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Focal Plane Metrology for the LSST Camera
Meeting the science goals for the Large Synoptic Survey Telescope (LSST) translates into a demanding set of imaging performance requirements for the optical system over a wide (3.5{sup o}) field of view. In turn, meeting those imaging requirements necessitates maintaining precise control of the focal plane surface (10 {micro}m P-V) over the entire field of view (640 mm diameter) at the operating temperature (T {approx} -100 C) and over the operational elevation angle range. We briefly describe the hierarchical design approach for the LSST Camera focal plane and the baseline design for assembling the flat focal plane at room temperature. Preliminary results of gravity load and thermal distortion calculations are provided, and early metrological verification of candidate materials under cold thermal conditions are presented. A detailed, generalized method for stitching together sparse metrology data originating from differential, non-contact metrological data acquisition spanning multiple (non-continuous) sensor surfaces making up the focal plane, is described and demonstrated. Finally, we describe some in situ alignment verification alternatives, some of which may be integrated into the camera's focal plane.
Date:
January 10, 2007
Creator:
A Rasmussen, Andrew P.; Hale, Layton; Kim, Peter; Lee, Eric; Perl, Martin; Schindler, Rafe et al.
Object Type:
Article
System:
The UNT Digital Library
Edge Turbulence Velocity Changes with Lithium Coating on NSTX
Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________
Date:
August 10, 2012
Creator:
A. Cao, S.J. Zweben, D.P. Stotler, M. Bell, A. Diallo, S.M. Kaye and B. LeBlanc
Object Type:
Report
System:
The UNT Digital Library
Potential for luminosity improvement for low-energy RHIC operation with long bunches
Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beams at low energies. Luminosity decreases as the square of bunch intensity due to the beam loss from the RF bucket as a result of the longitudinal intra beam scattering (IBS), as well as due to the transverse emittance growth because of the transverse IBS. Both transverse and longitudinal IBS can be counteracted with electron cooling. This would allow one to keep the initial peak luminosity close to constant throughout the store essentially without the beam loss. In addition, the phase-space density of the hadron beams can be further increased by providing stronger electron cooling. Unfortunately, the defining limitation for low energies in RHIC is expected to be the space charge. Here we explore an idea of additional improvement in luminosity, on top of the one coming from just IBS compensation and longer stores, which may be expected if one can operate with longer bunches at the space-charge limit in a collider. This approach together with electron cooling may result in about 10-fold improvement in total luminosity for low-energy RHIC program.
Date:
February 10, 2012
Creator:
A., Fedotov; Blaskiewicz, & M.
Object Type:
Report
System:
The UNT Digital Library
SUMMARY REPORT DIRECT PUSH TECHNOLOGY BOREHOLES FOR GEOPHYSICAL LOGGING 200-IS-1 OPERABLE UNIT FY2008
None
Date:
February 10, 2009
Creator:
AK, LEE
Object Type:
Report
System:
The UNT Digital Library
Prediction of Coal ash leaching behavior in acid mine water, comparison of laboratory and field studies
Strongly alkaline fluidized bed combustion ash is commonly used to control acid mine drainage in West Virginia coal mines. Objectives include acid neutralization and immobilization of the primary AMD pollutants: iron, aluminum and manganese. The process has been successful in controlling AMD though doubts remain regarding mobilization of other toxic elements present in the ash. In addition, AMD contains many toxic elements in low concentrations. And, each mine produces AMD of widely varying quality. So, predicting the effect of a particular ash on a given coal mine's drainage quality is of particular interest. In this chapter we compare the results of a site-specific ash leaching procedure with two large-scale field applications of FBC ash. The results suggested a high degree of predictability for roughly half of the 25 chemical parameters and poor predictability for the remainder. Of these, seven parameters were successfully predicted on both sites: acidity, Al, B, Ba, Fe, Ni and Zn while electrical conductivity, Ca, Cd, SO4, Pb and Sb were not successfully predicted on either site. Trends for the remaining elements: As, Ag, Be, Cu, Cr, Hg, Mg, Mn, pH, Se Tl and V were successfully predicted on one but not both mine sites.
Date:
January 10, 2005
Creator:
ANNA, KNOX
Object Type:
Report
System:
The UNT Digital Library
Luminosity Determination in pp Collisions at sqrt(s)=7 TeV Using the ATLAS Detector at the LHC
None
Date:
June 10, 2013
Creator:
Aad, Georges
Object Type:
Article
System:
The UNT Digital Library
Environmental tests of the Meteorological Data Acquisition system's remote station
We subjected the Meteorological Data Acquisition (MEDA) remote station hardware to temperature, vibration, and road tests. The MEDA equipment was designed at the Lawrence Livermore Laboratory (LLL) for the Air Resources Laboratory (ARL). ARL supplied all MEDA sensors. The prototype system passed these tests.
Date:
May 10, 1976
Creator:
Aaron, Jr., C. C.
Object Type:
Report
System:
The UNT Digital Library
[Studies of non-linear dynamics of dissipative systems]. [Final report, April 1, 1988--October 31, 1989]
In the period of this grant I worked on three main areas: (1) Symmetries in inviscid flow equations in one, two, and three dimensions and related nonlinear stability theorems for these flows; (2) applications of Hamiltonian mechanics to the problems of shallow water equations and internal wave dynamics in oceanic flows; and, (3) analysis of signals from chaotic systems with an eye toward learning how to build models of chaotic systems in nature.
Date:
September 10, 1990
Creator:
Abarbanel, D. I.
Object Type:
Report
System:
The UNT Digital Library
(Studies of non-linear dynamics of dissipative systems)
In the period of this grant I worked on three main areas: (1) Symmetries in inviscid flow equations in one, two, and three dimensions and related nonlinear stability theorems for these flows; (2) applications of Hamiltonian mechanics to the problems of shallow water equations and internal wave dynamics in oceanic flows; and, (3) analysis of signals from chaotic systems with an eye toward learning how to build models of chaotic systems in nature.
Date:
September 10, 1990
Creator:
Abarbanel, D.I.
Object Type:
Report
System:
The UNT Digital Library
Radiative higgs boson decays H {yields} f{anti f}{gamma}
Higgs boson radiative decays of the form H {r_arrow} f{ovr f}{gamma} are calculated in the Standard Model using the complete one-loop expressions for the decay amplitudes. Contributions to the radiative width from leptons and light quarks are given. We also present e{ovr e} invariant mass distributions for H {r_arrow} e{ovr e}{gamma}, which illustrate the importance of the photon pole contribution and the effects of the box diagrams. 4 refs., 6 figs.
Date:
October 10, 1996
Creator:
Abbasabadi, A.; Bowser-Chao, D.; Repko, W.W. & Dicus, D.A.
Object Type:
Report
System:
The UNT Digital Library
A Preliminary measurement of the gluon splitting rate into b\bar{b} pairs in hadronic Z0 decays
We present a measurement of the rate of gluon splitting into bottom quarks, g --> b anti-b, in hadronic Z<sup>0</sup> decays collected by SLD from 1996 to 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary avor. A topological vertex mass technique was used to tag the two jets with the smallest angle between them as b/anti-b. We obtained a rate of g --> b anti-b per hadronic event to be (3.07 ± 0.71(stat:) ± 0.66(syst:)) × 10³ (preliminary).
Date:
June 10, 1999
Creator:
Abe, Toshinori
Object Type:
Report
System:
The UNT Digital Library
Electric Reliability: Options for Electric Transmission Infrastructure Improvements
The electric utility industry is inherently capital intensive. At the same time, the industry must operate under a changing and sometimes unpredictable regulatory system at both the federal and state level. The Energy Policy Act of 2005 has set in place government activities intended to relieve congestion on the transmission system. Several factors have contributed to the lack of new transmission capacity; these are outlined within this report. This report also discusses earlier pieces of energy legislation.
Date:
June 10, 2005
Creator:
Abel, Amy
Object Type:
Report
System:
The UNT Digital Library
Electricity: The Road Toward Restructuring
This report talks about Electricity regulation and transmission issues. It also includes the history of the California Electricity Crisis.
Date:
August 10, 2004
Creator:
Abel, Amy
Object Type:
Report
System:
The UNT Digital Library
Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV
We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5<pT<50GeV/c and agree with next-to-leading order perturbative QCD evaluations.The A_LL data cover 5<pT<17 GeV/c and disfavor at 98 percentC.L. maximal positive gluon polarization in the polarizednucleon.
Date:
August 10, 2006
Creator:
Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type:
Article
System:
The UNT Digital Library
LIQUID THERMAL DIFFUSION
A revised and expanded version of NNES-DC-1. The liquid thermal diffusion method for the separation of isotopes is described. The discussion includes the experimental aspects of the method, description of equipment, and the theoretical aspects of the process as applied to the design, development, and performance criteria. A short history of the liquid thermal diffusion method from 1940 to 1945 is preserted along; with a survey of relevant literature prior to 1940. The remainder of the report is concerned with theoretical aspects. (J.R.D.)
Date:
September 10, 1946
Creator:
Abelson, P.H.; Rosen, N. & Hoover, J.I. eds.
Object Type:
Report
System:
The UNT Digital Library
SEISMIC SOURCE SCALING AND DISCRIMINATION IN DIVERSE TECTONIC ENVIRONMENTS
The objectives of this study are to improve low-magnitude regional seismic discrimination by performing a thorough investigation of earthquake source scaling using diverse, high-quality datasets from varied tectonic regions. Local-to-regional high-frequency discrimination requires an estimate of how earthquakes scale with size. Walter and Taylor (2002) developed the MDAC (Magnitude and Distance Amplitude Corrections) method to empirically account for these effects through regional calibration. The accuracy of these corrections has a direct impact on our ability to identify clandestine explosions in the broad regional areas characterized by low seismicity. Unfortunately our knowledge of source scaling at small magnitudes (i.e., m{sub b} < {approx}4.0) is poorly resolved. It is not clear whether different studies obtain contradictory results because they analyze different earthquakes, or because they use different methods. Even in regions that are well studied, such as test sites or areas of high seismicity, we still rely on empirical scaling relations derived from studies taken from half-way around the world at inter-plate regions. We investigate earthquake sources and scaling from different tectonic settings, comparing direct and coda wave analysis methods. We begin by developing and improving the two different methods, and then in future years we will apply them both to each …
Date:
July 10, 2007
Creator:
Abercrombie, Rachel E.; Mayeda, Kevin; Walter, William R.; Viegas, Gisela M. & Murphy, Katherine
Object Type:
Article
System:
The UNT Digital Library
III-Nitride Dry Etching - Comparison of Inductively Coupled Plasma Chemistries
A systematic study of the etch characteristics of GaN, AlN and InN has been performed with boron halides- (BI{sub 3} and BBr{sub 3}) and interhalogen- (ICl and IBr) based Inductively Coupled Plasmas. Maximum etch selectivities of -100:1 were achieved for InN over both GaN and AlN in the BI{sub 3} mixtures due to the relatively high volatility of the InN etch products and the lower bond strength of InN. Maximum selectivies of- 14 for InN over GaN and >25 for InN over AlN were obtained with ICl and IBr chemistries. The etched surface morphologies of GaN in these four mixtures are similar or better than those of the control sample.
Date:
November 10, 1998
Creator:
Abernathy, C.R.; Cho, H.; Donovan, S.M.; Hahn, Y-B.; Han, J.; Hays, D.C. et al.
Object Type:
Article
System:
The UNT Digital Library
A novel approach to highly dispersing catalytic materials in coal for gasification. Ninth quarterly report, October 1, 1991--December 31, 1991
This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO{sub 2} gasification activities which increased in the order pH 6 > pH 10 {much_gt} pH 1. The current report shows that a similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. Beyond this time, the coal impregnated with catalyst at pH 1 became more reactive, reaching 100% conversion after 1.5h. X-ray diffraction analysis suggest that the catalysts are well dispersed around pH 1 and 6 whereas reduced dispersion as obtained at pH 10. The reactivities are independent of the surface areas of the coals.
Date:
February 10, 1992
Creator:
Abotsi, G. M. K. & Bota, K. B.
Object Type:
Report
System:
The UNT Digital Library
A novel approach to highly dispersing catalytic materials in coal for gasification
This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO{sub 2} gasification activities which increased in the order pH 6 > pH 10 {much gt} pH 1. The current report shows that a similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. Beyond this time, the coal impregnated with catalyst at pH 1 became more reactive, reaching 100% conversion after 1.5h. X-ray diffraction analysis suggest that the catalysts are well dispersed around pH 1 and 6 whereas reduced dispersion as obtained at pH 10. The reactivities are independent of the surface areas of the coals.
Date:
February 10, 1992
Creator:
Abotsi, G.M.K. & Bota, K.B.
Object Type:
Report
System:
The UNT Digital Library
Leaching and Precipitation Tests on Grants Ores
Leaching tests were run on two samples from the Grants area in New Mexico. Uranium extractions of 94 per cent were obtained by leaching Sample 6-1 with solutions containing 240 lbs. of Na2CO3 and 60 lbs. of NaHCO3 per ton and by leaching Sample 6-2 with 270 lbs. of Na2CO3 and 180 lbs. of NaHCO3 per ton. Cyclic tests were completed using caustic precipitation of the leach liquor.
Date:
September 10, 1951
Creator:
Abrams, Charles S. & George, D'Arcy R.
Object Type:
Report
System:
The UNT Digital Library
Diffraction dissociation in 205 GeV/c $pi$$sup -$p two- and four-prong interactions
From meeting of the division of particles and fields; Berkeley, California, USA (13 Aug 1973). Data are presented on diffraction dissociation in pi /sup -/p yields pi /sup -/p and pi /sup -/p yields pi /sup -/ pi /sup - / pi /sup +/p interactions at 205 GeV/c. Mass spectra and cross sections for pion dissociation and nuclear dissociation are presented. (LBS)
Date:
August 10, 1973
Creator:
Abrams, G. S.; Bingham, H. H. & Chew, D. M.
Object Type:
Article
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).
Date:
August 10, 1999
Creator:
Abrefah, J.; Huang, F.H.; Gerry, W.M.; Gray, W.J.; Marschman, S.C. & Thornton, T.A.
Object Type:
Report
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Ignition tests and analyses of damage/corroded N-Reactor spent nuclear fuel (SNF) were performed by Pacific Northwest National Laboratory as part of a series of studies on the deteriorating spent fuel in the Hanford K-Basins. The ignition temperature tests were conducted to assess tie pyrophoric properties of selected spent fuel elements from K-West Basin. The objective of these tests was to determine pyrophoric characteristics of samples cut from both damaged and undamaged regions of fhel elements. Furnace ignition tests were also petiormed on samples subjected to the conditioning process proposed by the Independent Technical Assessment and the Integrated Process Strategy to establish any significant effect on the SNF pyrophoric pefiormance parameters. Part of the analysis of the ignition data in this report was petiormed by FIuor Daniel Northwest. One of the safety issues being evaluated is the possibility of a fiel ignition during processing, handling, and transportation to the interim storage facility.
Date:
August 10, 1999
Creator:
Abrefah, John; Huang, Fan-Hsiung F.; Gerry, William M.; Gray, Walter J.; Marschman, Steven C. & Thornton, Thomas A.
Object Type:
Report
System:
The UNT Digital Library
Theory of high-{Tc} superconducting cuprates based on experimental evidence
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of {Tc}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
Date:
December 10, 1999
Creator:
Abrikosov, A. A.
Object Type:
Article
System:
The UNT Digital Library