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open access

Mass by Energy Loss Quantitation as a Practical Sub-Microgram Balance

Description: A simple device integrating a thin film support and a standard microcentrifuge tube can be used for making solutions of accurately known concentration of any organic compound in a single step, avoiding serial dilution and the use of microgram balances. Nanogram to microgram quantities of organic material deposited on the thin film are quantified by ion energy loss and transferred to the microcentrifuge tube with high recovery.
Date: September 28, 2004
Creator: Palmblad, M; Bench, G & Vogel, J S
Item Type: Refine your search to only Article
open access

POLARIZED HYDROGEN JET TARGET FOR MEASUREMENT OF RHIC PROTON BEAM POLARIZATION.

Description: The performance and unique features of the RHIC polarized jet target and our solutions to the important design constraints imposed on the jet by the RHIC environment are described. The target polarization and thickness were measured to be 0.924 {+-} 2% and 1.3 {+-} 0.2 x 10{sup 12} atoms/cm{sup 2} respectively.
Date: January 28, 2005
Creator: Makdisi, Y.; Wise, T.; Chapman, M.; Graham, D.; Kponou, A.; Mahler, G. et al.
Item Type: Refine your search to only Article
open access

Institute for scientific computing research;fiscal year 1999 annual report

Description: Large-scale scientific computation, and all of the disciplines that support it and help to validate it, have been placed at the focus of Lawrence Livermore National Laboratory by the Accelerated Strategic Computing Initiative (ASCI). The Laboratory operates the computer with the highest peak performance in the world and has undertaken some of the largest and most compute-intensive simulations ever performed. Computers at the architectural extremes, however, are notoriously difficult to use effi… more
Date: March 28, 2000
Creator: Keyes, D
Item Type: Refine your search to only Report
open access

Level densities and gamma-ray strength functions in 170,171,172-Yb

Description: Level densities and radiative strength functions in {sup 171}Yb and {sup 170}Yb nuclei have been measured using the {sup 171}Yb({sup 3}He{sup 3}He{gamma}){sup 171}Yb and {sup 171}Yb({sup 3}He,{alpha}{gamma}){sup 170}Yb reactions. New data on {sup 171}Yb are compared to a previous measurement for {sup 171}Yb from the {sup 172}Yb({sup 3}He,{alpha}{gamma}){sup 171}Yb reaction. Systematics of level densities and radiative strength functions in {sup 170,171,172}Yb are established. The entropy excess… more
Date: July 28, 2004
Creator: Agvaanluvsan, U.; Schiller, A.; Becker, J.; Bernstein, L.; Garrett, P.; Guttormsen, M. et al.
Item Type: Refine your search to only Report
open access

Flor-Essence? Herbal Tonic Promotes Mammary Tumor Development in Sprague Dawley Rats

Description: Background: Women who are diagnosed with breast cancer often self-administer complementary and alternative medicines to augment their conventional treatments, improve health, or prevent recurrence. Flor-Essence{reg_sign} Tonic is a complex mixture of herbal extracts used by cancer patients because of anecdotal evidence that it can treat or prevent disease. Methods: Female Sprague Dawley rats were given water or exposed to 3% or 6% Flor-Essence{reg_sign} beginning at one day of age. Mammary tumo… more
Date: January 28, 2004
Creator: Bennett, L; Montgomery, J; Steinberg, S & Kulp, K
Item Type: Refine your search to only Article
open access

Hydrodynamic Modeling of a Multi-Pulse X-Ray Converter Target for DARHT - II

Description: In phase two of the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT-II), four electron beam pulses of variable pulse length strike an X-ray converter target to produce time-resolved X-ray image. An important requirement for the converter target is to minimize the hydrodynamic expansion of the converter material so that there is enough material to generate the required X-ray dose for all four pulses. Minimizing the hydrodynamic expansion is also important from the standpoint of beam tra… more
Date: June 28, 2001
Creator: Ho, D. D. M.; Chen, Y. J.; Harte, J. & Young, D.
Item Type: Refine your search to only Article
open access

Calculation of Radiative Corrections to E1 matrix elements in the Neutral Alkalis

Description: Radiative corrections to E1 matrix elements for ns-np transitions in the alkali metal atoms lithium through francium are evaluated. They are found to be small for the lighter alkalis but significantly larger for the heavier alkalis, and in the case of cesium much larger than the experimental accuracy. The relation of the matrix element calculation to a recent decay rate calculation for hydrogenic ions is discussed, and application of the method to parity nonconservation in cesium is described.
Date: September 28, 2004
Creator: Sapirstein, J & Cheng, K T
Item Type: Refine your search to only Article
open access

Using Independent Component Analysis to Separate Signals in Climate Data

Description: Global temperature series have contributions from different sources, such as volcanic eruptions and El Nino Southern Oscillation variations. We investigate independent component analysis as a technique to separate unrelated sources present in such series. We first use artificial data, with known independent components, to study the conditions under which ICA can separate the individual sources. We then illustrate the method with climate data from the National Centers for Environmental Predictio… more
Date: January 28, 2003
Creator: Fodor, I K & Kamath, C
Item Type: Refine your search to only Article
open access

Techniques for Judging Intent Behind Network Based Cyber Attacks

Description: This project developed a prototype system that can rapidly differentiate between undirected cyber attacks, and those that have a more specific and concerning intent behind them. The system responds to important cyber attacks in a tactically significant way as the attack is proceeding. It is also creates a prioritized list for the human analysts allowing them to focus on the threats mostly likely to be of interest. In the recent years the volume of attacks over the internet has increased exponen… more
Date: January 28, 2004
Creator: Allen, J M
Item Type: Refine your search to only Report
open access

Accurate wavelength measurements and modeling of FeXV to FeXIX spectra recorded in high density plasmas between 13.5 to 17 A.

Description: Iron spectra have been recorded from plasmas created at three different laser plasma facilities, the Tor Vergata University laser in Rome (Italy), the Hercules laser at ENEA in Frascati (Italy), and the Compact Multipulse Terawatt (COMET) laser at LLNL in California (USA). The measurements provide a means of identifying dielectronic satellite lines from FeXVI and FeXV in the vicinity of the strong 2p {yields} 3d transitions of FeXVII. About 80 {Delta}n {ge} 1 lines of FeXV (Mg-like) to FeXIX (O… more
Date: September 28, 2004
Creator: May, M.; Beiersdorfer, P.; Dunn, J.; Jordan, N.; Osterheld, A.; Faenov, A. et al.
Item Type: Refine your search to only Article
open access

Thick Liquid-Walled Spheromak Magnetic Fusion Power Plant

Description: We assume a spheromak configuration can be made and sustained by a steady plasma gun current, which injects particles, current and magnetic field, i.e., helicity injection. The magnetic configuration is evaluated with an axisymmetric free-boundary equilibrium code, where the current profile is tailored to support an average beta of 10%. An injection current of 100 kA (125 MW of gun power) sustains the toroidal current of 40 MA. The flux linking the gun is 1/1000th of the flux in the spheromak. … more
Date: April 28, 2003
Creator: Moir, R W; Bulmer, R H; Fowler, T K; Rognlien, T D & Youssef, M Z
Item Type: Refine your search to only Report
open access

Water at a hydrophilic solid surface probed by ab-initio molecular dynamics: inhomogeneous thin layers of dense fluid

Description: We present a microscopic model of the interface between liquid water and a hydrophilic, solid surface, as obtained from ab-initio molecular dynamics simulations. In particular, we focused on the (100)surface of cubic SiC, a leading candidate semiconductor for bio-compatible devices. Our results show that, in the liquid in contact with the clean substrate, molecular dissociation occurs in a manner unexpectedly similar to that observed in the gas phase. After full hydroxylation takes place, the f… more
Date: January 28, 2005
Creator: Cicero, G; Grossman, J; Galli, G & Catellani, A
Item Type: Refine your search to only Article
open access

Fast Fourier and Wavelet Transforms for Wavefront Reconstruction in Adaptive Optics

Description: Wavefront reconstruction techniques using the least-squares estimators are computationally quite expensive. We compare wavelet and Fourier transforms techniques in addressing the computation issues of wavefront reconstruction in adaptive optics. It is shown that because the Fourier approach is not simply a numerical approximation technique unlike the wavelet method, the Fourier approach might have advantages in terms of numerical accuracy. However, strictly from a numerical computations viewpoi… more
Date: July 28, 2000
Creator: Dowla, F. U.; Brase, J. M. & Olivier, S. S.
Item Type: Refine your search to only Article
open access

Beam-Target Interaction Experiments for Bremsstrahlung Converter Applications

Description: The DARHT TI accelerator uses a pulsed high current electron beam and Eiremsstrahlung converter target to generate an intense x-ray source for radiography. For the past several years, we have been performing an investigation of the possible adverse effects of (1) backstreaming ion emission from the Bremsstrahlung converter target and (2) the interaction of the resultant plasma with the electron beam during subsequent pulses. These effects would manifest themselves in a static focusing system as… more
Date: September 28, 2000
Creator: Sampayan, S.; Caporaso, G.; Chen, Y. J.; Falabella, S.; Ho, D.; Houck, T. et al.
Item Type: Refine your search to only Article
open access

Neutron Skyshine Considerations For The NIF Shielding Design

Description: A series of coupled neutron-photon transport Monte-Carlo calculations was performed to estimate the roof shielding required to limit the skyshine dose to less than 1 mrem/y at the site boundary when conducting DT experiments with annual fusion yields up to 1200 MJ (4.2E20 neutrons/y). The NIF shielding design consists of many different components. The basic components include 10-cm-thick Al chamber with 40-cm-thick target chamber gunite shield having multiple penetrations, 1.83-m-thick concrete… more
Date: January 28, 2004
Creator: Singh, M S; Mecozzi, J M & Tobin, M T
Item Type: Refine your search to only Article
open access

Proton reaction cross sections measured in the BNL/AGS E943 experiment

Description: We have measured proton reaction cross sections over a wide mass and energy range at the Brookhaven AGS accelerator. The samples were elemental Be, C, Al, Cu, W, and Pb; the measurements were carried out at ten incident proton kinetic energies in the range 0.54 to 7.8 GeV. The experiment was similar to an earlier experiment in the 200-550 MeV range by Renberg et al. The new results are in good agreement with those of Renberg et al. at the overlap point near 550 MeV. The combined results of the … more
Date: November 28, 2000
Creator: Dietrich, F S; Hartouni, E P; Schmid, G J; Soltz, R; Abfalterer, W P; Haight, R C et al.
Item Type: Refine your search to only Article
open access

Geochemistry of Samples from Borehole C3177(299-E24-21)

Description: This report contains the results of geochemical and physical property analyses of twelve samples from the Immobilized Low-Activity Waste (ILAW) borehole #2. The borehole is in the middle of the 200 East Area, at the northeast corner of the ILAW disposal site.
Date: May 28, 2003
Creator: Horton, Duane G.; Schaef, Herbert T.; Serne, R. Jeffrey; Brown, Christopher F.; Valenta, Michelle M.; Vickerman, Tanya S. et al.
Item Type: Refine your search to only Report
open access

Micro-Compatibility Testing of Polysulfone

Description: Polysulfone has many useful properties, and its compatibility with other materials is of interest. It is a tough, rigid, high-strength thermoplastic that maintains its properties over a wide temperature range. It is chemically resistant to mineral acids and alkali and moderately resistant to hydrocarbon oils; however, it is not resistant to polar organic solvents such as ketones, chlorinated hydrocarbons and aromatic hydrocarbons. Micro-compatibility experiments were initiated to determine poss… more
Date: September 28, 2004
Creator: Gregg, H; Harvey, C; Maxwell, R & Vance, A
Item Type: Refine your search to only Report
open access

Coalescence of Multiple Plasmoids as a Means of Efficient Spheromak Formation

Description: We have produced single bursts of helicity from the source in the SSPX spheromak in order to study the efficiency of the simplest example of helicity injection. We find that the helicity injection rate can be written in terms of the injected current and an inductance, and that a simple circuit analogue demonstrates unambiguously the relationship of helicity to energy: helicity injection is the addition of inductive loops. While helicity balance points to the conservation of helicity, the electr… more
Date: February 28, 2002
Creator: Woodruff, S; McLean, H S & Stallard, B W
Item Type: Refine your search to only Article
open access

DETERMINING CORRECT LOCATION OF INTERFACES IN X-RAY IMAGES

Description: X-ray phase-contrast enhanced imaging enables characterization of objects otherwise transparent to x-rays. Such imaging is accomplished with a point-source or plane-wave x-rays and in the simplest implementation takes advantage of the refraction of x-rays at interfaces to provide contrast. The refraction of x-rays, while small, can lead to measurable displacements of interfaces in the image plane. A simple approximate analytical expression is obtained for the required correction. The resulting … more
Date: September 28, 2004
Creator: Kozioziemski, B
Item Type: Refine your search to only Report
open access

Measurement of the Analyzing Power in PP Elastic Scattering in the Peak CNI Region at RHIC

Description: The analyzing power A{sub N} for pp elastic scattering is expected to reach a peak value of 0.045 in the Coulomb Nuclear Interference (CNI) region at a momentum transfer -t of 0.003 (GeV/c){sup 2}. During the 2004 RHIC Run, we completed a measurement of A{sub N} in the CNI region by detecting the recoil protons from pp elastic scattering using a polarized atomic hydrogen gas jet target and the 100 GeV RHIC proton beam. We report the first measurements of the A{sub N} absolute value and shape in… more
Date: January 28, 2005
Creator: Makdisi, Y.; Okada, H.; Alekseev, I. G.; Bravar, A.; Bunce, G. & AL, ET
Item Type: Refine your search to only Article
open access

A Comparison of Digital Signal Extraction Techniques

Description: We compare the performance of two methods of digital filtering to detect a radioactive source moving past a gamma-ray sensor. The first method is the box-car filter, which is a standard method used in the detection of a moving radioactive source. The second method is the matched filter, which takes into account the variation in the number of photons absorbed in a gamma-ray sensor as a source moves past the sensor. We optimize both methods to detect a source moving at 5, 10, 15 and 20 mph, and t… more
Date: December 28, 2004
Creator: Cunningham, M. & Dowla, F.
Item Type: Refine your search to only Report
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