1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS. (open access)

1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS.

A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) proton Accelerator is being studied as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The major benefit is that it would considerably shorten the overall AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power at the top energy of 28 GeV. This paper describes the FFAG design for acceleration of protons from 400 MeV to 1.5 GeV, with the same circumference of the AGS, and entirely housed in the AGS tunnel.
Date: July 5, 2004
Creator: Ruggiero, A. G.; Blaskiewicz, M.; Trbojevic, D.; Tsoupas, N. & Zhang, W.
Object Type: Article
System: The UNT Digital Library
A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT (open access)

A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT

We have achieved {approx}30 psec single-photoelectron and {approx}12ps for multi-photoelectron timing resolution with a new 64 pixel Burle MCP-PMT with 10 micron microchannel holes. We have also demonstrated that this detector works in a magnetic field of 15kG, and achieved a single-photoelectron timing resolution of better than 60 psec. The study is relevant for a new focusing DIRC RICH detector for particle identification at future Colliders such as the super B-factory or ILC, and for future TOF techniques. This study shows that a highly pixilated MCP-PMT can deliver excellent timing resolution.
Date: July 5, 2006
Creator: Va'vra, J.; Benitez, J.; Coleman, J.; Leith, D. W. G. S.; Mazaheri, G.; Ratcliff, B. et al.
Object Type: Article
System: The UNT Digital Library
100 Areas: (For technical progress letter No. 104), June 25--July 1 (open access)

100 Areas: (For technical progress letter No. 104), June 25--July 1

None
Date: July 5, 1946
Creator: Jordan, W. E.
Object Type: Report
System: The UNT Digital Library
ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES. (open access)

ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.
Date: July 5, 2004
Creator: ROSER,T. AHRENS,L. BAI,M. ET AL.
Object Type: Article
System: The UNT Digital Library
Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime (open access)

Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime

A CERN-SLAC-KEK collaboration on high gradient X-band accelerator structure development for CLIC has been ongoing for three years. The major outcome has been the demonstration of stable 100 MV/m gradient operation of a number of CLIC prototype structures. These structures were fabricated using the technology developed from 1994 to 2004 for the GLC/NLC linear collider initiative. One of the goals has been to refine the essential parameters and fabrication procedures needed to realize such a high gradient routinely. Another goal has been to develop structures with stronger dipole mode damping than those for GLC/NLC. The latter requires that the surface temperature rise during the pulse be higher, which may increase the breakdown rate. One structure with heavy damping has been RF processed and another is nearly finished. The breakdown rates of these structures were found to be higher by two orders of magnitude compared to those with equivalent acceleration mode parameters but without the damping features. This paper presents these results together with some of the earlier results from non-damped structures.
Date: July 5, 2012
Creator: Higo, Toshiyasu; Higashi, Yasuo; Matsumoto, Shuji; Yokoyama, Kazue; Adolphsen, Chris; Dolgashev, Valery et al.
Object Type: Article
System: The UNT Digital Library
Air quality impacts analysis for area G. Final report (open access)

Air quality impacts analysis for area G. Final report

The impact of fugitive radioactive emissions from the disposal site, Area G, was evaluated in support of site characterization for the Performance Assessment and for the Radioactive Air Emissions Management (RAEM) program. Fugitive emissions of tritiated water and contaminated windblown dust were considered. Data from an extensive field measurement program were used to estimate annual emissions of tritiated water. Fugitive dust models were used to calculate estimates of the annual emissions of windblown dust. These estimates were combined with data on contamination levels in surface soils to develop annual emission rates for specific radionuclides: tritium, uranium-238, cesium-137, plutonium-238, plutonium-239,240, and strontium-90. The CAP-88 atmospheric transport model was used to predict areas potentially affected by long-term dust deposition and atmospheric concentrations. The annual emission rate of tritiated water was estimated from the field data to be 14.0 Ci/yr. The emission rate of soil-borne radionuclides from open areas and from soils handling operations totaled less than 1x10{sup -4} Ci/yr. The CAP-88 results were used to develop effective dose equivalents (EDEs) for receptor locations downwind of Area G. All EDEs were several orders of magnitude below the national standard of 10 mrem/yr. Fugitive air emissions from Area G were found not to pose …
Date: July 5, 1995
Creator: Kowalewsky, K.; Eklund, B. & Vold, E. L.
Object Type: Report
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
Analysis of Electron Cloud at Rhic. (open access)

Analysis of Electron Cloud at Rhic.

