24 Matching Results

Search Results

Results: 1 - 24
open access

Analytic electrostatic solution of an axisymmetric accelerator gap

Description: Numerous computer codes calculate beam dynamics of particles traversing an accelerating gap. In order to carry out these calculations the electric field of a gap must be determined. The electric field is obtained from derivatives of the scalar potential which solves Laplace`s equation and satisfies the appropriate boundary conditions. An integral approach for the solution of Laplace`s equation is used in this work since the objective is to determine the potential and fields without solving on a… more
Date: March 15, 1995
Creator: Boyd, J. K.
Partner: UNT Libraries Government Documents Department
open access

The Speciation of Groundwater Contaminated with Coal Pile Leachate at the Savannah River Site, South Carolina

Description: Modeling the transport of contaminant metals and designing systems for their remediation requires an understanding of the metal`s speciation. Thus, analysis of contaminant speciation and evaluation of the processes that can change the speciation should be done during characterization of the contaminated site. This approach is being used at the Savannah River Site for a metals contaminated site that will serve as a test platform for metals remediation technologies. The site is adjacent to a coal… more
Date: May 15, 1995
Creator: Denham, M. E. & Nichols, R. L.
Partner: UNT Libraries Government Documents Department
open access

Non-universal SUSY breaking, hierarchy and squark degeneracty

Description: I discuss non-trivial effects in the soft SUSY breaking terms which appear when one integrates out heavy fields. The effects exist only when the SUSY breaking terms are non-universal. They may spoil (1) the hierarchy between the weak and high-energy scales, or (2) degeneracy among the squark masses even in the presense of a horizontal symmetry. I argue, in the end, that such new effects may be useful in probing physics at high-energy scales from TeV-scale experiments.
Date: March 15, 1995
Creator: Murayama, Hitoshi
Partner: UNT Libraries Government Documents Department
open access

FT-ICR mass spectrometry of very highly charged atomic ions

Description: The authors report FT-ICR measurements of samples trapped in the electron beam ion trap (EBIT) at Livermore. They made use of the access provided by the radial x-ray slots. They constructed two probes that could be inserted into the 2-mm wide slots. The probes each subtend only 25{degree} and face each other 180{degree} apart. They show a typical transformed spectrum of highly charged {sup 84}Kr ions obtained with this system. The spectrum was obtained by exciting with a 300-{mu}s sweep from 17… more
Date: May 15, 1995
Creator: Schweikhard, L.; Beck, B. & Beiersdorfer, P.
Partner: UNT Libraries Government Documents Department
open access

Safe new reactor for radionuclide production

Description: In late 1995, DOE is schedule to announce a new tritium production unit. Near the end of the last NPR (New Production Reactors) program, work was directed towards eliminating risks in current designs and reducing effects of accidents. In the Heavy Water Reactor Program at Savannah River, the coolant was changed from heavy to light water. An alternative, passively safe concept uses a heavy-water-filled, zircaloy reactor calandria near the bottom of a swimming pool; the calandria is supported on … more
Date: February 15, 1995
Creator: Gray, P.L.
Partner: UNT Libraries Government Documents Department
open access

Physics with the collider detectors at RHIC and the LHC

Description: On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on `Physics with the Collider Detectors at RHIC and the LHC`. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design is… more
Date: July 15, 1995
Creator: Thomas, J. & Hallman, T.
Partner: UNT Libraries Government Documents Department
open access

Recent results from the super EBIT

Description: The Super EBIT device at LLNL can produce and trap any highly charged ion at rest in the laboratory, including bare U{sup 92+} ions. Recently, the ionization cross sections for high-Z hydrogenlike ions have been measured for the first time, and measurements of the L-shell ionization cross sections for uranium ions are in progress. The two-electron contributions to the ground state energies of heliumlike ions have been directly measured using a novel technique, and spectra of 2s-2p transitions i… more
Date: September 15, 1995
Creator: Marrs, R.E.
Partner: UNT Libraries Government Documents Department
open access

A limit on {sigma} {center_dot} BR (B{sub c}{sup {+-}} {yields} J/{psi} + {pi}{sup {+-}})/{sigma} {center_dot} BR(B{sub u}{sup {+-}} {yields} J/{psi} + K{sup {+-}}) in {radical}s = 1.8 TeV proton-antiproton collisions

