138 Matching Results

Search Results

Results: 1 - 24 next
open access

High field solenoids for muon cooling

Description: The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in t… more
Date: September 8, 1999
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R. & Prestemon, S.
Partner: UNT Libraries Government Documents Department
open access

RHIC IR Quadrupoles and Field Quality State of the Art in Super Conducting Accelerator Magnets

Description: The interaction region (IR) quadrupoles [1] for the Relativistic Heavy Ion Collider (RHIC)[2]are the best field quality superconducting magnets ever built for any major accelerator. This field quality is primarily achieved with the help of eight tuning shims [3] that remove the residual errors from a magnet after it is built and tested. These shims overcome the limitations from the typical tolerances in parts and manufacturing. This paper describes the tuning shims and discusses the evolution o… more
Date: March 8, 1999
Creator: Gupta, R.; Anerella, M.; Cozzolino, J.; Ghosh, A.; Jain, A.; Kahn, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Installation of line replaceable units into the National Ignition Facility

Description: In the National Ignition Facility (NIF), currently under design and construction at Lawrence Livermore National Laboratory (LLNL), 192 high-power laser beamlines incorporating over 8,000 large optics, are focused onto a target smaller than a dime. The actual laser path will be contained within the Laser Target Area Building (LTAB), but the smaller adjacent building, the Optics Assembly Building, is where the optic modules are assembled and aligned. After the optics are finished in the OAB they … more
Date: March 8, 1999
Creator: Bahowick, S; Mcmahon, D; Rowe, A; Tiszauer, D & Yakuma, S
Partner: UNT Libraries Government Documents Department
open access

B Decays as a probe of spontaneous cp-violation in SUSY models

Description: We consider phenomenological implications of susy models with spontaneously broken CP-symmetry. In particular, we analyze CP-asymmetries in B decays and find that the predictions of these models are vastly different from those of the SM. These features are common to NMSSM-like models with an arbitrary number of sterile superfields and the MSSM with broken R-parity.
Date: July 8, 1999
Creator: Lebedev, Oleg
Partner: UNT Libraries Government Documents Department
open access

Gas Phase Chemical Detection with an Integrated Chemical Analysis System

Description: Microfabrication technology has been applied to the development of a miniature, multi-channel gas phase chemical laboratory that provides fast response, small size, and enhanced versatility and chemical discrimination. Each analysis channel includes a sample concentrator followed by a gas chromatographic separator and a chemically selective surface acoustic wave detector array to achieve high sensitivity and selectivity. The performance of the components, individually and collectively, is descr… more
Date: July 8, 1999
Creator: Baca, Albert G.; Casalnuovo, Stephen A.; Frye-Mason, Gregory C.; Heller, Edwin J.; Hietala, Susan L.; Hietala, Vincent M. et al.
Partner: UNT Libraries Government Documents Department
open access

RF and mm-Wave Photonics at Sandia National Laboratories

Description: RF and mm-wave photonic devices and circuits have been developed at Sandia National Laboratories for applications ranging from RF optical data links to optical generation of mm-wave frequencies. This talk will explore recent high-speed photonics technology developments at Sandia including: (1) A monolithic optical integrated circuit for all-optical generation of mm-waves. Using integrated mode-locked diode lasers, amplifiers, and detectors, frequencies between 30 GHz and 90 GHz are generated by… more
Date: July 8, 1999
Creator: Vawter, G. A. & Sullivan, C.
Partner: UNT Libraries Government Documents Department
open access

High-resolution wavefront control of high-power laser systems

Description: Nearly every new large-scale laser system application at LLNL has requirements for beam control which exceed the current level of available technology. For applications such as inertial confinement fusion, laser isotope separation, laser machining, and laser the ability to transport significant power to a target while maintaining good beam quality is critical. There are many ways that laser wavefront quality can be degraded. Thermal effects due to the interaction of high-power laser or pump lig… more
Date: July 8, 1999
Creator: Brase, J.; Brown, C.; Carrano, C.; Kartz, M.; Olivier, S.; Pennington, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Texture Development During Equal Channel Angular Forging of BCC Metals

Description: Equal channel angular forging (ECAF) has been proposed as a severe plastic deformation technique for processing metals, alloys, and composites [e.g. Segal, 1995] (Fig. 1). The technique offers two capabilities of practical interest: a high degree of strain can be introduced with no change in the cross-sectional dimensions of the work-piece, hence, even greater strains can be introduced by re-inserting the work-piece for further deformation during subsequent passes through the ECAF die. Addition… more
Date: August 8, 1999
Creator: Agnew, S. R.
Partner: UNT Libraries Government Documents Department
open access

