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Dipole magnet for use of RHIC EBIS HEBT line.
Construction and magnetic field measurement of dipole magnets for RHIC-EBIS HEBT line have completed. These magnets will be used to guide highly charged ion beams ranging from proton to Uranium provided by a new injector toward the Booster ring in BNL. In this paper, overview of the magnetic design of the dipoles and results of magnetic field measurement are summarized.
Date:
June 23, 2008
Creator:
Kanesue,T.; Okamura, M.; Ritter, J. & Raparia, D.
Object Type:
Article
System:
The UNT Digital Library
Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade
After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.
Date:
June 23, 2008
Creator:
Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R. et al.
Object Type:
Article
System:
The UNT Digital Library
A Les Houches Interface for BSM Generators
We propose to combine and slightly extend two existing 'Les Houches Accords' to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information--particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc.--is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.
Date:
January 23, 2008
Creator:
Alwall, J.; Boos, E.; Dudko, L.; Gigg, M.; Herquet, M.; Pukhov, A. et al.
Object Type:
Report
System:
The UNT Digital Library
Reduced Basis Method for Nanodevices Simulation
Ballistic transport simulation in nanodevices, which involves self-consistently solving a coupled Schrodinger-Poisson system of equations, is usually computationally intensive. Here, we propose coupling the reduced basis method with the subband decomposition method to improve the overall efficiency of the simulation. By exploiting a posteriori error estimation procedure and greedy sampling algorithm, we are able to design an algorithm where the computational cost is reduced significantly. In addition, the computational cost only grows marginally with the number of grid points in the confined direction.
Date:
May 23, 2008
Creator:
Pau, George Shu Heng
Object Type:
Article
System:
The UNT Digital Library
NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS (NESHAP) SUBPART H RADIONUCLIDES POTENTIAL TO EMIT CALCULATIONS
This document provides an update of the status of stacks on the Hanford Site and the potential radionuclide emissions, i.e., emissions that could occur with no control devices in place. This review shows the calculations that determined whether the total effective dose equivalent (TEDE) received by the maximum public receptor as a result of potential emissions from any one of these stacks would exceed 0.1 millirem/year. Such stacks require continuous monitoring of the effluent, or other monitoring, to meet the requirements of Washington Administrative code (WAC) 246-247-035(1)(a)(ii) and WAC 246-247-075(1), -(2), and -(6). This revised update reviews the potential-to-emit (PTE) calculations of 31 stacks for Fluor Hanford, Inc. Of those 31 stacks, 11 have the potential to cause a TEDE greater than 0.1 mrem/year.
Date:
July 23, 2008
Creator:
JN, EARLEY
Object Type:
Report
System:
The UNT Digital Library
Energy loss of coasting gold ions and deuterons in RHIC.
The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.
Date:
June 23, 2008
Creator:
Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M. et al.
Object Type:
Article
System:
The UNT Digital Library
FINAL REPORT: A Study of the Abundance and 13C/12C Ratio of Atmospheric Carbon Dioxide to Advance the Scientific Understanding of Terrestrial Processes Regulating the GCC
The main objective of this project was to continue research to develop carbon cycle relationships related to the land biosphere based on remote measurements of atmospheric CO2 concentration and its isotopic composition. The project continued time-series observations of atmospheric carbon dioxide and isotopic composition begun by Charles D. Keeling at remote sites, including Mauna Loa, the South Pole, and eight other sites. The program also included the development of methods for measuring radiocarbon content in the collected CO2 samples and carrying out radiocarbon measurements in collaboration with Tom Guilderson of Lawrence Berkeley National Laboratory (LLNL). The radiocarbon measurements can provide complementary information on carbon exchange rates with the land and oceans and emissions from fossil-fuel burning. Using models of varying complexity, the concentration and isotopic measurements were used to establish estimates of the spatial and temporal variations in the net CO2 exchange with the atmosphere, the storage of carbon in the land and oceans, and variable isotopic discrimination of land plants.
Date:
December 23, 2008
Creator:
Keeling, R. F. & Piper, S. C.
Object Type:
Report
System:
The UNT Digital Library
RHIC polarized proton performance in run-8.
During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.
Date:
June 23, 2008
Creator:
Montag, C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D. & al., et
Object Type:
Article
System:
The UNT Digital Library
PROBABILITY BASED CORROSION CONTROL FOR HIGH LEVEL WASTE TANKS: INTERIM REPORT
Controls on the solution chemistry (minimum nitrite and hydroxide concentrations) are in place to prevent the initiation and propagation of pitting and stress corrosion cracking in high level waste (HLW) tanks. These controls are based upon a series of experiments performed on carbon steel coupons in simulated waste solutions. An experimental program was undertaken to investigate reducing the minimum molar nitrite concentration required to confidently inhibit pitting. A statistical basis to quantify the probability of pitting for the tank wall, when exposed to various dilute solutions, is being developed. Electrochemical and coupon testing are being performed within the framework of the statistical test matrix to determine the minimum necessary inhibitor concentrations and develop a quantitative model to predict pitting propensity. A subset of the original statistical test matrix was used to develop an applied understanding of the corrosion response of the carbon steel in the various environments. The interim results suggest that there exists some critical nitrite concentration that sufficiently inhibits against localized corrosion mechanisms due to nitrates/chlorides/sulfates, beyond which further nitrite additions are unnecessary. The combination of visual observation and the cyclic potentiodynamic polarization scans indicate the potential for significant inhibitor reductions without consequence specifically at nitrate concentrations near …
Date:
April 23, 2008
Creator:
Hoffman, E & Karthik Subramanian, K
Object Type:
Report
System:
The UNT Digital Library
FEL-based coherent electron cooling for high-energy hadron colliders
Cooling intense high-energy hadron beams is a major challenge in modern accelerator physics. Synchrotron radiation is too feeble and two common methods--stochastic and electron cooling--are not efficient in providing significant cooling for high energy, high intensity proton colliders. In this paper they discuss a practical scheme of Coherent Electron Cooling (CeC), which promises short cooling times (below one hour) for intense proton beams in RHIC at 250 GeV or in LHC at 7 TeV. A possibility of CeC using various microwave instabilities was discussed since 1980s. In this paper, they present first evaluation of specific CeC scheme based on capabilities of present-day accelerator technology, ERLs, and high-gain Free-Electron lasers (FELs). They discuss the principles, the main limitations of this scheme and present some predictions for Coherent Electron Cooling in RHIC and the LHC operating with ions or protons, summarized in Table 1.
Date:
June 23, 2008
Creator:
Litvinenko,V. N. & Derbenev, Y. S.
Object Type:
Article
System:
The UNT Digital Library
INTERNATIONAL STUDY OF ALUMINUM IMPACTS ON CRYSTALLIZATION IN U.S. HIGH LEVEL WASTE GLASS
The objective of this task was to develop glass formulations for (Department of Energy) DOE waste streams with high aluminum concentrations to avoid nepheline formation while maintaining or meeting waste loading and/or waste throughput expectations as well as satisfying critical process and product performance related constraints. Liquidus temperatures and crystallization behavior were carefully characterized to support model development for higher waste loading glasses. The experimental work, characterization, and data interpretation necessary to meet these objectives were performed among three partnering laboratories: the V.G. Khlopin Radium Institute (KRI), Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL). Projected glass compositional regions that bound anticipated Defense Waste Processing Facility (DWPF) and Hanford high level waste (HLW) glass regions of interest were developed and used to generate glass compositions of interest for meeting the objectives of this study. A thorough statistical analysis was employed to allow for a wide range of waste glass compositions to be examined while minimizing the number of glasses that had to be fabricated and characterized in the laboratory. The glass compositions were divided into two sets, with 45 in the test matrix investigated by the U.S. laboratories and 30 in the test matrix investigated by KRI. …
Date:
September 23, 2008
Creator:
Fox, K; David Peeler, D; Tommy Edwards, T; David Best, D; Irene Reamer, I; Phyllis Workman, P et al.
Object Type:
Report
System:
The UNT Digital Library
RHIC and its upgrade programmes.
As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. After a brief review of the achieved performance the presentation will give an overview of the plans, challenges and status of machine upgrades, that range from a new heavy ion pre-injector and beam cooling at 100 GeV to a high luminosity electron-ion collider.
Date:
June 23, 2008
Creator:
Roser, T.
Object Type:
Article
System:
The UNT Digital Library
Operational experience with a near-integer working point at RHIC.
During the RHIC polarized proton run in N 2006 it became evident that the luminosity performance is limited by the beam-beam effect. With a working point between 213 and 7/10, and the necessity to mirror the tunes of the two RHIC rings at the diagonal, the beam with a horizontal tune closest to 213 showed poor lifetime. To overcome this limitation, a near-integer working point has been proposed. Tracking studies performed at both working points showed a larger dynamic aperture near the integer tune than above 2/3. In Run-8, this new working point was commissioned in one ring of RHIC, while the other ring was operated at the same working point as in Run-6. In this paper we report the commissioning process and operational experience with this new working point.
Date:
June 23, 2008
Creator:
Montag, C.; Bai, M.; Beebe-Wang, J.; FischW; Luo, Y.; Malitsky, N. et al.
Object Type:
Article
System:
The UNT Digital Library
The Role of Multiple Transcription Factors In Archaeal Gene Expression
Since the inception of this research program, the project has focused on two central questions: What is the relationship between the 'eukaryal-like' transcription machinery of archaeal cells and its counterparts in eukaryal cells? And, how does the archaeal cell control gene expression using its mosaic of eukaryal core transcription machinery and its bacterial-like transcription regulatory proteins? During the grant period we have addressed these questions using a variety of in vivo approaches and have sought to specifically define the roles of the multiple TATA binding protein (TBP) and TFIIB-like (TFB) proteins in controlling gene expression in Haloferax volcanii. H. volcanii was initially chosen as a model for the Archaea based on the availability of suitable genetic tools; however, later studies showed that all haloarchaea possessed multiple tbp and tfb genes, which led to the proposal that multiple TBP and TFB proteins may function in a manner similar to alternative sigma factors in bacterial cells. In vivo transcription and promoter analysis established a clear relationship between the promoter requirements of haloarchaeal genes and those of the eukaryal RNA polymerase II promoter. Studies on heat shock gene promoters, and the demonstration that specific tfb genes were induced by heat shock, provided the …
Date:
September 23, 2008
Creator:
Daniels, Charles J.
Object Type:
Report
System:
The UNT Digital Library
Coherent Control of Multiphoton Transitions in the Gas and Condensed Phases with Shaped Ultrashort Pulses
Controlling laser-molecule interactions has become an integral part of developing devices and applications in spectroscopy, microscopy, optical switching, micromachining and photochemistry. Coherent control of multiphoton transitions could bring a significant improvement of these methods. In microscopy, multi-photon transitions are used to activate different contrast agents and suppress background fluorescence; coherent control could generate selective probe excitation. In photochemistry, different dissociative states are accessed through two, three, or more photon transitions; coherent control could be used to select the reaction pathway and therefore the yield-specific products. For micromachining and processing a wide variety of materials, femtosecond lasers are now used routinely. Understanding the interactions between the intense femtosecond pulse and the material could lead to technologically important advances. Pulse shaping could then be used to optimize the desired outcome. The scope of our research program is to develop robust and efficient strategies to control nonlinear laser-matter interactions using ultrashort shaped pulses in gas and condensed phases. Our systematic research has led to significant developments in a number of areas relevant to the AMO Physics group at DOE, among them: generation of ultrashort phase shaped pulses, coherent control and manipulation of quantum mechanical states in gas and condensed phases, behavior of isolated …
Date:
September 23, 2008
Creator:
Dantus, Marcos
Object Type:
Report
System:
The UNT Digital Library
Performance of a Buried Radioactive High Level Waste Glass After 24 Years
None
Date:
May 23, 2008
Creator:
Jantzen, Carol M.; Kaplan, Daniel J.; Bibler, Ned E.; Peeler, David K. & Plodinec, M. J.
Object Type:
Article
System:
The UNT Digital Library
Integrated Global Orbit Feedback with Slow and Fast Correctors
The NSLS-II Light Source, which is planned to be built at Brookhaven National Laboratory, provides users with ultra-bright synchrotron radiation sources and is designed for horizontal beam emittances < 1 nm. Full utilization of the very small emittances and beam sizes requires sub-micron orbit stability in the storage ring. This can be provided by means of a wide bandwidth orbit feedback system. Traditional approach is to utilize a uniform set of fast correctors or use two separate systems with strong slow and weaker fast correctors. In the latter case two systems needed to communicate to suppress transients associated with different update rates of corrector settings. In this paper they consider an integrated system with two types of correctors. Its main feature is that setpoints of slow correctors are updated with the same rate as fast correctors; however the bandwidth is limited in order to stay in linear regime. Possible architectures and technical solutions as well as achievable performance are discussed.
Date:
June 23, 2008
Creator:
Pinayev,I.
Object Type:
Article
System:
The UNT Digital Library
Experience with IBS-suppression lattice in RHIC
An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression.
Date:
June 23, 2008
Creator:
Litvinenko,V. N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Ultra Low Emittance Light Sources
This paper outlines the special issues for reaching sub-nm emittance in a storage ring. Effects of damping wigglers, intra-beam scattering and lifetime issues, dynamic aperture optimization, control of optics, and their interrelations are covered in some detail. The unique choices for the NSLS-II are given as one example.
Date:
June 23, 2008
Creator:
Bengtsson,J.
Object Type:
Article
System:
The UNT Digital Library
Towards sub-10 nm resolution zone plates using the overlaynanofabrication processes
Soft x-ray zone plate microscopy has proven to be a valuable imaging technique for nanoscale studies. It complements nano-analytic techniques such as electron and scanning probe microscopies. One of its key features is high spatial resolution. We developed an overlay nanofabrication process which allows zone plates of sub-20 nm zone widths to be fabricated. Zone plates of 15 nm outer zones were successfully realized using this process, and sub-15 nm resolution was achieved with these zone plates. We extend the overlay process to fabricating zone plates of 12 nm outer zones, which is expected to achieve 10 nm resolution. In addition, we have identified a pathway to realizing sub-10 nm resolution, high efficiency zone plates with tilted zones using the overlay process.
Date:
January 23, 2008
Creator:
Chao, Weilun; Anderson, Erik H.; Fischer, Peter & Kim, Dong-Hyun
Object Type:
Article
System:
The UNT Digital Library
Measurement of ion beam from laser ion source for RHIC EBIS.
Laser ion source (LIS) is a candidate of the primary ion source for the RHIC EBIS. LIS will provide intense charge state 1+ ions to the EBIS for further ionization. We measured plasma properties of a variety of atomic species from C to Au using the second harmonics of Nd:YAG laser (532 nm wave length, up to 0.5 J/6 ns). Since properties of laser produced plasma is different from different species, laser power density for singly charged ion production should be verified experimentally for each atomic species. After plasma analysis experiments, Au ions was extracted from plasma and emittance of the ion beam was measured using a pepper pot type emittance monitor.
Date:
June 23, 2008
Creator:
Kanesue,T.; Tamura, J. & Okamura, M.
Object Type:
Article
System:
The UNT Digital Library
Large File System Backup: NERSC Global File System Experience
NERSC's Global File system (NGF), accessible from all compute systems at NERSC, holds files and data from many scientific projects. A full backup of this file system to our High Performance Storage System (HPSS) is performed periodically. Disk storage usage by projects at NERSC has grown seven fold over a two year period, from ~;;20TB in June 2006 to ~;;140 TB in June 2008. The latest full backup took about 13 days and more than 200 T10k tape cartridges (.5 TB capacity). Petabyte file systems are becoming a reality in the next few years and the existing utilities are already strained in handling backup tasks.
Date:
October 23, 2008
Creator:
Mokhtarani, Akbar; Andrews, Matthew; Hick, Jason & Kramer, William
Object Type:
Report
System:
The UNT Digital Library
DOECGF 2008 Site Report
The Data group provides data analysis and visualization support to its customers. This consists primarily of the development and support of VisIt, a data analysis and visualization tool. Support ranges from answering questions about the tool, providing classes on how to use the tool, and performing data analysis and visualization for customers. The Information Management and Graphics Group supports and develops tools that enhance our ability to access, display, and understand large, complex data sets. Activities include applying visualization software for terascale data exploration; running two video production labs; supporting graphics libraries and tools for end users; maintaining PowerWalls and assorted other displays; and developing software for searching, managing, and browsing scientific data. Researchers in the Center for Applied Scientific Computing (CASC) work on various projects including the development of visualization techniques for terascale data exploration that are funded by the ASC program, among others. The researchers also have LDRD projects and collaborations with other lab researchers, academia, and industry. During the past year we have completed our visualization cluster strategy of converting to Opteron/IB clusters. We support a 128-node Opteron/IB cluster providing a visualization production server for our unclassified systems and a 256-node Opteron/IB cluster for the classified systems, …
Date:
April 23, 2008
Creator:
Springmeyer, R & Brugger, E
Object Type:
Report
System:
The UNT Digital Library
Plasma Lens for Muon and Neutrino Beams
The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented.
Date:
June 23, 2008
Creator:
Kahn, S. A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J. C.; Hershcovitch, A. et al.
Object Type:
Article
System:
The UNT Digital Library