Resource Type

115 Matching Results

Results open in a new window/tab.

Computer graphics for extracting information from data. [Various techniques for data display] (open access)

Computer graphics for extracting information from data. [Various techniques for data display]

Computer graphics which are useful for displaying and analyzing data are presented. Many classical and several newly developed graphical techniques in statistical data analysis are presented for small univariate and multivariate data sets. These include histograms, empirical density functions, pie charts, contour plots, a discriminant analysis display, cluster analysis, Chernoff ''faces,'' and Andrews' sine curves. Recent advances in data collection technology and computer data base management systems have made it imperative to utilize computer graphics for large data sets. Several innovative graphical techniques are presented to handle this situation. Spatial relationships among the data (particularly geographic data) are difficult to conceptualize. Several cartographic techniques are presented which enhance the understanding of these spatial relationships within the data.
Date: October 28, 1977
Creator: Lohrding, R. K.; Johnson, M. M. & Whiteman, D. E.
System: The UNT Digital Library
Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source (open access)

Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source

An imaging beamline based on a Kirkpatrick-Baez mirror configuration has been designed to image the electron beam in the ALS storage ring, to measure its size and shape. The electron beam emittance will be small ({epsilon}h = 3.4 {times} 10{sup {minus}9} m rad) and the quality of the image is extremely sensitive to surface figure distortion of the mirrors. Thermal distortions and surface temperatures have been calculated for radiatively cooled mirrors of various materials in a search for a simple design which avoids water cooling. The choice of mirror material and the thermal and mechanical design is discussed. 6 refs.
Date: October 28, 1991
Creator: Warwick, T. (Lawrence Berkeley Lab., CA (United States)) & Sharma, S. (Brookhaven National Lab., Upton, NY (United States))
System: The UNT Digital Library
Advanced Light Source beam position monitor (open access)

Advanced Light Source beam position monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library
The EPRI Laboratory experiments at ANL. [Vaporization of core-concrete mixtures] (open access)

The EPRI Laboratory experiments at ANL. [Vaporization of core-concrete mixtures]

The vaporization of core-concrete mixtures is being measured using a transpiration method. Mixtures of stainless steel, concrete (limestone or basaltic) and urania (doped with La/sub 2/O/sub 3/, SrO, BaO, and ZrO/sub 2/) are vaporized at 2150 - 2400 K from a zirconia crucible into flowing He - 6% H/sub 2/ gas. Up to 600 ppM H/sub 2/O is added to the gas to fix the partial molar free energy of oxygen in the range -420 kJ to -550 kJ. The fraction of the sample that is vaporized is determined by weight change and by chemical analyses on the condensates that are collected in an Mo condenser tube. The results are being used to test the thermodynemic data base and the underlying assumptions of computer codes used for prediction of release during the severe accident. 13 refs., 2 tabs.
Date: October 28, 1987
Creator: Roche, M. F.; Settle, J. L.; Leibowitz, L.; Johnson, C. E. & Ritzman, R. L.
System: The UNT Digital Library
Water cooled metal optics for the Advanced Light Source (open access)

Water cooled metal optics for the Advanced Light Source

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.
Date: October 28, 1991
Creator: McKinney, W.R.; Irick, S.C. (Lawrence Berkeley Lab., CA (United States)) & Lunt, D.L.J. (Tucson Optical Research Corp., AZ (United States))
System: The UNT Digital Library
Polarization Studies of CdZnTe Detectors Using Synchrotron X-Ray Radiation. (open access)

Polarization Studies of CdZnTe Detectors Using Synchrotron X-Ray Radiation.

None
Date: October 28, 2007
Creator: Camarda, G. S.; Bolotnikov, A. E.; Cui, Y.; Hossain, A. & James, R. B.
System: The UNT Digital Library
An Evaluation of Three Commercially Available Technologies For Real-Time Measurement of Rates of Outdoor Airflow Into HVAC Systems (open access)

An Evaluation of Three Commercially Available Technologies For Real-Time Measurement of Rates of Outdoor Airflow Into HVAC Systems

During the last few years, new technologies have been introduced for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurements technologies has not previously been published. This document describes a test system and protocols developed for a controlled evaluation of these measurement technologies. The results of tests of three commercially available measurement technologies are also summarized. The test system and protocol were judged practical and very useful. The three commercially available measurement technologies should provide reasonably, e.g., 20%, accurate measurements of OA flow rates as long as air velocities are maintained high enough to produce accurately measurable pressure signals. In HVAC systems with economizer controls, to maintain the required air velocities the OA intake will need to be divided into two sections in parallel, each with a separate OA damper. All of the measurement devices had pressure drops that are likely to be judged acceptable. The influence of wind on the accuracy of these measurement technologies still needs to be evaluated.
Date: October 28, 2004
Creator: Fisk, William J.; Faulkner, David & Sullivan, Douglas P.
System: The UNT Digital Library
Mitigation of Laser Damage Growth in Fused Silica with a Galvanometer Scanned CO2 Laser (open access)

