247 Matching Results

Search Results

Results: 1 - 24 next
open access

Practical Thermal Evaluation Methods For HAC Fire Analysis In Type B Radiaoactive Material (RAM) Packages

Description: Title 10 of the United States Code of Federal Regulations Part 71 for the Nuclear Regulatory Commission (10 CFR Part 71.73) requires that Type B radioactive material (RAM) packages satisfy certain Hypothetical Accident Conditions (HAC) thermal design requirements to ensure package safety during accidental fire conditions. Compliance with thermal design requirements can be met by prototype tests, analyses only or a combination of tests and analyses. Normally, it is impractical to meet all the HA… more
Date: March 28, 2013
Creator: Abramczyk, Glenn; Hensel, Stephen J & Gupta, Narendra K.
Partner: UNT Libraries Government Documents Department
open access

Performance of the new EBIS preinjector

Description: The construction and initial commissioning phase of a new heavy ion preinjector was completed at Brookhaven in September, 2010, and the preinjector is now operational. This preinjector, using an EBIS source to produce high charge state heavy ions, provided helium and neon ion beams for use at the NASA Space Radiation Laboratory in the Fall of 2010, and gold and uranium beams are being commissioned during the 2011 run cycle for use in RHIC. The EBIS operates with an electron beam current of up t… more
Date: March 28, 2011
Creator: Alessi, J.; Beebe, E.; Binello, S.; Gardner, C.; Gould, O.; Hoff, L. et al.
Partner: UNT Libraries Government Documents Department
open access

Using life-cycle analysis to estimate economic performance

Description: One of the principal tools of industrial ecology is life-cycle assessment which intends to improve overall economic efficiency and to minimize negative environmental impacts of products, processes, and facilities. This paper describes a general methodology for environmentally responsible assessment of these activities; it discusses some of the underlying considerations for this assessment which are accessible by rigorous quantitative analysis; and an overall economic performance metric is propo… more
Date: March 28, 1996
Creator: Allenby, B.R.
Partner: UNT Libraries Government Documents Department
open access

Low Mach Number Modeling of Type Ia Supernovae. II. EnergyEvolution

Description: The convective period leading up to a Type Ia supernova (SNIa) explosion is characterized by very low Mach number flows, requiringhydrodynamical methods well-suited to long-time integration. We continuethe development of the low Mach number equation set for stellar scaleflows by incorporating the effects of heat release due to externalsources. Low Mach number hydrodynamics equations with a time-dependentbackground state are derived, and a numerical method based on theapproximate projection form… more
Date: March 28, 2006
Creator: Almgren, Ann S.; Bell, John B.; Rendleman, Charles A. & Zingale,Mike
Partner: UNT Libraries Government Documents Department
open access

The machine protection system for the R&D energy recovery LINAC

Description: The Machine Protection System (MPS) is a device-safety system that is designed to prevent damage to hardware by generating interlocks, based upon the state of input signals generated by selected sub-systems. It protects all the key machinery in the R&D Project called the Energy Recovery LINAC (ERL) against the high beam current. The MPS is capable of responding to a fault with an interlock signal within several microseconds. The ERL MPS is based on a National Instruments CompactRIO platform… more
Date: March 28, 2011
Creator: Altinbas, Z.; Kayran, D.; Jamilkowski, J.; Lee, R.C. & Oerter, B.
Partner: UNT Libraries Government Documents Department
open access

Design Construction and Test Results of a HTS Solenoid For Energy Recovery Linac

Description: An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at {approx}77 K is simpler and cheaper than 4 K testing. This paper will present the design, construction and test results of this HTS solenoid. The HTS solenoid… more
Date: March 28, 2011
Creator: Anerella, M.; Ben-Zvi, Ilan; Kayran, D.; McIntyre, G.; Muratore, J.; Plate, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Measurement of CP Violation Parameters with a Dalitz Plot Analysis of B+- to D(pi+pi-pi0)K+-

