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Effects of Global Boundary and Local Collisionality on Magnetic Reconnection in a Laboratory Plasma
The magnetic reconnection process is studied in a wide range of operating conditions in the well-controlled Magnetic Reconnection Experiment. The reconnection rate is observed to be a function of both global (i.e., system size) and local (collisionality) plasma parameters. When only local collisionality is lowered, the current sheet is shortened while effective resistivity is enhanced, both accelerating reconnection rates. At a fixed collisionality, the current sheet length increases with system size, resulting in the reduction of the reconnection rate. These results quantitatively agree with a generalized Sweet-Parker analysis.
Date:
July 24, 2007
Creator:
A. Kuritsyn, H. Ji, S.P. Gerhardt, Y. Ren, and M. Yamada
Object Type:
Report
System:
The UNT Digital Library
Part II/Addendum Electron Beam Cooling between EBIS LINAC and Booster; Is Single Pass Cooling Possible?
N/A
Date:
July 1, 2008
Creator:
A., Hershcovitch
Object Type:
Report
System:
The UNT Digital Library
Electron Gun for RHIC EBIS
N/A
Date:
July 1, 2006
Creator:
A., Pikin
Object Type:
Report
System:
The UNT Digital Library
Optical, Thermal and Stress Simulations of a 300-kwatt Electron Collector
N/A
Date:
July 1, 2006
Creator:
A., Pikin; Kponou, A. & Snydstrup, L.
Object Type:
Report
System:
The UNT Digital Library
F(1) for B (forward) D*ln from lattice QCD
The authors would like to determine |V{sub cb}| from the exclusive semi-leptonic decay B{yields}D*lv. The differential decay rate is d{Lambda}/dw = G{sub F}{sup 2}/4{pi}{sup 3}(w{sup 2}-1){sup 1/2}m{sub D*}{sup 3} (m{sub B}-m{sub D*}){sup 2}G(w)|V{sub cb}|{sup 2}|F{sub B{yields}D*}(w)|{sup 2}, where w = v {center_dot} v{prime} and G(1) = 1. At zero recoil (w = 1) heavy-quark symmetry requires F{sub B{yields}D*}(1) to be close to 1. So, |V{sub cb}| is determined by dividing measurements of d{Lambda}/dw by the phase space and well-known factors, and extrapolating to w {yields} 1. This yields |V{sub cb}|F{sub B{yields}D*}(1), and F{sub B{yields}D*}(1) is taken from ''theory''. To date models [1] or a combination of a rigorous inequality plus judgement [2] have been used to estimate F{sub B{yields}D*}(1) - 1. In this work [3] they calculate F{sub B{yields}D*}(1) with lattice gauge theory, in the so-called quenched approximation, but the uncertainty from quenching is included in the error budget.
Date:
July 12, 2002
Creator:
A.S. Kronfeld, P.B. Mackenzie and J.N. Simone
Object Type:
Article
System:
The UNT Digital Library
Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data
Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.
Date:
July 20, 2000
Creator:
ALAM,TODD M. & ALAM,M. KATHLEEN
Object Type:
Article
System:
The UNT Digital Library
Acoustic Wave Equations for a Linear Viscous Fluid and An Ideal Fluid
The mathematical description of acoustic wave propagation within a time- and space-varying, and moving, linear viscous fluid is formulated as a system of coupled linear equations. This system is rigorously developed from fundamental principles of continuum mechanics (conservation of mass, balance of linear and angular momentum, balance of entropy) and various constitutive relations (for stress, entropy production, and entropy conduction) by linearizing all expressions with respect to the small-amplitude acoustic wavefield variables. A significant simplification arises if the fluid medium is neither viscous nor heat conducting (i.e., an ideal fluid). In this case the mathematical system can be reduced to a set of five, coupled, first-order partial differential equations. Coefficients in the systems depend on various mechanical and thermodynamic properties of the ambient medium that supports acoustic wave propagation. These material properties cannot all be arbitrarily specified, but must satisfy another system of nonlinear expressions characterizing the dynamic behavior of the background medium. Dramatic simplifications in both systems occur if the ambient medium is simultaneously adiabatic and stationary.
Date:
July 1, 2002
Creator:
ALDRIDGE, DAVID F.
Object Type:
Report
System:
The UNT Digital Library
Elastic Wave Radiation from a Pressurized Spherical Cavity
None
Date:
July 1, 2002
Creator:
ALDRIDGE, DAVID F.
Object Type:
Report
System:
The UNT Digital Library
Fast Grid Search Algorithm for Seismic Source Location
The spatial and temporal origin of a seismic energy source are estimated with a first grid search technique. This approach has greater likelihood of finding the global rninirnum of the arrival time misiit function compared with conventional linearized iterative methods. Assumption of a homogeneous and isotropic seismic velocity model allows for extremely rapid computation of predicted arrival times, but probably limits application of the method to certain geologic environments and/or recording geometries. Contour plots of the arrival time misfit function in the vicinity of the global minimum are extremely useful for (i) quantizing the uncertainty of an estimated hypocenter solution and (ii) analyzing the resolving power of a given recording configuration. In particular, simultaneous inversion of both P-wave and S-wave arrival times appears to yield a superior solution in the sense of being more precisely localized in space and time. Future research with this algorithm may involve (i) investigating the utility of nonuniform residual weighting schemes, (ii) incorporating linear and/or layered velocity models into the calculation of predicted arrival times, and (iii) applying it toward rational design of microseismic monitoring networks.
Date:
July 1, 2000
Creator:
ALDRIDGE,DAVID F.
Object Type:
Report
System:
The UNT Digital Library
AN APPROACH TO EXTREME-SCALE SIMULATION OF NOVEL ARCHITECTURES
None
Date:
July 1, 2001
Creator:
ALEXANDER, F. J.; BERKBIGLER, K. & AL, ET
Object Type:
Article
System:
The UNT Digital Library
Frequency Doubling Broadband Light in Multiple Crystals
The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.
Date:
July 26, 2000
Creator:
ALFORD,WILLIAM J. & SMITH,ARLEE V.
Object Type:
Article
System:
The UNT Digital Library
Wavelength Variation of the Second-Order Nonlinear Coefficients of KNbO3, KTiOPO4, KTiOAsO4, LiNbO3, LiIO3, B-BaB2O4, KH2PO4, and LiB3O5 Crystals: A Test of Miller Wavelength Scaling
None
Date:
July 17, 2000
Creator:
ALFORD,WILLIAM J. & SMITH,ARLEE V.
Object Type:
Article
System:
The UNT Digital Library
Cooperative Monitoring Center Occasional Paper/16: The Potential of Technology for the Control of Small Weapons: Applications in Developing Countries
For improving the control of small arms, technology provides many possibilities. Present and future technical means are described in several areas. With the help of sensors deployed on the ground or on board aircraft, larger areas can be monitored. Using tags, seals, and locks, important objects and installations can be safeguarded better. With modern data processing and communication systems, more information can be available, and it can be more speedily processed. Together with navigation and transport equipment, action can be taken faster and at greater range. Particular considerations are presented for cargo control at roads, seaports, and airports, for monitoring designated lines, and for the control of legal arms. By starting at a modest level, costs can be kept low, which would aid developing countries. From the menu of technologies available, systems need to be designed for the intended application and with an understanding of the local conditions. It is recommended that states start with short-term steps, such as acquiring more and better radio transceivers, vehicles, small aircraft, and personal computers. For the medium term, states should begin with experiments and field testing of technologies such as tags, sensors, and digital communication equipment.
Date:
July 1, 2000
Creator:
ALTMANN, JURGEN
Object Type:
Report
System:
The UNT Digital Library
Land-Based Geologic Emplacement of Mercury Wastes
None
Date:
July 20, 2000
Creator:
ANDERSON,D. RICHARD
Object Type:
Article
System:
The UNT Digital Library
THE PHENIX EXPERIMENT AT RHIC.
PHENIX is a large detector at the Relativistic Heavy Ion Collider (RHIC) at BNL. RHIC and PHENIX have recently operated for the first time, producing and detecting collisions of gold ions at beam energies of 30 and 65 GeV per nucleon. The current performance and future plans of PHENIX and of RHIC are presented.
Date:
July 27, 2000
Creator:
ARONSON,S. FOR THE PHENIX COLLABORATION
Object Type:
Article
System:
The UNT Digital Library
An Overview of High Reliability Transformer Encapsulation Materials
None
Date:
July 12, 2000
Creator:
ARRIS,HOWARD W.
Object Type:
Article
System:
The UNT Digital Library
Conductivities and Seebeck Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping
The most conspicuous feature of boron carbides' electronic transport properties is their having both high carrier densities and large Seebeck coefficients. The magnitudes and temperature dependencies of the Seebeck coefficients are consistent with large contributions from softening bipolarons: singlet bipolarons whose stabilization is significantly affected by their softening of local vibrations. Boron carbides' high carrier densities, small activation energies for hopping ({approx} 0.16 eV), and anomalously large Seebeck coefficients combine with their low, glass-like thermal conductivities to make them unexpectedly efficient high-temperature thermoelectrics.
Date:
July 20, 2000
Creator:
ASELAGE,TERRENCE L.; EMIN,DAVID JACOB & MCCREADY,STEVEN S.
Object Type:
Article
System:
The UNT Digital Library
ATLAS TrackingEvent Data Model -- 12.0.0
In this report the event data model (EDM) relevant for tracking in the ATLAS experiment is presented. The core component of the tracking EDM is a common track object which is suited to describe tracks in the innermost tracking sub-detectors and in the muon detectors in offline as well as online reconstruction. The design of the EDM was driven by a demand for modularity and extensibility while taking into account the different requirements of the clients. The structure of the track object and the representation of the tracking-relevant information are described in detail.
Date:
July 23, 2006
Creator:
ATLAS; Akesson, F.; Atkinson, T.; Costa, M.J.; Elsing, M.; Fleischmann, S. et al.
Object Type:
Article
System:
The UNT Digital Library
NUFACT02 MACHINE WORKING GROUP SUMMARY.
At {nu}Fact'02, the muon-based neutrino factory was confronted with existing and planned neutrino facilities. When it was first discussed in 1999 in Lyon [1], it raised great enthusiasm, especially because it was thought to be the only machine capable of measuring CP violation in the leptonic sector. Since that time the pendulum has partially swung back. Two successive detailed studies [2, 3] have shown that a neutrino Factory and the needed R&D were both expensive. In terms of present experiments, neutrino oscillations have been confirmed at SuperK and SNO and results are soon expected from KamLAND. K2K, MniBOONE, MINOS and CNGS are going ahead and new perspectives have been opened by off-axis pion-based neutrino beams and the approval of the high intensity Japanese Hadron Facility. Crests and troughs of a wave are common in long term projects. They are even healthy because they force us to scrutinize the first ideas and sometimes to invent new ones to reach a realistic and affordable design. This analysis has been applied to target systems (section 2), RF capture and cooling of the muons (section 4) and accelerators (section 5). The new concept of pure electron neutrino or anti-neutrino beams produced by, {beta}-decay is …
Date:
July 1, 2002
Creator:
AUTIN,B. FERNOW,R. C. MACHIDA,S. HARRIS,D. A.
Object Type:
Article
System:
The UNT Digital Library
First measurement of the W boson mass in run II of the Tevatron
We present a measurement of the W boson mass using 200 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at Run II of the Fermilab Tevatron. With a sample of 63964 W {yields} ev candidates and 51128 W W {yields} {mu}v candidates, we measure M{sub W} = (80413 {+-} 34{sub stat} {+-}34{sub syst} = 80413 {+-} 48) MeV/c{sup 2}. This is the most precise single measurement of the W boson mass to date.
Date:
July 1, 2007
Creator:
Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, Anthony Allen; Akimoto, T.; Albrow, Michael G. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for a high-mass diphoton state and limits on Randall-Sundrum gravitons at CDF
We have performed a search for new particles which decay to two photons using 1.2 fb{sup -1} of integrated luminosity from p{bar p} collisions at {radical}s=1.96 TeV collected using the CDF II Detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230 GeV/c{sup 2} and 850 GeV/c{sup 2}, at the 95% confidence level, for coupling parameters (k/{bar M}{sub pl}) of 0.01 and 0.1 respectively.
Date:
July 1, 2007
Creator:
Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, Anthony Allen; Akimoto, T.; Albrow, Michael G. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for new physics in high mass electron-positron events in p anti-p collisions at s**(1/2) = 1.96-TeV
We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c{sup 2} using 1.3 fb{sup -1} of p{bar p} collision data at {radical}s=1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard model-like Z{prime} with a mass below 923 GeV/c{sup 2} and the Randall-Sundrum graviton with a mass below 807 GeV/c{sup 2} for k/{bar M}{sub pl} = 0.1, both at the 95% confidence level. Combining with di-photon data excludes the Randall-Sundrum graviton for masses below 889 GeV/c{sup 2} for k/{bar M}{sub pl} = 0.1
Date:
July 1, 2007
Creator:
Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, Anthony Allen; Akimoto, T.; Albrow, Michael G. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the fraction of t anti-t production via gluon-gluon fusion in p anti-p collisions at s**(1/2) = 1.96-TeV
None
Date:
July 1, 2008
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for charged Higgs bosons in decays of top quarks in p anti-p collisions at s**(1/2) = 1.96 TeV
We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2}, assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0. The upper limits on {Beta}(t {yields} H{sup +}b) can also be used as model-independent limits on the decay branching ratio of top quarks to generic scalar charged bosons beyond the standard model.
Date:
July 1, 2009
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type:
Article
System:
The UNT Digital Library