The United States and Europe: Current Issues (open access)

The United States and Europe: Current Issues

This report examines the current state of the transatlantic relationship and key issues that may have implications for U.S. interests during the 109th Congress.
Date: July 5, 2006
Creator: Archick, Kristin & Morelli, Vince L.
Object Type: Report
System: The UNT Digital Library
Measurement of the Spin of the Omega- Hyperon at Babar (open access)

Measurement of the Spin of the Omega- Hyperon at Babar

A measurement of the spin of the {Omega}{sup -} hyperon produced through the exclusive process {Xi}{sub c}{sup 0} {yields} {Omega}{sup -}K{sup +} is presented using a total integrated luminosity of 116 fb{sup -1} recorded with the BABAR detector at the e{sup +}e{sup -} asymmetric-energy B-Factory at SLAC. Under the assumption that the {Xi}{sub c}{sup 0} has spin 1/2, the angular distribution of the {Lambda} from {Omega}{sup -} {yields} {Lambda}K{sup -} decay is inconsistent with all half-integer {Omega}{sup -} spin values other than 3/2. Lower statistics data for the process {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} from a 230 fb{sup -1} sample are also found to be consistent with {Omega}{sup -} spin 3/2. If the {Xi}{sub c}{sup 0} spin were 3/2, an {Omega}{sup -} spin of 5/2 cannot be excluded.
Date: July 5, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
STOCHASTIC COOLING STUDIES IN RHIC, II. (open access)

STOCHASTIC COOLING STUDIES IN RHIC, II.

Intra-beam scattering (IBS) is unavoidable for highly charged heavy ions and causes emittance growth during the store for collision physics. A longitudinal bunched beam stochastic cooling system will confine the bunch within the RF bucket increasing the useful luminosity. We describe a series of measurements in RHIC that have been used to verify our understanding of the relevant physics and the cooling system architecture that is being prototyped.
Date: July 5, 2004
Creator: BLASKIEWICZ,M. BRENNAN,J. M. WEI,J.
Object Type: Article
System: The UNT Digital Library
RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC. (open access)

RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC.

The luminosity of the Relativistic Heavy Ion Collider has improved significantly [1] over the first three physics runs. A number of special rf techniques have been developed to facilitate higher luminosity. The techniques described herein include: an ultra low-noise rf source for the 197 MHz storage rf system, a frequency shift switch-on technique for transferring bunches from the acceleration to the storage system, synchronizing the rings during the energy ramp (including crossing the transition energy) to avoid incidental collisions, installation of dedicated 200 MHZ cavities to provide longitudinal Landau damping on the ramp, and the development of a bunch merging scheme in the Booster to increase the available bunch intensity from the injectors.
Date: July 5, 2004
Creator: BRENNAN,J. M. BLASKIEWICZ,J. BUTLER,J. DELONG,J. FISCHER,W. HAYES,T.
Object Type: Article
System: The UNT Digital Library
RESULTS OF THE NASA SPACE RADIATION LABORATORY BEAM STUDIES PROGRAM AT BNL. (open access)

RESULTS OF THE NASA SPACE RADIATION LABORATORY BEAM STUDIES PROGRAM AT BNL.

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. The purpose of the NSRL Beam Studies Program is to develop a clear understanding of the beams delivered to the facility, to fully characterize those beams, and to develop new capabilities in the interest of understanding the radiation environment in space. In this report we will describe the first results from this program.
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BEUTTENMULLER,R. H. ET AL.
Object Type: Article
System: The UNT Digital Library
RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL. (open access)

RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL.

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The results of commissioning of this new facility were reported in [l]. In this report we will describe the results of the first run. The NSRL is capable of making use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. Many modes of operation were explored during the first run, demonstrating all the capabilities designed into the system. Heavy ion intensities from 100 particles per pulse up to 12 x 10{sup 9} particles per pulse were delivered to a large variety of experiments, providing a dose range up to 70 Gy/min over a 5 x 5 cm{sup 2} area. Results presented will include those related to the production of beams that are highly uniform in both the transverse and longitudinal planes of motion [2].
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BRENNAN,J. M. ET. AL.
Object Type: Article
System: The UNT Digital Library
MINI-BUNCHED AND MICRO-BUNCHED SLOW EXTRACTED BEAMS FROM THE AGS. (open access)

MINI-BUNCHED AND MICRO-BUNCHED SLOW EXTRACTED BEAMS FROM THE AGS.

