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1

Recent developments on ECR sources at LBL  

SciTech Connect

After a number of refinements, the stability and ease of tuning of the LBL AECR ion source are greatly improved. Several nuclear science experiments have now used cyclotron ion beams injected by the AECR ion source and have taken advantage of its good short and long term-stability and high performance. Refinements include installation of a dc filament power supply for the electron gun, improved gas flow control.and temperature stabilization of parts of the microwave transmission network. Measurements of the mean plasma potential and plasma potential difference were made on the AECR and the LBL ECR sources. The absolute. mean potentials of plasmas of oxygen, argon, and argon mixed with oxygen in the AECR have been determined. These plasma potentials are positive with respect to the plasma wall and are on the order of a few tens of volts for microwave power up to 600 W and normal operating gas flow. Electrons injected by an electron gun into the AECR plasma reduce the plasma potentials. Beam energy spreads of oxygen, argon and argon mixed with oxygen have also been measured. Measurement of the plasma potential difference between the first and the second stage of the LBL ECR ion source shows that the plasma potential in the first stage is higher than the second stage. Such plasma potential differences range from about 10 to 200 volts depending on the microwave power and density of neutral atoms. With these potential differences, typically of 10 to 40 V at the LBL ECR running conditions, most of the 1+ ions produced by the first stage are probably not be confined by the second state plasma. Thus it appears that the main function of a microwave-driven first stage is to provide electrons to the second stage plasma, as is done with an electron gun in the AECR source.

Xie, Z.Q.; Lyneis, C.M.

1993-05-05

2

Integrating a Traveling Wave Tube into an AECR-U ion source  

SciTech Connect

An RF system of 500W - 10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance - Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion source and results from commissioning are presented.

Covo, Michel Kireeff; Benitez, Janilee Y.; Ratti, Alessandro; Vujic, Jasmina L.

2011-07-01

3

U5.0 undulator design for the advanced light source at LBL.  

National Technical Information Service (NTIS)

The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5 cm period, 5 m length with a 0.837 T maximum field at a 14 mm gap. A hybrid configuration u...

E. Hoyer J. Chin K. Halbach W. Hassenzahl D. Humphries

1989-01-01

4

Vacuum System for the LBL (Lawrence Berkeley Laboratory) Advanced Light Source (ALS).  

National Technical Information Service (NTIS)

A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit most synchrotron photons to escape the electron channel and be absorbed in an antechamber. The gas generated by the photons hitting the absorbers in t...

K. Kennedy T. Henderson J. Meneghetti

1989-01-01

5

Insertion devices for the Advanced Light Source at LBL  

SciTech Connect

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory will be the first of the new generation of dedicated synchrotron light sources to be put into operation. Specially designed insertion devices will be required to realize the high brightness photon beams made possible by the low emittance of the electron beam. The complement of insertion devices on the ALS will include undulators with periods as short as 3.9 cm and one or more high field wigglers. The first device to be designed is a 5 m long, 5 cm period, hybrid undulator. The goal of very high brightness and high harmonic output imposes unusually tight tolerances on the magnetic field quality and thus on the mechanical structure. The design process, using a generic structure for all undulators, is described. 5 refs., 4 figs., 1 tab.

Hassenzahl, W.; Chin, J.; Halbach, K.; Hoyer, E.; Humphries, D.; Kincaid, B.; Savoy, R.

1989-03-01

6

Scientific program of the Advanced Light Source at LBL  

SciTech Connect

Construction of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory is nearing completion, with operation as a US Department of Energy national user facility scheduled to begin in the spring of 1993. Based on a low-emittance, 1.5-GeV electron storage ring with 10 long straight sections available for insertion devices and, initially, 24 bend-magnet ports, the ALS will be a third-generation source of soft x-ray and ultraviolet (collectively, the XUV) synchrotron radiation. Experimental facilities (insertion devices, beamlines, and end stations) will be developed and operated by participating research teams working with the ALS staff. The ability to exploit the high spectral brightness of the ALS was the main criterion for PRT selection. In the XUV spectral regions served by the ALS, a major benefit of high brightness will be the ability to achieve spatial resolution in the neighborhood of 200 angstroms in x-ray microscopy and holography and in spatially resolved spectroscopy. Other beneficiaries of high brightness include very-high-resolution spectroscopy, spectroscopy of dilute species, diffraction from very small samples, and time-resolved spectroscopy and diffraction.

Robinson, A.L.; Schlachter, A.S.

1991-10-01

7

Report on the engineering test of the LBL 30 second neutral beam source for the MFTF-B project  

SciTech Connect

Positive ion based neutral beam development in the US has centered on the long pulse, Advanced Positive Ion Source (APIS). APIS eventually focused on development of 30 second sources for MFTF-B. The Engineering Test was part of competitive testing of the LBL and ORNL long pulse sources carried out for the MFTF-B Project. The test consisted of 500 beam shots with 80 kV, 30 second deuterium, and was carried out on the Neutral Beam Engineering Test Facility (NBETF). This report summarizes the results of LBL testing, in which the LBL APIS demonstrated that it would meet the requirements for MFTF-B 30 second sources. In part as a result of this test, the LBL design was found to be suitable as the baseline for a Common Long Pulse Source design for MFTF-B, TFTR, and Doublet Upgrade.

Vella, M.C.; Pincosy, P.A.; Hauck, C.A.; Pyle, R.V.

1984-08-01

8

Measurements and simulations of emittance growth of an H- beam from an LBL volume source  

NASA Astrophysics Data System (ADS)

Measurements of emittance and emittance growth in an H- beam extracted from an LBL volume source will be presented. Effects of introducing cesium into the arc chamber will be shown. Some differences are noted depending on whether cesium is actively entering the chamber, or whether the source is running on residual Cs. Also, the effect of beam perveance will be shown. At a fixed location, the dependence of emittance on perveance is similar to the dependence of beam width on perveance, as if emittance is proportional to beam divergence. This data will be compared with WOLF simulations of emittance growth at different currents, with a non-uniform initial current density distribution.

Gammel, G.; Ng, Y.; Debiak, T.; Kuehne, F.

1991-05-01

9

Ground motion measurements at the LBL Light Source site, the Bevatron and at SLAC  

SciTech Connect

This report describes the technique for measuring ground motion at the site of the 1.0 to 2.0 GeV Synchrotron Radiation Facility which was known as the Advanced Light Source (in 1983 when the measurements were taken). The results of ground motion measurements at the Light Source site at Building 6 at LBL are presented. As comparison, ground motion measurements were made at the Byerly Tunnel, the Bevatron, Blackberry Canyon, and SLAC at the Spear Ring. Ground Motion at the Light Source site was measured in a band from 4 to 100 Hz. The measured noise is primarily local in origin and is not easily transported through LBL soils. The background ground motion is for the most part less than 0.1 microns. Localized truck traffic near Building 6 and the operation of the cranes in the building can result in local ground motions of a micron or more for short periods of time. The background motion at Building 6 is between 1 and 2 orders of magnitude higher than ground motion in a quiet seismic tunnel, which is representative of quiet sites worldwide. The magnitude of the ground motions at SLAC and the Bevatron are comparable to ground motions measured at the Building 6 Light Source site. However, the frequency signature of each site is very different.

Green, M.A.; Majer, E.I.; More, V.D.; O'Connell, D.R.; Shilling, R.C.

1986-12-01

10

ECR heavy-ion source for the LBL 88-inch cyclotron  

SciTech Connect

An Electron Cyclotron Resonance (ECR) heavy-ion source is under construction at the LBL 88-Inch Cyclotron. This source will produce very-high-charge-state heavy ions, such as 0/sup 8 +/ and Ar/sup 12 +/, which will increase cyclotron energies by a factor of 2-4, up to A = 80. It is a two-stage source using room-temperature coils, a permanent-magnet sextupole, and a 6-9 GHz microwave system. Design features include adjustable first-to-second-stage plasma coupling, a variable second-stage mirror ratio, high-conductance radial pumping of the second stage, and a beam-diagnostic system. A remotely movable extraction electrode will optimize extraction efficiency. The project includes construction of a transport line and improvements to the cyclotron axial-injection system. The construction period is expected to be two years.

Clark, D.J.; Kalnins, J.G.; Lyneis, C.M.

