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Supersymmetry: proceedings

Description: Some lectures in these proceedings examine the theoretical basis for supersymmetry, recent developments in theories with compact dimensions, and experimental searches for supersymmetric signatures. Technologies are explored for obtaining very high energy electron-positron colliding beams. Separate abstracts were prepared for 35 papers in these conference proceedings. (LEW)
Date: July 1, 1985
Creator: Brennan, E.C. (ed.)
Partner: UNT Libraries Government Documents Department

Organoactinide chemistry: synthesis, structure, and solution dynamics

Description: This thesis considers three aspects of organoactinide chemistry. In chapter one, a bidentate phosphine ligand was used to kinetically stabilize complexes of the type Cp/sub 2/MX/sub 2/. Ligand redistribution processes are present throughout the synthetic work, as has often been observed in uranium cyclopentadienyl chemistry. The effects of covalent M-L bonding on the solution and solid state properties of U(III) coordination complexes are considered. In particular, the nature of the more subtle interaction between the metal and the neutral ligand are examined. Using relative basicity data obtained in solution, and solid state structural data (and supplemented by gas phase photoelectron measurements), it is demonstrated that the more electron rich U(III) centers engage in significant U ..-->.. L ..pi..-donation. Trivalent uranium is shown to be capable of acting either as a one- or two-electron reducing agent toward a wide variety of unsaturated organic and inorganic molecules, generating molecular classes unobtainable via traditional synthetic approaches, as well as offering an alternative synthetic approach to molecules accessible via metathesis reactions. Ligand redistribution processes are again observed, but given the information concerning ligand lability, this reactivity pattern is applied to the synthesis of pure materials inaccessible from redox chemistry. 214 refs., 33 figs., 10 tabs.
Date: December 1, 1985
Creator: Brennan, J.G.
Partner: UNT Libraries Government Documents Department

Alternative Fuels and Advanced Vehicles: Resources for Fleet Managers (Clean Cities) (Presentation)

Description: A discussion of the tools and resources on the Clean Cities, Alternative Fuels and Advanced Vehicles Data Center, and the FuelEconomy.gov Web sites that can help vehicle fleet managers make informed decisions about implementing strategies to reduce gasoline and diesel fuel use.
Date: April 1, 2011
Creator: Brennan, A.
Partner: UNT Libraries Government Documents Department

The upgraded rf system for the AGS and high intensity proton beams

Description: The AGS has been upgraded over the past three years to produce a record beam intensity of 6 {times} 10{sup 13} protons per pulse for the fixed-target physics program. The major elements of the upgrade are: the new 1.5 GeV Booster synchrotron, the main magnet power supply, a high frequency longitudinal dilution cavity, a feedback damper for transverse instabilities, a fast gamma transition jump system, and a new high-power rf system. The new rf system and its role in achieving the high intensity goal are the subjects of this report. The rf system is heavily beam loaded, with 7 Amps of rf current in the beam and a peak power of 0.75 MW delivered to the beam by ten cavities. As an example of the scale of beam loading, at one point in the acceleration cycle the cavities are operated at 1.5 kV/gap; whereas, were it not for the new power amplifiers, the beam-induced voltage on the cavities would be over 25 kV/gap. The upgraded rf system, comprising: new power amplifiers, wide band rf feedback, improved cavities, and new low-level beam control electronics, is described. Results of measurements with beam, which characterize the system`s performance, are presented. A typical high intensity acceleration cycle is described with emphasis on the key challenges of beam loading.
Date: May 1, 1995
Creator: Brennan, J.M.
Partner: UNT Libraries Government Documents Department

Structure of tris(trimethylsilylcyclopentadienyl)uranium(III), ((CH/sub 3/)/sub 3/SiC/sub 5/H/sub 43/U. [Tris(trimethylsilylcyclopentadienyl)uranium]