Brookhaven National Laboratory's (BNLs) Alternating Gradient Synchrotron (AGS) has a long history of providing slow extracted proton beams to fixed target experiments. This program of providing high quality high intensity beams continues with two new experiments currently being designed for operation at the AGS. Both experiments require slow extracted beam, but with an added requirement that those beams be bunched. Bunched beam slow extraction techniques have been developed for both experiments and initial tests have been performed. In this report we describe the beam requirements for the two experiments, and present results of detailed simulations and initial beam tests.
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BRENNAN,J. M. GLENN,J. W. SIVERTZ,M. KOSCIELNIAK,S. R.
Object Type: Article
System: The UNT Digital Library
The Case for a 500 GeV e+e- Linear Collider (open access)

The Case for a 500 GeV e+e- Linear Collider

Several proposals are being developed around the world for an e+e- linear collider with an initial center of mass energy of 500 GeV. In this paper, we will discuss why a project of this type deserves priority as the next major initiative in high energy physics.
Date: July 5, 2000
Creator: Baggers, J.; Baltay, C.; Barker, T.; Barklow, T.; Bauer, U.; Bolton, T. et al.
Object Type: Report
System: The UNT Digital Library
Non-Destructive Beam Measurements (open access)

Non-Destructive Beam Measurements

In high energy accelerators, especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is an ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with a Schottky detector, phase advance measurements as well as nonlinear resonance measurements with the ac dipoles in the Brookhaven RHIC.
Date: July 5, 2004
Creator: Bai, M.
Object Type: Article
System: The UNT Digital Library
All One-loop Maximally Helicity Violating Gluonic Amplitudes in QCD (open access)

All One-loop Maximally Helicity Violating Gluonic Amplitudes in QCD

We use on-shell recursion relations to compute analytically the one-loop corrections to maximally-helicity-violating n-gluon amplitudes in QCD. The cut-containing parts have been computed previously; our work supplies the remaining rational parts for these amplitudes, which contain two gluons of negative helicity and the rest positive, in an arbitrary color ordering. We also present formulae specific to the six-gluon cases, with helicities (-+-+++) and (-++-++), as well as numerical results for six, seven, and eight gluons. Our construction of the n-gluon amplitudes illustrates the relatively modest growth in complexity of the on-shell-recursive calculation as the number of external legs increases. These amplitudes add to the growing body of one-loop amplitudes known for all n, which are useful for studies of general properties of amplitudes, including their twistor-space structure.
Date: July 5, 2006
Creator: Berger, Carola F.; Bern, Zvi; Dixon, Lance J.; Forde, Darren & Kosower, David A.
Object Type: Report
System: The UNT Digital Library
Nuclear Waste Repository Siting: Expedited Procedures for Congressional Approval (open access)

Nuclear Waste Repository Siting: Expedited Procedures for Congressional Approval

None
Date: July 5, 2002
Creator: Beth, Richard S.
Object Type: Report
System: The UNT Digital Library
Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser (open access)

Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser

A single-pass, high-gain free-electron laser (FEL) x-ray amplifier was simulated using the 3D, polychromatic simulation code MEDUSA. The seed for the system is a table-top, soft x-ray laser. The simulated fundamental and nonlinear harmonic x-ray output wavelengths are discussed.
Date: July 5, 2000
Creator: Biedron, S. G.; Freund, H. P.; Li, Y. & Milton, S. V.
Object Type: Article
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: July 5, 2001
Creator: Bivins, Steven R & Stoetzel, Gregory A
Object Type: Report
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: July 5, 2001
Creator: Bivins, Steven R. & Stoetzel, Gregory A.
Object Type: Report
System: The UNT Digital Library
Final Technical Report - In-line Uranium Immunosensor (open access)

Final Technical Report - In-line Uranium Immunosensor

In this project, personnel at Tulane University and Sapidyne Instruments Inc. developed an in-line uranium immunosensor that could be used to determine the efficacy of specific in situ biostimulation approaches. This sensor was designed to operate autonomously over relatively long periods of time (2-10 days) and was able to provide near real-time data about uranium immobilization in the absence of personnel at the site of the biostimulation experiments. An alpha prototype of the in-line immmunosensor was delivered from Sapidyne Instruments to Tulane University in December of 2002 and a beta prototype was delivered in November of 2003. The beta prototype of this instrument (now available commercially from Sapidyne Instruments) was programmed to autonomously dilute standard uranium to final concentrations of 2.5 to 100 nM (0.6 to 24 ppb) in buffer containing a fluorescently labeled anti-uranium antibody and the uranium chelator, 2,9-dicarboxyl-1,10-phenanthroline. The assay limit of detection for hexavalent uranium was 5.8 nM or 1.38 ppb. This limit of detection is well below the drinking water standard of 30 ppb recently promulgated by the EPA. The assay showed excellent precision; the coefficients of variation (CV’s) in the linear range of the assay were less than 5% and CV’s never rose above …
Date: July 5, 2006
Creator: Blake, Diane A.
Object Type: Report
System: The UNT Digital Library
High Brightness Electron Guns for Next-Generation Light Sources and Accelerators. (open access)

High Brightness Electron Guns for Next-Generation Light Sources and Accelerators.