1983-03-01

11

Some novel design features of the LBL metal vapor vacuum arc ion sources  

SciTech Connect

The family of MEVVA (metal vapor vacuum arc) high current metal ion sources developed at LBL over the past several years has grown to include a number of different source versions with a wide range of some of the design and operational parameters. The MicroMEVVA source is a particularly compact version, about 2 cm diameter and 10 cm long, while the MEVVA IV weighs some 30 kG. MEVVAs IV and V incorporate multiple cathode assemblies (16 and 18 separate cathodes, respectively), and the operating cathode can be switched rapidly and without down-time. The new MEVVA V embodiment is quite compact considering its broad beam (10 cm), high voltage (100 kV) and multiple cathode features. The large-area extractor grids used in the MEVVA V were fabricated using a particularly simple technique, and they are clamped into position and so can be changed simply and quickly. The electrical system used to drive the arc is particularly simple and incorporates several attractive features. In this paper we review and describe a number of the mechanical and electrical design features that have been developed for these sources. 9 refs., 5 figs.

MacGill, R.A.; Brown, I.G.; Galvin, J.E.

1989-06-01

12

LBL EBIS Program.  

National Technical Information Service (NTIS)

It has been decided to increase the energy range of the LBL 88-Inch Cyclotron by constructing an advanced ion source for installation on the existing axial injection system. The type of advanced ion source chosen is the Electron Beam Ion Source. The energ...

I. Brown B. Feinberg

1981-01-01

13

Radioactive Beams Using the AECR-U and the 88-Inch Cyclotron  

SciTech Connect

The high ionization efficiency of an Electron Cyclotron Resonance (ECR) ion source combined with the mass resolution of a cyclotron is ideal for the generation of some ISOL-type radioactive ion beams (RIBs). In two separate projects at the 88-Inch Cyclotron at LBNL - BEARS and the Recyclotron - we have developed techniques to efficiently ionize and accelerate beams of gaseous species of 11C (t1/2 = 20 min), 14,15O (t1/2 = 70 sec, 2 min) and 76,79Kr (t1/2 = 14,35 hours). Measurements of the ionization efficiency and hold-up times are discussed, along with issues of source contamination and poisoning encountered in running both RIBs and high-intensity stable beam experiments using the same ion source, the LBNL AECR-U. Methods used to tune clean RIBs through the Cyclotron with high efficiency are also discussed, including the use and limitations of analog beams.

McMahan, M.A.; Leitner, D.; Powell, J.; Silver, C. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2005-03-15

14

Single particle dynamics in the LBL 1-2 GeV synchrotron radiation source in the presence of magnetic imperfections, magnet displacement errors and insertion devices  

SciTech Connect

The effects arising from sources of perturbing fields that can be predicted in advance of construction of the LBL 1 to 2 GeV Synchrotron Radiation Source are investigated. These include field errors (systematic and random) introduced through magnet design and finite construction tolerances; a random quadrupole component arising from a finite closed orbit distortion in the sextupoles; and the intrinsic focusing and nonlinear fields associated with the insertion devices (undulators and wigglers). (LEW)

Jackson, A.; Nishimura, H.

1987-03-01

15

High Performance Single Stage Operation of the LBL ECR (Lawrence Berkeley Laboratory Electron Cyclotron-Resonance) and the Design of an Advanced ECR Ion Source.  

National Technical Information Service (NTIS)

A new mode of operation using only the second stage of the LBL ECR has been developed. This single stage mode produces charge states and currents equal to or better than the traditional two stage operation of the LBL ECR for a variety of gases such as nit...

C. M. Lyneis

1988-01-01

16

News from LBL  

SciTech Connect

We present a brief summary of recent news from LBL related to accelerator physics. This talk was given on October 29, 1993 at the 6th Advanced ICFA Beam Dynamics Workshop on the subject ``Synchro- Betraton Resonances,`` held in Funchal (Madeira, Portugal), October 24--30, 1993.

Furman, M.A.

1994-01-26

17

Calculation of Collective Effects and Beam Lifetimes for the LBL 1-2 GeV Synchrotron Radiation Source  

Microsoft Academic Search

In designing a third-generation high brightness synchrotron radiation source, attention must be paid to the various collective effects that can influence beam performance. We report on calculations, performed with the code ZAP, of the bunch length, the transverse emittance and the beam lifetime (from both Touschek and gas scattering) for our l-2 GeV storage ring. In addition, we estimate the

S. Chattopadhyay; M. S. Zisman

1987-01-01

18

75 FR 64691 - Information Collection; Land Between The Lakes (LBL) Communication Effectiveness Study  

Federal Register 2010, 2011, 2012, 2013

...USDA Forest Service. Current and potential users of LBL receive information about the facility through sources such as co-op advertising and tourism promotions, as well as LBL's own Web site. The Forest Service is proposing a study...

2010-10-20

19

RFQ development at LBL  

SciTech Connect

The radio frequency quadrupole (FRQ) is a structure which can efficiently focus, bunch and accelerate low velocity ion beams. It has many features which make it particularly attractive for applications in the biomedical and nuclear sciences. There are two projects in progress at LBL where the incorporation of heavy ion RFQ technology offers substantial benefits: in the upgrade of the Bevatron local injector, and in the design of a dedicated heavy ion medical accelerator. In order to meet the requirements of these two important applications, a 200 MHz RFQ structure has been designed for ions with charge to mass ratios as low as 0.14, and a low rf power scale model has been built and tested. Construction of the high power model has begun. The status of this project is reviewed and a summary of technical specifications given.

Abbott, S.; Brodzik, D.; Gough, R.A.; Howard, D.; Lancaster, H.; MacGill, R.; Rovanpera, S.; Schneider, H.; Staples, J.; Yourd, R.

1982-11-01

20

High intensity metal ion beam production with ECR ion sources atthe Lawrence Berkeley National Laboratory  

SciTech Connect

The large number of different experiments performed at the 88 Inch Cyclotron requires great variety and flexibility in the production of ion beams. This flexibility is provided by the two high performance electron cyclotron resonance (ECR) ion sources, the LBL ECR and the AECR-U, which can produce beams of ions as light as hydrogen and as heavy as uranium. With these two sources, up to six different metals can be preloaded using two types of ovens. The ovens are mounted radially on the ion sources and inject the metal vapor though the open sextupole structure into the plasma chamber. For the superconducting ECR ion source VENUS, which is under construction at Lawrence Berkeley National Laboratory, the use of radial ovens is no longer possible, because the magnetic structure is closed radially. Therefore, we are developing two new axial oven types for low and high temperature applications. Metal ion beam production in ECR ion sources using the oven technique is discussed. The design of the axial oven is presented. Finally, the efficiency of the axial oven is compared with the radial oven for the production of Ca.

Wutte, D.; Abbott, S.; Leitner, M.A.; Lyneis, C.M.

2001-09-01

21

Sintering behavior of Ca or Sr-doped LaCrO 3 perovskites including second phase of AECrO 4 (AE=Sr, Ca) in air  

Microsoft Academic Search

The sintering characteristics and mechanisms of stoichiometric alkaline earth metal (AE)-doped lanthanum chromites, including the second phase of AECrO4 with low-melting point in air, (La1?xAExCrO3, AE=Ca and Sr, 0?x?0.3), have been discussed. When x?0.2, the sintering properties of La1?xCaxCrO3 are lower than those of La1?xSrxCrO3. However, the reverse results were observed at x=0.3. The mixtures of LaCrO3 and AECrO4 showed

Masashi Mori; Yoshiko Hiei; Nigel M Sammes

2000-01-01

22

Beam Dynamics Activities and Plans at LBL  

SciTech Connect

On-going beam dynamics studies at LBL are performed in connection with the 1-2 GeV Advanced Light Source (ALS), the SSC, Collider Physics (Novel Power Sources) and Heavy Ion Fusion Accelerator Research (HIFAR). Exploratory activities include generic research on (a) high-brightness, low-emittance storage rings and linacs for the TeV-scale future linear colliders, b{bar b} facilities, etc., (b) beam dynamics and optics of incoherent and coherent undulator radiation, (c) Free Electron Laser Studies, (d) development of a high-brightness laser-driven RF photocathode electron source for the LBL-LLNL-SLAC collaboration on Relativistic Klystrons and (e) new methods of acceleration. The major physics issues being studied in connection with the ALS are the effects of undulators and wigglers on storage ring beam dynamics (nonlinear stability and stable dynamic aperture), short bunch-length collective phenomena and multi-loop high-fidelity orbit and photon beam feedback for stability of the radiation source. In connection with the first issue, detailed nonlinear behavior of the electron beam in presence of insertion devices in an otherwise symmetric low-emittance lattice are being pursued and various compensation schemes are being investigated. We held a workshop on this specialized topic May 17-20, 1988 at LBL, where participants from international laboratories such as Sincrotrone Trieste, KEK, SLAC, BNL, ANL, etc., participated. Contributions will soon be published as proceedings to this workshop. Considerable insight into the physics of short bunches has been gained through a similar workshop last year on the 'Impedance Beyond Cutoff' at LBL, where a realistic picture of the impedance spectrum at high frequencies corresponding to short bunch lengths emerged. The focus at the moment is on the nature of coherent instabilities potentially driven by this high-frequency impedance. Securing a stable photon beam against vibrations and other noise sources simultaneously at several beam lines in a synchrotron radiation source is nontrivial and requires multi-loop orbit feedback system with accompanying cross-talk. A possible control algorithm is under investigation. In other matters, experimental study of dynamic effects with undulators is being planned at BESSY and other laboratories; impedance measurement test facility; instrumentation and feedback, advanced accelerator control systems and optics of synchrotron radiation are being pursued actively. Possibilities of infra-red and XUV FEL's as upgrades to the ALS are also being considered. Collaboration with LLNL and SLAC for the Relativistic Klystron is an ongoing activity. This promising power-source is being actively investigated both theoretically and experimentally with a goal towards a 1 GeV test experiment in late 1989. In this connection, studies of a conceptual design of a bright injector for the test experiment has been undertaken at Berkeley. The Conceptual Design Report will be completed in October, 1988. The design utilizes a high-brightness laser-driven RF photocathode electron gun, similar to the LANL early experiments, together with achromatic magnetic bunching and transport systems and diagnostics. The design is performed with attention to possible use in an FEL as well. Heteroenergetic collision optics for a possible b{bar b} facility based on 12 GeV PEP and a 2 GeV high-brightness ring has been obtained. The possible implications of collective effects is under study presently.

Chattopadhyay, S.

1988-07-01

23

Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets  

SciTech Connect

A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.

Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

1989-03-01

24

Multi-beam injector development at LBL  

SciTech Connect

LBL is developing a multi-beam injector that will be used for scaled accelerator experiments related to Heavy Ion Fusion. The device will produce sixteen 0.5 Amp beams of C+ at 2 MeV energy. The carbon arc source has been developed to the point where the emittance is within a factor of four of the design target. Modelling of the source behavior to find ways to reduce the emittance is discussed. Source lifetime and reliability is also of paramount importance to us and data regarding the lifetime and failure modes of different source configurations is discussed. One half of the accelerating column has been constructed and tested at high voltage. One beam experiments in this half column are underway. The second half of the column is being built and the transition 2 MV experiments should begin soon. In addition to beam and source performance we also discuss the controls for the injector and the electronics associated with the source and current injection. 3 refs., 2 figs.

Rutkowski, H.L.; Faltens, A.; Brodzik, D.A.; Johnson, R.M.; Pike, C.D.; Vanecek, D.L. (Lawrence Berkeley Lab., CA (United States)); Humphries, S. Jr. (New Mexico Univ., Albuquerque, NM (United States)); Meyer, E.A. (Los Alamos National Lab., NM (United States)); Hewett, D.W. (Lawrence Livermore National Lab., CA (United States))

1990-06-01

25

Emittance measurements on the LBL ECR source  

SciTech Connect

Measurements of radial emittance and the upper limit of energy spread have been made using a scanning Faraday cup after a waist, on beams of oxygen, argon and krypton. The general features are that the divergence seen at the scanning cup shows a central core and tails on each side. The un-normalized emittance of the beam core decreases with increasing Q/A in a way that is not explained by simple assumptions about the plasma or extraction system. Data from an experimental 1 mm diameter extraction aperture indicates that plasma density is about the same as over the standard aperture, but that the plasma energy spread is reduced to an upper limit of .2 to .4 V, and beam brightness is up by a factor of 10 for medium charge states. 9 refs., 10 figs., 1 tab.

Clark, D.J.

1987-11-01

26

Electron Injector Studies at LBL  

SciTech Connect

Two recent LBL design studies, (1) an rf gun with a laser driven photocathode, (2) and a conventional thermionic gun with three stages of bunching, are summarized and compared. The rf gun was designed as a possible injector to a 1 GeV test experiment consisting of a high gradient rf structure and a relativistic klystron. The rf gun cavity had (1/2 + 2) cells. Analytic calculations and computer simulations suggest that emittance growth was mainly caused by space-charge effects and the rf fringe field effects at the exit of the last cell. Emittance growth was found to be strongly dependent on the size and the length of the pulse. The conventional gun is being considered as an injector for the proposed Infra-Red-Free-Electron-Laser (IRFEL) facility. In order to reduce the space charge effects the final bunching is done in a tapered L-band tank where acceleration and bunching occur at the same time. Beam emittance of a conventional gun was measured at the ALS gun-test-stand and found to be satisfactory for the IRFEL application.

Kim, C.H.

1990-06-01

27

The LBL 55-meter spherical grating monochromator at SSRL (Stanford Synchrotron Radiation Laboratory)  

Microsoft Academic Search

The Lawrence Berkeley Laboratory 55-m spherical grating monochromator (SGM) beamline is located as a branch line of the 54-pole wiggler\\/undulator at the Stanford Synchrotron Radiation Laboratory (SSRL). It was designed and constructed by LBL's Center for X-Ray Optics and the engineering staff of LBL's Advanced Light Source with the cooperation and assistance of the research group of David Shirley at

W. R. McKinney; M. R. Howells; T. Lauritzen; J. Chin; R. DiGennaro; E. Fong; W. Gath; J. Guigli; H. Hogrefe; J. Meneghetti; D. Plate; P. A. Heimann; L. Terminello; Z. Ji; D. Shirley; S. Senf

1989-01-01

28

Studies of bright beam transport by the LBL MFE group  

NASA Astrophysics Data System (ADS)

We describe the coordination of theory and experiment in the study of bright beam systems by the LBL Magnetic Fusion Energy group. We have developed new analytic [1] and computational [2] tools for designing practical ESQ-focused systems, including the LBL CCVV (Constant Current Variable Voltage) prototype. This prototype has been tested both as a modular accelerator [3] and as part of a LEBT [4] for injection into an RFQ. We have also found these mathematical tools to be useful in setting up the bright-beam measurements on our test stand [5]. Our measurements showed no emittance growth in ESQ-focused 84 mA He+ beams with emittances of 0.0075? mrad-cm (normalized rms). We discuss analytical work on emittance growth in segmented beams [6] these results have been used as criteria for designing accelerators with multi-aperture sources [7]. The problem of emittance growth from beam size mismatch [8] is reviewed.

Anderson, O. A.; Soroka, L.; Kwan, J. W.

1992-04-01

29

Multiple beam induction linac research at LBL  

SciTech Connect

We present results of progress on the LBL multiple beam induction linac experiment (MBE-4). This machine models the accelerator physics of the electric-focused portion of a driver for heavy ion inertial confinement fusion. Four beams of cesium ions are accelerated in common through twenty four induction gaps while being separately focused in individual electrostatic AG focusing channels. Early experiments have demonstrated current amplification in the linac, from 10 mA to 90 mA per beam. This is achieved both by acceleration (from 200 keV to 1 MeV) and by carefully controlled bunch compression. Recent experiments have concentrated on studies of beams extracted from an ion source which produces 5 mA cesium beams at emittances near 0.03 {pi} mm-mrad (normalized). Experiments and theory show a growth of emittance (by about a factor of 2) as these beams are accelerated through the linac. Results of recent measurements of the transverse emittance behavior of these strongly space-charge-dominated ion beams are reviewed and compared with theory. 9 refs., 3 figs.

Garvey, T.; Eylon, S.; Fessenden, T.J.; Hahn, K.; Henestroza, E.; Keefe, D.

1990-06-01

30

Debittering of Protein Hydrolysates by Lactobacillus LBL-4 Aminopeptidase  

PubMed Central

Yoghurt strain Lactobacillus LBL-4 cultivated for 8–10?h at pH ~6.0 was investigated as a considerable food-grade source of intracellular aminopeptidase. Cell-free extract manifesting >200?AP U/l was obtained from cells harvested from 1?L culture media. Subtilisin-induced hydrolysates of casein, soybean isolate, and Scenedesmus cell protein with degree of hydrolysis 20–22% incubated at 45°C for 10?h by 10 AP?U/g peptides caused an enlarging of DH up to 40–42%, 46–48%, and 38–40% respectively. The DH increased rapidly during the first 4?h, but gel chromatography studies on BioGel P-2 showed significant changes occurred during 4–10?h of enzyme action when the DH increased gradually. After the digestion, the remained AP activity can be recovered by ultrafiltration (yield 40–50%). Scenedesmus protein hydrolysate with DH 20% was inoculated by Lactobacillus LBL-4 cells, and after 72?h cultivation the DH reached 32%. The protein hydrolysates (DH above 40%) obtained from casein and soybean isolate (high Q value) demonstrated a negligible bitterness while Scenedesmus protein hydrolysates (low Q value) after both treatments were free of bitterness.

Tchorbanov, Bozhidar; Marinova, Margarita; Grozeva, Lydia

2011-01-01

31

Preliminary Ionization Efficiencies of {sup 11}C and {sup 14}O with the LBNL ECR Ion Sources  

SciTech Connect

High charge states, up to fully stripped {sup 11}C and {sup 14}O ion, beams have been produced with the electron cyclotron resonance ion sources (LBNL, ECR and AECR-U) at Lawrence Berkeley National Laboratory. The radioactive atoms of {sup 11}C and {sup 14}O were collected in batch mode with an LN{sub 2} trap and then bled into the ECR ion sources. Ionization efficiency as high as 11% for {sup 11}C{sup 4+} was achieved.

Xie, Z.Q.; Cerny, J.; Guo, F.Q.; Joosten, R.; Larimer, R.M.; Lyneis, C.M.; McMahan, P.; Norman, E.B.; O'Neil, J.P.; Powell, J.; Rowe, M.W.; VanBrocklin, H.F.; Wutte, D.; Xu, X.J.; Haustein, P.

1998-10-05

32

INSTRUCTIONS FOR OPERATING LBL FORMALDEHYDE SAMPLER  

SciTech Connect

The LBL formaldehyde sampler consists of two parts: 1) a pump box and 2) a small refrigerator housing sampling bubblers. The pump box contains two pumps, a timer, a flow controller, an electrical cord, and a ten-foot piece of tubing to connect the refrigerator to the pump box. The small refrigerator contains four columns of bubbler sampling trains attached to a metal plate. Two sampling trains each are plumbed in parallel to two sampling ports on the back of the refrigerator. The two sampling lines supplied are to be attached to these ports to allow two locations to be sampled at once (usually one indoor and one outdoor). The refrigerator also contains a rack for holding bubbler tubes. In the sampling process, air is drawn through a sampling line attached to the fitting at the back of the refrigerator and into a prlmary bubbler containing a trapping solution. This trapping solution can be distilled water or an aqueous solution of some compound that reacts with formaldehyde. From this bubbler the air goes through a second bubbler containing the same trapping solution as the first bubbler. (To maintain sample integrity, all parts that the air sample contacts are made of Teflon, polypropylene, and stainless steel.) The air then goes into the third bubbler, which contains no liquid. This bubbler contains a hypodermic needle that serves as a flow-control orifice. The hypodermic needle, in conjunction with the flow controller in the pump box, ensures a constant a flow rate. The refrigerator contains four columns of these sets of three bubblers. After samples have been collected, the bubbler bottoms are detached and the contents of the first and second bubblers in each column are poured together, capped, and labeled. The use of a refrigerated primary and secondary bubbler whose contents are combined at the end of a sampling period ensures 95% collection efficiency. After the bubbler tubes are capped and labeled, they are stored either in the rack supplied in the refrigerator or in one of the styrofoam shipping boxes with some frozen blue ice. LBL has found that formaldehyde samples collected in water degrade significantly in a matter of hours if they are not kept cool, whereas refrigerated samples remain stable for as long as a month. Directions are provided for unpacking the apparatus, setting up sampling trains, performing the sampling, procedures after sampling, and shipping samples.

Fanning, L.Z.; Allen, J.R.; Miksch, R.R.

1981-09-01

33

SSC Quadrupole Magnet Performance at LBL  

SciTech Connect

Lawrence Berkeley Laboratory (LBL) contracted to design, construct, and test four short (1m) models and six full-size (5m) models of the Superconducting Super Collider (SSC) main-ring 5 meter focusing quadrupole magnet (211 Tesla/meter). The training performance of these magnets is summarized. Magnets were tested in a horizontal boiling helium (1 Atm) cryostat. The magnetic, strain-gage and training responses to two thermal cycles were measured. The quadrupole gradient, and relative multipole purity were determined from Fourier analysis of the rotating coil signals. Magnetic and strain-gage measurements were taken on-the-fly. The voltage-tap data was analyzed to determine quench-origin and propagation characteristics. Quench-training proceeded at 4.3K until a plateau was achieved or sub-cooling (2.5K) was used to accelerate the training process. The early short (1m) magnets were also trained at 1.8K (10kA) to help identify potential weak areas. The MIITs were calculated to compare various magnet protection methods. Except for modest training above the anticipated SSC operating point, the magnets performed very well and proved to be self-protecting. Some design flaws were identified and corrected. The last two 1 m models and all the 5m models have been reinstalled in cryostats at the SSC Laboratory, retested and used to achieve various milestones in their program.

Lietzke, A.F.; Barale, P.; Benjegerdes, r.; Caspi, S.; Cortella, J.; Dell'Orco, D.; Gilbert, W.; Green, M.I.; Mirk, K.; Peters, C.; Scalan, R.; Taylor, C.E.; Wandesforde, A.

1992-10-01

34

LBL Magnetic-Measurements Data-Acquisition System.  

National Technical Information Service (NTIS)

The LBL Magnetic Measurements Engineering (MME) Group has developed a Real-Time Data Acquisition System (DAS) for magnetic measurements. The design objective was for a system that was versatile, portable, modular, expandable, quickly and easily reconfigur...

M. I. Green D. H. Nelson

1983-01-01

35

LBL/AGMEF/JSU El Yunque Environmental Research Initiative.  

National Technical Information Service (NTIS)

The LBL/AGMEF/JSU Environmental Research Initiative has had several noteworthy successes. Faculty and student development is apparent. A research project involving atmospheric aerosol sampling was established at Universidad Metropolitana under Prof. Ferna...

R. L. Dod F. Diaz L. Feliu C. D. Parker

1989-01-01

36

LAYER BY LAYER (LbL) SELF-ASSEMBLY STRATEGY AND ITS APPLICATIONS  

Microsoft Academic Search

This report reviews the technique of layer-by-layer (LbL) self-assembly, in particular cases involving electrostatic interactions between thin film monolayers. LbL self- assembly is used in a variety of different applications, two of which discussed in the report are LbL MEMS and LbL protein multilayers. In the fabrication of LbL MEMS, multilayers of polymer-clay-magnetite nanocrystal are deposited via photolithographic steps on

A. Z. Cheng; R. Swaminathan

37

Linear collider research and development at SLAC, LBL and LLNL  

SciTech Connect

The study of electron-positron (e/sup +/e/sup /minus//) annihilation in storage ring colliders has been very fruitful. It is by now well understood that the optimized cost and size of e/sup +/e/sup /minus// storage rings scales as E(sub cm//sup 2/ due to the need to replace energy lost to synchrotron radiation in the ring bending magnets. Linear colliders, using the beams from linear accelerators, evade this scaling law. The study of e/sup +/e/sup /minus// collisions at TeV energy will require linear colliders. The luminosity requirements for a TeV linear collider are set by the physics. Advanced accelerator research and development at SLAC is focused toward a TeV Linear Collider (TLC) of 0.5--1 TeV in the center of mass, with a luminosity of 10/sup 33/--10/sup 34/. The goal is a design for two linacs of less than 3 km each, and requiring less than 100 MW of power each. With a 1 km final focus, the TLC could be fit on Stanford University land (although not entirely within the present SLAC site). The emphasis is on technologies feasible for a proposal to be framed in 1992. Linear collider development work is progressing on three fronts: delivering electrical energy to a beam, delivering a focused high quality beam, and system optimization. Sources of high peak microwave radio frequency (RF) power to drive the high gradient linacs are being developed in collaboration with Lawrence Berkeley Laboratory (LBL) and Lawrence Livermore National Laboratory (LLNL). Beam generation, beam dynamics and final focus work has been done at SLAC and in collaboration with KEK. Both the accelerator physics and the utilization of TeV linear colliders were topics at the 1988 Snowmass Summer Study. 14 refs., 4 figs., 1 tab.

Mattison, T.S.

1988-10-01

38

The LBL\\/AGMEF\\/JSU El Yunque Environmental Research Initiative  

Microsoft Academic Search

The LBL\\/AGMEF\\/JSU Environmental Research Initiative has had several noteworthy successes. Faculty and student development is apparent. A research project involving atmospheric aerosol sampling was established at Universidad Metropolitana under Prof. Fernando Diaz. A National Science Foundation grant received to expand upon that project. Review of analyses carried out since 1986 supports the original view that El Yunque peak on the

R. L. Dod; F. Diaz; L. Feliu; C. D. Parker

1989-01-01

39

The LBL 55-meter spherical grating monochromator at SSRL (Stanford Synchrotron Radiation Laboratory)  

SciTech Connect

The Lawrence Berkeley Laboratory 55-m spherical grating monochromator (SGM) beamline is located as a branch line of the 54-pole wiggler/undulator at the Stanford Synchrotron Radiation Laboratory (SSRL). It was designed and constructed by LBL's Center for X-Ray Optics and the engineering staff of LBL's Advanced Light Source with the cooperation and assistance of the research group of David Shirley at LBL and the staff of SSRL. The main goals of the project were to test the SGM concept and to develop a capability for designing and building a water-cooled mirror and grating capability in anticipation of the ALS. A water-cooled plane mirror deflects the beam horizontally, taking in general a small fraction of the flux from the 54-pole insertion device. This mirror is a brazed assembly of Glidcop (a proprietary alumina-dispersion-strengthened copper alloy) and OFHC copper. Its surface was finished in polished electroless nickel, then overcoated with gold as all optics in the beamline are overcoated. Next in the line is a fused silica toroid which focuses the SPEAR source vertically onto the entrance slit of the monochromator and horizontally onto the nominal position of the exit slit, in the manner of Rense and Violett. The magnification factors are 0.3x vertically and 0.7x horizontally. The monochromator is a Rowland-circle design; both slits move on large granite-based slides that maintain flatness of travel to {plus minus}2 {mu}m in peak-to-peak variation from straightness.

McKinney, W.R.; Howells, M.R.; Lauritzen, T.; Chin, J.; DiGennaro, R.; Fong, E.; Gath, W.; Guigli, J.; Hogrefe, H.; Meneghetti, J.; Plate, D.; Heimann, P.A.; Terminello, L.; Ji, Z.; Shirley, D. (Lawrence Berkeley Lab., CA (USA)); Senf, S. (Stanford Univ., CA (USA). Stanford Synchrotron Radiation Lab.)

1989-08-01

40

Detailed examination of the LBL infiltration model using the Mobile Infiltration Test Unit  

SciTech Connect

The LBL infiltration model is a simplified method for combining weather information with air tightness to calculate residential air infiltration. In this report, we compare infiltration-model predictions with data collected by our Mobile Infiltration Test Unit (MITU), a full-scale test structure that gathers detailed weather and infiltration measurements. To probe for sources of prediction errors, we examine four simplifying assumptions made in the LBL infiltration model: 1) that the flow through the cracks in the building shell can be approximated by orifice flow, 2) that wind-induced and stack-induced infiltration can be represented in quadrature, 3) that wind-induced infiltration can be represented by averaging the valued for three typical aspect ratios, and 4) that wind-induced infiltration can be represented by averaging the values for all wind directions. We make comparisons with measured data to examine these effects qualitatively, and use detailed computer simulations of infiltration in MITU to quantify each effect. The effects of each assumption are represented by the bias and scatter. (The bias is the average error; the scatter is a measure of the ability of a model to track short-term fluctuations in infiltration rate.) We show that the orifice-flow assumption causes an 8% bias and a scatter of 20%, and that the quadrature assumption causes consistent overprediction (bias = 12%, scatter = 6%). For MITU, averaging over aspect ratio causes some ability of the model to track infiltration (scatter = 14%). Although it reduces the ability of the model to track infiltration (scatter = 19%), averaging over wind direction has little effect on the mean infiltration rate (bias = 0). When compared to measured data, the LBL model has a bias of 10% and scatter of 28%.

Modera, M.P.; Sherman, M.H.; Levin, P.A.

1983-07-01

41

Electron beam transport for the LBL IR-FEL  

SciTech Connect

The infrared flee-electron laser (IR-FEL) proposed by LBL as part of the Combustion Dynamics Research Laboratory (CDRL) consists of a multiple-pass accelerator with superconducting cavities supplying a 55 MeV 12 mA beam to an undulator within a 24-meter optical cavity. Future options include deceleration through the same cavities for energy recovery and reducing the power in the beam dump. The electron transport system from the injector through the cavities and undulator must satisfy conditions of high order achromaticity, isochronicity, unity first-order transport matrix around the recirculation loop, variable betatron match into the undulator, ease of operation and economical implementation. This paper presents a workable solution that satisfies these requirements.

Staples, J.; Edighoffer, J.; Kim, Kwang-Je

1992-07-01

42

Tuning the nanostructure of DODAB/nickel tetrasulfonated phthalocyanine bilayers in LbL films.  

PubMed

Nanostructured films of dioctadecyldimethylammonium bromide (DODAB) and nickel tetrasulfonated phthalocyanine (NiTsPc) were layer-by-layer (LbL) assembled to achieve a synergistic effect considering the distinct properties of both materials. Prior to LbL growth, the effect of NiTsPc on the structure of DODAB vesicles in aqueous medium was investigated by differential scanning calorimetry (DSC). Therefore, DODAB/NiTsPc LbL films were prepared using NiTsPc at concentrations below and above the limit concentration of vesicle formation according to our DSC experiments. As a result, LbL films with distinct nanostructures were obtained, which were studied at micro and nanoscales by micro-Raman and atomic force microscopy, respectively. A linear growth of the LbL films was observed by ultraviolet-visible absorption spectroscopy. However, the bilayer thickness and the surface morphology of the LbL films were radically affected depending on NiTsPc concentration. The electrostatic interaction between DODAB and NiTsPc was identified via Fourier transform infrared (FTIR) absorption spectroscopy as the main driving force responsible for LbL growth. Because LbL films have been widely applied as transducers in sensing devices, DODAB/NiTsPc LbL films having distinct nanostructures were tested as proof-of-principle in preliminary sensing experiments toward dopamine detection using impedance spectroscopy (e-tongue system). The real capacitance vs. dopamine concentration curves were treated using Principal Component Analysis (PCA) and an equivalent electric circuit, revealing the role played by the LbL film nanostructure and the possibility of building calibration curves. PMID:23623117

Furini, L N; Feitosa, E; Alessio, P; Shimabukuro, M H; Riul, A; Constantino, C J L

2013-03-21

43

LBL Magnetic-Measurements Data-Acquisition System  

SciTech Connect

The LBL Magnetic Measurements Engineering (MME) Group has developed a Real-Time Data Acquisition System (DAS) for magnetic measurements. The design objective was for a system that was versatile, portable, modular, expandable, quickly and easily reconfigurable both in hardware and software, and inexpensive. All objectives except the last were attained. An LSI 11/23 microcomputer is interfaced to a clock-calendar, printer, CRT control terminal, plotter with hard copy, floppy and hard disks, GPIB, and CAMAC buses. Off-the-shelf hardware and software have been used where possible. Operational capabilities include: (1) measurement of high permeability materials; (2) harmonic error analysis of (a) superconducting dipoles and (b) rare earth cobalt (REC) and conventional quadrupole magnets; and (3) 0.1% accuracy x-y mapping with Hall probes. Results are typically presented in both tabular and graphical form during measurements. Only minutes are required to switch from one measurement capability to another. Brief descriptions of the DAS capabilities, some of the special instrumentation developed to implement these capabilities, and planned developments are given below.