Description: We report on the results of a search for the B{sub c} (b{bar c}) meson in the decay B{sub c}{sup +-} {yields} J/{psi} + {pi}{sup +-}. This search is guided by a control sample of decays of B{sub u} mesons to J/{psi} + K and uses {approx_equal} 75pb{sup -1} of data collected at the Collider Detector Facility (CDF) at Fermilab. The lifetime of the B{sub c} meson is unknown, so the 95% confidence level limit on {sigma} {center_dot} BR(B{sub c} {yields} {psi} + {pi})/{sigma} {center_dot} BR(B{sub u… more
Date: July 15, 1995
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department
open access

Xtoys: Cellular automata on xwindows

Description: Xtoys is a collection of xwindow programs for demonstrating simulations of various statistical models. Included are xising, for the two dimensional Ising model, xpotts, for the q-state Potts model, xautomalab, for a fairly general class of totalistic cellular automata, xsand, for the Bak-Tang-Wiesenfield model of self organized criticality, and xfires, a simple forest fire simulation. The programs should compile on any machine supporting xwindows.
Date: August 15, 1995
Creator: Creutz, M.
Partner: UNT Libraries Government Documents Department
open access

Laser Properties of an Improved Average-Power Nd-Doped Phosphate Glass

Description: The Nd-doped phosphate laser glass described herein can withstand 2.3 times greater thermal loading without fracture, compared to APG-1 (commercially-available average-power glass from Schott Glass Technologies). The enhanced thermal loading capability is established on the basis of the intrinsic thermomechanical properties (expansion, conduction, fracture toughness, and Young`s modulus), and by direct thermally-induced fracture experiments using Ar-ion laser heating of the samples. This Nd-dop… more
Date: March 15, 1995
Creator: Payne, S. A.; Marshall, C. D. & Bayramian, A. J.
Partner: UNT Libraries Government Documents Department
open access

Low-energy vibrations at the InSb(110) surface

Description: Article on low-energy vibrations at the InSb(110) surface along the ΓΥ direction.
Date: December 15, 1995
Creator: Buongiorno Nardelli, Marco; Cvetko, D.; De Renzi, V.; Floreano, L.; Morgante, A.; Peloi, M. et al.
Partner: UNT College of Arts and Sciences
open access

Copper electroplating process for sub-half-micron ULSI structures

Description: We have utilized electroplating technology in a damascene process to produce low resistance copper interconnects in sub-half-micron ULSI patterns having aspect ratios of 2.4:1. The use of a pulsed-voltage plating technique allows trench filling capability without voids. Samples of 150 mm diameter were patterned and sputtered with a barrier layer, followed by a copper seed layer. Pulsed-voltage electroplating, deposited about 2 microns of copper uniformly (1 sigma < 5%) over the surface. The ele… more
Date: May 15, 1995
Creator: Contolini, Robert J.; Tarte, Lisa; Graff, Robert T.; Evans, Leland B.; Cox, J. Neal; Puich, Marc et al.
Partner: UNT Libraries Government Documents Department
open access

Combline antenna modeling for plasma heating

Description: The combline antenna for plasma heating, as proposed by General Atomics, has unique potential for solving many plasma drive problems. The benefit of the combline design is the utilization of the coupling between elements that avoids a more cumbersome multidrive system. This design is being investigated using computational EM modeling codes in the 100-400 MHz band using resources at General Atomics and LLNL. Preliminary experimental results, using a combline mockup, agree well with 3D modeling e… more
Date: May 15, 1995
Creator: Nelson, S. D.; Kamin, G. & Van Maren, R.
Partner: UNT Libraries Government Documents Department
open access

No-thermal plasma processing of VOCs and NO{sub x} at LLNL

Description: For the past few years, Lawrence Livermore National Laboratory has been conducting a comprehensive research program on the application of non-thermal plasmas for air pollution control and abatement. This program combines an extensive modeling effort with an experimental facility and test program. We believe that there are two major issues to be addressed in order to apply non-thermal plasma processing to air pollution control; these are electrical energy consumption and byproduct identification… more
Date: February 15, 1995
Creator: Merritt, B. T.; Hsiao, M. C.; Penetrante, B. M.; Vogtlin, G. E. & Wallman, P. H.
Partner: UNT Libraries Government Documents Department
open access

Applying simulation and logistics modeling to tansportation issues

Description: This paper describes an application where transportation logistics and simulation tools are integrated to create a modeling environment for transportation planning. The Transportation Planning Model (TPM) is a tool developed for the Department of Energy (DOE) to aid in the long-term planning of their transportation resources. The focus of the tool is to aid DOE and Sandia National Laboratory analysts in the planning of future fleet sizes, driver and support personnel sizes, base site locations,… more
Date: August 15, 1995
Creator: Funkhouser, B. R.; Ballweg, E. L. & Mackoy, R. D.
Partner: UNT Libraries Government Documents Department
open access

