Cactus and Visapult: A case study of ultra-high performance distributed visualization using connectionless protocols (open access)

Cactus and Visapult: A case study of ultra-high performance distributed visualization using connectionless protocols

This past decade has seen rapid growth in the size, resolution, and complexity of Grand Challenge simulation codes. Many such problems still require interactive visualization tools to make sense of multi-terabyte data stores. Visapult is a parallel volume rendering tool that employs distributed components, latency tolerant algorithms, and high performance network I/O for effective remote visualization of massive datasets. In this paper we discuss using connectionless protocols to accelerate Visapult network I/O and interfacing Visapult to the Cactus General Relativity code to enable scalable remote monitoring and steering capabilities. With these modifications, network utilization has moved from 25 percent of line-rate using tuned multi-streamed TCP to sustaining 88 percent of line rate using the new UDP-based transport protocol.
Date: May 7, 2002
Creator: Shalf, John & Bethel, E. Wes
Object Type: Article
System: The UNT Digital Library
Cleanliness Validation of NIF Small Optics (open access)

Cleanliness Validation of NIF Small Optics

The National Ignition Facility will be the highest energy laser in the world when completed. Many small optics ({le} 14 inches in diameter) have stringent transport efficiency and some have very high laser fluence requirements. For optics to sustain high spectral efficiencies and survive high fluences for a 30-year operation, these optics have cleanliness requirements to assure optimal laser system performance. These optical components have insufficient surface areas to validate the particulate and organic contamination requirements by methods used for mechanical parts. Also, the common validation techniques require some sort of surface contact which is not compatible with handling of laser optics. This presentation describes alternate cleanliness validation methods developed for the NIF small optical components. An organic validation procedure was devised based on the spectral transmission sensitivity to contamination layers on coated and uncoated fused silica windows. Optics were scanned in the near infrared before and after an application of a specific amount of organic contamination onto the surface. Changes in transmission correlated to organic contamination levels and used to determine non-volatile organic contamination optics. A validation method for particulate contamination was demonstrated on a large window, showing that acceptable cleanliness levels could be achieved after a wet-wipe and …
Date: May 7, 2002
Creator: Chow, R.; Bickel, R.; Ertel, J.; Pryatel, J.; Loomis, G.; Stowers, I. et al.
Object Type: Article
System: The UNT Digital Library
Dense ceramic membranes for hydrogen separation. (open access)

Dense ceramic membranes for hydrogen separation.

We have developed cermet membranes that nongalvanically separate hydrogen from gas mixtures. The highest measured hydrogen flux was 20.0 cm{sup 3} (STP)/min-cm{sup 2} for an ANL-3a membrane at 900 C. For ANL-3 membranes with thickness of 40-500 {micro}m, hydrogen permeation is limited by the bulk diffusion of hydrogen through the metal phase. The effect of hydrogen partial pressure on permeation rate confirmed this conclusion, suggesting that higher permeation rates may be obtained by decreasing the membrane thickness. Permeation rate in a syngas atmosphere for times up to 190 h showed no degradation in performance, which indicates that ANL-3 membranes may be suitable for long-term, practical hydrogen separation.
Date: May 7, 2002
Creator: Balachandran, U.; Lee, T. H.; Wang, S.; Zhang, G. & Dorris, S. E.
Object Type: Article
System: The UNT Digital Library
Energy Policy: Setting the Stage for the Current Debate (open access)

Energy Policy: Setting the Stage for the Current Debate

The Bush Administration issued its plan for a national energy policy on May 16, 2001. The plan was controversial, characterized by some as leaner on conservation and renewables than Democratic proposals, and predisposed to trade off environmental considerations to increase supply. Comprehensive energy legislation was introduced in the Senate by both parties by late March (S. 388, S. 389, S. 596, S. 597). Bills reported by several House committees (H.R. 2436, H.R. 2460, H.R. 2511, and H.R. 2587) were combined in a single bill, H.R. 4, passed by the House, August 1, 2001. The House version of H.R. 4 would require a 5 billion gallon reduction in light-duty truck and SUV fuel consumption and would open the Arctic National Wildlife Refuge (ANWR) to leasing.
Date: May 7, 2002
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Energy Provisions of the Farm Bill: Comparison of Current Law with House and Senate Bills (open access)

Energy Provisions of the Farm Bill: Comparison of Current Law with House and Senate Bills

None
Date: May 7, 2002
Creator: Yacobucci, Brent D.
Object Type: Report
System: The UNT Digital Library
Ergonomics in the Workplace: Is It Time for an OSHA Standard? (open access)

Ergonomics in the Workplace: Is It Time for an OSHA Standard?

This report debates implementing an OSHA (Occupational Safety and Health Administration) standard for ergonomics. This standard would be motivated by the fact that one third of state employer's costs are related to improper ergonomic design causing illness. The report details that standards suggested in the past have been rejected by Congress.
Date: May 7, 2002
Creator: Rappaport, Edward
Object Type: Report
System: The UNT Digital Library
Ergonomics in the Workplace: Is It Time for an OSHA Standard? (open access)

Ergonomics in the Workplace: Is It Time for an OSHA Standard?

Improper ergonomic design of jobs is one of the leading causes of work-related illness, accounting for perhaps a third of employers’ costs under state workers’ compensation laws. Due to the wide variety of circumstances, however, any comprehensive standard would probably have to be complex and costly, while scientific understanding of the problem is not complete.
Date: May 7, 2002
Creator: Rappaport, Edward B.
Object Type: Report
System: The UNT Digital Library
Free-boundary Full-pressure Island Healing in a Stellarator: Coil-healing (open access)

Free-boundary Full-pressure Island Healing in a Stellarator: Coil-healing

The lack of axisymmetry in stellarators guarantees that in general magnetic islands and chaotic magnetic field lines will exist. As particle transport is strongly tied to the magnetic field lines, magnetic islands and chaotic field lines result in poor plasma confinement. For stellarators to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux-surfaces, and the suppression of magnetic islands is a critical issue for stellarator coil design, particularly for small aspect ratio devices. A procedure for modifying stellarator coil designs to eliminate magnetic islands in free-boundary full-pressure magnetohydrodynamic equilibria is presented. Islands may be removed from coil-plasma free-boundary equilibria by making small changes to the coil geometry and also by variation of trim coil currents. A plasma and coil design relevant to the National Compact Stellarator Experiment is used to illustrate the technique.
Date: May 7, 2002
Creator: S.R.Hudson; Reiman, A.; Strickler, D.; Brooks, A.; Monticello, D.A. & Hirshman, and S.P.
Object Type: Report
System: The UNT Digital Library
Groundwater Quality Assessment Plan for Single-Shell Tank Waste Management Area B-BX-BY at the Hanford Site, Interim Change Notice 1 (open access)

Groundwater Quality Assessment Plan for Single-Shell Tank Waste Management Area B-BX-BY at the Hanford Site, Interim Change Notice 1

This ICN updates the assessment plan to reflect the addition of wells newly installed in FY2001. Project scientists will provide a schedule change request identifying the wells as new and providing a list of constituents and sample frequencies to the sample scheduler.
Date: May 7, 2002
Creator: Narbutovskih, Susan M.
Object Type: Report
System: The UNT Digital Library
Hybrid Chirped Pulse Amplification (open access)

Hybrid Chirped Pulse Amplification

We present a novel chirped pulse amplification method which combines optical parametric amplification and laser amplification. We have demonstrated this hybrid CPA concept with a combination of beta-barium borate and Ti:sapphire. High-efficiency, multi-terawatt compatible amplification is achieved without gain narrowing and without electro-optic modulators using a simple commercial pump laser.
Date: May 7, 2002
Creator: Jovanovic, I & Barty, C P J
Object Type: Article
System: The UNT Digital Library
Nonlinear d--ta-f Simulation Studies of Intense Charged Particle Beams with Large Temperature Anisotropy (open access)

Nonlinear d--ta-f Simulation Studies of Intense Charged Particle Beams with Large Temperature Anisotropy

In this paper, a 3-D nonlinear perturbative particle simulation code (BEST) [H. Qin, R.C. Davidson and W.W. Lee, Physical Review Special Topics on Accelerators and Beams 3 (2000) 084401] is used to systematically study the stability properties of intense nonneutral charged particle beams with large temperature anisotropy (T{sub {perpendicular}b} >> T{sub {parallel}b}). The most unstable modes are identified, and their eigen frequencies, radial mode structure, and nonlinear dynamics are determined for axisymmetric perturbations with {partial_derivative}/{partial_derivative}{theta} = 0.
Date: May 7, 2002
Creator: Startsev, Edward A.; Davidson, Ronald C. & Qin, Hong
Object Type: Report
System: The UNT Digital Library
Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array (open access)

Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array

The Antarctic Muon and Neutrino Detector Array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 10{sup 6} times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 x 10{sup 9} cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90 percent of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.
Date: May 7, 2002
Creator: Ahrens, J.; Andres, E.; Bai, X.; Barouch, G.; Barwick, S. W.; Bay, R. C. et al.
Object Type: Article
System: The UNT Digital Library
Proceedings of Riken Bnl Research Center Workshop, Theory Studies for Rhic-Spin, Volume 40. (open access)

Proceedings of Riken Bnl Research Center Workshop, Theory Studies for Rhic-Spin, Volume 40.

None
Date: May 7, 2002
Creator: Vogelsang, W.
Object Type: Report
System: The UNT Digital Library
Recent Progress on the Standardized DOE Spent Nuclear Fuel Canister (open access)

Recent Progress on the Standardized DOE Spent Nuclear Fuel Canister

The Department of Energy (DOE) has developed a set of containers for the handling, interim storage, transportation, and disposal in the national repository of DOE spent nuclear fuel (SNF). This container design, referred to as the standardized DOE SNF canister or standardized canister, was developed by the Department's National Spent Nuclear Fuel Storage Program (NSNFP) working in conjunction with the Office of Civilian Radioactive Waste Management (OCRWM) and the DOE spent fuel sites. This canister had to have a standardized design yet be capable of accepting virtually all of the DOE SNF, be placed in a variety of storage and transportation systems, and still be acceptable to the repository. Since specific design details regarding the storage, transportation, and repository disposal of DOE SNF were not finalized, the NSNFP recognized the necessity to specify a complete DOE SNF canister design. This allowed other evaluations of canister performance and design to proceed as well as providing standardized canister users adequate information to proceed with their work. This paper is an update of a paper presented to the 1999 American Nuclear Society of Mechanical Engineers (ASME) Pressure Vessels and Piping (PVP) Conference. It discusses recent progress achieved in various areas to enhance acceptance …
Date: May 7, 2002
Creator: Morton, D.K.; Snow, S.D.; Rahl, T.E.; Hill, T.J. (INEEL) & Morissette, R.P. (Beckman and Associates, Inc.)
Object Type: Article
System: The UNT Digital Library
Solid-State Heat-Capacity-Laser Review (open access)

Solid-State Heat-Capacity-Laser Review

We describe our recent progress in the area of solid-state heat-capacity-lasers (SSHCL). In particular, we examine the physics of heat-capacity operation of a solid state laser and give the present technology status of our 10 kW flashlamp-pumped laser The current status of work leading to a diode-pumped Nd:GGG HCL is also described.
Date: May 7, 2002
Creator: Rotter, M D & Dane, C B
Object Type: Article
System: The UNT Digital Library
Strong Earthquake Motion Estimates for Three Sites on the U.C. San Diego Campus (open access)

Strong Earthquake Motion Estimates for Three Sites on the U.C. San Diego Campus

The approach of the Campus Earthquake Program (CEP) is to combine the substantial expertise that exists within the UC system in geology, seismology, and geotechnical engineering, to estimate the earthquake strong motion exposure of UC facilities. These estimates draw upon recent advances in hazard assessment, seismic wave propagation modeling in rocks and soils, and dynamic soil testing. The UC campuses currently chosen for application of our integrated methodology are Riverside, San Diego, and Santa Barbara. The procedure starts with the identification of possible earthquake sources in the region and the determination of the most critical fault(s) related to earthquake exposure of the campus. Combined geological, geophysical, and geotechnical studies are then conducted to characterize each campus with specific focus on the location of particular target buildings of special interest to the campus administrators. We drill, sample, and geophysically log deep boreholes next to the target structure, to provide direct in-situ measurements of subsurface material properties, and to install uphole and downhole 3-component seismic sensors capable of recording both weak and strong motions. The boreholes provide access below the soil layers, to deeper materials that have relatively high seismic shear-wave velocities. Analyses of conjugate downhole and uphole records provide a basis …
Date: May 7, 2002
Creator: Day, S.; Doroudian, M.; Elgamal, A.; Gonzales, S.; Heuze, F.; Lai, T. et al.
Object Type: Report
System: The UNT Digital Library
Summer Workshop: Molecular Basis, Physiology and Diversity of Microbial Adaptation (open access)

Summer Workshop: Molecular Basis, Physiology and Diversity of Microbial Adaptation

This summer workshop successfully exposed beginning graduate students, research technicians from industry, and other scientists to modern concepts and experimental protocols in an area that both DOE and NSF perceived to be lacking in U.S. science. 70 students participated in this workshop over 5 summers. Each summer, 12-16 students spent 2-4 weeks at The Ohio State University covering four distinct modules through lectures, laboratory sessions, and interaction with internationally recognized eminent scientists.
Date: May 7, 2002
Creator: Tabita, F. R.
Object Type: Report
System: The UNT Digital Library
Ultrasonic Testing of NIF Amplifier FAU Top Plates (open access)

Ultrasonic Testing of NIF Amplifier FAU Top Plates

A key component in the National Ignition Facility (NIF) laser optic system is the amplifier frame assembly unit (FAU). The cast aluminum top plate that supports the FAU is required to withstand loads that would occur during an earthquake with a recurrence period of 1000 years. The stringent seismic requirements placed on the FAU top plate induced a study of the cast aluminum material used in the top plate. Ultrasonic testing was used to aid in characterizing the aluminum material used in the plates. This report documents the work performed using contact ultrasonic testing to characterize the FAU top plate material. The ultrasonic work reported here had 3 objectives: (1) inspect the plate material before cyclic testing conducted at the Pacific Earthquake Engineering Research Center (PEER); (2) determine the overall quality of individual plates; and (3) detect large defects in critical areas of individual plates. Section III, ''Pre-cyclic test inspection'', describes work performed in support of Objective 1. Section IV, ''Ultrasonic field measurements'', describes work performed in support of Objectives 2 and 3.
Date: May 7, 2002
Creator: Chinn, D. J.; Huber, R. D.; Haskins, J. J.; Rodriguez, J. A.; Souza, P. R. & Le, T. V.
Object Type: Report
System: The UNT Digital Library
Understanding of Neutral Gas Transport in the Alcator C-Mod Tokamak Divertor (open access)

Understanding of Neutral Gas Transport in the Alcator C-Mod Tokamak Divertor

A series of experiments on the effect of divertor baffling on the Alcator C-Mod tokamak provides stringent tests on models of neutral gas transport in and around the divertor region. One attractive feature of these experiments is that a trial description of the background plasma can be constructed from experimental measurements using a simple model, allowing the neutral gas transport to be studied with a stand-alone code. The neutral-ion and neutral-neutral elastic scattering processes recently added to the DEGAS 2 Monte Carlo neutral transport code permit the neutral gas flow rates between the divertor and main chamber to be simulated more realistically than before. Nonetheless, the simulated neutral pressures are too low and the deuterium Balmer-alpha emission profiles differ qualitatively from those measured, indicating an incomplete understanding of the physical processes involved in the experiment. Some potential explanations are examined and opportunities for future exploration a re highlighted. Improvements to atomic and surface physics data and models will play a role in the latter.
Date: May 7, 2002
Creator: Stotler, D. P.; Pitcher, C. S.; Boswell, C. J.; LaBombard, B.; Terry, J. L.; Elder, J. D. et al.
Object Type: Report
System: The UNT Digital Library
Updated ENDL99 Cross Sections for U(n.y) and U(n,f) (open access)

Updated ENDL99 Cross Sections for U(n.y) and U(n,f)

In this note, we describe the first of two updates to the uranium isotopes in Livermore's Evaluated Neutron Data Library, ENDL99. Here, we concentrate on improving the (n, f) and (n, {gamma}) evaluations for a limited set of uranium isotopes. The first improvement consisted of creating an evaluation for {sup 232}U using a combination of fission and capture cross sections from the JENDL-3.2 database and the outgoing particle distributions from the exiting ENDL99 {sup 234}U evaluation. The second improvement consisted of updating existing (n, f) and (n, {gamma}) evaluations for uranium isotopes with A=233-238. These improvements are particularly apparent in the neutron resonance region as ENDL99 often contains gross averages over the resonances. We have propagated these updates into various Livermore application libraries.
Date: May 7, 2002
Creator: Brown, D.; Dietrich, F.; Hill, T. & McNabb, D.
Object Type: Report
System: The UNT Digital Library