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in subjects: "Signal-To-Noise Ratio"

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High-Sensitivity Single-Molecule Fluorescence Detection in Theory and Practice

The number of emitted photons that can be obtained from a fluorophore increases with the incident light intensity and the duration of illumination. However, saturation of the absorption transition and photodestruction place natural limits on the ultimate signal-to-noise ratio that can be obtained. Equations have been derived to describe the fluorescence-to-background-noise ratio in the presence of saturating light intensities and photodestruction. The fluorescence lifetime and the photodestruct… more

Date: 1989

Creator: Mathies, R. A.; Peck, K. & Stryer, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultraviolet imaging of hydrogen flames

We have assembled an ultraviolet-sensitive intensified camera for observing hydrogen combustion by imaging the OH, A/sup 2/..sigma.. - X/sup 2//Pi/ bandhead emissions near 309 nm. The camera consists of a quartz and CaF achromat lense-coupled to an ultraviolet image intensifier which is in turn fiber-coupled to a focus projection scan (FPS) vidicon. The emission band is selected with interference filters which serve to discriminate against background. The camera provides optical gain of 100 to … more

Date: January 1, 1988

Creator: Yates, G. J.; Wilke, M. & King, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The Mark II Silicon Strip Vertex Detector and performance of a silicon detector telescope in the Mark II detector at the SLC

A Silicon Strip Vertex Detector (SSVD) consisting of 36 independent silicon detector modules has been built for use in the Mark II detector at the SLAC Linear Collider (SLC). We discuss the performance of the individual modules and the stability and accuracy of their placement in the mechanical support. To gain operational experience at the SLC, we have assembled and placed inside the Mark II a telescope made of three Silicon Detector Modules. We present results from the first data run of the S… more

Date: December 1, 1989

Creator: Labarga, L.; Adolphsen, C.; Gratta, G.; Litke, A.; Turala, M.; Zaccardelli, C. (California Univ., Santa Cruz, CA (USA). Inst. for Particle Physics) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SATER/LLNL: an interactive identification/estimation/control package

This issue of the computer program newsletter focuses on SATER/LLNL - an interactive code for identification, estimation, and classical control. A brief description of the SATER/LLNL operation is included as well as a sample session. Attached is the fundamental reference that details more of the package.

Date: September 1, 1982

Creator: Candy, J V & Journeay, C H

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Application of ultrasonic waves to assess grain structure in cast stainless steel

Although the ASME code requires the inspection of cast stainless steel (CSS) piping in nuclear reactors, it has not been possible to demonstrate unambiguously that current inspection techniques are adequate. Ultrasonic inspection is difficult because the microstructure of CSS can vary considerably, from elastically isotropic with equiaxed, relatively small grains to elastically anisotropic with a columnar grain structure to a combination of the two. For the near term, improvements that may incr… more

Date: April 1, 1985

Creator: Kupperman, D.S.; Reimann, K.J. & Abrego-Lopez, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Improved methods for computing masses from numerical simulations

An important advance in the computation of hadron and glueball masses has been the introduction of non-local operators. This talk summarizes the critical signal-to-noise ratio of glueball correlation functions in the continuum limit, and discusses the case of (q{bar q} and qqq) hadrons in the chiral limit. A new strategy for extracting the masses of excited states is outlined and tested. The lessons learned here suggest that gauge-fixed momentum-space operators might be a suitable choice of int… more

Date: November 22, 1989

Creator: Kronfeld, A.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

New techniques for positron emission tomography in the study of human neurological disorders

The general goals of the physics and kinetic modeling projects are to: (1) improve the quantitative information extractable from PET images, and (2) develop, implement and optimize tracer kinetic models for new PET neurotransmitter/receptor ligands aided by computer simulations. Work towards improving PET quantification has included projects evaluating: (1) iterative reconstruction algorithms using supplemental boundary information, (2) automated registration of dynamic PET emission and transmi… more

Date: January 1, 1992

Creator: Kuhl, D.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Benchmark cross sections for bottom quark production

A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.

Date: January 7, 1988

Creator: Berger, E. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Remote controlled signal conditioner and fiber optic data link system development CPRF (Confinement Physics Research Facility)

The ZTH reversed-field pinch to be installed in the Confinement Physics Research Facility (CPRF) will produce a significant ambient magnetic field. To avoid ground-loop and other electrical problems, the diagnostics in direct or possible contact with the experiment will be accessed through a fiber optic data way. The frequency-modulated analog links developed for this system have a bandwidth of dc to 100 kHz and a signal-to-noise ratio of better than 60 dB. The fiber optic transmitter units inc… more

Date: January 1, 1989

Creator: Schrank, L.S.; Caudill, L.D.; Haberstich, A.; Klare, K.A. & Reass, W.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterization results from several commercial soft x-ray streak cameras

The spatio-temporal performance of four soft x-ray streak cameras has been characterized. The objective in evaluating the performance capability of these instruments is to enable us to optimize experiment designs, to encourage quantitative analysis of streak data and to educate the ultra high speed photography and photonics community about the x-ray detector performance which is available. These measurements have been made collaboratively over the space of two years at the Forge pulsed x-ray so… more

Date: January 1, 1986

Creator: Stradling, G.L.; Studebaker, J.K.; Cavailler, C.; Launspach, J. & Planes, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Infrared synchrotron radiation instrumentation and applications

Infrared synchrotron radiation (IRSR) in the wavelength range from 1{mu}m to {approximately}1cm has now been used quite extensively both in Japan at UVSOR, Okasaki and in the United States at the NSLS, Brookhaven. The use of IRSR poses many new challenges, none the least of which is the fact that the radiation covers four decades of energy and is also very divergent and subject to diffraction. However the advantages are particularly significant due to the 1000 fold increase in brightness availa… more

Date: January 1, 1991

Creator: Williams, G. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A slit aperture for the monitoring x-ray experiment (MOXE)

We have investigated a slit aperture as an alternative to the square pinhole aperture for the MOXE detectors, which are to be put on the Soviet satellite Spectrum X-Gamma. A slit offers advantages for better discrimination of sources in crowded regions, eliminates the need for support structures for the aperture window, and does not compromise the signal-to-noise (S/N) of a point source. We find that in a single 24 hr pointing of the satellite, MOXE can determine the position of a 10 mCrab sour… more

Date: January 1, 1991

Creator: Lochner, J.C. & Priedhorsky, W.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High spatial resolution in x-ray fluorescence

The design of diffracting crystals for use in x-ray fluorescence spectrometers is discussed. Characteristics of the Johan and Johansson geometries are discussed and intensity profiles are developed. If the diffraction line has a finite width, concentration gradients will not be faithfully reproduced by gradients in the signal as the sample is scanned. Boundary effects for four types of concentration gradient are presented; as step function, linear gradients, exponential gradient, and Gaussian g… more

Date: January 1, 1986

Creator: Zahrt, J. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The initial scientific program at the NSLS infrared beamline

Unique extraction optics (90 {times} 90 mrads) at the NSLS U4IR line offer high brightness beams at up to mm wavelengths with a {approximately}1ns pulse structure. Radiation from this port has now been carefully characterized and agrees well with calculations, making it 100--1000 times brighter than conventional sources in the middle and far infrared regions. Using rapid scan Michelson interferometers with liquid He cooled bolometer detectors we have been able for the first time to measure mole… more

Date: January 1, 1989

Creator: Williams, G. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation hardness and annealing tests of a custom VLSI device

Several NMOS custom VLSI ( Microplex'') circuits have been irradiated with a 500 rad/hr {sup 60}Co source. With power off three of four chips tested have survived doses exceeding 1 Mrad. With power on at a 25% duty cycle, all chips tested failed at doses ranging from 10 to 130 krad. Annealing at 200{degree}C was only partially successful in restoring the chips to useful operating conditions. 10 refs., 4 figs., 1 tab.

Date: October 1, 1986

Creator: Breakstone, A.; Parker, S.; Adolphsen, C.; Litke, A.; Schwarz, A.; Turala, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Test beam results for silicon microstrip detectors with VLSI read-out

A telescope consisting of three silicon microstrip detectors has been tested in a high energy positron beam at SLAC. Each detector has trips with 25 micron pitch and is read out by two 128-channel NMOS integrated circuits (''Microplex''). Results on the signal-to-noise ratio, spatial resolution, and two-track separation are given.

Date: April 1, 1986

Creator: Adolphsen, C.; Litke, A.; Schwarz, A.; Turala, M.; Lueth, V.; Breakstone, A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Estimating Filtering Errors Using the Peano Kernel Theorem

The Peano Kernel Theorem is introduced and a frequency domain derivation is given. It is demonstrated that the application of this theorem yields simple and accurate formulas for estimating the error introduced into a signal by filtering it to reduce noise.

Date: March 1, 2008

Creator: Blair, Jerome

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SYNTHESIS OF METAL HYDRIDES BY MECHANICAL ALLOYING IN AN ATTRITOR MILL: FY07 STATUS REPORT

The objective of this task was to demonstrate that metal hydrides could be produced by mechanical alloying in the quantities needed to support the tritium production facilities at the Savannah River Site. The objective for the FY07 portion of this task was to demonstrate the production of Zr-Fe getter materials by mechanical alloying and begin to optimize the milling parameters. Three starting compositions (ratios of elemental Zr and Fe powders) were selected and attritor milled under argon for… more

Date: November 8, 2007

Creator: Fox, K

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

Magnetic resonance imaging (MRI) has developed into a powerful clinical tool for imaging the human body (1). This technique is based on nuclear magnetic resonance (NMR) of protons (2, 3) in a static magnetic field B{sub 0}. An applied radiofrequency pulse causes the protons to precess about B{sub 0} at their Larmor frequency {nu}{sub 0} = ({gamma}/2{pi})B{sub 0}, where {gamma} is the gyromagnetic ratio; {gamma}/2{pi} = 42.58 MHz/tesla. The precessing protons generate an oscillating magnetic fie… more

Date: August 14, 2006

Creator: Moessle, Michael; Hatridge, Michael & Clarke, John

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The SEGUE Stellar Parameter Pipeline. III. Comparison with High-Resolution Spectroscopy of SDSS/SEGUE Field Stars

The authors report high-resolution spectroscopy of 125 field stars previously observed as part of the Sloan Digital Sky Survey and its program for Galactic studies, the Sloan Extension for Galactic Understanding and Exploration (SEGUE). These spectra are used to measure radial velocities and to derive atmospheric parameters, which they compare with those reported by the SEGUE Stellar Parameter Pipeline (SSPP). The SSPP obtains estimates of these quantities based on SDSS ugriz photometry and low… more

Date: October 1, 2007

Creator: Allende Prieto, C.; Sivarani, T.; Beers, T. C.; Lee, Y. S.; Koesterke, L.; Shetrone, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Restoration of Weak Phase-Contrast Images Recorded With a High Degree of Defocus: The "Twin Image" Problem Associated With CTF Correction

Relatively large values of objective-lens defocus must normally be used to produce detectable levels of image contrast for unstained biological specimens, which are generally weak phase objects. As a result, a subsequent restoration operation must be used to correct for oscillations in the contrast transfer function (CTF) at higher resolution. Currently used methods of CTF-correction assume the ideal case in which Friedel mates in the scattered wave have contributed pairs of Fourier components … more

Date: March 28, 2008

Creator: Downing, Kenneth H. & Glaeser, Robert M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Suzaku Observations of Extreme MeV Blazar Swift J0746.3+2548

We report the Suzaku observations of the high luminosity blazar SWIFT J0746.3+2548 (J0746) conducted in November 2005. This object, with z = 2.979, is the highest redshift source observed in the Suzaku Guaranteed Time Observer (GTO) period, is likely to show high gamma-ray flux peaking in the MeV range. As a result of the good photon statistics and high signal-to-noise ratio spectrum, the Suzaku observation clearly confirms that J0746 has an extremely hard spectrum in the energy range of 0.3-24… more

Date: December 1, 2008

Creator: Watanabe, Shin; Sato, Rie; Takahashi, Tadayuki; Kataoka, Jun; Madejski, Greg; Sikora, Marek et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High resolution 17 keV to 75 keV backlighters for High Energy Density experiments

We have developed 17 keV to 75 keV 1-dimensional and 2-dimensional high-resolution (< 10 {micro}m) radiography using high-intensity short pulse lasers. High energy K-{alpha} sources are created by fluorescence from hot electrons interacting in the target material after irradiation by lasers with intensity I{sub L} > 10{sup 17} W/cm{sup 2}. We have achieved high resolution point projection 1-dimensional and 2-dimensional radiography using micro-foil and micro-wire targets attached to low-Z… more

Date: February 25, 2008

Creator: Park, H.; Maddox, B. R.; Giraldez, E.; Hatchett, S. P.; Hudson, L.; Izumi, N. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Identifying Isotropic Events Using an Improved Regional Moment Tensor Inversion Technique

Using a regional time-domain waveform inversion for the complete moment tensor we calculate the deviatoric and isotropic source components for several explosions at the Nevada Test Site as well as earthquakes, and collapses in the surrounding region of the western US. The events separate into specific populations according to their deviation from a pure double-couple and ratio of isotropic to deviatoric energy. The separation allows for anomalous event identification and discrimination between … more

Date: July 6, 2007

Creator: Ford, S R; Dreger, D S & Walter, W R

Item Type: Article

Partner: UNT Libraries Government Documents Department