Pressure rises with high intense beams are among the main luminosity limitations at RHIC. Observations during the latest runs show beam induced electron multipacting as one of the causes for these pressure rises. Experimental studies are carried out at RHIC using devoted instrumentation to understand the mechanism leading to electron clouds. In the following, we report the experimental electron cloud data and the analyzed results using computer simulation codes.
Date: July 5, 2004
Creator: Iriso, U.; Blaskiewicz, M.; Cameron, P.; Drees, A.; Fischer, W. & Al., Et
Object Type: Article
System: The UNT Digital Library
Analysis on linac quadrupole misalignment in FACET commissioning 2012 (open access)

Analysis on linac quadrupole misalignment in FACET commissioning 2012

In this note, the analysis on linac quadrupole misalignment is presented for the FACET linac section LI05-09 plus LI11-19. The effectiveness of the beam-based alignment technique is preliminarily confirmed by the measurement. Beam-based alignment technique was adopted at SLAC linac since SLC time. Here the beam-based alignment algorithms are further developed and applied in the FACET commissioning during 2012 run.
Date: July 5, 2012
Creator: Sun, Yipeng
Object Type: Report
System: The UNT Digital Library
Apparatus and techniques for the study of precipitation of solids and silica from hypersaline geothermal brine (open access)

Apparatus and techniques for the study of precipitation of solids and silica from hypersaline geothermal brine

The kinetics of precipitation reactions in geothermal brines can be studied accurately only if the brine samples are collected and examined under anaerobic conditions and with minimum cooling. Apparatus and techniques were developed that achieve this for brine temperatures below 100/sup 0/C. The concentration of suspended solids is measured gravimetrically after filtration, and the concentration of dissolved silica is measured by atomic absorption spectrophotometry. Data from Woolsey No. 1 well of the Salton Sea Geothermal Field illustrate typical results of the procedures.
Date: July 5, 1979
Creator: Hill, J. H.; Harrar, J. E.; Otto, C. H., Jr.; Deutscher, S. B.; Crampton, H. E.; Grogan, R. G. et al.
Object Type: Report
System: The UNT Digital Library
Application of a New Method for Analyzing Images: Two-Dimensional Non-Linear Additive Decomposition (open access)

Application of a New Method for Analyzing Images: Two-Dimensional Non-Linear Additive Decomposition

This paper documents the application of a new image processing algorithm, two-dimensional non-linear additive decomposition (NLAD), which is used to identify regions in a digital image whose gray-scale (or color) intensity is different than the surrounding background. Standard image segmentation algorithms exist that allow users to segment images based on gray-scale intensity and/or shape. However, these processing techniques do not adequately account for the image noise and lighting variation that typically occurs across an image. NLAD is designed to separate image noise and background from artifacts thereby providing the ability to consistently evaluate images. The decomposition techniques used in this algorithm are based on the concepts of mathematical morphology. NLAD emulates the human capability of visually separating an image into different levels of resolution components, denoted as ''coarse'', ''fine'', and ''intermediate''. Very little resolution information overlaps any two of the component images. This method can easily determine and/or remove trends and noise from an image. NLAD has several additional advantages over conventional image processing algorithms, including no need for a transformation from one space to another, such as is done with Fourier transforms, and since only finite summations are required, the calculational effort is neither extensive nor complicated.
Date: July 5, 2006
Creator: Zaccaria, M. A.; Drudnoy, D. M. & Stasenko, J. E.
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
ASPEN computer simulations of the mixed waste treatment project baseline flowsheet (open access)

ASPEN computer simulations of the mixed waste treatment project baseline flowsheet