Description: Crystals of ((CH/sub 3/)/sub 3/SiC/sub 5/H/sub 4/)/sub 3/U are orthorhombic, Pbca, with a = 22.630(8), b = 29.177(10) and c = 8.428(3) A at 23/sup 0/C. For Z = 8 the calculated density is 1.551 g/cm/sup 3/. The structure was refined by full-matrix least-squares to a conventional R factor of 0.041 (2251 data, F/sup 2/ > 2 sigma(F/sup 2/)). The uranium atom is bonded to the three cyclopentadienyl rings in a pentahapto fashion and is in the plane of the ring centroids. The U to ring distances are 2.54, 2.47 and 2.51 A, and the average U-C distance is 2.78 +- 0.04 A. 7 refs., 1 fig., 3 tabs.
Date: February 1, 1986
Creator: Brennan, J.; Andersen, R.A. & Zalkin, A.
Partner: UNT Libraries Government Documents Department

The RF beam control system for the Brookhaven AGS synchrotron

Description: The new 1.5 GeV Booster synchrotron completes the injector chain for the Relativistic Heavy Ion Collider, RHIC. It enables the AGS to accelerate all heavy ions to 14 GeV/c for collider operation and also in the intensity of the AGS for fixed-target experiments by a factor of four. The ultra-high vacuum enables acceleration of partially stripped ions from the Tandem Van de Graaff to energies sufficient for complete stripping. For high intensities, it accelerates the 200 MeV linac beam in four batches of three bunches per AGS cycle. At 1.5 {times} 10{sup 13} protons per batch, it has the same space charge tune spread as the AGS at 200 MeV. This variety of applications means the Booster must accommodate a very wide range of particle masses and intensities. Since it operates in a Pulse-by-Pulse Modulation mode at 7.5 Hz, the computer controlled functions of time and magnetic field, and the 64 timing triggers of the beam control system take on unique values for each of four PPM users. Beams of {sup 197}Au{sup +33} ions and protons have been accelerated in the same PPM cycle.
Date: September 1, 1992
Creator: Brennan, J. M.
Partner: UNT Libraries Government Documents Department

Rf beam control for the AGS Booster

Description: RF beam control systems for hadron synchrotrons have evolved over the past three decades into an essentially standard design. The key difference between hadron and lepton machines is the absence of radiation damping and existence of significant frequency variation in the case of hadrons. Although the motion of the hadron in the potential well of the rf wave is inherently stable it is not strongly damped. Damping must be provided by electronic feedback through the accelerating system. This feedback is typically called the phase loop. The technology of the rf beam control system for the AGS Booster synchrotron is described. First, the overall philosophy of the design is explained in terms of a conventional servo system that regulates the beam horizontal position in the vacuum chamber. The concept of beam transfer functions is fundamental to the mathematics of the design process and is reviewed. The beam transfer functions required for this design are derived from first principles. An overview of the beam signal pick-ups and high level rf equipment is given. The major subsystems, the frequency program, the heterodyne system, and beam feedback loops, are described in detail. Beyond accelerating the beam, the rf system must also synchronize the bunches in the Booster to the buckets in the AGS before transfer. The technical challenge in this process is heightened by the need to accomplish synchronization while the frequency is still changing. Details of the synchronization system are given. This report is intended to serve two purposes. One is to document the hardware and performance of the systems that have been built. The other is to serve as a tutorial vehicle from which the non-expert can not only learn the details of this system but also learn the principles of beam control that have led to the particular design choices made.
Date: September 26, 1994
Creator: Brennan, J. M.
Partner: UNT Libraries Government Documents Department

NSRL Extraction Bump Control in the Booster

Description: Due to inadequacies in the user interface of the booster orbit control system, a number of new tools were developed. The first priority was an accurate calculation of the winding currents given specific displacements at each extraction septa. Next, the physical limits of the power supplies ({+-}600 amps) needed to be taken into account. In light of this limit, a system is developed that indicates to the user what the allowed values of one bump parameter are once the other two have been specified. Finally, techniques are developed to account for the orbit behavior once power supplies are requested to exceed their {+-}600 amp limit. This includes a recalculation of bump parameters and a calculation of the amplitude of the residuals. Following this, possible areas for further development are outlined. These techniques were computationally developed in Mathematica and tested in the Methodical Accelerator Design (MAD) program before they were implemented into the control system. At the end, a description of the implementation of these techniques in a new interface is described. This includes a depiction of the appearance and functionality of the graphical user interface, a description of the input and output flow, and an outline of how each important calculation is performed.
Date: October 1, 2008
Creator: Brennan,L.
Partner: UNT Libraries Government Documents Department