Unattended Monitoring System Design Methodology

Description: A methodology for designing Unattended Monitoring Systems starting at a systems level has been developed at Sandia National Laboratories. This proven methodology provides a template that describes the process for selecting and applying appropriate technologies to meet unattended system requirements, as well as providing a framework for development of both training courses and workshops associated with unattended monitoring. The design and implementation of unattended monitoring systems is gener… more
Date: July 8, 1999
Creator: Drayer, D. D.; DeLand, S. M.; Harmon, C. D.; Matter, J. C.; Martinez, R. L. & Smith, J. D.
Partner: UNT Libraries Government Documents Department
open access

Radial Excitations

Description: In this contribution I discuss recent experimental developments in the Spectroscopy of higher-mass mesons, especially candidate radial excitations discussed at the WHS99 meeting in Frascati.
Date: March 8, 1999
Creator: Barnes, T.
Partner: UNT Libraries Government Documents Department
open access

Experiences Using a Meta-Data Based Integration Infrastructure

Description: A data warehouse that presents data from many of the genomics community data sources in a consistent, intuitive fashion has long been a goal of bioinformatics. Unfortunately, it is one of the goals that has not yet been achieved. One of the major problems encountered by previous attempts has been the high cost of creating and maintaining a warehouse in a dynamic environment. In this abstract we have outlined a meta-data based approach to integrating data sources that begins to address this prob… more
Date: July 8, 1999
Creator: Critchlow, T.; Masick, R. & Slezak, T.
Partner: UNT Libraries Government Documents Department
open access

Optical Readout of Micro-Accelerometer Code Features

Description: Micromachine accelerometers offer a way to enable critical functions only when a system encounters a particular acceleration environment. This paper describes the optical readout of a surface micromachine accelerometer containing a unique 24-bit code. The readout uses waveguide-based optics, which are implemented as a photonic integrated circuit (PIC). The PIC is flip-chip bonded over the micromachine, for a compact package. The shuttle moves 500 {micro}m during readout, and each code element i… more
Date: July 8, 1999
Creator: Dickey, Fred M.; Holswade, Scott C.; Polosky, Marc A.; Shagam, Richard N. & Sullivan, Charles T.
Partner: UNT Libraries Government Documents Department
open access

3-D Silicon Photonic Lattices- Cornerstone of an Emerging Photonics Revolution

Description: Three-dimensional photonic lattices are engineered materials which are the photonic analogues of semiconductors. These structures were first proposed and demonstrated in the mid-to-late 1980's. However, due to fabrication difficulties, lattices active in the infrared are only just emerging. Wide ranges of structures and fabrication approaches have been investigated. The most promising approach for many potential applications is a diamond-like structure fabricated using silicon microprocessing t… more
Date: July 8, 1999
Creator: Fleming, J.G. & Lin, Shawn-Yu
Partner: UNT Libraries Government Documents Department
open access

Application of the Two-Parameter J-A2 Description to Ductile Crack Growth

Description: Typical ASTM fracture testing determines J-integral resistance (J-R) curve or fracture toughness (JIC) based on specimens with high constraint geometry such as those specified in ASTM E1737-96. A three-term asymptotic solution with two parameters J and A2 (a constraint parameter) has been developed for characterizing the constraint effect of various geometries. The present paper extends the J-A2 characterization of a stationary crack tip to the regime of stable crack growth. Similar to the conc… more
Date: July 8, 1999
Creator: Lam, P.S.
Partner: UNT Libraries Government Documents Department
open access

The Potential for Low-Cost Concentrating Solar Power Systems

Description: Concern over the possibility of global climate change as a result of anthropogenic greenhouse gas buildup in the atmosphere is resulting in increased interest in renewable energy technologies. The World Bank recently sponsored a study to determine whether solar thermal power plants can achieve cost parity with conventional power plants. The paper reviews the conclusions of that study.
Date: July 8, 1999
Creator: Price, H. W. (National Renewable Energy Laboratory) & Carpenter, S. (Enermodal Engineering Limited)
Partner: UNT Libraries Government Documents Department
open access

Self-Adjoint Angular Flux Equation for Coupled Electron-Photon Transport

Description: Recently, Morel and McGhee described an alternate second-order form of the transport equation called the self adjoint angular flux (SAAF) equation that has the angular flux as its unknown. The SAAF formulation has all the advantages of the traditional even- and odd-parity self-adjoint equations, with the added advantages that it yields the full angular flux when it is numerically solved, it is significantly easier to implement reflective and reflective-like boundary conditions, and in the appro… more
Date: July 8, 1999
Creator: Liscum-Powell, J. L.; Lorence, L. J., Jr.; Morel, J. E. & Prinja, A. K.
Partner: UNT Libraries Government Documents Department
open access