The treatment and disposal of mixed waste (i.e., waste containing both hazardous and radioactive components) is a challenging waste- management problem of particular concern to Department of Energy (DOE) sites throughout the United States. Traditional technologies used for destroying hazardous wastes must be re- evaluated for their ability to handle mixed wastes, and, in some cases, new technologies must be developed. The Mixed Waste Treatment Project (MWTP), a collaborative effort between Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, and Pacific Northwest Laboratory (PNL), was established by the DOE`s Waste Operations Program (EM-30) to develop and analyze alternative mixed waste treatment approaches. One of the MWTP`s initiatives, and the objective of this study, was to develop flowsheets for prototype, integrated, mixed-waste treatment facilities that can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modeling. The objectives of the flowsheet simulations are to compare process effectiveness and costs of alternative flowsheets and to determine if commercial process-simulation software could be used on the large, complex process of an integrated mixed waste processing facility. Flowsheet modeling is needed to evaluate many aspects of proposed flowsheet designs. A …
Date: July 5, 1994
Creator: Dietsche, L. J.; Upadhye, R. S.; Camp, D. W.; Pendergrass, J. A.; Borduin, L. C. & Thompson, T. K.
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
Azimuthal Charged-Particle Correlations and Possible Local Strong Parity Violation (open access)

Azimuthal Charged-Particle Correlations and Possible Local Strong Parity Violation

Parity-odd domains, corresponding to non-trivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three particle azimuthal correlator which is a {Rho} even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au+Au and Cu+Cu collisions at {radical}s{sub NN} = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.
Date: July 5, 2010
Creator: STAR Collaboration
Object Type: Article
System: The UNT Digital Library
Beam Conditioning and Harmonic Generation in Free ElectronLasers (open access)

Beam Conditioning and Harmonic Generation in Free ElectronLasers

The next generation of large-scale free-electron lasers (FELs) such as Euro-XFEL and LCLS are to be devices which produce coherent X-rays using Self-Amplified Spontaneous Emission (SASE). The performance of these devices is limited by the spread in longitudinal velocities of the beam. In the case where this spread arises primarily from large transverse oscillation amplitudes, beam conditioning can significantly enhance FEL performance. Future X-ray sources may also exploit harmonic generation starting from laser-seeded modulation. Preliminary analysis of such devices is discussed, based on a novel trial-function/variational-principle approach, which shows good agreement with more lengthy numerical simulations.
Date: July 5, 2004
Creator: Charman, A.E.; Penn, G.; Wolski, A. & Wurtele, J.S.
Object Type: Article
System: The UNT Digital Library
BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN. (open access)

BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN.

One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. A beam scrubbing study shows that with a reasonable period of time of running high intensity 112-bunch proton beam, the pressure rise can be reduced, allowing higher beam intensity.
Date: July 5, 2004
Creator: ZHANG,S. Y. FISCHER,W. HUANG,H. ROSER,T.
Object Type: Article
System: The UNT Digital Library
Biomolecular Origin of The Rate-Dependent Deformation of Prismatic Enamel (open access)

Biomolecular Origin of The Rate-Dependent Deformation of Prismatic Enamel

Penetration deformation of columnar prismatic enamel was investigated using instrumented nanoindentation testing, carried out at three constant strain rates (0.05 s{sup -1}, 0.005 s{sup -1}, and 0.0005 s{sup -1}). Enamel demonstrated better resistance to penetration deformation and greater elastic modulus values were measured at higher strain rates. The origin of the rate-dependent deformation was rationalized to be the shear deformation of nanoscale protein matrix surrounding each hydroxyapatite crystal rods. And the shear modulus of protein matrix was shown to depend on strain rate in a format: G{sub p} = 0.213 + 0.021 ln {dot {var_epsilon}}. Most biological composites compromise reinforcement mineral components and an organic matrix. They are generally partitioned into multi-level to form hierarchical structures that have supreme resistance to crack growth [1]. The molecular mechanistic origin of toughness is associated with the 'sacrificial chains' between the individual sub-domains in a protein molecule [2]. As the protein molecule is stretched, these 'sacrificial chains' break to protect its backbone and dissipate energy [3]. Such fresh insights are providing new momentum toward updating our understanding of biological materials [4]. Prismatic enamel in teeth is one such material. Prismatic microstructure is frequently observed in the surface layers of many biological materials, as …
Date: July 5, 2006
Creator: Zhou, J & Hsiung, L
Object Type: Article
System: The UNT Digital Library
BUNCH PATTERNS AND PRESSURE RISE IN RHIC. (open access)

BUNCH PATTERNS AND PRESSURE RISE IN RHIC.