Description: We report the results of a CP violation analysis of the decay B{sup {+-}} {yields} D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}}K{sup {+-}}, where D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}} indicates a neutral D meson detected in the final state {pi}{sup +}{pi}{sup -}{pi}{sup 0}, excluding K{sub S}{sup 0}{pi}{sup 0}. The analysis makes use of 324 million e{sup +}e{sup -} {yields} B{bar B} events recorded by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage ring. By analyzing the {pi}{sup +}{… more
Date: March 28, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Beam losses due to abrupt crab cavity failures in the LHC

Description: A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting bea… more
Date: March 28, 2011
Creator: Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B. et al.
Partner: UNT Libraries Government Documents Department
open access

Dark Matter Jets at the LHC

Description: We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such strongly interacting particles by looking for a signal of two trackless jets. We show that suitable cuts can plausibly allow us to find these signals at the LHC even in … more
Date: March 28, 2012
Creator: Bai, Yang & Rajaraman, Arvind
Partner: UNT Libraries Government Documents Department
open access

Booster main magnet power supply, present operation and potential future upgrades

Description: The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, +/-2000 Volts, or 3000 Amps, +/-6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the differ… more
Date: March 28, 2011
Creator: Bajon, E.; Bannon, M.; Marneris, I.; Danowski, G.; Sandberg, J. & Savatteri, S.
Partner: UNT Libraries Government Documents Department
open access

Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings

Description: We have investigated collective effects in an ultimate storage ring, i.e. one with diffraction limited emittances in both planes, using PEP-X as an example. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, a 4.5 GeV ring running round beams at 200 mA in 3300 bunches, IBS doubles the emittances to 11.5 pm at the design current. The Touschek lifetime is 11 hours. Impedance driven collective effects tend not to be important since the beam curr… more
Date: March 28, 2012
Creator: Bane, Karl
Partner: UNT Libraries Government Documents Department
open access

Study of Single and Coupled-Bunch Instabilities for NSLS-II

Description: We study single and coupled-bunch instabilities for the NSLS-II storage ring with a recently developed parallel tracking code. For accurate modelling of the coupled-bunch instability, we investigate improvements to current point-bunch models to take into account finite bunch-size effects. Accurate modelling of single and coupled-bunch instabilities is of crucial importance for the machine performance of light sources such as NSLS-II, that provide high current beams. The complexity of the model … more
Date: March 28, 2011
Creator: Bassi, G. & Blednykh, A.
Partner: UNT Libraries Government Documents Department
open access

Comparison of 1D and 2D CSR Models with Application to the FERMI@ELETTRA Bunch Compressors

Description: We compare our 2D mean field (Vlasov-Maxwell) treatment of coherent synchrotron radiation (CSR) effects with 1D approximations of the CSR force which are commonly implemented in CSR codes. In our model we track particles in 4D phase space and calculate 2D forces [1]. The major cost in our calculation is the computation of the 2D force. To speed up the computation and improve 1D models we also investigate approximations to our exact 2D force. As an application, we present numerical results for t… more
Date: March 28, 2011
Creator: Bassi, G.; Ellison, J. A. & Heinemann, K.
Partner: UNT Libraries Government Documents Department
open access

Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis

Description: Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental… more
Date: March 28, 2012
Creator: Behrens, Malte
Partner: UNT Libraries Government Documents Department
open access

Design and first cold test of BNL superconducting 112 MHz QWR for electron gun applications

Description: Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was propose… more
Date: March 28, 2011
Creator: Belomestnykh, S.; Ben-Zvi, Ilan; Boulware, C. H.; Chang, X.; Grimm, T. L.; Siegel, B. et al.
Partner: UNT Libraries Government Documents Department
open access

