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Operating experience with the ALS linac

Description: The linac injector for the Advanced Light Source (ALS) at LBL was recently put into operation. Energy is 50 MeV, frequency 3 GHz. The electron gun delivers up to 6nC in a 3.0-ns bunch at 120 kV. A train of bunches is injected into a 1-Hz booster and accelerated to 1.5 GHz for storage ring injection. A magnetic analysis system is used for optimizing the linac. Measured beam properties from the gun and after acceleration in the linac are described. 9 refs., 3 figs.
Date: May 1, 1991
Creator: Selph, F. & Massoletti, D.
Partner: UNT Libraries Government Documents Department
open access

Laser diagnostics of H sup minus formation in a magnetic multicusp ion source

Description: The populations of ground electronic state atomic hydrogen and ground electronic state, vibrationally-rotationally excited hydrogen molecules in a negative hydrogen ion source discharge have been measured using vacuum ultraviolet (VUV) laser absorption spectroscopy. Vibrational states up to v=8 and rotational levels as high as J=15 have been measured. The measurements have been made under a range of discharge conditions. The complete vibrational population distribution for v=1-8, J=1 has been o… more
Date: May 1, 1991
Creator: Young, A. T.; Chen, P.; Kunkel, W. B.; Leung, K. N.; Li, C. Y. & Stutzin, G. C.
Partner: UNT Libraries Government Documents Department
open access

Effect of Au on the reliability of fine pitch surface mount solder joints

Description: The effect of Au on the reliability of 0.65 mm pitch surface mount solder joints between plastic quad flat packs and Cu-Ni-Au FR-4 printed circuit boards was investigated. Cu-Ni-Au is a desirable printed circuit board finish for multi-chip modules or printed circuit boards that would otherwise require a selective Au finish, for example for edge connectors or wire bondable parts. However, Au is known to embrittle solder when it is present in sufficiently high concentrations, creating a concern t… more
Date: May 1, 1991
Creator: Glazer, J. (Hewlett-Packard Co., Palo Alto, CA (United States)); Kramer, P. & Morris, J.W. Jr. (Lawrence Berkeley Lab., CA (United States))
Partner: UNT Libraries Government Documents Department
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Numerical simulations of turbulent flow fields caused by spraying of water on large releases of hydrogen fluoride

Description: The effectiveness of water sprays in absorbing HF releases was recently demonstrated in extended laboratory and field tests. In this paper, computer simulations are presented of the Hawk, Nevada Test Site, series of field tests. The model used, HFSPRAY, is a Eulerean/Lagrangian model which simulates the momentum, mass and energy interactions between a water spray and a turbulent plume of HF in air; the model can predict the flow velocities, temperature, water vapor, and HF concentration fields … more
Date: May 1, 1991
Creator: Fthenakis, V.M. (Brookhaven National Lab., Upton, NY (United States)) & Schatz, K.W. (Mobil Research and Development Corp., Princeton, NJ (United States))
Partner: UNT Libraries Government Documents Department
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D. phi. vertex drift chamber construction and test results

Description: A jet-cell based vertex chamber has been built for the D{O} experiment at Fermilab and operated in a test beam there. Low drift velocity and diffusion properties were achieved using CO{sub 2}(95%)-ethane(5%) at atmospheric pressure. The drift velocity is found to be consistent with (9.74+8.68( E -1.25)) {mu}m/nsec where E is the electric field strength in (kV/cm < E z 1.6 kV/cm.) An intrinsic spatial resolution of 60 {mu}m or better for drift distances greater than 2 mm is measured. The track p… more
Date: May 1, 1991
Creator: Clark, A.R.; Goozen, F.; Grudberg, P.; Klopfenstein, C.; Kerth, L.T.; Loken, S.C. et al.
Partner: UNT Libraries Government Documents Department
open access

Magnetic data analysis for the ALS lattice magents

Description: The Advanced Light Source (ALS), now under construction at Lawrence Berkeley Laboratory, is a third-generation synchrotron radiation source designed to produce extremely bright photon beams in the UV and soft X-ray regions. The lattice magnets to be installed in the two rings, a 1--1.9 GeV storage ring, and a 1.5 GeV booster synchrotron, have been magnetically measured to ascertain their excitation curves and field uniformity. In this paper the analysis of these data is discussed, and results f… more
Date: May 1, 1991
Creator: Keller, R.
Partner: UNT Libraries Government Documents Department
open access

Critical flow: General theory and spurious solutions

Description: It is hardly necessary to emphasize the importance that an accurate prediction of the parameters of critical flow plays in a number of industries, notably in nuclear reactor safety calculations and in metering. In spite of its importance, the literature of the subject still contains erroneous statements. Many of them result from an unjustified belief in the generality of certain conclusions drawn in the elementary study of one-dimensional isentropic flow of a perfect gas with constant specific … more
Date: May 1, 1991
Creator: Kestin, J.
Partner: UNT Libraries Government Documents Department
open access

Pulse code modulation data compression for automated test equipment

Description: Development of automated test equipment for an advanced telemetry system requires continuous monitoring of PCM data while exercising telemetry inputs. This requirements leads to a large amount of data that needs to be stored and later analyzed. For example, a data stream of 4 Mbits/s and a test time of thirty minutes would yield 900 Mbytes of raw data. With this raw data, information needs to be stored to correlate the raw data to the test stimulus. This leads to a total of 1.8 Gb of data to be… more
Date: May 1, 1991
Creator: Navickas, T.A. & Jones, S.G.
Partner: UNT Libraries Government Documents Department
open access

Broadband diffractive lens

Description: Significant progress has been made toward solving the century-old problem of chromatic aberrations in diffractive optics. Our approach exploits modern materials and microfabrication technology and is very different from the purely diffractive strategy,'' which is commonly employed and which results in multiple diffractive elements separated by a finite distance. We have developed a Fresnel zone plate lens comprised of a serial stack of patterned minus-filters which allows broadband radiation to… more
Date: May 28, 1991
Creator: Ceglio, N. M.; Hawryluk, A. M.; London, R. A.; Seppala, L. G. (Lawrence Livermore National Lab., CA (USA)) & Gaines, D. P. (Brigham Young Univ., Provo, UT (USA))
Partner: UNT Libraries Government Documents Department
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W mass and W asymmetry at CDF

Description: The lepton charge asymmetry from W decaying into a lepton and a neutrino is discussed (preliminary result). This measurement gives information on parton distribution functions at low x values. The derivation of the recently published W mass value of 79.91 {plus minus} 0.39 GeV/c{sup 2} is also presented. M{sub W} is used to set an upper limit on the top quark mass. 13 refs., 4 figs., 1 tab.
Date: May 1, 1991
Creator: Leone, S. (Pisa Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Pisa (Italy))
Partner: UNT Libraries Government Documents Department
open access

High-intensity photoionization of H sub 2

Description: A tunable, high-intensity picosecond dye laser system has been employed with electron energy analysis to investigate the dynamics of (3+1) resonance-enhanced multiphoton ionization of H{sub 2} via different vibrational levels of its B{sub 1}{Sigma}{sub u}{sup +} and C{sup 1}{Pi}{sub u} electronic states. We observe production of molecular ions in various vibrational levels, with a shift to increased population of lower vibrational states of H{sub 2}{sup +} consistent with the a.c. Stark shift o… more
Date: May 1, 1991
Creator: Allendorf, S.W. & Szoeke, A.
Partner: UNT Libraries Government Documents Department
open access

Report of the group on beam-beam effects in circular colliders

Description: We present a summary of the discussions and conclusions of the working group on beam-beam effects for circular colliders. This group was part of the larger beam-beam dynamics group at the 7th ICFA Workshop on Beam Dynamics, on the subject Beam-Beam and Beam-Radiation Interactions,'' held at UCLA, May 13--16, 1991. 15 refs.
Date: May 1, 1991
Creator: Furman, M. A.
Partner: UNT Libraries Government Documents Department
open access

The Advanced Light Source

Description: The Advanced Light Source (ALS), a national user facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation in the energy range from a few eV to 10 keV. The design is based on a 1--1.9-GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the… more
Date: May 1, 1991
Creator: Jackson, A.
Partner: UNT Libraries Government Documents Department
open access

Transport and error sensitivity in a heavy-ion recirculator

Description: An envelope code has been developed to facilitate the design of a recirculating accelerator for a heavy-ion fusion reactor. A novel feature of the model is the treatment of the beam charge density as a Lagrangian fluid in the axial direction. Transport results for a preliminary recirculator design are presented, and sensitivity of the transport to errors in the magnet strength is discussed. 4 refs., 4 figs.
Date: May 1, 1991
Creator: Sharp, W. M.; Barnard, J. J. & Yu, S. S.
Partner: UNT Libraries Government Documents Department
open access

New design concepts for ferrite-tuned low-energy-booster cavities

Description: The design concepts for ferrite-tuned accelerating cavities discussed in this paper differ from conventional solutions using thick ferrite toroids for frequency tuning. Instead, tuners consisting of an array of ferrite-loaded striplines are investigated. These promise more efficient cooling and higher operational reliability. Layout examples for the SSC-LEB rf system are presented (tuning range 47.5 to 59.8 MHz, repetition frequency 10 Hz). 15 refs., 4 figs., 1 tab.
Date: May 1, 1991
Creator: Schaffer, G.
Partner: UNT Libraries Government Documents Department
open access

Geothermal waste treatment biotechnology

Description: Technical feasibility of a biotechnology based on biochemical reactions for detoxification of geothermal brines has been demonstrated. Laboratory-scale studies have shown that the emerging biotechnology is versatile and is applicable to a variety of geothermal sludges and materials with similar geochemical properties. Materials suitable for treatment are those which may contain few or many metals in concentrations exceeding those allowed by regulatory agencies. Comparison of several possible ty… more
Date: May 1, 1991
Creator: Premuzic, E.T. & Lin, M.S.
Partner: UNT Libraries Government Documents Department
open access

Laser produced plasma soft x-ray generation

Description: The efficiency of soft x-ray production from laser-irradiated plasmas is simulated for two different spectral regions. These two regions, 14{Angstrom} {plus minus} 15% and 130{Angstrom} {plus minus} 1%, were chosen for proximity mask or point-projection technological applications. Relatively large conversion efficiencies were obtained from irradiation of a stainless steel target using the conditions suggested by recent Hampshire Instruments' experiments for proximity masking. Pulse-width and la… more
Date: May 20, 1991
Creator: Cerjan, C. & Rosen, M.D.
Partner: UNT Libraries Government Documents Department
open access

Commissioning experiences of the ALS booster synchrotron

Description: Installation of the ALS booster synchrotron proper was completed on April 30, 1991, and commissioning has just begun. Circulating beam around the booster was observed on the first day of operation, May 3, 1991. The beam was visible for about 400 turns. In this paper we describe the status and commissioning experience of the 1.5-GeV electron synchrotron accelerator. 14 refs., 2 figs., 4 tabs.
Date: May 1, 1991
Creator: Kim, C.
Partner: UNT Libraries Government Documents Department
open access

Power and particle balance during neutral beam injection in TFTR

Description: Detailed boundary plasma measurements on TFTR have been made during a NBI power scan in the range P{sub tot} {equals} 1MW--20MW in the L-mode regime. The behavior of the plasma density {l angle}n{sub e}{r angle}, radiated power P{sub rad}, carbon and deuterium fluxes {Gamma}{sub C}, {Gamma}{sub D}, and {Zeta}{sub eff} can be summarized as, {l angle}n{sub e}{r angle} {proportional to} P{sub tot}{sup {1/2}}, P{sub rad}, {Gamma}{sub C}, {Gamma}{sub D} {proportional to} P{sub tot}, and {Zeta}{sub e… more
Date: May 1, 1991
Creator: Pitcher, C. S.; Budny, R. V.; Hill, K. W.; Kilpatrick, S. J.; Manos, D. M.; Medley, S. S. et al.
Partner: UNT Libraries Government Documents Department
open access

Equation-of-state from SiO sub 2 aerogel Hugoniot data

Description: The significance of the new aerogel data for the equation-of-state of SiO{sub 2} is discussed. On this basis the use of SiO{sub 2} aerogels as a standard witness material for Hugoniot release wave measurements is advocated. We compare the Hugoniot data of Holmes on aerogel samples of density 0.128 gm/cm{sup 3} with a multiphase EOS for quartz developed by F. Ree some 15 years ago. His tabular EOS includes compositional changes arising from both chemical and ionization equilibrium, and is found … more
Date: May 1, 1991
Creator: Grover, R.; Ree, F. & Holmes, N.
Partner: UNT Libraries Government Documents Department
open access

A wide band slot-coupled beam sensing electrode for the advanced light source

Description: Stripline electrodes (traveling wave electrodes, directional couplers) are commonly used in particle accelerators as beam pickups and kickers. The longitudinally symmetric stripline has a constant beam coupling impedance as a function of length and has a characteristic magnitude sin(x) amplitude response in the frequency domain. An experimentally tapered stripline provides nearly constant coupling impedance vs. frequency and yields superior frequency-domain performance. In practice it is diffic… more
Date: May 1, 1991
Creator: Hinkson, J. & Rex, K.
Partner: UNT Libraries Government Documents Department
open access

Misalignment study of NLC bunch compressor

Description: Results of computer simulations of the misalignments in the 180{degree}-bend angle second-stage bunch compressor for the NLC are described. The aim of this study was to evaluate alignment and production error tolerances. Three versions of the second stage, differing in their minimum obtainable bunch length (44 {mu}, 60 {mu}, and 86 {mu}) were studied. Simulations included orbit correction produced by errors and misalignments of the compressor elements. The orbit correction itself was done withi… more
Date: May 1, 1991
Creator: Rogers, R.P. & Kheifets, S.A.
Partner: UNT Libraries Government Documents Department
open access

Molten salt processing of mixed wastes with offgas condensation

Description: We are developing an advanced process for treatment of mixed wastes in molten salt media at temperatures of 700--1000{degrees}C. Waste destruction has been demonstrated in a single stage oxidation process, with destruction efficiencies above 99.9999% for many waste categories. The molten salt provides a heat transfer medium, prevents thermal surges, and functions as an in situ scrubber to transform the acid-gas forming components of the waste into neutral salts and immobilizes potentially fugit… more
Date: May 13, 1991
Creator: Cooper, J.F.; Brummond, W.; Celeste, J.; Farmer, J.; Hoenig, C.; Krikorian, O.H. et al.
Partner: UNT Libraries Government Documents Department
open access

Use of digital control theory state space formalism for feedback at SLC

Description: The algorithms used in the database-driven SLC fast-feedback system are based on the state space formalism of digital control theory. These are implemented as a set of matrix equations which use a Kalman filter to estimate a vector of states from a vector of measurements, and then apply a gain matrix to determine the actuator settings from the state vector. The matrices used in the calculation are derived offline using Linear Quadratic Gaussian minimization. For a given noise spectrum, this pro… more
Date: May 1, 1991
Creator: Himel, T.; Hendrickson, L.; Rouse, F. & Shoaee, H.
Partner: UNT Libraries Government Documents Department
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