Musical Ekphrasis in the Poetry of Nicolás Guillén, Federico García Lorca, and Langston Hughes

Description: Musical ekphrasis was occurring in the twentieth century in different centers around the world, Cuba: Andalusia, Spain; and Harlem, New York, simultaneously. The writers at the heart of this movement used poetry about music as a means to celebrate the cultures of the marginalized people in their lands, los negros, los gitanos, and African-Americans. The purpose of this study is to define musical ekphrasis and identify it in the works of Nicolás Guillén, Federico García Lorca, and Langston Hughes. Also explored are the common characteristics in ekphrastic poetry by the three poets and the common themes found in their ekphrastic poetry, as well as common influences. Each author is considered in the context of his surroundings and his respective culture, and how that influenced his musical tastes as well as his writing style.
Date: December 2016
Creator: Divett, Andrew Brennan
Partner: UNT Libraries

University Student's Self-Perception of Selected Characteristics Related to Sex and to Ordinal Position

Description: Nineteen selected self-perception characteristics of university students were related to sex and to ordinal position. The 60 selected males and 120 selected females were enrolled during the summer of 1976 at North Texas State University in Denton County, Texas. A self-rating, group-administered instrument was originated for collecting information. Ordinal positions were only child, first-born with later siblings, intermediate, and last-born. The intermediates had the most positive self-perceptions. Of the males, intermediates were highest and only children lowest. Of the females, only children reported more positive self-perceptions. Females had more positive self-perceptions than males. Effects of ordinal positions tended to depend on the child's sex. Further study was recommended utilizing a larger, more varied population.
Date: May 1977
Creator: Skelton, Carol Ann Brennan
Partner: UNT Libraries

The new BNL AGS phase, radial and synchronization loops

Description: The AGS and the RHIC must be synchronized before bunch-to-bucket transfer of the beam. A feedback loop has been designed and an improvement has been made to the AGS phase and radial loops. In both cases, the design uses a state variable representation to achieve greater stability and smaller errors. The state variables are beam phase, frequency and radius , the integral of the difference between the radius and its reference and the phase deviation of the bunch from the synchronous phase. Furthermore, the feedback gains are programmed as a function of the beam parameters to keep the same loop performances through the acceleration cycle.
Date: July 1, 1996
Creator: Onillon, E. & Brennan, J.M.
Partner: UNT Libraries Government Documents Department

High intensity performance of the Brookhaven AGS

Description: Experience and results from recent high intensity proton running periods of the Brookhaven AGS, during which a record intensity for a proton synchrotron of 6.3 x 10{sup 13} protons/pulse was reached, is presented. This high beam intensity allowed for the simultaneous operation of three high precision rare kaon decay experiments. The record beam intensities were achieved after the 1.5 GeV Booster was commissioned and a transition jump system, a powerful transverse damper, and an rf upgrade in the AGS were completed. Recently even higher intensity proton synchrotrons are studied for neutron spallation sources or proton driver for a muon collider. Implications of the experiences from the AGS to these proposals and also possible future upgrades for the AGS are discussed.
Date: July 1, 1996
Creator: Brennan, J.M. & Roser, T.
Partner: UNT Libraries Government Documents Department

A barrier bucket experiment for accumulating de-bunched beam in the GAS

Description: The AGS accumulates four batches of two bunches from the 1.5GeV Booster at 7.5Hz. At an intensity of 6 x 10{sup 13} protons per AGS cycle, slow beam loss during the 400ms accumulation time is important. The experiment demonstrated the principle of accumulating beam and storing it in an essentially debunched state by using barrier cavities. When the beam is de-bunched the peak-to-average current ratio drops by an order of magnitude. By using two barriers with time varying relative phase, any number of injections is possible, limited only by the momentum acceptance of the ring. In a test with beam, six injections of one bunch yielded 3 x 10{sup 13} protons in the AGS. The benefits of reduced space charge tune shift from lower peak current suggest that barrier cavities may be a path to higher AGS intensities.
Date: July 1, 1996
Creator: Blaskiewicz, M. & Brennan, J.M.
Partner: UNT Libraries Government Documents Department

Alternative Fuel News: May 2000 Special Edition

Description: In this special issue of Alternative Fuel News, the authors summarize DOE's current position on the local government and private fleet rulemaking that has been under consideration. The authors also look at the new area of focus, niche markets. Your participation and input are invited as the authors craft new directions for the nation's transportation future.
Date: May 3, 2000
Creator: Brennan, A. & Ficker, C.
Partner: UNT Libraries Government Documents Department

Search of medical literature for indoor carbon monoxide exposure

Description: This report documents a literature search on carbon monoxide. The search was limited to the medical and toxicological databases at the National Library of Medicine (MEDLARS). The databases searched were Medline, Toxline and TOXNET. Searches were performed using a variety of strategies. Combinations of the following keywords were used: carbon, monoxide, accidental, residential, occult, diagnosis, misdiagnosis, heating, furnace, and indoor. The literature was searched from 1966 to the present. Over 1000 references were identified and summarized using the following abbreviations: The major findings of the search are: (1) Acute and subacute carbon monoxide exposures result in a large number of symptoms affecting the brain, kidneys, respiratory system, retina, and motor functions. (2) Acute and subacute carbon monoxide (CO) poisonings have been misdiagnosed on many occasions. (3) Very few systematic investigations have been made into the frequency and consequences of carbon monoxide poisonings.
Date: December 1, 1995
Creator: Brennan, T. & Ivanovich, M.
Partner: UNT Libraries Government Documents Department

Approximate method for calculating motions in angles of attack and sideslip due to step pitching- and yawing-moment inputs during steady roll

Description: Report presenting an extension of a method for calculating motions in angles of attack and sideslip resulting from a trim angle of attack and steady rolling velocity to the condition of pitching- and yawing-moment inputs. The resulting formulas are intended primarily for rolling-velocity conditions in which rolling divergence is not encountered.
Date: September 1958
Creator: Moul, Martin T. & Brennan, Teresa R.
Partner: UNT Libraries Government Documents Department

H/sup -/ source and beam transport experiments for a new RFQ

Description: A new RFQ preinjector is being built for the 200 MeV Linac at the AGS. For injection into this RFQ, a symmetric emittance has been obtained from a circular aperture magnetron H/sup -/ source. Transport studies are beginning to address possible problems with space charge or instabilities in the 35 keV line. A volume H/sup -/ source is being tested as an eventual replacement for the magnetron.
Date: January 1, 1987
Creator: Alessi, J.G.; Brennan, J.M.; Kponou, A. & Prelec, K.
Partner: UNT Libraries Government Documents Department

Spallation neutron source/proposed rf system

Description: The rf system for the synchrotrons of the spallation neutron source is designed to accelerate 1.4 {times} 10{sup 14} protons/pulse to an energy of 3.6 GeV. Injection energy is 600 MeV. The synchrotron repetition frequency is 30 Hz, with a 50% duty factor. The choice of operating frequency is somewhat arbitrary. The authors propose a low frequency of 1.3 to 1.6 MHz, which is the second harmonic of the revolution frequency. The advantages of such a low frequency system are: (1) There will be two bunches in the machines and the time between bunches will be sufficiently long to allow for the rise time of the extraction kicker. No missing bunches will be necessary, which simplifies injection, and transient beam loading problems are avoided. (2) With only two bunches there are no unstable coupled-bunch modes of longitudinal instability. (3) In multi-gap low frequency cavities the transient time factor is essentially unity because the rf wavelength is much longer than the cavity dimensions. (4) Cavities in this low frequency range are basically lumped-element type structures, where the sources of the inductance and capacitance are clearly identified. This allows effective control of higher order mode impedances in such cavities. (5) Ferrite-loaded low-frequency cavities are necessarily low impedance structures; ferrites are lossy. This low impedance makes it possible to achieve system stability without large amounts of feedback in a heavily beam loaded system. (6) BNL has a good deal of experience in building rf systems in this range of frequency, voltage, and power level. This report outlines the essential parameters of a practical rf system for the synchrotrons of the Spallation Neutron Source. The design uses materials, ferrites and vacuum tubes, that are commercially available and with which the laboratory has recent experience.
Date: September 30, 1993
Creator: Meth, M. & Brennan, J. M.
Partner: UNT Libraries Government Documents Department