On the road to the solution of the Solar Neutrino Problem

Description: The present status of solar neutrino experiments is reviewed. The discrepancy between the experimental results and the theoretical expectations has come to be known as the Solar Neutrino Problem. Possible solutions to this problem are discussed. The next generation of solar neutrino experiments are described.
Date: August 15, 1995
Creator: Norman, E.B.
Partner: UNT Libraries Government Documents Department
open access

Smoothing by spectral dispersion using random phase modulation for inertial confinement fusion

Description: Numerical simulations of beam smoothing using random phase modulation and grating dispersion are presented. Spatial spectra of the target illumination show that significantly improved smoothing at low spatial frequency is achieved while maintaining uniform intensity in the laser amplifier.
Date: November 15, 1995
Creator: Rothenberg, J.E.
Partner: UNT Libraries Government Documents Department
open access

System study of a diode-pumped solid-state-laser driver for inertial fusion energy

Description: The present a conceptual design of a diode-pumped solid-state-laser (DPSSL) driver for an inertial fusion energy (IFE) power plant based on the maximized cost of electricity (COE) as determined in a comprehensive systems study. This study contained extensive detail for all significant DPSSL physics and costs, plus published scaling relationships for the costs of the target chamber and the balance of plant (BOP). Our DPSSL design offers low development cost because it is modular, can be fully te… more
Date: June 15, 1995
Creator: Orth, C.D. & Payne, S.A.
Partner: UNT Libraries Government Documents Department
open access

Magnetic correlations in doped transition metal oxides

Description: The authors review recent reactor- and spallation-source-based neutron scattering experiments on the magnetic fluctuations and order in a variety of doped transition metal oxides. In particular, data are shown for the NiO chain compound, Y{sub 2{minus}x}Ca{sub x}BaNiO{sub 5}, the two-dimensional cuprate superconductors La{sub 2{minus}x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3} O{sub 6+x}, and the classical three-dimensional ``Mott-Hubbard`` system V{sub 2{minus}y}O{sub 3}.
Date: February 15, 1995
Creator: Aeppli, G.; Bao, W. & Broholm, C.
Partner: UNT Libraries Government Documents Department
open access

Ball lens reflections by direct solution of Maxwell`s equations

Description: Ball lenses are important for many applications. For example, ball lenses can be used to match the mode of a laser diode (LD) to a single mode fiber (SMF), essential for low-loss, high bit rate communication systems. Modeling the propagation of LD light through a ball lens presents a challenge due to the large angular divergence of the LD field (typically > 20{degrees} HWHM) and the subsequent significant effect of spherical aberration. Accurately calculating the reflected power is also difficu… more
Date: February 15, 1995
Creator: Ratowsky, R. P.; Deri, R. J.; Kallman, J. S. & Trott, G.
Partner: UNT Libraries Government Documents Department
open access

New solid state lasers from the ultraviolet to the mid-infrared

Description: The authors discuss three new laser materials that offer improved access to the ultraviolet, near infrared and mid-infrared spectral regions. In order for each of these materials to have been identified, a particular hurdle needed to be overcome with respect to the fundamental laser physics impacting the material. In the case of the 280-320nm Ce:LiSAF laser, the main issue is the need to reduce the loss associated with excited state absorption, while for 1047nm Yb:S-FAP it is the ground state a… more
Date: August 15, 1995
Creator: Payne, S. A.; Krupke, W. F. & Beach, R. J.
Partner: UNT Libraries Government Documents Department
open access

CRYSTALLINE CERAMICS: WASTE FORMS FOR THE DISPOSAL OF WEAPONS PLUTONIUM

Description: At present, there are three seriously considered options for the disposition of excess weapons plutonium: (i) incorporation, partial burn-up and direct disposal of MOX-fuel; (ii) vitrification with defense waste and disposal as glass ``logs``; (iii) deep borehole disposal (National Academy of Sciences Report, 1994). The first two options provide a safeguard due to the high activity of fission products in the irradiated fuel and the defense waste. The latter option has only been examined in a pr… more
Date: May 15, 1995
Creator: Ewing, R. C.; Lutze, W. & Weber, W. J.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Bespalov-Talanov gain spectrum in a dispersive medium with large n{sub 2}

Description: Conditions which seed the self focussing of high-power broadband laser beams are determined by examining growth rates for plane-wave perturbations on a strong pump field as a function of frequency and angle. Measurements verifying predictions of growth based on the linearized stability analysis of Bespalov and Talanov extended to broadband fields are reported.
Date: June 15, 1995
Creator: Wegner, P. J.; Feit, M. D.; Fleck, J. A., Jr. & Eimerl, D.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen