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rSUGRA: Putting Nonuniversal Gaugino Masses on the (W)MAP (open access)

rSUGRA: Putting Nonuniversal Gaugino Masses on the (W)MAP

In this talk, we investigate the relic density and direct detection prospects of rSUGRA, a simple paradigm for supersymmetry breaking that allows for nonuniversal gaugino masses. We present updated plots reflecting the latest cosmological measurements from WMAP.
Date: June 17, 2003
Creator: Birkedal-Hansen, Andreas
System: The UNT Digital Library
Repair of a Melter Pour Spout Using an Expanding Ring (open access)

Repair of a Melter Pour Spout Using an Expanding Ring

An expanding ring was developed that provided remote repair of the pour spout for a radioactive waste vitrification melter. This passive device used gas pressure to expand a metal ring against the irregularly shaped pour spout wall. Laboratory modeling and testing were performed for proof of concept and optimization before final design and field deployment. The ring expanded radially more than 4.8 mm and successfully repaired the melter pour spout allowing continued glass pouring operation.
Date: June 17, 2003
Creator: Imrich, K. J.
System: The UNT Digital Library
Jet Breakup and Spray Formation in a Diesel Engine (open access)

Jet Breakup and Spray Formation in a Diesel Engine

The breakup of injected fuel into spray is of key interest to the design of a fuel efficient, nonpolluting diesel engine. We report preliminary progress on the numerical simulation of diesel fuel injection spray with the front tracking code FronTier. Our simulation design is set to match experiments at ANL, and our present agreement is semi-quantitative. Future efforts will include mesh refinement studies, which will better model the turbulent flow.
Date: June 17, 2003
Creator: Glimm, J.; Li, X.; Kim, M. N.; Oh, W.; Marchese, A.; Samulyak, R. et al.
System: The UNT Digital Library
Measurements of field decay and snapback effect on Tevatron dipole magnets (open access)

Measurements of field decay and snapback effect on Tevatron dipole magnets

The performance of Fermilab's Tevatron accelerator, currently in its Run II stage, is degraded by beam loss and emittance dilution during ramping from injection to collision energy. This could be related in part to insufficient compensation of dynamic effects such as the decay of the magnetic field in the dipoles during the dwell at injection and the following so-called snapback during the first few seconds of the energy ramp. The two effects are closely related and depend on the powering history of the magnets. Dynamic effects, which were originally discovered at the Tevatron, were investigated on Tevatron magnets in various past measurement campaigns in the 1980s and later in 1996. This paper reports on the most recent measurements performed on an additional set of Tevatron magnets.
Date: June 17, 2003
Creator: al., Gueorgui V Velev et
System: The UNT Digital Library
Prospects for next generation long-baseline oscillation experiments (open access)

Prospects for next generation long-baseline oscillation experiments

This document describes some of the exciting possibilities for the next steps in the field of long baseline neutrino oscillation measurements. Because the primary goals of these new experiments are so different from those of the current generation, one cannot simply increase the running time or detector mass of the current programs. There are several new strategies which have been discussed for taking the next steps: sometimes the detectors, sometimes the beamlines, and sometimes both are radically different from what is now in place.
Date: June 17, 2003
Creator: Harris, Deborah A
System: The UNT Digital Library
Challenges of Non-Destructive Assay Waste Measurement (open access)

Challenges of Non-Destructive Assay Waste Measurement

Historically, the Savannah River Site (SRS) routinely produced special nuclear material (SNM), which provided stable measurement conditions for the non-destructive assay (NDA) methods. However, the main mission of SRS has changed from the production of SNM to the processing of waste and material stabilization. Currently, the purpose of processing is to recover the SNM from the waste and stabilization materials, much of which is from other DOE facilities. These missions are usually of a short duration, but require non-destructive assay (NDA) accountability measurements on materials of varying composition and geometric configuration. These missions usually have cost and time constraints, which sometimes require re-application of existing NDA methods to waste measurements. Usually, each new material or re-application of the NDA method to a different SNM campaign requires new standards and timely re-calibration of the method. These constraints provide numerous challenges for the NDA methods, particularly in the area of measurement uncertainty. This paper will discuss the challenges of these situations, mainly from a measurement and statistical point of view and provide some possible solutions to the problems encountered. Specific examples will be discussed for the segmented gamma scanner (SGS), neutron multiplicity counter (NMC) and passive neutron coincidence counter (PNCC), which are …
Date: June 17, 2003
Creator: Shull, A.H.
System: The UNT Digital Library
Modern Trends in Induction Accelerator Technology (open access)

Modern Trends in Induction Accelerator Technology

None
Date: June 17, 2003
Creator: Caporaso, G J
System: The UNT Digital Library
Molecular Dynamics Study of Void Growth and Dislocations in Dynamic Fracture of FCC and BCC Metals (open access)

Molecular Dynamics Study of Void Growth and Dislocations in Dynamic Fracture of FCC and BCC Metals

Void growth with concomitant dislocation formation has been studied in single crystal face-centered-cubic and body-centered-cubic metals using molecular dynamics method with Embedded-Atom and Finnis-Sinclair potentials for copper and tantalum, respectively. We have concentrated on the quantitative analysis of the void shape evolution, on the structure of dislocations, which emerge from the void, and on the continuum measures such as plastic strain. The effects of strain-rate, differences between lattice structures, and loading conditions as uniaxial, biaxial, and triaxial expansion on the shape of the void and on the dislocations have been investigated.
Date: June 17, 2003
Creator: Seppala, E T; Belak, J & Rudd, R E
System: The UNT Digital Library
Percolation Fractal Dimension in Scattering Line Shapes of the Random-Field Ising Model (open access)

Percolation Fractal Dimension in Scattering Line Shapes of the Random-Field Ising Model

Neutron scattering and simulation line shape data show evidence for fractal structure from spanning clusters in the d = 2 and d = 3 random-field Ising models as realized in dilute antiferromagnets.
Date: June 17, 2003
Creator: Ye, F.; Matsuda, M.; Katano, S.; Yoshizawa, H.; Belanger, D. P.; Seppala, E. T. et al.
System: The UNT Digital Library