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Improved methods for computing masses from numerical simulations

Description: 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: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

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

Description: 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: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Doppler electron velocimetry : notes on creating a practical tool.

Description: The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theore… more
Date: November 1, 2008
Creator: Reu, Phillip L. & Milster, Tom (University of Arizona)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Search for a permanent electric dipole moment using liquid 129Xe

Description: Search for an electric dipole moment is one of the best motivated low-energy approaches for investigating physics beyond the Standard Model. Our experimental effort is focused on improving the limit on EDM in liquid 129Xe to put constraints on nuclear CP-violating interactions. High nuclear spin density and high electrical breakdown strength make 129Xe a promising medium for EDM searches. At the time the project started, the transverse nuclear spin relaxation time T2 of 129Xe was unknown. We ma… more
Date: November 24, 2008
Creator: ROMALIS, PROFESSOR MICHAEL
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development and evaluation of a workpiece temperature analyzer for industrial furnaces

Description: The Workpiece Temperature Analyzer (WPTA) is a unique approach for measuring bulk temperature for metallic materials. It applies polarizing interferometer technique with an impulse laser to measure time-of-flight (TOF) for ultrasonic waves and converts these measurements to bulk temperatures. It has potential applications for controlling or monitoring several metallurgical heat treatment processes. During Phase 1A of the development program a bench scale unit was built and operated. The TOF for… more
Date: November 1, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A preliminary calculation of the background to t detection with tagged bs

Description: We investigate the utility of using tagged b jets as a probe for the top quark. We present an approximate calculation of the QCD rate at Tevatron energies for the production of six jets where one of the jets is required to contain a b quark, along with the corresponding rate involving an intermediate t{bar t} pair. With a minimal set of cuts, the signal-to-background is expected to be of order one-to-one, in contrast to the case where no jets are tagged, when the signal-to-background is at leas… more
Date: November 1, 1990
Creator: Giele, W.T.; Kosower, D.A. (Fermi National Accelerator Lab., Batavia, IL (USA)) & Kuijf, H. (Rijksuniversiteit Leiden (Netherlands). Inst. Lorentz)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Development and evaluation of a workpiece temperature analyzer for industrial furnaces. Phase 1-A

Description: The Workpiece Temperature Analyzer (WPTA) is a unique approach for measuring bulk temperature for metallic materials. It applies polarizing interferometer technique with an impulse laser to measure time-of-flight (TOF) for ultrasonic waves and converts these measurements to bulk temperatures. It has potential applications for controlling or monitoring several metallurgical heat treatment processes. During Phase 1A of the development program a bench scale unit was built and operated. The TOF for… more
Date: November 1, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Trace organic chemical detection using an ultraviolet excitation molecular beam fluorometer

Description: Detection of air-borne environmental contaminants, such as organic solvents, requires unambiguous compound identification and sensitivity to concentrations below those permitted by regulating agencies. One promising detection approach uses a pulsed supersonic molecular beam vacuum expansion in combination with fluorescence signal spectral analysis to identify species in a chemical mixture. This report describes the use and performance of the ultraviolet excitation molecular beam fluorometer.
Date: November 1, 1993
Creator: Preppernau, B. L. & Hargis, P. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Understanding correlation coefficients in treaty verification

Description: When a pair of images are compared on a point-by-point basis, the linear-correlation coefficient is usually used as a measure of similarity or dissimilarity. This paper evaluates the theoretical underpinnings and limitation of the linear-correlation coefficient, as well as other related statistics, particularly for cases where inherent white noise is present. As a result of the limitations in linear-correlation, an additional step has been derived -- local-sum clustering -- in order to improve … more
Date: November 1, 1991
Creator: DeVolpi, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Continental seismic events observed by the MPL vertical DIFAR array

Description: The vertical DIFAR array, an underwater acoustic sensor system, deployed by the Marine Physical Laboratory (MPL) was in place over the continental shelf off of Southern California and recorded the HUNTERS TROPHY nuclear test and nearly a score of after-shocks of the Landers/Big Bear earthquakes. Data from this array raise the possibility that detection thresholds for continental events may be significantly lower for arrays over the continental shelf than for arrays in the deep ocean basins. Off… more
Date: November 1, 1993
Creator: Harris, D. B. & D`Spain, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Femtosecond nonlinear spectroscopy at surfaces: Second-harmonic probing of hole burning at the Si(111)7x7 surface and fourier-transform sum-frequency vibrational spectroscopy

Description: The high temporal resolution and broad bandwidth of a femtosecond laser system are exploited in a pair of nonlinear optical studies of surfaces. The dephasing dynamics of resonances associated with the adatom dangling bonds of the Si(111)7 x 7 surface are explored by transient second-harmonic hole burning, a process that can be described as a fourth-order nonlinear optical process. Spectral holes produced by a 100 fs pump pulse at about 800 nm are probed by the second harmonic signal of a 100 f… more
Date: November 24, 2004
Creator: McGuire, John Andrew
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Seismic Imaging of UXO-Contaminated Underwater Sites (Interim Report)

Description: Finite difference modeling with 2-dimensional models were conducted to evaluate the performance of source-receiver arrays to locate UXO in littoral environments. The model parameters were taken from measurements in coastal areas with typical bay mud and from examples in the literature. Seismic arrays are well suited to focus energy by steering the elements of the array to any point in the medium that acts as an energy source. This principle also applies to seismic waves that are backscattered b… more
Date: November 30, 2004
Creator: Gritto, Roland; Korneev, Valeri; Nihei, Kurt & Johnson, Lane
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The CDF silicon vertex detector SVX and its upgrades

Description: The three generations of CDF silicon vertex detectors, SVX, SVX{prime}, and SVX II, are described. SVX, which operated during Tevatron run Ia, achieved 10.6 {mu}m resolution in r {minus} {phi}. SVX{prime} is a radiation-hard device for run Ib with a similar but improved mechanical design and improved signal/noise. SVX II, which will be installed for run II, will track in three dimensions with radiation tolerance and electronics appropriate to a Main Injector environment.
Date: November 1994
Creator: Seidel, Sally
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Undecimated Wavelet Transforms for Image De-noising

Description: A few different approaches exist for computing undecimated wavelet transform. In this work we construct three undecimated schemes and evaluate their performance for image noise reduction. We use standard wavelet based de-noising techniques and compare the performance of our algorithms with the original undecimated wavelet transform, as well as with the decimated wavelet transform. The experiments we have made show that our algorithms have better noise removal/blurring ratio.
Date: November 19, 2002
Creator: Gyaourova, A; Kamath, C & Fodor, I K
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Understanding correlation coefficients in treaty verification

Description: When a pair of images are compared on a point-by-point basis, the linear-correlation coefficient is usually used as a measure of similarity or dissimilarity. This paper evaluates the theoretical underpinnings and limitation of the linear-correlation coefficient, as well as other related statistics, particularly for cases where inherent white noise is present. As a result of the limitations in linear-correlation, an additional step has been derived -- local-sum clustering -- in order to improve … more
Date: November 1, 1991
Creator: DeVolpi, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Model-based Processing of Micro-cantilever Sensor Arrays

Description: We develop a model-based processor (MBP) for a micro-cantilever array sensor to detect target species in solution. After discussing the generalized framework for this problem, we develop the specific model used in this study. We perform a proof-of-concept experiment, fit the model parameters to the measured data and use them to develop a Gauss-Markov simulation. We then investigate two cases of interest: (1) averaged deflection data, and (2) multi-channel data. In both cases the evaluation proc… more
Date: November 17, 2004
Creator: Tringe, J W; Clague, D S; Candy, J V; Lee, C L; Rudd, R E & Burnham, A K
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Primary Standards Laboratory report 1st half 1993

Description: Sandia National Laboratories operates the Primary Standards Laboratory for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the first half of 1993 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.
Date: November 1, 1993
Creator: Levy, W. G. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Noninterceptive transverse emittance measurement diagnostic for an 800 MeV H{sup {minus}} transport line

Description: A nonintrusive diagnostic device that will measure the transverse-phase-space parameters of an 800 MeV H{sup {minus}} beam is under development. The diagnostic device will make the measurements under normal operating conditions and will not perturb the particle beam or produce unwanted radiation. The diagnostic will use the phenomenon of laser-induced photodissociation to sample the H{sup {minus}} beam. This paper discusses the preliminary design of the diagnostic device.
Date: November 1, 1994
Creator: Sandoval, D. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Generalized Error Analysis for Conventional and Remote Reference Magnetotellurics

Description: An error analysis which applies to both conventional and remote reference magnetotelluric impedance and tipper estimates is developed based on the assumption that noise in the field measurements is governed by a complex normal distribution. Under the assumed model of noise it is shown that the theoretical expressions for the variances and covariances derived recently by Gamble et al (1979b) specifically for remote reference estimates apply to conventional estimates as well. However, calculation… more
Date: November 1, 1982
Creator: Stodt, John A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Optimization of signal extraction and front-end design in a fast,multigap ionization chamber

Description: This paper discusses the criteria that have been adopted tooptimize the signal processing in a shower detector to be employed as LHCbeam luminosity monitor. The original aspect ofthis instrument is itsablility to operate on a bunch-by-bunch basis. This means that it mustperform accurate charge measurements at a repetition rate of 40 MHz. Thedetector must withstand an integrated dose of 100 Grad, that is, two tothree orders of magnitude beyond those expected in the experiments. Tomeet the above … more
Date: November 5, 2001
Creator: Datte, P.S.; Manfredi, P.F.; Millaud, J.E.; Placidi, M.; Ratti,L.; Speziali, V. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Terahertz spectral signatures :measurement and detection LDRD project 86361 final report.

Description: LDRD Project 86361 provided support to upgrade the chemical and material spectral signature measurement and detection capabilities of Sandia National Laboratories using the terahertz (THz) portion of the electromagnetic spectrum, which includes frequencies between 0.1 to 10 THz. Under this project, a THz time-domain spectrometer was completed. This instrument measures sample absorption spectra coherently, obtaining both magnitude and phase of the absorption signal, and has shown an operating si… more
Date: November 1, 2005
Creator: Wanke, Michael Clement; Brener, Igal & Lee, Mark
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Compact QEPAS sensor for trace methane and ammonia detection in impure hydrogen

Description: A compact two-gas sensor based on quartz enhanced photoacoustic spectroscopy (QEPAS) was developed for trace methane and ammonia quantification in impure hydrogen. The sensor is equipped with a micro-resonator to confine the sound wave and enhance QEPAS signal. The normalized noise-equivalent absorption coefficients (1{sigma}) of 2.45 x 10{sup -8} cm{sup -1}W/{radical}Hz and 9.1 x 10{sup -9} cm{sup -1}W/{radical}Hz for CH{sub 4} detection at 200 Torr and NH{sub 3} detection at 50 Torr were demo… more
Date: November 2, 2011
Creator: Wright, J.; Ferguson, B.; Peters, B. & Mcwhorter, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Linear low power preamplifier for the atlas liquid argon em calorimeter

Description: In a previous paper, it was shown that, for shaping times of the order of the transmission line delay, a remote, external preamplifier could perform as well as one connected directly to a liquid argon calorimeter. Here we describe an improved circuit configuration where, by attributing the functions of low noise and high dynamic range to two different transistors, the linearity can be improved and the noise can be decreased while reducing the power dissipation by a factor of three (to about 40 … more
Date: November 1, 1996
Creator: Chase, R.L. & Rescia, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A room temperature LSO/PIN photodiode PET detector module that measures depth of interaction

Description: We present measurements of a 4 element PET detector module that uses a 2{times}2 array of 3 mm square PIN photodiodes to both measure the depth of interaction (DOI) and identify the crystal of interaction. Each photodiode is coupled to one end of a 3{times}3{times}25 mm LSO crystal, with the opposite ends of all 4 crystals attached to a single PMT that provides a timing signal and initial energy discrimination. Each LSO crystal is coated with a {open_quotes}lossy{close_quotes} reflector, so the… more
Date: November 1, 1994
Creator: Moses, W. W.; Derenzo, S. E.; Melcher, C. L. & Manente, R. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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