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Unquenched Studies Using the Truncated Determinant Algorithm
A truncated determinant algorithm is used to study the physical effects of the quark eigenmodes associated with eigenvalues below 420 MeV. This initial high statistics study focuses on coarse (6{sup 4}) lattices (with O(a{sup 2}) improved gauge action), light internal quark masses and large physical volumes. Three features of full QCD are examined: topological charge distributions, string breaking as observed in the static energy and the eta prime mass.
Date:
November 29, 2001
Creator:
A. Duncan, E. Eichten and H. Thacker
System:
The UNT Digital Library
Fabrication of high-density cantilever arrays and through-wafer interconnects
Processes to fabricate dense, dry released microstructures with electrical connections on the opposite side of the wafer are described. A 10 x 10 array of silicon and polysilicon cantilevers with high packing density (5 tips/mm<sup>2</sup>) and high uniformity (<10 µm length variation across the wafer) are demonstrated. The cantilever release process uses a deep SF<sub>6</sub>/C<sub>4</sub>F<sub>8</sub>, plasma etch followed by a HBr plasma etch to accurately release cantilevers. A process for fabricating electrical contacts through the backside of the wafer is also described. Electrodeposited resist, conformal CVD metal deposition and deep SF<sub>6</sub>/C<sub>4</sub>F<sub>8</sub> plasma etching are used to make 30 µm/side square vias each of which has a resistance of 50 m(omega).
Date:
November 3, 1998
Creator:
A. Harley, J.; Abdollahi-Alibeik, S.; Chow, E. M.; Kenney, T. W.; McCarthy, A. M.; McVittie, J. P. et al.
System:
The UNT Digital Library
Analysis of NSTX Upgrade OH Magnet and Center Stack
The new ohmic heating (OH) coil and center stack for the National Spherical Torus Experiment (NSTX) upgrade are required to meet cooling and structural requirements for operation at the enhanced 1 Tesla toroidal field and 2 MA plasma current. The OH coil is designed to be cooled in the time between discharges by water flowing in the center of the coil conductor. We performed resistive heating and thermal hydraulic analyses to optimize coolant channel size to keep the coil temperature below 100 C and meet the required 20 minute cooling time. Coupled electromagnetic, thermal and structural FEA analyses were performed to determine if the OH coil meets the requirements of the structural design criteria. Structural response of the OH coil to its self-field and the field from other coils was analyzed. A model was developed to analyze the thermal and electromagnetic interaction of centerstack components such as the OH coil, TF inner legs and the Bellville washer preload mechanism. Torsional loads from the TF interaction with the OH and poloidal fields are transferred through the TF flag extensions via a torque transfer coupling to the rest of the tokamak structure. A 3D FEA analysis was performed to qualify this design. …
Date:
November 30, 2010
Creator:
A. Zolfaghari, P. Titus, J. Chrzanowski, A. Salehzadeh, F. Dahlgren
System:
The UNT Digital Library
Onset and Saturation of Ion Heating by Odd-parity Rotating-magnetic-fields in a Field-reversed Configuration
Heating of figure-8 ions by odd-parity rotating magnetic fields (RMFο) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances (s ≡ ω(sub)R⁄ω) of the RMFο frequency, ω(sub)R, with the figure-8 orbital frequency, ω, and is proportional to s^2 for s – even resonances and to s for s – odd resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude.
Date:
November 1, 2005
Creator:
A.S. Landsman, S.A. Cohen, A.H. Glasser
System:
The UNT Digital Library
QCD sum rule calculation of {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0} transition form factor
The authors develop a QCD sum rule analysis of the form factor F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(q{sup 2},Q{sup 2}) in the region where virtuality of one of the spacelike photons is small q{sup 2} {much_lt} 1 GeV{sup 2} while another is large: Q{sup 2} {approx_gt} 1 GeV{sup 2}. They construct the operator product expansion suitable for this kinematic situation and obtain a QCD sum rule for F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(0, Q{sup 2}). Their results confirm expectation that the momentum transfer dependence of F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(0,Q{sup 2}) is close to interpolation between its Q{sup 2}=0 value fixed by the axial anomaly and Q{sup {minus}2} pQCD behavior for large Q{sup 2}. Their approach, in contrast to pQCD, does not require additional assumptions about the shape of the pion distribution amplitude {var_phi}{sub {pi}}(x). The absolute value of the 1/Q{sup 2} term obtained in this paper favors {var_phi}{sub {pi}}(x) close to the asymptotic form {var_phi}{sub {pi}}{sup as}(x) = 6f{sub {pi}}x(1{minus}x).
Date:
November 1, 1995
Creator:
A.V.Radyushkin & R.T.Ruskov
System:
The UNT Digital Library
GLASSES CONTAINING IRON (II III) OXIDES FOR IMMOBILIZATION OF RADIOACTIVE TECHNETIUM
Technetium-99 (Tc-99) has posed serious environmental threats as US Department of Energy's high-level waste. This work reports the vitrification of Re, as surrogate for Tc-99, by iron-borosilicate and iron-phosphate glasses, respectively. Iron-phosphate glasses can dissolve Re as high as {approx} 1.2 wt. %, which can become candidate waste forms for Tc-99 disposal, while borosilicate glasses can retain less than 0.1 wt. % of Re due to high melting temperature and long melting duration. Vitrification of Re as Tc-99's mimic was investigated using iron-borosilicate and iron-phosphate glasses. The retention of Re in borosilicate glasses was less than 0.1 wt. % and more than 99 wt. % of Re were volatilized due to high melting temperature and long melting duration. Because the retention of Re in iron-phosphate glasses is as high as 1.2 wt. % and the volatilization is reduced down to {approx}50 wt. %, iron-phosphate glasses can be one of the glass waste form candidates for Tc (or Re) disposal. The investigations of chemical durability and leaching test of iron-phosphate glasses containing Re are now underway to test the performance of the waste form.
Date:
November 7, 2011
Creator:
AA, KRUGER; J, HEO; K, XU; JK, CHOI; PR, HRMA & W, UM
System:
The UNT Digital Library
A MOBILE MELT-DILUTE MODULE FOR THE TREATMENT OF ALUMINUM RESEARCH REACTOR SPENT FUEL
A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed jointly by the Savannah River National Laboratory and Argonne National Laboratory. The process uses a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain an isotopic content of less than 20 percent. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form.
Date:
November 3, 2004
Creator:
ADAMS, THAD
System:
The UNT Digital Library
Micromilling of Metal Alloys with Focused Ion Beam-Fabricated Tools
This work combines focused ion beam sputtering and ultra-precision machining as a first step in fabricating microstructure in metals and alloys. Specifically, {approx}25{micro}m diameter micro-end mills are made from cobalt M42 high-speed steel and C2 micrograin tungsten carbide tool blanks by ion beam sputtering. A 20 keV focused gallium beam defines tool cutting edges having radii of curvature < 0.1{micro}m. Micro-end mills having 2, 4 and 5 cutting edges successfully machine small trenches in 6061-T4 aluminum, brass, 4340 steel and polymethyl methacrylate. Machined trench widths are approximately equal to the tool diameters and surface roughnesses (rms) are {approx}150 nm or less. Microtools are robust and operate for more than 6 hours without fracture. Results from ultra-precision machining aluminum at feed rates as high as 50 mm/minute are included.
Date:
November 5, 1999
Creator:
ADAMS,DAVID P.; VASILE,M.J.; BENAVIDES,GILBERT L. & CAMPBELL,ANN N.
System:
The UNT Digital Library
Antireflection Coating Design for Series Interconnected Multi-Junction Solar Cells
AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub SC}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices.
Date:
November 29, 1999
Creator:
AIKEN,DANIEL J.
System:
The UNT Digital Library
EXAMPLE OF A RISK BASED DISPOSAL APPROVAL SOLIDIFICATION OF HANFORD SITE TRANSURANIC (TRU) WASTE
The Hanford Site requested, and the U.S. Environmental Protection Agency (EPA) Region 10 approved, a Toxic Substances Control Act of 1976 (TSCA) risk-based disposal approval (RBDA) for solidifying approximately four cubic meters of waste from a specific area of one of the K East Basin: the North Loadout Pit (NLOP). The NLOP waste is a highly radioactive sludge that contained polychlorinated biphenyls (PCBs) regulated under TSCA. The prescribed disposal method for liquid PCB waste under TSCA regulations is either thermal treatment or decontamination. Due to the radioactive nature of the waste, however, neither thermal treatment nor decontamination was a viable option. As a result, the proposed treatment consisted of solidifying the material to comply with waste acceptance criteria at the Waste Isolation Pilot Plant (WPP) in Carlsbad, New Mexico, or possibly the Environmental Restoration Disposal Facility at the Hanford Site, depending on the resulting transuranic (TRU) content of the stabilized waste. The RBDA evaluated environmental risks associated with potential airborne PCBs. In addition, the RBDA made use of waste management controls already in place at the treatment unit. The treatment unit, the T Plant Complex, is a Resource Conservation and Recovery Act of 1976 (RCRA)-permitted facility used for storing and …
Date:
November 14, 2007
Creator:
AL, PRIGNANO
System:
The UNT Digital Library
QUIET DIRECT SIMULATION OF PLASMAS
None
Date:
November 1, 2001
Creator:
ALBRIGHT, B. J.; DAUGHTON, W. & AL, ET
System:
The UNT Digital Library
STATUS OF THE ACCELERATOR PRODUCTION OF TRITIUM (APT) PROJECT
None
Date:
November 1, 1999
Creator:
ANDERSON, J. L.; LISOWSKI, P. W. & AL, ET
System:
The UNT Digital Library
DEVELOPMENT OF REMOTE MONITORING SYSTEM FOR THE UNATTENDED MODE NDA IN PFPF
None
Date:
November 1, 1999
Creator:
ASAKURA, K.; OHTANI, T. & AL, ET
System:
The UNT Digital Library
Status of the DOE/Sandia Blade Manufacturing Program
None
Date:
November 1, 2000
Creator:
ASHWILL,THOMAS D.
System:
The UNT Digital Library
EXACT SOLUTION OF HEAT CONDUCTION IN A TWO-DOMAIN COMPOSITE CYLINDER WITH AN ORTHOTROPIC OUTER LAYER.
The transient exact solution of heat conduction in a two-domain composite cylinder is developed using the separation of variables technique. The inner cylinder is isotropic and the outer cylindrical layer is orthotropic. Temperature solutions are obtained for boundary conditions of the first and second kinds at the outer surface of the orthotropic layer. These solutions are applied to heat flow calorimeters modeling assuming that there is heat generation due to nuclear reactions in the inner cylinder. Heat flow calorimeter simulations are carried out assuming that the inner cylinder is filled with plutonium oxide powder. The first objective in these simulations is to predict the onset of thermal equilibrium of the calorimeter with its environment. Two types of boundary conditions at the outer surface of the orthotropic layer are used to predict thermal equilibrium. The procedure developed to carry out these simulations can be used as a guideline for the design of calorimeters. Another important application of these solutions is on the estimation of thermophysical properties of orthotropic cylinders. The thermal conductivities in the vertical, radial and circumferential directions of the orthotropic outer layer can be estimated using this exact solution and experimental data. Simultaneous estimation of the volumetric heat capacity …
Date:
November 1, 2000
Creator:
AVILES-RAMOS, C. & RUDY, C.
System:
The UNT Digital Library
Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics
The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where groundbreaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999 [1]. A survey of physics capabilities of the CMS detector was published in [2]. The design of the ATLAS detector has now been finalised, and its construction and installation have been completed [3]. An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have …
Date:
November 28, 2011
Creator:
Aad, G.; Abat, E.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A. et al.
System:
The UNT Digital Library
Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions
We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the …
Date:
November 4, 2009
Creator:
Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D et al.
System:
The UNT Digital Library
Measurement of the cross section for W-boson production in association with jets in ppbar collisions at s**(1/2) = 1.96-TeV
We present a measurement of the cross section for W-boson production in association with jets in p{bar p} collisions at {radical}s = 1.96 TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb{sup -1} collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W + {ge} n-jet sample (n = 1-4) we measure {sigma}(p{bar p} {yields} W + {ge} n-jet) x {Beta}(W {yields} e{nu}) with respect to the transverse energy E{sub T} of the nth-highest E{sub T} jet above 20 GeV, for a restricted W {yields} e{nu} decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level W + jet(s) predictions. We present here comparisons to leading order and next-to-leading order predictions.
Date:
November 1, 2007
Creator:
Aaltonen, T.
System:
The UNT Digital Library
Measurement of correlated b-bbar production in p-pbar collisions at s**(1/2) = 1960 GeV
We present a measurement of the correlated b{bar b} production cross section. The data used in this analysis were taken with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider, and correspond to an integrated luminosity of 742 pb{sup -1}. We utilize muon pairs with invariant mass 5 {le} m{sub {mu}{mu}} {le} 80 GeV/c{sup 2} produced by b{bar b} double semileptonic decays. For muons with p{sub T} {ge} 3 GeV/c and |{eta}| {le} 0.7, that are produced by b and {bar b} quarks with p{sub T} {ge} 2 GeV/c and |y| {le} 1.3, we measure {sigma}{sub b{yields}{mu},{bar b}{yields}{mu}} = 1549 {+-} 133 pb. We compare this result with theoretical predictions and previous measurements. We also report the measurement of {sigma}{sub c{yields}{mu},{bar c}{yields}{mu}}, a by-product of the study of the background to b{bar b} production.
Date:
November 1, 2007
Creator:
Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G. et al.
System:
The UNT Digital Library
Inclusive Search for Squark and Gluino Production in p anti-p Collisions at s**(1/2) = 1.96-TeV
We report on a search for inclusive production of squarks and gluinos in p{bar p} collisions at {radical}s = 1.96 TeV, in events with large missing transverse energy and multiple jets of hadrons in the final state. The study uses a CDF Run II data sample corresponding to 2 fb-1 of integrated luminosity. The data are in good agreement with the standard model predictions, giving no evidence for any squark or gluino component. In an R-parity conserving minimal supergravity scenario with A{sub 0} = 0, mu < 0 and tan beta = 5, 95% C.L. upper limits on the production cross sections in the range between 0.1 pb and 1 pb are obtained, depending on the squark and gluino masses considered. For gluino masses below 280 GeV/c2, arbitrarily large squark masses are excluded at the 95%C.L., while for mass degenerate gluinos and squarks, masses below 392 GeV/c2 are excluded at the 95% C.L.
Date:
November 1, 2008
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Alvarez Gonzalez, B.; Amerio, S. et al.
System:
The UNT Digital Library
Search for chargino-neutralino production in p anti-p collisions at 1.96-TeV with high-p(T) leptons
The authors present a search for the associated production of charginos and neutralinos in p{bar p} collisions at {radical}s = 1.96 TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0 fb{sup -1}. They look for final states with one high-p{sub T} electron or muon, and two additional leptons. The results are consistent with the standard model expectations, and they set limits on the cross section as a function of the chargino mass in three different supersymmetric scenarios. For a specific MSSM scenario with no slepton mixing they set a 95% C.L. limit at 151 GeV/c{sup 2}.
Date:
November 1, 2007
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Alvarez Gonzalez, B.; Amerio, S. et al.
System:
The UNT Digital Library
Measurement of the k(T) Distribution of Particles in Jets Produced in p anti-p Collisions at s**(1/2) = 1.96-TeV
We present a measurement of the transverse momentum with respect to the jet axis (k{sub T}) of particles in jets produced in p{bar p} collisions at {radical}s = 1.96 TeV. Results are obtained for charged particles within a cone of opening angle 0.5 radians around the jet axis in events with dijet invariant masses between 66 and 737 GeV/c{sup 2}. The experimental data are compared to theoretical predictions obtained for fragmentation partons within the framework of resummed perturbative QCD using the modified leading log and next-to-modified leading log approximations. The comparison shows that trends in data are successfully described by the theoretical predictions, indicating that the perturbative QCD stage of jet fragmentation is dominant in shaping basic jet characteristics.
Date:
November 1, 2008
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E. et al.
System:
The UNT Digital Library
Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using costheta*
None
Date:
November 1, 2008
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E. et al.
System:
The UNT Digital Library
Measurement of the WW+WZ Production Cross Section Using the Lepton+Jets Final State at CDF II
We report two complementary measurements of the diboson (WW + WZ) cross section in the final state consisting of an electron or muon, missing transverse energy, and jets, performed using p{bar p} collision data at {radical}s = 1.96 TeV collected by the Collider Detector at Fermilab. The first method uses the dijet invariant mass distribution while the second method uses more of the kinematic information in the event through matrix-element calculations of the signal and background processes and has a higher sensitivity. The result from the second method has a signal significance of 5.4{sigma} and is the first observation of WW + WZ production using this signature. Combining the results from both methods gives {sigma}{sub WW+WZ} = 16.0 {+-} 3.3 pb, in agreement with the standard model prediction.
Date:
November 1, 2009
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
System:
The UNT Digital Library