Next-generation light sources and accelerators are being proposed that set unique requirements for the electron source parameters. No single source is suitable for the diverse applications, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with our various partners, is developing a variety of electron gun concepts for these important applications.
Date: July 5, 2004
Creator: Bluem, H. P.; Ben-Zvi, Ilan; Srinivasan-Rao, T. & AL., ET
Object Type: Article
System: The UNT Digital Library
Iraq:  U.S. Military Operations (open access)

Iraq: U.S. Military Operations

Iraq’s chemical, biological, and nuclear weapons programs, together with Iraqi long-range missile development and support for al-Queda terrorism, were the primary justifications put forward for military action. On March 17, 2003, President Bush issued an ultimatum demanding that Saddam Hussein and his sons depart from Iraq within 48 hours. On March 19, offensive operations began with air strikes against Iraqi leadership positions. By April 15, after 27 days of operations, coalition forces were in relative control of all major Iraqi cities and Iraqi political and military leadership had disintegrated. On May 1, 2003, President Bush declared an end to major combat operations. There was no use of chemical or biological (CB)weapons, and no CB or nuclear weapons stockpiles or production facilities have been found.
Date: July 5, 2005
Creator: Bowman, Steven R.
Object Type: Report
System: The UNT Digital Library
Atomistic Modeling of Wave Propagation in Nanocrystals (open access)

Atomistic Modeling of Wave Propagation in Nanocrystals

We present non-equilibrium molecular dynamics (MD) simulations of wave propagation in nanocrystals. We find that the width of the traveling wave front increases with grain size, d, as d{sup 1/2}. This width also decreases with the pressure behind the front. We extrapolate our results to micro-crystals and obtain reasonable agreement with experimental data. In addition, our extrapolation agrees with models that only take into account the various velocities of propagation along different crystalline orientations, without including grain boundary effects. Our results indicate that, even at the nanoscale, the role of grain boundaries as scattering centers or as sources of plasticity does not increase significantly the width of the traveling wave.
Date: July 5, 2005
Creator: Bringa, E; Caro, A; Victoria, M & Park, N
Object Type: Article
System: The UNT Digital Library
Growth of large patterned arrays of neurons using plasma methods (open access)

Growth of large patterned arrays of neurons using plasma methods

None
Date: July 5, 2002
Creator: Brown, I. G.; Bjornstad, K. A.; Blakely, E. A.; Galvin, J. E.; Monteiro, O. R. & Sangyuenyongpipat, S.
Object Type: Article
System: The UNT Digital Library
United Nations Peacekeeping: Issues for Congress (open access)

United Nations Peacekeeping: Issues for Congress

None
Date: July 5, 2006
Creator: Browne, Marjorie Ann
Object Type: Report
System: The UNT Digital Library
HIGH CURRENT SUPERCONDUCTING CAVITIES AT RHIC. (open access)

HIGH CURRENT SUPERCONDUCTING CAVITIES AT RHIC.

A five-cell high current superconducting cavity for the electron cooling project at RHIC is under fabrication. Higher order modes (HOMs), one of main limiting factors for high current energy-recovery operation, are under investigation. Calculations of HOMs using time-domain methods in Mafia will be discussed and compared to calculations in the frequency domain. Beam breakup thresholds determined from numerical codes for the five-cell cavity will be presented. A possible motivation towards a 2 x 2 superstructure using the current five-cell design will also be discussed.
Date: July 5, 2004
Creator: CALAGA,R. BEN-ZVI,I. ZHAO,Y. ET AL.
Object Type: Article
System: The UNT Digital Library
RHIC BPM Performance: Comparison of Run 2003 and 2004. (open access)

RHIC BPM Performance: Comparison of Run 2003 and 2004.

Identification of malfunctioning beam position monitors (BPMs) play an important role in any orbit or turn-by-turn analysis. Singular value decomposition (SVD) and Fourier transform methods were recently employed to identify malfunctioning BPMs at RHIC. A detailed statistical comparison between the two methods for Run 2003 was in good agreement and proved to be a robust method to identify faulty BPMs. We evaluate detailed BPM performance for different upgrades of BPM low-level software during Run 2003 and 2004.
Date: July 5, 2004
Creator: Calaga, R.
Object Type: Article
System: The UNT Digital Library
Transverse Coupling Measurement Using SVD Modes From Beam Histories. (open access)

Transverse Coupling Measurement Using SVD Modes From Beam Histories.

In this report we investigate the measurement of local transverse coupling from turn-by-turn data measured at a large number of beam position monitors. We focus on a direct measurement of coupled lattice functions using the singular value decomposition (SVD) modes and explore the accuracy of this method.
Date: July 5, 2004
Creator: Calaga, R. & Wang, C.
Object Type: Article
System: The UNT Digital Library
RHIC OPTICS MEASUREMENTS AT DIFFERENT WORKING POINTS. (open access)

RHIC OPTICS MEASUREMENTS AT DIFFERENT WORKING POINTS.

Working point scans at RHIC were performed during 2004 to determine the effect on lifetime and luminosity. Linear optics were measured for different working point tunes by exciting coherent oscillations with the aid of RHIC AC dipoles. Two methods are currently used to measure the beta functions and phases advances: a conventional fitting technique, and an alternate method based on singular value decomposition (SVD). This paper focuses on the effect of working point on the measurement of linear optics using a SVD based technique. The use of a 3-bump beta wave algorithm to identify quadrupole error sources is also presented.
Date: July 5, 2004
Creator: Calaga, R.; Bai, M.; Peggs, S.; Roser, T. & Satogata, T.
Object Type: Article
System: The UNT Digital Library