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Material transfer system in support of the plutonium immobilization program (open access)

Material transfer system in support of the plutonium immobilization program

The Plutonium Immobilization Program requires development of the process and plant prototypic equipment to immobilize surplus plutonium in ceramic for long-term storage. Because of the hazardous nature of plutonium, it was necessary to develop a remotely operable materials transfer system which can function within the confines of a glovebox. In support of this work at LLNL, such a material transfer system (MTS) was developed. This paper presents both the mechanical and controls parts making up this system, and includes photographs of the key components and diagrams of their assemblies, as well as a description of the control sequence used to validate the MTS capabilities.
Date: December 20, 2000
Creator: Pak, D
System: The UNT Digital Library
Laser Raster Conditioning of KDP and KDKP Crystals Using XeCl and ND:YAG Lasers (open access)

Laser Raster Conditioning of KDP and KDKP Crystals Using XeCl and ND:YAG Lasers

Laser conditioning by raster scanning KDP and DKDP crystals using Nd:YAG and XeCl excimer laser systems was demonstrated. The laser systems were evaluated to determine their respective feasibility of improving the damage thresholds of the harmonic materials for use on the National Ignition Facility (NIF). Crystals were first evaluated using an Nd:YAG laser (355 nm, 7.6 ns) by scanning 2 x 2 cm2 areas with sub-damage threshold fluences and then performing unconditioned (SA) damage tests at 355-nm in the respectively scanned regions. Subsequently, five KDP and DKDP samples of various damage quality were raster scanned in a similar fashion at MicroLas GmbH (Goettingen, Germany) using a commercial Lambda Physik Excimer system (XeCl, {lambda} = 308 nm, 20 ns). The samples treated in Germany were then tested at Livermore National Laboratory (LLNL) at 355 nm to demonstrate the excimer's potentia1 as an alternative conditioning source. The excimer scan results suggest that crystals can be treated at high fluence (50 Ycm2, 308-nm, 204s) levels without noticeable bulk damage. In addition, comparable conditioning is possible even with the fluence set at 30% of the 308-nm damage threshold. The laser damage tests with 355-nrn on the majority of the excimer laser-treated crystals demonstrates the …
Date: December 20, 2000
Creator: Staggs, M; Yan, M & Runkel, M
System: The UNT Digital Library
CDF: Run II Physics Projections (open access)

CDF: Run II Physics Projections

In March 2001, the Fermilab Tevatron will start a new physics run of p{bar p} collisions at {radical}s = 2.0 TeV. The CDF experiments will collect a data sample of 2 fb{sup {minus}1} in the first two years. In this paper the authors describe the B physics prospects at CDF during the upcoming run.
Date: December 20, 2000
Creator: Tanaka, Maashi
System: The UNT Digital Library
Charmed meson and onium production at the Tevatron (open access)

Charmed meson and onium production at the Tevatron

The authors report recent results of D*{sup {+-}} meson, J/{psi} and {Upsilon} production at the Fermilab Tevatron. They observe about 8,000 D*{sup {+-}} mesons reconstructed in the decay chain of D* {r_arrow} D{sub {pi}}{sup 0}, D{sup 0} {r_arrow} K{mu}+X. They measure the integrated D*{sup +} production cross section to be 347 {+-} 65(stat.) {+-} 58(sys.) nb for the rapidity range {vert_bar}{eta}(D*{sup +}){vert_bar} < 1.0 and the transverse momentum range p{sub T} (D*{sup +}) > 10 GeV/c. The measurement is slightly higher than the theoretical prediction, especially at lower pT range. We also measure the polarization of J/{psi} at production and find that the measured transverse polarization is not well explained by the color-octet model proposed to explain the anomalously high J/{psi} production cross section. We also present a new result on {Upsilon} production and polarization. Production of the {Upsilon} is consistent with being unpolarized.
Date: December 20, 2000
Creator: Nakaya, T.
System: The UNT Digital Library
Ultrahigh Resolution Multicolor Colocalization of Single Fluorescent Nanocrystals (open access)

Ultrahigh Resolution Multicolor Colocalization of Single Fluorescent Nanocrystals

A new method for in vitro and possibly in vivo ultrahigh-resolution colocalization and distance measurement between biomolecules is described, based on semiconductor nanocrystal probes. This ruler bridges the gap between FRET and far-field (or near-field scanning optical microscope) imaging and has a dynamic range from few nanometers to tens of micrometers. The ruler is based on a stage-scanning confocal microscope that allows the simultaneous excitation and localization of the excitation point-spread-function (PSF) of various colors nanocrystals while maintaining perfect registry between the channels. Fit of the observed diffraction and photophysics-limited images of the PSFs with a two-dimensional Gaussian allows one to determine their position with nanometer accuracy. This new high-resolution tool opens new windows in various molecular, cell biology and biotechnology applications.
Date: December 20, 2000
Creator: Michalet, X.; Lacoste, T. D.; Pinaud, F.; Chemla, D. S.; Alivisatos, A. P. & Weiss, S.
System: The UNT Digital Library
Status of CDF Run II Upgrade (open access)

Status of CDF Run II Upgrade

For the past several years, the CDF collaboration has been upgrading its detector to accommodate the higher luminosity and beam energy expected during Run II (2001-2006) at the Tevatron p{bar p} collider. Accelerator improvements include increasing the instantaneous luminosity by an order of magnitude with respect to Run I to 2 x 10{sup 32} cm{sup {minus}2} s{sup {minus}1} and increasing the center of mass energy from 1.8 TeV to 2.0 TeV. The detector upgrades include replacing the entire tracking volume, extending the muon coverage, adding a time of flight system, and improving the selection capabilities of the trigger. The partially instrumented detector underwent a commissioning run during September/October 2000 in preparation for starting data taking in Spring 2001 with the full detector. Now that Run II has been extended through 2006, we expect to collect an integrated luminosity of 2 fb{sup {minus}1} during the first two years of running and up to a total of 15 fb{sup {minus}1} by the end of Run II.
Date: December 20, 2000
Creator: Cranshaw, Jack
System: The UNT Digital Library
Tectonic Setting and Characteristics of Natural Fractures in MesaVerde and Dakota Reservoirs of the San Juan Basin (open access)

Tectonic Setting and Characteristics of Natural Fractures in MesaVerde and Dakota Reservoirs of the San Juan Basin

The Cretaceous strata that fill the San Juan Basin of northwestern New Mexico and southwestern Colorado were shortened in a generally N-S to NN13-SSW direction during the Laramide orogeny. This shortening was the result of compression of the strata between southward indentation of the San Juan Uplift at the north edge of the basin and northward to northeastward indentation of the Zuni Uplift from the south. Right-lateral strike-slip motion was concentrated at the eastern and western basin margins of the basin to form the Hogback Monocline and the Nacimiento Uplift at the same time, and small amounts of shear may have been pervasive within the basin as well. Vertical extension fractures, striking N-S to NNE-SSW with local variations (parallel to the Laramide maximum horizontal compressive stress), formed in both Mesaverde and Dakota sandstones under this system, and are found in outcrops and in the subsurface of the San Juan Basin. The immature Mesaverde sandstones typically contain relatively long, irregular, vertical extension fractures, whereas the quartzitic Dakota sandstones contain more numerous, shorter, sub-parallel, closely spaced, extension fractures. Conjugate shear planes in several orientations are also present locally in the Dakota strata.
Date: December 20, 2000
Creator: Lorenz, John C. & Cooper, Scott P.
System: The UNT Digital Library
In Situ Template Generation for Zincophosphate Synthesis Leading to C2H7N4O-ZnPO4 Containing Template-to-Template N--H...O Hydrogen Bonds (open access)

In Situ Template Generation for Zincophosphate Synthesis Leading to C2H7N4O-ZnPO4 Containing Template-to-Template N--H...O Hydrogen Bonds