The RHIC luminosity is limited by pressure rises with high intensity beams. At injection and store, the dominating cause for the pressure rise was shown to be electron clouds. We discuss bunch distributions along the circumference that minimize the electron cloud effect in RHIC. Simulation results are compared with operational observations.
Date: July 5, 2004
Creator: FISCHER,W. IRISO-ARIZ,U.
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
Cavitational Hydrothermal Oxidation: A New Remediation Process - Final Report (open access)

Cavitational Hydrothermal Oxidation: A New Remediation Process - Final Report

During the past year, we have continued to make substantial scientific progress on our understanding of cavitation phenomena in aqueous media and applications of cavitation to remediation processes. Our efforts have focused on three separate areas: sonoluminescence as a probe of conditions created during cavitational collapse in aqueous media, the use of cavitation for remediation of contaminated water, and an addition of the use of ultrasound in the synthesis of novel heterogeneous catalysts for hydrodehalogenation of halocarbons under mild conditions.
Date: July 5, 2001
Creator: Suslick, K. S.
Object Type: Report
System: The UNT Digital Library
Center of mass energy and system-size dependence of photon production at forward rapidity at RHIC (open access)

Center of mass energy and system-size dependence of photon production at forward rapidity at RHIC

We present the multiplicity and pseudorapidity distributions of photons produced in Au+Au and Cu+Cu collisions at {radical}s{sub NN} = 62.4 and 200 GeV. The photons are measured in the region -3.7 < {eta} < -2.3 using the photon multiplicity detector in the STAR experiment at RHIC. The number of photons produced per average number of participating nucleon pairs increases with the beam energy and is independent of the collision centrality. For collisions with similar average numbers of participating nucleons the photon multiplicities are observed to be similar for Au+Au and Cu+Cu collisions at a given beam energy. The ratios of the number of charged particles to photons in the measured pseudorapidity range are found to be 1.4 {+-} 0.1 and 1.2 {+-} 0.1 for {radical}s{sub NN} = 62.4 GeV and 200 GeV, respectively. The energy dependence of this ratio could reflect varying contributions from baryons to charged particles, while mesons are the dominant contributors to photon production in the given kinematic region. The photon pseudorapidity distributions normalized by average number of participating nucleon pairs, when plotted as a function of {eta} - ybeam, are found to follow a longitudinal scaling independent of centrality and colliding ion species at both beam …
Date: July 5, 2010
Creator: STAR Collaboration
Object Type: Article
System: The UNT Digital Library
Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study (open access)

Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study

The prior project consisted of two main project lines. First, characterization of novel nanomaterials for hydrodesulfurization (HDS) applications. Second, studying more traditional model systems for HDS such as vapor-deposited silica-supported Mo and MoSx clusters. In the first subproject, we studied WS2 and MoS2 fullerene-like nanoparticles as well as WS2 nanotubes. Thiophene (C4H4S) was used as the probe molecule. Interestingly, metallic and sulfur-like adsorption sites could be identified on the silica-supported fullerene-particles system. Similar structures are seen for the traditional system (vapor-deposited clusters). Thus, this may be a kinetics fingerprint feature of modern HDS model systems. In addition, kinetics data allowed characterization of the different adsorption sites for thiophene on and inside WS2 nanotube bundles. The latter is a unique feature of nanotubes that has not been reported before for any inorganic nanotube system; however, examples are known for carbon nanotubes, including prior work of the PI. Although HDS has been studied for decades, utilizing nanotubes as nanosized HDS reactors has never been tried before, as far as we know. This is of interest from a fundamental perspective. Unfortunately, the HDS activity of the nanocatalysts at ultra-high vacuum (UHV) conditions was close to the detection limit of our techniques. Therefore, we …
Date: July 5, 2012
Creator: Burghaus, U.
Object Type: Report
System: The UNT Digital Library