Refractive Index and Hygroscopic Stability of Al(x)Ga(1-x)As Native Oxides

Description: The authors present prism coupling measurements on Al{sub x}Ga{sub 1{minus}x}As native oxides showing the dependence of refractive index on composition (0.3 {le} x {le} 0.97), oxidation temperature (400 {le} T {le} 500), and carrier gas purity. Index values range from n = 1.490 (x = 0.9, 400) to 1.707 (x = 0.3, 500 C). The oxides are shown to adsorb moisture, increasing their index by up to 0.10 (7%). Native oxides of Al{sub x}Ga{sub 1{minus}x}As (x {le} 0.5) have index values up to 0.27 higher… more
Date: July 8, 1999
Creator: Blum, O.; Epstein, R. J.; Hou, H.; Hall, D. C.; Kou, L.; Luo, Y. et al.
Partner: UNT Libraries Government Documents Department
open access

Operational Restoration of the Pen Branch Bottomland Hardwoos and Swamp Wetlands-The Research Setting

Description: Historiexecy the SRS swamp was largely composed of bald cypress and tupelo forest with lesser amounts of hardwoods. Upstream impacts from dam construction have altered the composition of the forest through changes in the flooding regimes. Pumping of hot water in to Pen Branch resulted in destruction of several hundred acres of the native forest. Overflow of the forest redistributed sediment, eroded the channel and deposition of silt. No natural regeneration of hardwoods or cypress were observed… more
Date: June 8, 1999
Creator: Nelson, E. A.; Dulohery, N. C.; Kolka, R. K. & McKee, W.
Partner: UNT Libraries Government Documents Department
open access

Observation of Secondary Plasma Waves in Laser-Plasma Interaction Experiments

Description: An experiment is described where the two products of the Langmuir Decay Instability (LDI) of a primary electron plasma wave have been observed and identified without any ambiguity. Primary Langmuir waves are driven by Stimulated Raman Scattering (SRS) of an incident laser which provides well-defined electron plasma waves. Thomson scattering of a short wavelength probe beam yields measurements of the amplitude of the waves resolved in time, space, wavelength and wavevector, that allow identifica… more
Date: December 8, 1999
Creator: Depierreux, S.; Labaune, C.; Baldis, H. A.; Fuchs, J. & Michard, A.
Partner: UNT Libraries Government Documents Department
open access

["A friend indeed?" article, June 8, 1999]

Description: An article, written by Chris Bull for The Advocate, about hopes for George W. Bush's future actions and policies on gay and lesbian rights. It highlights Bush's friendship with Charles C. Francis and includes the words of other activists and people interested in the topic.
Date: June 8, 1999
Creator: Bull, Chris
Partner: UNT Libraries Special Collections
open access

Progress and future plans for MPC and A at Chelyabinsk-70

Description: This paper describes that portion of the Nuclear Materials Protection, Control, and Accounting (MPC and A) program that is directed specifically to the needs of the All Russian Scientific Research Institute of Technical Physics (VNIITF), also called Chelyabinsk-70. Chelyabinsk-70 is located in the Ural Mountains, approximately 2000 km east of Moscow and 100 km south of Ekaterinburg. The MPC and A work that has been completed, is underway and planned at the facility will be described. During the… more
Date: July 8, 1999
Creator: Apt, K.; Blasy, J.; Bukin, D.; Cahalane, P.; Churikov, Y.; Curtis, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Beam tests of the 12 MHz RFQ RIB injector for ATLAS.

Description: In recent tests without beam, the Argonne 12 MHz split-coaxial radio-frequency quadruple (RFQ) achieved a cw intervane voltage of more than 100 kV, the design operating voltage for the device. This voltage is sufficient for the RFQ to function as the first stage of a RIB injector for the Argonne Tandem Linear Accelerator System (ATLAS). Previously reported beam dynamics calculations for the structure predict longitudinal emittance growth of only a few keV{center_dot}ns for beams of mass 132 and… more
Date: February 8, 1999
Creator: Kaye, R. A.
Partner: UNT Libraries Government Documents Department
open access

Medical applications of ultra-short pulse lasers

Description: The medical applications for ultra short pulse lasers (USPLs) and their associated commercial potential are reviewed. Short pulse lasers offer the surgeon the possibility of precision cutting or disruption of tissue with virtually no thermal or mechanical damage to the surrounding areas. Therefore the USPL offers potential improvement to numerous existing medical procedures. Secondly, when USPLs are combined with advanced tissue diagnostics, there are possibilities for tissue-selective precisio… more
Date: June 8, 1999
Creator: Kim, B. M. & Marion, J. E.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen