Review of North American Neutrino Factory R and D (open access)

Review of North American Neutrino Factory R and D

We report here on the R and D program of the U.S. Neutrino Factory and Muon Collider Collaboration. Our effort includes work on targetry, muon ionization cooling, simulation work, and development of superconducting RF cavities. In addition, we are involved in the international effort toward a Muon Ionization Cooling Experiment (MICE). Recent activities in all these areas will be described.
Date: October 7, 2002
Creator: Zisman, Michael S. & Collaboration, Neutrino Factory and Muon Collider
System: The UNT Digital Library
Determining worst-case fatigue thresholds for grain-bridging ceramics (open access)

Determining worst-case fatigue thresholds for grain-bridging ceramics

A method for determining worst-case cyclic fatigue thresholds in grain-bridging ceramics by quantifying the role of bridging is demonstrated for a model alumina. Crack-growth properties for both long and short (< 2 mm) cracks emanating from machined notches (root radii, (rho) {approx}; 15 - 150 (mu)m) were investigated. When compared as a function of the applied stress-intensity range (delta K), growth rates (da/dN) were far higher and fatigue thresholds (Delta)KTH were markedly lower with short cracks, with growth being observable at the lowest driving forces for short cracks emanating from razor micronotches ((rho)is approximately equal to 15 (mu)m). For growth rates < 10-8 m/cycle, da/dN vs. (delta)K data for short cracks merged with the steady-state data for long cracks after {approx}2 mm of extension.
Date: October 7, 2002
Creator: Kruzic, J. J.; Yuan, R.; Canon, R. M. & Ritchie, R. O.
System: The UNT Digital Library
Measurement of inter-strand contact resistance in epoxy impregnated Nb3Sn Rutherford cables (open access)

Measurement of inter-strand contact resistance in epoxy impregnated Nb3Sn Rutherford cables

An apparatus for the measurement, under transverse pressure, of the inter-strand contact resistance in epoxy-impregnated Nb{sub 3}Sn Rutherford cables has been recently assembled at Fermilab. Procedures have been developed to instrument and measure samples extracted from Nb{sub 3}Sn coils. Samples were extracted from coils fabricated with the Wind-and-React and the React-and-Wind technology, both presently under development at Fermilab. A ceramic binder is used to improve the insulation and to simplify the fabrication of coils using the Wind-and-React technology. Synthetic oil is used to prevent sintering during the heat treatment of coils to be wound after reaction. In order to evaluate the effects of the ceramic binder and of the synthetic oil on the inter-strand resistance, measurements of samples extracted from coils were compared with measurements of cable stacks with varying characteristics. In this paper we describe the apparatus, the sample preparation, the measurement procedure, and the results of the first series of tests.
Date: October 7, 2003
Creator: al., Giorgio Ambrosio et
System: The UNT Digital Library
Design modifications, fabrication and test of HFDB-03 racetrack magnet wound with pre-reacted Nb3Sn Rutherford cable (open access)

Design modifications, fabrication and test of HFDB-03 racetrack magnet wound with pre-reacted Nb3Sn Rutherford cable

A 10 T racetrack magnet (HFDB-03) wound with pre-reacted Nb{sub 3}Sn Rutherford cable has been fabricated and tested at Fermilab. This magnet is the third one in a proof-of-principle series for the use of the React-and-Wind technology in common-coil dipole magnets for future accelerators. It consists of two flat racetrack coils (28 turns each) separated by 5 mm. The maximum field on the coil, at the short sample limit of 16530 A, is 10 tesla. The cable has 41 strands with 0.7 mm diameter and the minimum bend radius in the magnet ends is 90 mm. The predecessor of this magnet (HFDB-02) reached 78% of the short sample limit at 7.7 T. The mechanical design was improved and the fabrication procedure was slightly modified in order to address possible causes of limitation. In this paper we present the mechanical design and analysis of HFDB-03, the modifications to the fabrication procedure and the test results.
Date: October 7, 2003
Creator: al., Giorgio Ambrosio et
System: The UNT Digital Library
KTeV results: Re(e'/e) and rare decay results (open access)

KTeV results: Re(e'/e) and rare decay results

The KTeV physics program encompasses many goals including a precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) in K{sub S,L} {yields} {pi}{pi} decays, and studies of rare neutral kaon decays. The KTeV detector collected data during the Fermilab fixed-target runs of 1996-97 and 1999. This article focuses on the precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) using the 1996-97 data set. In addition, measurements of the neutral kaon parameters {tau}{sub s}, {Delta}m, {phi}{sub {+-}}, {Delta}{phi} from that data set and a new measurement of the branching fraction of K{sub L} {yields} e{sup +}e{sup -} {mu}{sup +}{mu}{sup -} from the 1997 and 1999 data also are presented.
Date: October 7, 2002
Creator: Whitmore, Juliana
System: The UNT Digital Library
CDF Status and B Physics Prospects (open access)

CDF Status and B Physics Prospects

With extensive upgrades to the detector and electronics, CDF has started collecting data with Run II of the Tevatron. The enhanced silicon coverage and the use of silicon based tracks in the trigger, make CDF well suited for a broad program of B hadron measurements. We present the current status of the experiment and prospects for measurements in Run II.
Date: October 7, 2002
Creator: Miller, J. Stephen
System: The UNT Digital Library
B physics in Run II (open access)

B physics in Run II

Run II at the Tevatron started on March 1, 2001 with a design instantaneous luminosity of 2 x 10{sup 32} cm{sup -2} s{sup -1}. The upgraded D0 detector is expected to collect 2 fb{sup -1} of data at {radical}s = 2.0 TeV in approximately 2 years. The D0 collaboration is planning to make measurements in a number of important areas of B physics, including sin(2{beta}), B{sub s} mixing, the {Lambda}{sub b} lifetime and rare B decays. In this note we describe the upgraded D0 detector and highlights of the B physics program in D0.
Date: October 7, 2002
Creator: Kuznetsov, Valentin E
System: The UNT Digital Library
The integration of web technology at ATLAS. (open access)

The integration of web technology at ATLAS.

ATLAS (Argonne Tandem Linear Accelerator System) accelerates heavy-ion elements, and consists of 2 separate ion source injectors, 64 superconducting resonators, and 3 target areas. As with any complex accelerator facility, database management systems are used extensively to support both the archival of operational data, and the realtime control needs of the accelerator. Web technology has recently been integrated into the already existing ATLAS Oracle Rdb database system and control system documentation to enhance communication with the operators, control system engineers, and other technical support staff at ATLAS. This paper reviews the historical development of the control system database structure and user interface, and the Internet software developer tools used to create a new online interface.
Date: October 7, 2002
Creator: Quock, D.; Munson, F.; Raffenetti, R. & Enshiwat, R.
System: The UNT Digital Library
The status of Run II at Fermilab (open access)

The status of Run II at Fermilab

The Run II at Fermilab is progressing steadily. In the Run IIa scheme, 36 antiproton bunches collide with 36 proton bunches at CDF and D0 interaction regions in the Tevatron at 980 GeV beam energy. The current status and performance of the Fermilab Accelerator Complex is reviewed. The plans for Run IIb along with the Antiproton Source upgrade and incorporation of the Recycler Ring in the accelerator chain are outlined. The prospects of achieving Run II integrated luminosity goal of 15 fb{sup -1} are discussed.
Date: October 7, 2002
Creator: Gounder, Krish
System: The UNT Digital Library
SU(2) lattice gauge theory at nonzero chemical potential and temperature. (open access)

SU(2) lattice gauge theory at nonzero chemical potential and temperature.

SU(2) lattice gauge theory with four flavors of quarks is simulated at nonzero chemical potential {mu} and temperature T and the results are compared to the predictions of Effective Lagrangians. Simulations on 16{sup 4} lattices indicate that at zero T the theory experiences a second order phase transition to a diquark condensate state which is well described by mean field theory. Nonzero T and {mu} are studied on 12{sup 3} x 6 lattices. For low T, increasing {mu} takes the system through a line of second order phase transitions to a diquark condensed phase. Increasing T at high {mu}, the system passes through a line of first order transitions from the diquark phase to the quark-gluon plasma phase.
Date: October 7, 2002
Creator: Kogut, J. B.; Toublan, D. & Sinclair, D. K.
System: The UNT Digital Library
QCD physics in Atlas at the large hadron collider. (open access)

QCD physics in Atlas at the large hadron collider.

The Large Hadron Collider (LHC) is a proton-proton collider with a 14 TeV center of mass energy. The design luminosity is 10{sup 34} cm{sup -1}s{sup -1} with beam collisions separated by 25 ns. The initial operation for physics will take place at a luminosity of 10{sup 33}cm{sup -1}s{sup -1} and it is expected that the integrated luminosity delivered in the first year will be 10 fb{sup -1}. This integrated luminosity will result in very large event samples for most processes, for example: {approx}10{sup 8} leptonic W decays, 10{sup 4} {gamma}'s with E{sub t} > 500GeV and 10{sup 4} jets with E{sub t} > 1TeV. As a result of the high statistics event samples, the understanding of most QCD processes at 14TeV will be systematics limited after the first year of running. The Atlas detector [1] is a general purpose detector designed to be sensitive to the many physics processes which are expected at the LHC. It contains high performance tracking using silicon detectors and a transition radiation tracker in a 2 Tesla solenoidal magnetic field, a high resolution electromagnetic calorimeter based on lead-liquid argon, a hadron calorimeter based on steel-scintillator and Cu/W-liquid argon, and a large instrumented air-core toroid magnet …
Date: October 7, 2002
Creator: Proudfoot, J.
System: The UNT Digital Library
POWER LEVEL EFFECT IN A PWR ROD EJECTION ACCIDENT. (open access)

POWER LEVEL EFFECT IN A PWR ROD EJECTION ACCIDENT.

The purpose of this study is to determine the effect of the initial power level during a rod ejection accident (REA) on the ejected rod worth and the resulting energy deposition in the fuel. The model used is for the hot zero power (HZP) conditions at the end of a typical fuel cycle for the Three Mile Island Unit 1 pressurized water reactor. PARCS, a transient, three-dimensional, two-group neutron nodal diffusion code, coupled with its own thermal-hydraulics model, is used to perform both steady-state and transient simulations. The worth of an ejected control rod is affected by both power level, and the positions of control banks. As the power level is increased, the worth of a single central control rod tends to drop due to thermal-hydraulic feedback and control bank removal, both of which flatten the radial neutron flux and power distributions. Although the peak fuel pellet enthalpy rise during an REA will be greater for a given ejected rod worth at elevated initial power levels, it is more likely the HZP condition will cause a greater net energy deposition because an ejected rod will have the highest worth at HZP. Thus, the HZP condition can be considered the most …
Date: October 7, 2002
Creator: Diamond, D. J.; Bromley, B. P. & Aronson, A. L.
System: The UNT Digital Library
Electrochemical characterization of manganese oxide cathode materials based on Na{sub 0.4}MnO{sub 2} (open access)

Electrochemical characterization of manganese oxide cathode materials based on Na{sub 0.4}MnO{sub 2}

None
Date: October 7, 2003
Creator: Hu, Felix & Doeff, Marca M.
System: The UNT Digital Library
Computational Chemical Dynamics: From Gas- Phase to Condensed - Phase Systems (Poster Book) (open access)

Computational Chemical Dynamics: From Gas- Phase to Condensed - Phase Systems (Poster Book)

None
Date: October 7, 2004
Creator: Cramer, Christopher J.
System: The UNT Digital Library
Photoionization of multiply charged ions at the advanced light source (open access)

Photoionization of multiply charged ions at the advanced light source

Photoionization of multiply charged ions is studied using the merged-beams technique at the Advanced Light Source. Absolute photoionization cross sections have been measured for a variety of ions along both isoelectronic and isonuclear sequences.
Date: October 7, 2004
Creator: Schlachter, A. S.; Kilcoyne, A. L. D.; Aguilar, A.; Gharaibeh, M. F.; Emmons, E. D.; Scully, S. W. J. et al.
System: The UNT Digital Library
Trends in the design of front-end systems for room temperature solid state detectors (open access)

Trends in the design of front-end systems for room temperature solid state detectors

The paper discusses the present trends in the design of low-noise front-end systems for room temperature semiconductor detectors. The technological advancement provided by submicron CMOS and BiCMOS processes is examined from several points of view. The noise performances are a fundamental issue in most detector applications and suitable attention is devoted to them for the purpose of judging whether or not the present processes supersede the solutions featuring a field-effect transistor as a front-end element. However, other considerations are also important in judging how well a monolithic technology suits the front-end design. Among them, the way a technology lends itself to the realization of additional functions, for instance, the charge reset in a charge-sensitive loop or the time-variant filters featuring the special weighting functions that may be requested in some applications of CdTe or CZT detectors.
Date: October 7, 2003
Creator: Manfredi, Pier F. & Re, Valerio
System: The UNT Digital Library
Fick's Insights on Liquid Diffusion (open access)

Fick's Insights on Liquid Diffusion

In 1855, Adolph Fick published ''On Liquid Diffusion'', mathematically treating salt movements in liquids as a diffusion process, analogous to heat diffusion. Less recognized is the fact that Fick also provided a detailed account of the implications of salt diffusion to transport through membranes. A careful look at Fick (1855) shows that his conceptualization of molecular diffusion was more comprehensive than could be captured with the mathematical methods available to him, and therefore his expression, referred to as Fick's Law, dealt only with salt flux. He viewed salt diffusion in liquids as a binary process, with salt moving in one way and water moving in the other. Fick's analysis of the consequences of such a binary process operating in a hydrophilic pore in a membrane offers insights that are relevant to earth systems. This paper draws attention to Fick's rationale, and its implications to hydrogeological systems. Fick (1829-1901; Figure 1), a gifted scientist, published the first book on medical physics (Fick, 1858), discussing the application of optics, solid mechanics, gas diffusion, and heat budget to biological systems. Fick's paper is divisible into two parts. The first describes his experimental verification of the applicability of Fourier's equation to liquid diffusion. The …
Date: October 7, 2004
Creator: Narasimhan, T. N.
System: The UNT Digital Library
Gross shell structure at high spin in heavy nuclei (open access)

Gross shell structure at high spin in heavy nuclei

Experimental nuclear moments of inertia at high spins along the yrast line have been determined systematically and found to differ from the rigid-body values. The difference is attributed to shell effect and these have been calculated microscopically. The data and quantal calculations are interpreted by means of the semiclassical Periodic Orbit Theory. From this new perspective, features in the moments of inertia as a function of neutron number and spin, as well as their relation to the shell energies can be understood. Gross shell effects persist up to the highest angular momenta observed.
Date: October 7, 2003
Creator: Deleplanque, Marie-Agnes; Frauendorf, Stefan; Pashkevich, Vitaly V.; Chu, S.Y. & Unzhakova, Anja
System: The UNT Digital Library
High gain free electron lasers driven by flat electron beam (open access)

High gain free electron lasers driven by flat electron beam

None
Date: October 7, 2002
Creator: Xie, Ming
System: The UNT Digital Library
Baryon-strangeness correlations: a diagnostic of stronglyinteracting matter (open access)

Baryon-strangeness correlations: a diagnostic of stronglyinteracting matter

The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the critical temperature severely limits the presence of q{bar q} bound states, thus supporting a picture of independent (quasi)quarks. Details may be found in [1].
Date: October 7, 2005
Creator: Koch, Volker; Majumder, Abhijit & Randrup, Jorgen
System: The UNT Digital Library
EXPERIENCE MONITORING FOR LOW LEVEL NEUTRON RADIATION AT THE H-CANYON AT THE SAVANNAH RIVER SITE (open access)

EXPERIENCE MONITORING FOR LOW LEVEL NEUTRON RADIATION AT THE H-CANYON AT THE SAVANNAH RIVER SITE

Department of Energy contractors are required to monitor external occupational radiation exposure of an individual likely to receive an effective dose equivalent to the whole body of 0.1 rem (0.001sievert) or more in a year. For a working year of 2000 hours, this translates to a dose rate of 0.05 mrem/hr (0.5 {micro}Sv/hr). This can be a challenging requirement for neutron exposure because traditional surveys with shielded BF{sub 3} proportional counters are difficult to conduct, particularly at low dose rates. A modified survey method was used at the Savannah River Site to find low dose rates in excess of 0.05 mrem/hr. An unshielded He{sup 3} detector was used to find elevated gross slow neutron counts. Areas with high count rates on the unshielded He{sup 3} detector were further investigated with shielded BF{sub 3} proportional counters and thermoluminescent neutron dosimeters were placed in the area of interest. An office area was investigated with this method. The data initially suggested that whole body neutron dose rates to office workers could be occurring at levels significantly higher than 0.1 rem (0.001sievert). The final evaluation, however, showed that the office workers were exposed to less than 0.1 rem/yr (0.001sievert/yr) of neutron radiation.
Date: October 7, 2005
Creator: HOGUE, MARK
System: The UNT Digital Library
Sources of groundwater nitrate revealed using residence time and isotope methods (open access)

Sources of groundwater nitrate revealed using residence time and isotope methods

Nitrate concentrations approaching and greater than the maximum contaminant level (MCL) are impairing the viability of many groundwater basins as drinking water sources. Nitrate isotope data are effective in determining contaminant sources, especially when combined with other isotopic tracers such as stable isotopes of water and tritium-helium ages to give insight into the routes and timing of nitrate inputs to the flow system. This combination of techniques is demonstrated in Livermore, CA, where it is determined that low nitrate reclaimed wastewater predominates in the northwest, while two flowpaths with distinct nitrate sources originate in the southeast. Along the eastern flowpath, {delta}{sup 15}N values greater than 10{per_thousand} indicate that animal waste is the primary source. Diminishing concentrations over time suggest that contamination results from historical land use practices. The other flowpath begins in an area where rapid recharge, primarily of low-nitrate imported water (identified by stable isotopes of water and a tritium-helium residence time of less than 1 year), mobilizes a significant local nitrate source, bringing groundwater concentrations up to 53 mg NO{sub 3} L{sup -1}. In this area, artificial recharge of imported water via local arroyos increases the flux of nitrate to the regional aquifer. The low {delta}{sup 15}N value …
Date: October 7, 2004
Creator: Moore, K. B.; Ekwurzel, B.; Esser, B. K.; Hudson, G. B. & Moran, J. E.
System: The UNT Digital Library
Effect of single-point sequence alterations on the aggregationpropensity of a model protein (open access)

Effect of single-point sequence alterations on the aggregationpropensity of a model protein

Sequences of contemporary proteins are believed to have evolved through process that optimized their overall fitness including their resistance to deleterious aggregation. Biotechnological processing may expose therapeutic proteins to conditions that are much more conducive to aggregation than those encountered in a cellular environment. An important task of protein engineering is to identify alternative sequences that would protect proteins when processed at high concentrations without altering their native structure associated with specific biological function. Our computational studies exploit parallel tempering simulations of coarse-grained model proteins to demonstrate that isolated amino-acid residue substitutions can result in significant changes in the aggregation resistance of the protein in a crowded environment while retaining protein structure in isolation. A thermodynamic analysis of protein clusters subject to competing processes of folding and association shows that moderate mutations can produce effects similar to those caused by changes in system conditions, including temperature, concentration, and solvent composition that affect the aggregation propensity. The range of conditions where a protein can resist aggregation can therefore be tuned by sequence alterations although the protein generally may retain its generic ability for aggregation.
Date: October 7, 2005
Creator: Bratko, Dusan; Cellmer, Troy; Prausnitz, John M. & Blanch, Harvey W.
System: The UNT Digital Library
Experimental Study of Crossing-Angle and Parasitic Effects at the PEP-II e+e- Collider (open access)

Experimental Study of Crossing-Angle and Parasitic Effects at the PEP-II e+e- Collider

In a series of dedicated accelerator experiments, we measure the dependence of the PEP-II luminosity performance on small horizontal crossing angles and on the horizontal separation at the first parasitic crossing. The experiment is carried out by varying the IP angle of one of the beams in two different bunch patterns, one with and one without parasitic crossings. The measurements show satisfactory agreement with three-dimensional beam-beam simulations.
Date: October 7, 2005
Creator: Kozanecki, W.; Narsky, Ilya V.; Cai, Y.; Seeman, J. T. & Sullivan, M.
System: The UNT Digital Library