The synthesis, structure and some properties of C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4} (guanylurea zinc phosphate) are reported. The cationic template was prepared in situ by partial hydrolysis of the neutral 2-cyanoguanidine starting material. The resulting structure contains a new, unprotonated, zincophosphate layer topology as well as unusual N-H-O template-to-template hydrogen bonds which help to stabilize a ''double sandwich'' of templating cations between the inorganic sheets. Crystal data: C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4}, M{sub r} = 229.44, monoclinic, P2{sub 1}/c, a = 13.6453 (9) {angstrom}, b = 5.0716 (3) {angstrom}, c = 10.6005 (7) {angstrom}, {beta} = 95.918 (2){sup 0}, V = 729.7 (1) {angstrom}{sup 3}, R(F) = 0.034, wR(F) = 0.034.
Date: December 20, 2000
Creator: Harrison, William T. A.; Rodgers, Jennifer A.; Phillips, Mark L. F. & Nenoff, Tina M.
System: The UNT Digital Library
Near Infrared (NIR) Imaging Techniques Using Lasers and Nonlinear Crystal Optical Parametric Oscillator/Amplifier (OPO/OPA) Imaging and Transferred Electron (TE) Photocathode Image Intensifiers (open access)

Near Infrared (NIR) Imaging Techniques Using Lasers and Nonlinear Crystal Optical Parametric Oscillator/Amplifier (OPO/OPA) Imaging and Transferred Electron (TE) Photocathode Image Intensifiers

Laboratory experiments utilizing different near-infrared (NIR) sensitive imaging techniques for LADAR range gated imaging at eye-safe wavelengths are presented. An OPO/OPA configuration incorporating a nonlinear crystal for wavelength conversion of 1.56 micron probe or broadcast laser light to 807 nm light by utilizing a second pump laser at 532 nm for gating and gain, was evaluated for sensitivity, resolution, and general image quality. These data are presented with similar test results obtained from an image intensifier based upon a transferred electron (TE) photocathode with high quantum efficiency (QE) in the 1-2 micron range, with a P-20 phosphor output screen. Data presented include range-gated imaging performance in a cloud chamber with varying optical attenuation of laser reflectance images.
Date: December 20, 2000
Creator: Yates, George J.; Mcdonald, Thomas E., Jr.; Bliss, David E.; Cameron, Stewart M.; Greives, Kenneth H. & Zutavern, Fred J.
System: The UNT Digital Library
Range-Gated LADAR Coherent Imaging Using Parametric Up-Conversion of IR and NIR Light for Imaging with a Visible-Range Fast-Shuttered Intensified Digital CCD Camera (open access)

Range-Gated LADAR Coherent Imaging Using Parametric Up-Conversion of IR and NIR Light for Imaging with a Visible-Range Fast-Shuttered Intensified Digital CCD Camera

Research is presented on infrared (IR) and near infrared (NIR) sensitive sensor technologies for use in a high speed shuttered/intensified digital video camera system for range-gated imaging at ''eye-safe'' wavelengths in the region of 1.5 microns. The study is based upon nonlinear crystals used for second harmonic generation (SHG) in optical parametric oscillators (OPOS) for conversion of NIR and IR laser light to visible range light for detection with generic S-20 photocathodes. The intensifiers are ''stripline'' geometry 18-mm diameter microchannel plate intensifiers (MCPIIS), designed by Los Alamos National Laboratory and manufactured by Philips Photonics. The MCPIIS are designed for fast optical shattering with exposures in the 100-200 ps range, and are coupled to a fast readout CCD camera. Conversion efficiency and resolution for the wavelength conversion process are reported. Experimental set-ups for the wavelength shifting and the optical configurations for producing and transporting laser reflectance images are discussed.
Date: December 20, 2000
Creator: Yates, George J.; Mcdonald, Thomas E., Jr.; Bliss, David E.; Cameron, Stewart M. & Zutavern, Fred J.
System: The UNT Digital Library