PREFERENTIAL INHIBITION OF THE GROWTH OF VIRUS-TRANSFORMED CELLS IN CULTURE BY RIFAZONE-82, A NEW RIFAMYCIN DERIVATIVE

Description: Rifazone-8{sub 2} (R-8{sub 2}), a new rifamycin derivative, is shown to preferentially inhibit the growth of virus-transformed chick cells in culture. Macromolecular synthesis and glucose uptake of transformed cells are also appreciably decreased in the presence of low concentrations of R-8{sub 2} where the normal cells appear unaffected. While R-8{sub 2} is shown to be a selective inhibitor of RNA-directed DNA polymerase in vitro, its action on the growth of transformed cells may involve some … more
Date: March 28, 1974
Creator: Bissell, Mina J.; Hatie, Carroll; Tischler, Allan N. & Calvin, Melvin.
Partner: UNT Libraries Government Documents Department
open access

Loss Factor of Tapered Structures for Short Bunches

Description: Using the electromagnetic simulation code ECHO, we have found a simple phenomenological formula that accurately describes the loss factor for short bunches traversing an axisymmetric tapered collimator. In this paper, we consider tapered collimators with rectangular cross-section and use the GdfidL code to calculate the loss factor dependence on the geometric parameters for short bunches. The results for both axisymmetric and rectangular collimators are discussed. The behaviour of the impedance… more
Date: March 28, 2011
Creator: Blednykh, A.
Partner: UNT Libraries Government Documents Department
open access

NSLS-II BPM System Protection from Rogue Mode Coupling

Description: Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.
Date: March 28, 2011
Creator: Blednykh, A.; Bach, B.; Borrelli, A.; Ferreira, M.; Hseuh, H. C.; Hetzel, C. et al.
Partner: UNT Libraries Government Documents Department
open access

Community-Owned wind power development: The challenge of applying the European model in the United States, and how states are addressing that challenge

Description: Local farmers, towns, schools, and individual investors are, however, beginning to invest in wind power. With the help of state policy and clean energy fund support, new federal incentives, and creative local wind developers who have devised ownership structures that maximize the value of both state and federal support, community wind power is beginning to take a foothold in parts of the US, in particular the upper Midwest. The purpose of this report is to describe that foothold, as well as the… more
Date: March 28, 2004
Creator: Bolinger, Mark
Partner: UNT Libraries Government Documents Department
open access

Comment on "Methodology and results of calculating Central California surface temperature trends: evidence of human-induced climate change?" by Christy et al. (2006)

Description: Understanding the causes of observed regional temperature trends is essential to projecting the human influences on climate, and the societal impacts of these influences. In their recent study, Christy et al. (2006, hereinafter CRNG06) hypothesized that the presence of irrigated soils is responsible for rapid warming of summer nights occurring in California's Central Valley over the last century (1910-2003), an assumption that rules out any significant effect due to increased greenhouse gases, … more
Date: March 28, 2006
Creator: Bonfils, C; Duffy, P & Lobell, D
Partner: UNT Libraries Government Documents Department
open access

Energetic Processing of Interstellar Silicate Grains by Cosmic Rays

Description: While a significant fraction of silicate dust in stellar winds has a crystalline structure, in the interstellar medium nearly all of it is amorphous. One possible explanation for this observation is the amorphization of crystalline silicates by relatively 'low' energy, heavy ion cosmic rays. Here we present the results of multiple laboratory experiments showing that single-crystal synthetic forsterite (Mg{sub 2}SiO{sub 4}) amorphizes when irradiated by 10 MeV Xe{sup ++} ions at large enough flu… more
Date: March 28, 2007
Creator: Bringa, E M; Kucheyev, S O; Loeffler, M J; Baragiola, R A; Tielens, A G Q M; Dai, Z R et al.
Partner: UNT Libraries Government Documents Department
open access

Creating Interoperable Meshing and Discretization Software: The Terascale Simulation Tools and Technology Center

Description: We present an overview of the technical objectives of the Terascale Simulation Tools and Technologies center. The primary goal of this multi-institution collaboration is to develop technologies that enable application scientists to easily use multiple mesh and discretization strategies within a single simulation on terascale computers. The discussion focuses on our efforts to create interoperable mesh generation tools, high-order discretization techniques, and adaptive meshing strategies.
Date: March 28, 2002
Creator: Brown, D.; Freitag, L. & Glimm, J.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen