI) (open access)

Shock initiation of 2,4-dinitroimidazole (2,4-DNI)

The shock sensitivity of the pressed solid explosive 2,4-dinitroimidazole (2,4-DNI) was determined using the embedded manganin pressure gauge technique. At an initial shock pressure of 2 GPa, several microseconds were required before any exothermic reaction was observed. At 4 GPa, 2,4-DNI reacted more rapidly but did not transition to detonation at the 12 mm deep gauge position. At 6 GPa, detonation occurred in less than 6 mm of shock propagation. Thus, 2,4-DNI is more shock sensitive than TATB-based explosives but is considerably less shock sensitive than HMX-based explosives. An Ignition and Growth reactive flow model for 2,4-DNI based on these gauge records showed that 2,4-DNI exhibits shock initiation characteristics similar to TATB but reacts faster. The chemical structure of 2,4-DNI suggests that it may exhibit thermal decomposition reactions similar to nitroguanine and explosives with similar ring structures, such as ANTA and NTO.
Date: July 19, 1995
Creator: Urtiew, P. A.; Tarver, C. M. & Simpson, R. L.
System: The UNT Digital Library
Shock initiation of an {epsilon}-CL-20-estane formulation (open access)

Shock initiation of an {epsilon}-CL-20-estane formulation

The shock sensitivity of a pressed solid explosive formulation, LX-19, containing 95.2% by weight epsilon phase 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) and 4.8% Estane binder, was determined using the wedge test and embedded manganin pressure gauge techniques. This formulation was shown to be slightly more sensitive than LX-14, which contains 95.5% HMX and 4.5% Estane binder. The measured pressure histories for LX-19 were very similar to those obtained using several HMX-inert binder formulations. An Ignition and Growth reactive model for LX-19 was developed which differed from those for HMX-inert binder formulations only by a 25% higher hot spot growth rate.
Date: July 19, 1995
Creator: Tarver, C. M.; Simpson, R. L. & Urtiew, P. A.
System: The UNT Digital Library
Ultra high resolution soft x-ray tomography (open access)

Ultra high resolution soft x-ray tomography

Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by {approximately}5{mu}m. A series of nine 2-D images of the object were recorded at angles between {minus}50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of {approximately}1000 {Angstrom} was observed. Artifacts in the reconstruction limited the overall depth resolution to {approximately}6000 {Angstrom}, however some features were clearly reconstructed with a depth resolution of {approximately}1000 {Angstrom}. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to {approximately}1200 {Angstrom} overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range.
Date: July 19, 1995
Creator: Haddad, W. S.; Trebes, J. E. & Goodman, D. M.
System: The UNT Digital Library
Instrumentation for the determination of material properties from spectroscopic measurements of total integrated scatter (open access)

Instrumentation for the determination of material properties from spectroscopic measurements of total integrated scatter

A variety of important optical properties can be determined from spectroscopic analysis of diffuse reflectance of surfaces. The design of a small user friendly, light-weight, field hardened, computer controlled device for performing infrared spectroscopic analysis of trace contaminants on surfaces is described. The device employs a miniature Fourier transform infrared (FTIR) spectrometer with very efficient diffuse reflectance optics and a portable computer to provide reflectance spectra of surfaces measured relative to some idealized surface. These spectra yield qualitative and quantitative chemical information from a host of surfaces that has imminently practical applications in the determination of surface identification, contamination, and degradation.
Date: June 19, 1995
Creator: Powell, G. L.; Barber, T. E. & Neu, J. T.
System: The UNT Digital Library
Multilayer Thin Film Thermoelectrics Produced by Sputtering (open access)

Multilayer Thin Film Thermoelectrics Produced by Sputtering

In this work we explore the possibility of achieving bulk electrical properties in single layer sputter deposited films grown epitaxially on (111) oriented BaF{sub 2} substrates. There are a number of sputter deposition parameters that can be varied in order to optimize the film quality. It is important to understand the effect of varying the deposition temperature, Ar sputtering gas pressure, and the substrate bias. We will consider only Bi and Bi{sub 0.86}Sb{sub 0.14} films in this paper. These materials were chosen since they have the same simple structure, two different band gaps and do not change significantly either in physical or electrical properties with small amounts of cross contamination. We will also present our work on multilayer thermoelectrics made of Bi and Bi{sub 0.86}Sb{sub 0.14} layers. There has been considerable interest in this multilayer structure in the literature. Theoretical calculations of the band structure and interface states of these multilayer structures have been made by Mustafaev and Agassi et al. respectively [6,7]. Experimentally Yoshida et al. have examined similar multilayer structures grown by MBE as well as Bi/Sb multilayer samples in which report an anomalous thermoelectric power [8].
Date: June 19, 1995
Creator: Wagner, A. V.; Foreman, R. J.; Summers, L. J.; Barbee, T. W., Jr. & Farmer, J. C.
System: The UNT Digital Library
Performance of the beamlet laser, a testbed for the National Ignition Facility (open access)

Performance of the beamlet laser, a testbed for the National Ignition Facility

We present initial performance studies for Beamlet, a single-beam prototype for megajoule-class neodymium-glass laser fusion drivers using a multipass main amplifier, adaptive optics, and efficient, high-fluence conversion to the third harmonic. The Beamlet final amplifier uses Brewsters-angle glass slabs with a square 39 {times} 39 cm{sup 2} aperture and a full-aperture plasma-electrode Pockels cell switch. The laser has been tested at the fundamental wavelength over a range of pulselengths from 1-10 ns up to energies of 5.8 kJ at 10 ns and 17.3 kJ at 10 ns at a beam area of 35 {times} 35 cm{sup 2}. A 39-actuator deformable mirror system corrects the beam to a Strehl ratio of 0.4.
Date: June 19, 1995
Creator: Van Wonterghem, B. M.; Caird, J. A.; Barker, C. E.; Campbell, J. H.; Murray, J. R. & Speck, D. R.
System: The UNT Digital Library
Numerical simulation of a wave-guide mixing layer on a Cray C-90 (open access)

Numerical simulation of a wave-guide mixing layer on a Cray C-90

The development of a three-dimensional spatially evolving compressible mixing layer is investigated numerically using a parallel implementation of Adaptive Mesh Refinement (AMR) on a Cray C-90. The parallel implementation allowed the flow to be highly resolved while significantly reducing the wall-clock runtime. A sustained computation rate of 5.3 Gigaflops including I/O was obtained for a typical production run on a 16 processor machine. A novel mixing layer configuration is investigated where a pressure mismatch is maintained between the two inlet streams. In addition, the sonic character of the two streams is sufficiently different so that the pressure relief wave is trapped in the high speed stream. The trapped wave forces the mixing layer to form a characteristic cellular pattern. The cellular structure introduces curvature into the mixing layer that excites centrifugal instabilities characterized by large-scale counter-rotating vortical pairs embedded within the mixing layer. These are the dominant feature of the flow. Visualizations of these structures in cross-section show the pumping action which lifts dense fluid up into light gas. This effect has a strong impact on mixing enhancement as monitored by a conserved scalar formulation. Once the large-scale structures axe well established in the flow and undergo intensification from favorable …
Date: May 19, 1995
Creator: Greenough, J. A.; Crutchfield, W. Y. & Rendleman, C. A.
System: The UNT Digital Library
The Phenix Detector magnet subsystem (open access)

The Phenix Detector magnet subsystem

The PHENIX [Photon Electron New Heavy Ion Experiment] Detector is one of two large detectors presently under construction for RHIC (Relativistic Heavy Ion Collider) located at Brookhaven National Laboratory. Its primary goal is to detect a new phase of matter; the quark-gluon plasma. In order to achieve this objective, the PHENIX Detector utilizes a complex magnet subsystem which is comprised of two large magnets identified as the Central Magnet (CM) and the Muon Magnet (MM). Muon Identifier steel is also included as part of this package. The entire magnet subsystem stands over 10 meters tall and weighs in excess of 1900 tons (see Fig. 1). Magnet size alone provided many technical challenges throughout the design and fabrication of the project. In addition, interaction with foreign collaborators provided the authors with new areas to address and problems to solve. Russian collaborators would fabricate a large fraction of the steel required and Japanese collaborators would supply the first coil. This paper will describe the overall design of the PHENIX magnet subsystem and discuss its present fabrication status.
Date: May 19, 1995
Creator: Yamamoto, R. M.; Bowers, J. M. & Harvey, A. R.
System: The UNT Digital Library
Photographic as-builts for Argonne National Laboratory-West (open access)

Photographic as-builts for Argonne National Laboratory-West

Located 35 miles West of Idaho Falls, Idaho, Argonne National Laboratory-West operates a number of nuclear facilities for the Department of Energy (DOE) through the University of Chicago. Part of the present mission of Argonne National Laboratory-West includes shutdown of the EBR-II Reactor. In order to accomplish this task the Engineering-Drafting Department is exploring cost effective methods of providing as-building services. A new technology of integrating photographic images and AUTOCAD drawing files is considered one of those methods that shows promise.
Date: April 19, 1995
Creator: Sherman, E. K. & Wiegand, C. V.
System: The UNT Digital Library
Advanced source studies on laser produced plasmas for EUV lithography (open access)

Advanced source studies on laser produced plasmas for EUV lithography

Laser-produced plasmas are source candidates for EUV lithography. The radiation angular distribution for several target materials is investigated and source debris is characterized.
Date: January 19, 1995
Creator: Spitzer, R. C. & Gaines, D. P.
System: The UNT Digital Library
Beneficial reuse of US DOE Radioactive scrap metal (open access)

Beneficial reuse of US DOE Radioactive scrap metal

The US Department of Energy (DOE) has more than 2.5 million tons of radioactive scrap metal (RSM) that is either in inventory or expected to be generated over the next 25 years as major facilities within the weapons complex are decommissioned. Since much of this metal cannot be decontaminated easily, past practice has been to either retain this material in inventory or ship it to DOE disposal sites for burial. In an attempt to conserve natural resources and to avoid burial of this material at DOE disposal sites, options are now being explored to ``beneficially reuse`` this material. Under the beneficial reuse concept, RSM that cannot be decontaminated and free released is used in applications where the inherent contamination is not a detriment to its end use. This paper describes initiatives currently in progress in the United States that support the DOE beneficial reuse concept.
Date: January 19, 1995
Creator: Motl, G.P.
System: The UNT Digital Library
EUV lithography cost of ownership analysis (open access)

EUV lithography cost of ownership analysis

The cost of fabricating state-of-the-art integrated circuits (ICs) has been increasing and it will likely be economic rather than technical factors that ultimately limit the progress of ICs toward smaller devices. It is estimated that lithography currently accounts for approximately one-third the total cost of fabricating modem ICs({sup 1}). It is expected that this factor will be fairly stable for the forseeable future, and as a result, any lithographic process must be cost-effective before it can be considered for production. Additionally, the capital equipment cost for a new fabrication facility is growing at an exponential rate (2); it will soon require a multibillion dollar investment in capital equipment alone to build a manufacturing facility. In this regard, it is vital that any advanced lithography candidate justify itself on the basis of cost effectiveness. EUV lithography is no exception and close attention to issues of wafer fabrication costs have been a hallmark of its early history. To date, two prior cost analyses have been conducted for EUV lithography (formerly called {open_quotes}Soft X-ray Projection Lithography{close_quotes}). The analysis by Ceglio, et. al., provided a preliminary system design, set performance specifications and identified critical technical issues for cost control. A follow-on analysis by Early, …
Date: January 19, 1995
Creator: Hawryluk, A.M. & Ceglio, N.M.
System: The UNT Digital Library
EUV reticle pattern repair experiments using 10 KeV neon ions (open access)

EUV reticle pattern repair experiments using 10 KeV neon ions

Any potential lithography must demonstrate an industrially-compatable reticle pattern repair process before the lithographic process can be seriously considered for production. Repair of clear defects on ELTV reticles (i.e., regions on the mask which are reflective and should be non-reflective) requires the deposition of a thin layer of absorbing material. This process has been demonstrated in commercially available tools which were originally developed to repair proximity-print x-ray lithography masks. However, the repair of opaque defects (i.e., the recovery of reflectivity from regions on the reticle covered with an absorber) is more difficult. Opaque defect repair requires the removal of the absorber layer without damaging the underlying multilayer, a process which could degrade the mirror reflectivity. While opaque defect repair processes have been demonstrated in a research environment these processes may not be commercially suitable. We are developing reticle repair processes that will be consistent with a commercially available repair tool. In this paper, we report on our first results.
Date: January 19, 1995
Creator: Hawryluk, A.M.; Kania, D.R.; Celliers, P.; DaSilva, L.; Stith, A.; Stewart, D. et al.
System: The UNT Digital Library