Mitigation of Laser Damage Growth in Fused Silica with a Galvanometer Scanned CO2 Laser

At the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL), mitigation of laser surface damage growth on fused silica using single and multiple CO{sub 2} laser pulses has been consistently successful for damage sites whose lateral dimensions are less than 100 {micro}m, but has not been for larger sites. Cracks would often radiate outward from the damage when a CO{sub 2} pulse was applied to the larger sites. An investigation was conducted to mitigate large surface damage sites using galvanometer scanning of a tightly focused CO{sub 2} laser spot over an area encompassing the laser damage. It was thought that by initially scanning the CO{sub 2} spot outside the damage site, radiating crack propagation would be inhibited. Scan patterns were typically inward moving spirals starting at radii somewhat larger than that of the damage site. The duration of the mitigation spiral pattern was {approx}110 ms during which a total of {approx}1.3 J of energy was delivered to the sample. The CO{sub 2} laser spot had a 1/e{sup 2}-diameter of {approx}200 {micro}m. Thus, there was general heating of a large area around the damage site while rapid evaporation occurred locally at the laser spot position in the spiral. …
Date: October 28, 2005
Creator: Bass, I L; Guss, G M & Hackel, R P
System: The UNT Digital Library
Observation of amplification of a 1ps pulse by SRS of a 1 ns pulse in a plasma with conditions relevant to pulse compression (open access)

Observation of amplification of a 1ps pulse by SRS of a 1 ns pulse in a plasma with conditions relevant to pulse compression

The compression of a laser pulse by amplification of an ultra short pulse beam which seeds the stimulated Raman scatter of the first beam has been long been discussed in the context of solid and gas media. We investigate the possibility of using intersecting beams in a plasma to compress nanosecond pulses to picosecond duration by scattering from driven electron waves. Recent theoretical studies have shown the possibility of efficient compression with large amplitude, non-linear Langmuir waves driven either by SRS [1] or non-resonantly [2].
Date: October 28, 2005
Creator: Kirkwood, R K; Dewald, E; Wilks, S C; Meezan, N; Niemann, C; Divol, L et al.
System: The UNT Digital Library
Looking Ahead - Biofuels, H2, & Vehicles: 21st Industry Growth Forum (open access)

Looking Ahead - Biofuels, H2, & Vehicles: 21st Industry Growth Forum

This presentation on the future of biofuels, hydrogen, and hybrid vehicles was presented at NREL's 21st Industry Growth Forum in Denver, Colorado, on October 28, 2008.
Date: October 28, 2008
Creator: Gardner, D.
System: The UNT Digital Library
Calculational comparison of DT, neon, and argon implosions (open access)

Calculational comparison of DT, neon, and argon implosions

A number of laboratories have been doing laser driven implosions of pure neon and argon gas as a diagnostic of the peak imploded conditions. The relationship of these implosions to DT implosions has been unclear. This paper will explore the physics of these higher Z gases and show that they are fundamentally easier to compress than DT gas. Specifically, this paper will show that, for the same initial mass density, and the same capsule design and drive conditions, the calculated peak compressed density is dependent on the type of fill gas, being substantially higher for Ne and Ar implosions than for DT implosions.
Date: October 28, 1980
Creator: Stevens, J. C.
System: The UNT Digital Library
3D field calculation of the GEM prototype magnet and comparison with measurements (open access)

3D field calculation of the GEM prototype magnet and comparison with measurements

The proposed 4 GeV Electron Microtron (GEM) is designed to fill the existing buildings left vacant by the demise of the Zero Gradient Synchrotron (ZGS) accelerator. One of the six large dipole magnets is shown as well as the first 10 electron orbits. A 3-orbit prototype magnet has been built. The stepped edge of the magnet is to keep the beam exiting perpendicular to the pole. The end guards that wrap around the main coils are joined together by the 3 shield plates. The auxiliary coils are needed to keep the end guards and shield plates from saturating. A 0.3 cm Purcell filter air gap exists between the pole and the yoke. Can anyone question this being a truly three-dimensional magnetostatic problem. The computer program TOSCA, developed at the Rutherford Appleton Laboratory by the Computing Applications Group, was used to calculate this magnet and the results have been compared with measurements.
Date: October 28, 1983
Creator: Lari, R.J.
System: The UNT Digital Library
Advanced Light Source Beam Position Monitor (open access)

Advanced Light Source Beam Position Monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library
Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source (open access)

Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source

An imaging beamline based on a Kirkpatrick-Baez mirror configuration has been designed to image the electron beam in the ALS storage ring, to measure its size and shape. The electron beam emittance will be small ({epsilon}h = 3.4 {times} 10{sup {minus}9} m rad) and the quality of the image is extremely sensitive to surface figure distortion of the mirrors. Thermal distortions and surface temperatures have been calculated for radiatively cooled mirrors of various materials in a search for a simple design which avoids water cooling. The choice of mirror material and the thermal and mechanical design is discussed. 6 refs.
Date: October 28, 1991
Creator: Warwick, T. & Sharma, S.
System: The UNT Digital Library
Bubbles and their implications for laser-fusion (open access)

Bubbles and their implications for laser-fusion

Bubbles are concentrations of electromagnetic energy in the region of the critical density that force out the plasma to form a void. Since the critical density surface is cratered, absorption may be greater than a smooth surface since a larger area will be available for absorption and the reflected light will have a large probability of restriking the critical density. The distance between bubbles is several wavelengths and consequently they may encourage Rayleigh--Taylor instabilities. The threshold, magnetic field generation, and possible experimental evidence for bubbles are discussed. Also, the competition between sidescatter and self focusing in an entirely underdense plasma is studied and it is found that sidescatter dominates for polarization out of the simulation plane.
Date: October 28, 1975
Creator: Estabrook, K. G. & Valeo, E. J.
System: The UNT Digital Library
Argus Laser Fusion Facility (open access)

Argus Laser Fusion Facility

ARGUS is a two-beam Nd: glass laser system built for laser fusion irradiation experiments. It is the first glass laser system planned and built with the understanding that small-scale beam break-up is the dominant performance limiting factor in obtaining high output power. Accordingly, five vacuum spatial filters are located at strategic intervals along each chain to eliminate the accumulated small-scale filamentation. This strategy permits cascading of amplifiers to obtain a focusable output of more than one terawatt per arm in a spatially clean beam of 20 centimeter diameter. Beam diagnostics which characterize each shot include the time-integrated spatial profile and the time resolved intensity/power at the target. Demonstrated performance to date includes: (1) Peak power in excess of 2 TW at the target is achieved with regularity. (2) Maximum system brightness is in excess of 10/sup 17/ watts/cm/sup 2/ ster. (3) Shot-to-shot pointing stability within 50 ..mu.. radians is achieved over periods of days. (4) Successful target experiments have been performed with pulses of from 30 to 500 ps duration.
Date: October 28, 1976
Creator: Speck, D. R. & Simmons, W. W.
System: The UNT Digital Library
Study of the neutron damage on electronics at the National Ignition Facility (open access)

Study of the neutron damage on electronics at the National Ignition Facility

The NIF environment is very complex leading to a large and non trivial radiation background. A shield surrounding the electronics is required to lower the neutron background to less than 1e7 n/cm{sup 2}. Moving electronics to behind the 6 foot-thick target bay wall is the best shield.
Date: October 28, 2010
Creator: Dauffy, L S; Mcnaney, J M & Khater, H Y
System: The UNT Digital Library
Gain of laser fusion pellets (open access)

Gain of laser fusion pellets

The gain of thermonuclear pellets containing a pusher-tamper of high density high-Z material surrounding the DT fuel is considered. Other significant characteristics of such capsules are briefly mentioned. (MOW)
Date: October 28, 1974
Creator: Nuckolls, J. & Pan, Y. L.
System: The UNT Digital Library
Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior (open access)

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior

Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the alpha-pinene + O3 reaction (alphaP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the alphaP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the alphaP spectra suggest that the evaporation of alphaP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from the alphaP particles existing as in a glassy state instead of having the expected liquid-like behavior. To reconcile these observations with decades of aerosol growth measurements, which indicate …
Date: October 28, 2010
Creator: Davis, UC; Cappa, Christopher D. & Wilson, Kevin R.
System: The UNT Digital Library
Beta-Phosphinoethylboranes as Ambiphilic Ligands in Nickel-Methyl Complexes (open access)

Beta-Phosphinoethylboranes as Ambiphilic Ligands in Nickel-Methyl Complexes

The ambiphilic {beta}-phosphinoethylboranes Ph{sub 2}PCH{sub 2}CH{sub 2}BR{sub 2} (BR{sub 2} = BCy{sub 2} (1a), BBN (1b)), which feature a ethano spacer CH{sub 2}CH{sub 2} between the Lewis acidic boryl and Lewis basic phosphino groups, were synthesized in nearly quantitative yields via the hydroboration of vinyldiphenylphosphine. Compounds 1a and 1b were fully characterized by elemental analysis, and by NMR and IR spectroscopy. X-ray crystallographic studies of compound 1b revealed infinite helical chains of the molecules connected through P{hor_ellipsis}B donor-acceptor interactions. The ability of these ambiphilic ligands to concurrently act as donors and acceptors was highlighted by their reactions with (dmpe)NiMe{sub 2}. Zwitterionic complexes (dmpe)NiMe(Ph{sub 2}PCH{sub 2}CH{sub 2}BCy{sub 2}Me) (2a) and (dmpe)NiMe(Ph{sub 2}PCH{sub 2}CH{sub 2}[BBN]Me) (2b) were generated via the abstraction of one of the methyl groups, forming a borate, and intramolecular coordination of the phosphine moiety to the resulting cationic metal center. Compound 2b was characterized by X-ray crystallography. Furthermore, B(C{sub 6}F{sub 5}){sub 3} abstracts the methyl group of a coordinated borate ligand to generate a free, 3-coordinate borane center in [(dmpe)NiMe(1a)]{sup +}[MeB(C{sub 6}F{sub 5}){sub 3}]{sup -} (3).
Date: October 28, 2007
Creator: Fischbach, Andreas; Bazinet, Patrick R.; Waterman, Rory & Tilley, T. Don
System: The UNT Digital Library
Water cooled metal optics for the Advanced Light Source (open access)

Water cooled metal optics for the Advanced Light Source

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.
Date: October 28, 1991
Creator: McKinney, W. R.; Irick, S. C. & Lunt, D. L. J.
System: The UNT Digital Library
Scanning Josephson Tunneling Microscopy of Single Crystal Bi2Sr2CaCu2O8+delta with a Conventional Superconducting Tip (open access)

Scanning Josephson Tunneling Microscopy of Single Crystal Bi2Sr2CaCu2O8+delta with a Conventional Superconducting Tip

We have performed both Josephson and quasiparticle tunneling in vacuum tunnel junctions formed between a conventional superconducting scanning tunneling microscope tip and overdoped Bi2Sr2CaCu2O8+ single crystals. A Josephson current is observed with a peak centered at a small finite voltage due to the thermal-fluctuation-dominated superconducting phase dynamics. Josephson measurements at different surface locations yield local values for the Josephson ICRN product. Corresponding energy gap measurements were also performed and a surprising inverse correlation was observed between the local ICRN product and the local energy gap.
Date: October 28, 2009
Creator: Kimura, H.; Barber Jr., R. P.; Ono, S.; Ando, Yoichi & Dynes, Robert C.
System: The UNT Digital Library
Energy and system size dependence of phi meson production in Cu+Cu and Au+Au collisions (open access)

Energy and system size dependence of phi meson production in Cu+Cu and Au+Au collisions

We study the beam-energy and system-size dependence of {phi} meson production (using the hadronic decay mode {phi} {yields} K{sup +}K{sup -}) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at {radical}s{sub NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from midrapidity (|y| < 0.5) for 0.4 < p{sub T} < 5 GeV/c. At a given beam energy, the transverse momentum distributions for {phi} mesons are observed to be similar in yield and shape for Cu + Cu and Au + Au colliding systems with similar average numbers of participating nucleons. The {phi} meson yields in nucleus-nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p + p collisions with a different trend compared to strange baryons. The enhancement for {phi} mesons is observed to be higher at {radical}s{sub NN} = 200 GeV compared to 62.4 GeV. These observations for the produced {phi}(s{bar s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions …
Date: October 28, 2008
Creator: STAR Collaboration
System: The UNT Digital Library
Improvement of Laser Damage Resistance and Diffraction Efficiency of Multilayer Dielectric Diffraction Gratings by HF-Etchback Linewidth Tailoring (open access)

Improvement of Laser Damage Resistance and Diffraction Efficiency of Multilayer Dielectric Diffraction Gratings by HF-Etchback Linewidth Tailoring

Multilayer dielectric (MLD) diffraction gratings for Petawatt-class laser systems possess unique laser damage characteristics. Details of the shape of the grating lines and the concentration of absorbing impurities on the surface of the grating structures both have strong effects on laser damage threshold. It is known that electric field enhancement in the solid material comprising the grating lines varies directly with the linewidth and inversely with the line height for equivalent diffraction efficiency. Here, they present an overview of laser damage characteristics of MLD gratings, and describe a process for post-processing ion-beam etched grating lines using very dilute buffered hydrofluoric acid solutions. This process acts simultaneously to reduce grating linewidth and remove surface contaminants, thereby improving laser damage thresholds through two pathways.
Date: October 28, 2010
Creator: Nguyen, H T; Larson, C C & Britten, J A
System: The UNT Digital Library