Green, M.I.; Nelson, D.H.

1983-03-01

44

Report on the 1984 LBL workshop on detectors for relativistic nuclear collisions  

SciTech Connect

Highlights of the Workshop on Detectors for Relativistic Nuclear Collisions, held March 26-30, 1984, at the Lawrence Berkeley Laboratory are reviewed. (Complete proceedings are available as report LBL-18225.) (WHK)

Schroeder, L.S.

1984-11-01

45

Detailed Examination of the LBL (Lawrence Berkeley Laboratory) Infiltration Model Using the Mobile Infiltration Test Unit.  

National Technical Information Service (NTIS)

The LBL infiltration model is a simplified method for combining weather information with air tightness to calculate residential air infiltration. In this report, we compare infiltration-model predictions with data collected by our Mobile Infiltration Test...

M. P. Modera M. H. Sherman P. A. Levin

1983-01-01

46

Case study data base companion report 3 to simulation of geothermal subsidence (LBL-10571)  

SciTech Connect

The data base developed for selection and evaluation of geothermal subsidence case studies is presented. Data from this data base were used in case studies of Wairakei, The Geysers, and Austin Bayou Prospect (Report LBL 10571).

Miller, I.; Dershowitz, W.; Jones, K.; Myer, L.; Roman, K.; Schauer, M.

1980-03-01

47

Effect of thickness on the thermal properties of hydrogen-bonded LbL assemblies.  

PubMed

Layer-by-layer (LbL) assemblies have attracted much attention for their functional versatility and ease of fabrication. However, characterizing their thermal properties in relation to the film thickness has remained a challenging topic. We have investigated the role of film thickness on the glass transition temperature (T(g)) and coeffecient of thermal expansion for poly(ethylene oxide)/poly(acrylic acid) (PEO/PAA) and PEO/poly(methacrylic acid) (PEO/PMAA) hydrogen-bonded LbL assemblies in both bulk and ultrathin films using modulated differential scanning calorimetry (modulated DSC) and temperature-controlled ellipsometry. In PEO/PAA LbL films, a single, well-defined T(g) was observed regardless of film thickness. The T(g) increased by 9 °C relative to the bulk T(g) as film thickness decreased to 30 nm because of interactions between the film and its substrate. In contrast, PEO/PMAA LbL films show a single glass transition only after a thermal cross-linking step, which results in anhydride bonds between PMAA groups. The T(g), within error, was unaffected by film thickness, but PEO/PMAA LbL films of thicknesses below ~2.7 ?m exhibited a small amount of PEO crystallization and phase separation for the thermally cross-linked films. The coefficients of thermal expansion of both types of film increased with decreasing film thickness. PMID:22551218

Sung, Choonghyun; Vidyasagar, Ajay; Hearn, Katelin; Lutkenhaus, Jodie L

2012-05-14

48

LBL research on The Geysers: Conceptual models, simulation and monitoring studies  

SciTech Connect

As part of The Geysers research activities of DOE`s Geothermal Reservoir Technology Program, LBL, in close co-operation with industry, is performing fundamental and applied studies of vapor- dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

1982-03-01

49

LBL research on The Geysers: Conceptual models, simulation and monitoring studies  

SciTech Connect

As part of The Geysers research activities of DOE's Geothermal Reservoir Technology Program, LBL, in close co-operation with industry, is performing fundamental and applied studies of vapor- dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

1992-03-01

50

LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies  

SciTech Connect

As part of The Geysers research activities of DOE's Geothermal Reservoir Technology Program, LBL, in close cooperation with industry, is performing fundamental and applied studies of vapor-dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

1992-03-24

51

LBL fabricated biopolymer-layered silicate based nanofibrous mats and their cell compatibility studies.  

PubMed

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) was synthesized from chitosan (CS). Organic rectorite (OREC) added into cellulose acetate (CA) was used to fabricate electrospun nanofibrous mats with improved thermal properties, as a result of depositing multilayers of the positively charged HTCC-OREC composites and the negatively charged sodium alginate (ALG) via layer-by-layer (LBL) technique. The morphology was affected by the number of deposition bilayers and the component of the outmost layer. Observed from the field emission scanning electron microscopy (FE-SEM) images, the LBL structured nanofibrous mats had much larger fiber sizes than CA-OREC nanofibrous mats. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results further confirmed that HTCC-OREC was assembled on nanofibrous mats. Additionally, cell experiments and MTT results demonstrated that OREC had little effect on the cytotoxicity of LBL template, but obviously affected both the cytotoxicity and the cell compatibility of LBL structured mats when OREC was in the deposition films. PMID:22840026

Huang, Rong; Li, Yuejun; Zhou, Xue; Zhang, Qi; Jin, Huanguang; Zhao, Jiemin; Pan, Siyi; Deng, Hongbing

2012-06-18

52

Development and implementation of a low-cost LBL navigation system for an AUV  

Microsoft Academic Search

A reliable navigation system is a key factor for the success of an operational mission with an AUV in a real scenario. We address the main issues involved in the implementation of a long baseline (LBL) navigation system for a REMUS AUV. This system replaces both the original hardware and software of the vehicle with a simpler, faster, less expensive

Anibal Matos; Nuno Cruz; A. Martins; F. Lobo Pereira

1999-01-01

53

Overview of current radon and radon daughter research at LBL  

SciTech Connect

This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations.

Not Available

1983-01-01

54

Production of lepton pairs at the LBL Bevelac  

SciTech Connect

We discuss the physics objectives for the DLS program with some emphasis on the possible use of dileptons as a probe of pion dynamics in nuclear matter. Data on p-Be reactions at 1-5 GeV and Ca-Ca at 1-2 A GeV are presented. The observation of a structure at about twice the pion mass in the e/sup +/e/sup /minus// invariant mass spectra above 2 GeV beam energy and the excitation function for the p-Be reaction suggest that pion annihilation is a significant dielectron source above 2 GeV. The dielectron mass spectrum from Ca-Ca at 1 A GeV exhibits an inverse slope larger than the one from p-Be at the same beam energy. 22 refs., 12 figs., 3 tabs.

Roche, G.

1989-06-01

55

The effect of gas mixing and biased disc voltage on the preglow transient of electron cyclotron resonance ion source  

SciTech Connect

The effect of gas mixing and biased disc voltage on the preglow of electron cyclotron resonance ion source plasma has been studied with the AECR-U type 14 GHz ion source. It was found that gas mixing has a significant effect on the preglow. The extracted transient beam currents and efficiency of the heavier species increase, while the currents and efficiency of the lighter species decrease when gas mixing is applied. The effect of the biased disc was found to be pronounced in continuous operation mode in comparison to preglow. The data provide information on the time scales of the plasma processes explaining the effects of gas mixing and biased disc. The results also have implications on production of radioactive ion beams in preglow mode for the proposed Beta Beam neutrino factory.

Tarvainen, O.; Toivanen, V.; Komppula, J.; Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae 40500 (Finland)

2012-02-15

56

The LBL Advanced Light Source (ALS) transverse coupled-bunch feedback system: Recent commissioning results  

SciTech Connect

The ALS transverse coupled-bunch feedback system is described along with some recent commissioning results. Results presented include transfer function measurements, demonstrations of multi-bunch damping, and demonstrations of simultaneous transverse and longitudinal systems operation.

Barry, W.; Byrd, J.; Corlett, J.

1994-10-01

57

The LBL (Lawrence Berkeley Laboratory) multiple beam experiments  

SciTech Connect

The multiple-beam induction linac approach to a heavy ion driver for inertial confinement, fusion features continuous current amplification along the accelerator and a minimum of beam manipulations from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. MBE-4 is designed as a four-beam induction linac that models much of the accelerator physics of the electrostatically focused section of a significantly longer induction accelerator. Four space-charge-dominated Cs/sup +/ beams, initially about one meter in length at a current of 13 mA, are focused by electrostatic quadrupoles and accelerated in parallel from 200 to nearly 600 keV. The energy will reach approximately one MeV when the accelerator is complete. Experiments have proceeded in parallel with the construction of the apparatus which began in FY 85 and is now more than half complete. The results show a current amplification, so far, by a factor of 2.8 in good agreement with the longitudinal acceleration calculations.

Fessenden, T.J.; Keefe, D.; Kim, C.; Meuth, H.; Warwick, A.

1987-03-01

58

Effects of undulators on the ALS: The early work on the LBL (Lawrence Berkeley Laboratory)  

SciTech Connect

In this paper we describe the early work carried out at LBL on the consequences of installing insertion devices (wigglers and undulators) on the beam dynamics of the ALS. This included analytical and tracking studies, and led to an insight to the reasons behind the predicted reduction in dynamic aperture. For completeness, a description of the unperturbed storage ring characteristics are also given. 3 refs., 16 figs., 2 tabs.

Jackson, A.

1988-05-01

59

Transparent Conductors from Carbon Nanotubes LBL-Assembled with Polymer Dopant with ?-? Electron Transfer  

PubMed Central

Single-walled carbon nanotube (SWNT) and other carbon-based coatings are being considered as replacements for indium tin oxide (ITO). The problems of transparent conductors (TCs) coatings from SWNT and similar materials include poor mechanical properties, high roughness, low temperature resilience, and fast loss of conductivity. The simultaneous realization of these desirable characteristics can be achieved using high structural control of layer-by-layer (LBL) deposition, which is demonstrated by the assembly of hydroethyl cellulose (HOCS) and sulfonated polyetheretherketone (SPEEK)-SWNTs. A new type of SWNT doping based on electron transfer from valence bands of nanotubes to unoccupied levels of SPEEK through ?-? interactions was identified for this system. It leads to a conductivity of 1.1×105 S/m at 66wt% loadings of SWNT. This is better than other polymer/SWNT composites and translates into surface conductivity of 920 ohms/sq and transmittance of 86.7% at 550nm. The prepared LBL films also revealed unusually high temperature resilience up to 500°C, and low roughness of 3.5 nm (ITO glass - 2.4 nm). Tensile modulus, ultimate strength, and toughness of such coatings are 13±2 GPa, 366±35 MPa and 8±3 kJ/m3, respectively, and exceed corresponding parameters of all similar TCs. The cumulative figure of merit, ?TC, which included the critical failure strain relevant for flexible electronics, was ?TC = 0.022 and should be compared to ?TC = 0.006 for commercial ITO. Further optimization is possible using stratified nanoscale coatings and improved doping from the macromolecular LBL components.

Zhu, Jian; Shim, Bong Sup; Di Prima, Matthew; Kotov, Nicholas A.

2011-01-01

60

Transparent conductors from carbon nanotubes LBL-assembled with polymer dopant with ?-? electron transfer.  

PubMed

Single-walled carbon nanotube (SWNT) and other carbon-based coatings are being considered as replacements for indium tin oxide (ITO). The problems of transparent conductors (TCs) coatings from SWNT and similar materials include poor mechanical properties, high roughness, low temperature resilience, and fast loss of conductivity. The simultaneous realization of these desirable characteristics can be achieved using high structural control of layer-by-layer (LBL) deposition, which is demonstrated by the assembly of hydroethyl cellulose (HOCS) and sulfonated polyetheretherketone (SPEEK)-SWNTs. A new type of SWNT doping based on electron transfer from valence bands of nanotubes to unoccupied levels of SPEEK through ?-? interactions was identified for this system. It leads to a conductivity of 1.1 × 10(5) S/m at 66 wt % loadings of SWNT. This is better than other polymer/SWNT composites and translates into surface conductivity of 920 ?/? and transmittance of 86.7% at 550 nm. The prepared LBL films also revealed unusually high temperature resilience up to 500 °C, and low roughness of 3.5 nm (ITO glass -2.4 nm). Tensile modulus, ultimate strength, and toughness of such coatings are 13 ± 2 GPa, 366 ± 35 MPa, and 8 ± 3 kJ/m(3), respectively, and exceed corresponding parameters of all similar TCs. The cumulative figure of merit, ?(TC), which included the critical failure strain relevant for flexible electronics, was ?(TC) = 0.022 and should be compared to ?(TC) = 0.006 for commercial ITO. Further optimization is possible using stratified nanoscale coatings and improved doping from the macromolecular LBL components. PMID:21524068

Zhu, Jian; Shim, Bong Sup; Di Prima, Matthew; Kotov, Nicholas A

2011-04-27

61

From the {psi} to charmed mesons: Three years with the SLAC-LBL detector at SPEAR  

SciTech Connect

As I look back at the first three years or so at SPEAR, I consider this one of the most revolutionary or perhaps the most revolutionary, experiment in the 60 year history of particle physics. It certainly was the most exciting time, in a laboratory that is, that I have ever experienced. In my talk I will cover the period 1973--1976 which saw the discoveries of the {psi} and {psi}{prime} resonances the {chi} states and most of the Psion spectroscopy, the D{degree}, D{sup +}* charmed meson doublet as well as the D{degree}* and D{sup +}* doublet. I will also refer briefly to some more recent results. Most of the discoveries I will mention were made with the SLAC-LBL Magnetic Detector or ``MARK I`` which we operated at SPEAR from 1973 to 1976. In 1976 the MARK I was modified to include a ``Lead Glass Wall`` (LGW) for improved photon and electron detection. This involved a new physics group from LBL, who built the LGW, Lina Barbaro-Galtieri et al. as well as a continuing group from SLAC, Martin Perl and Gary Feldman et al. to provide continuity in the running of the MARK I and to continue the study of the anomalous e{mu}events which Martin found earlier and which eventually were identified as the signature of the {tau} lepton.

Goldhaber, G.

1992-06-01

62

From the. psi. to charmed mesons: Three years with the SLAC-LBL detector at SPEAR  

SciTech Connect

As I look back at the first three years or so at SPEAR, I consider this one of the most revolutionary or perhaps the most revolutionary, experiment in the 60 year history of particle physics. It certainly was the most exciting time, in a laboratory that is, that I have ever experienced. In my talk I will cover the period 1973--1976 which saw the discoveries of the {psi} and {psi}{prime} resonances the {chi} states and most of the Psion spectroscopy, the D{degree}, D{sup +}* charmed meson doublet as well as the D{degree}* and D{sup +}* doublet. I will also refer briefly to some more recent results. Most of the discoveries I will mention were made with the SLAC-LBL Magnetic Detector or MARK I'' which we operated at SPEAR from 1973 to 1976. In 1976 the MARK I was modified to include a Lead Glass Wall'' (LGW) for improved photon and electron detection. This involved a new physics group from LBL, who built the LGW, Lina Barbaro-Galtieri et al. as well as a continuing group from SLAC, Martin Perl and Gary Feldman et al. to provide continuity in the running of the MARK I and to continue the study of the anomalous e{mu}events which Martin found earlier and which eventually were identified as the signature of the {tau} lepton.

Goldhaber, G.

1992-06-01

63

Direct-write maskless lithography of LBL nanocomposite films and its prospects for MEMS technologies.  

PubMed

Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to the production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation-pads (BLASPs) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1 ?m. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites, possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45 × 10(-5)? m and 3.80 × 10(-6)? m at 20 °C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed. PMID:22740054

Bai, Yongxiao; Ho, Szushen; Kotov, Nicholas A

2012-06-27

64

Highly photoluminescent multilayer QD-glass films prepared by LbL self-assembly.  

PubMed

A novel and facile preparation method for layer-by-layer (LbL) self-assembled films incorporating quantum dots (QDs) and having intense photoluminescence (PL) from blue to red is presented. Functional sol-gel-derived glass layers prepared by the hydrolysis of 3-aminopropyltrimethoxysilane (APS) or 3-mercaptopropyltrimethoxysilane (MPS) have been used as a linkage between QD layers. Absorption, PL spectroscopy, transmission electron microscopy, and atomic force microscopy were employed for characterization, which revealed that the QDs in the prepared films had a nearly close-packed coverage and were not aggregated. The PL efficiencies of the QDs (CdTe or ZnSe, both are thioglycolic acid-stabilized) dispersed in the films were roughly half that of the initial colloidal solutions but reached 24% before a refractive index correction. The thickness of the red-emitting film with 10 CdTe QD layers was approximately 50 nm. The concentration of QDs in the film derived from the first absorption peak was approximately 0.01 M. Because the PL starts to show a red shift, the obtained concentration is practically the ultimate one in the glass matrix. The mercapto, amino, and carboxyl groups play important roles in LbL self-assembling processes. PMID:16142978

Yang, P; Li, C L; Murase, N

2005-09-13

65

Direct-Write Maskless Lithography of LBL Nanocomposite Films and its Prospects for MEMS Technologies  

PubMed Central

Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation pads (BLASP) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1?m. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45×10?5 ?·m and 3.80×10?6 ?·m at 20°C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed.

Bai, Yongxiao; Ho, Szushen; Kotov, Nicholas A.

2012-01-01

66

Automatic tuning of the LBL SuperHILAC third-injector transport line  

SciTech Connect

Testing of a new automatic tuning procedure in an LBL SuperHILAC beam transport line has been conducted with the third injector microcomputer control system. This technique is an advance over the sequential station-by-station automatic tuning method developed for the Bevalac transfer line. The computer now performs steering/focusing adjustments simultaneously on a number of quadrupole and dipole magnets comprising multiple-station sections of the injection line. New magnet currents are computed from equations governing beam optics in a real-time simulation of the beam line. The key to this emittance utilizing the same control magnets and beam profile monitors used for manual tuning of the line. This emittance calculation requires high resolution beam profile measurements using multi-wire profile monitors recently installed in the third injector line.

Pines, H.

1983-03-01

67

Direct-write maskless lithography of LBL nanocomposite films and its prospects for MEMS technologies  

NASA Astrophysics Data System (ADS)

Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to the production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation-pads (BLASPs) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1 ?m. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites, possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45 × 10-5 ? m and 3.80 × 10-6 ? m at 20 °C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed.Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to the production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation-pads (BLASPs) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1 ?m. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites, possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45 × 10-5 ? m and 3.80 × 10-6 ? m at 20 °C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr30197k

Bai, Yongxiao; Ho, Szushen; Kotov, Nicholas A.

2012-07-01

68

Electron beam transport for the LBL IR-FEL. [Infrared free-electron laser  

SciTech Connect

The infrared flee-electron laser (IR-FEL) proposed by LBL as part of the Combustion Dynamics Research Laboratory (CDRL) consists of a multiple-pass accelerator with superconducting cavities supplying a 55 MeV 12 mA beam to an undulator within a 24-meter optical cavity. Future options include deceleration through the same cavities for energy recovery and reducing the power in the beam dump. The electron transport system from the injector through the cavities and undulator must satisfy conditions of high order achromaticity, isochronicity, unity first-order transport matrix around the recirculation loop, variable betatron match into the undulator, ease of operation and economical implementation. This paper presents a workable solution that satisfies these requirements.

Staples, J.; Edighoffer, J.; Kim, Kwang-Je.

1992-07-01

69

RGO LBL modified biomimetic electrochemical sensor for detection of Sildenafil in herbal sexual health products.  

PubMed

In this work, a highly sensitive and selective biomimetic electrochemical sensor for Sildenafil in herbal sexual health products was prepared. Reduced graphene oxide (RGO), a novel highly conductive material was used to modify glassy carbon electrode (GCE) through layer-by-layer (LBL) self-assembly. The conductive molecularly imprinted films were constructed on the functional electrode surface using Sildenafil as template molecules, p-phenylenediamine (p-PD) as functional monomers. The obtained molecularly imprinted electrochemical sensor (MIES) was successfully used to detect Sildenafil in herbal sexual health products. The limit of detection (LOD) was 6.2 nmol L?¹. The recoveries for the spiked Sildenafil contents were in the range of 92.34-97.71% with the RSD < 2.31%. The selective efficiencies for Sildenafil and other structurally related analogues only slightly varied from 0.93 to 1.09. PMID:23208100

Li, Yun; Wen, Tingting; Xue, Cheng; Han, Qing; Wang, Yang; Hong, Junli; Zhou, Xuemin; Jiang, Huijun

2012-10-26

70

High Charge State Multicusp Ion Source.  

National Technical Information Service (NTIS)

Attempts have been made to generate high charge state ion beams by employing a multicusp plasma source. Three experimental investigations have been performed at LBL and at GSI to study the charge state distributions and the emittance of the extracted beam...

K. N. Leung R. Keller

1989-01-01

71

Advanced Light Source (ALS) Radiation Safety System. Revised.  

National Technical Information Service (NTIS)

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 Gev synchrotron light source facility consisting of a 120 kev electron gun, 50 Mev linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage...

A. L. Ritchie D. E. Oldfather A. F. Lindner

1993-01-01

72

Training of LBL-SSC model dipole magnets at 1. 8 K  

SciTech Connect

We present the 1.8K training behavior of SSC Magnets, several of which have reached a peak current of 9400 A; a central field of 9 Tesla. For the SSC Project, more than 30 one meter long dipole magnets have been built and tested. The test results for the 4.3K operation have been presented previously. Magnet operation, primarily reaching design field without premature training, is expected to be superior in superfluid helium at 1.8K as compared with helium I at 4.3K. Not only is the critical current increased at the lower temperature, but the heat transfer is much improved. LBL has had an operating helium II facility for nine years and our standard test sequence has been to check for training in helium I at 4.3K and then cool the system down to 1.8K and train the magnet to its new, high limit. Because the mechanical forces are much greater at the higher currents and fields achieved at the lower temperature, information has been obtained on the adequacy of the mechanical design. Even for those magnets in which training quenches occurred in the inner layer at 4.3K, many of the quenches at 1.8K occurred in the outer layer. 10 refs., 8 figs.

Gilbert, W.S.; Althaus, R.; Benjegerdes, R.; Caspi, S.; Peters, C.; Rechen, J.; Royet, J.; Scanlan, R.; Taylor, C.; Wandesforde, A.

1989-03-01

73

Experimental reestablishment of red wolves (Canis rufus) on the Tennessee Valley Authority's Land Between the Lakes (LBL)  

SciTech Connect

For all practical purposes the red wolf (Canis rufus) is extirpated in its final range in southeast Texas and southwest Louisiana. Although the species can be preserved in captivity, the only means by which it can be preserved as a naturally occurring element of our national heritage is to reestablish viable populations within the wolf's historic range in the southeastern United States. This proposal outlines a suggested procedure for reestablishing red wolves at Land Between The Lakes (LBL) by initially releasing five adult mated pairs of animals on the area over a two-year period. Recommendations for additions, changes, and deletions to this proposal have been received from the Kentucky Department of Fish and Wildlife Resources, Tennessee Wildlife Resources Agency, other governmental agencies, and interested organizations and individuals in the surrounding area. This proposal includes information describing probable environmental impacts associated with the experimental reestablishment of red wolves at LBL. 39 references, 16 figures, 6 tables.

Carley, C.J.; Mechler, J.L.

1983-10-01

74

The use of TOUGH2 for the LBL\\/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada  

Microsoft Academic Search

The three-dimensional site-scale numerical model o the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km² and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge

G. Bodvarsson; G. Chen; C. Haukwa; E. Kwicklis

1995-01-01

75

LBL/GRP studies of fractured rocks: Summary FY 1986--1990  

SciTech Connect

Recent interest in site characterization and performance assessment of rock masses for the design and construction of nuclear waste repositories provided the motivation for the LBL studies of the hydraulic, mechanical geophysical, and geochemical properties of discontinuities. These studies are grouped into eight topics: (1) The study of the correlation between the mechanical properties of a fracture, its hydraulic conductivity, and the amount of seismic attenuation it causes; (2) the phenomenon of flow channeling through preferred pathways in the s, which has important implications for radionuclide transport; (3) the hydrologic characterization of near-vertical faults and odier potentially highly conductive features with a view to analyzing the flow of water and air in an unsaturated fault-rock system; (4) the use of Vertical Seismic Profiling (VSP) and cross-hole seismic tomography to map elastic properties indicative of fracture density and structure, and to detect and characterize fractures and fault zones away from subsurface workings; (5) as a complement to seismic methods, studies of the use of electrical resistivity properties of the subsurface to detect the presence of fractures and their geometric orientation away from boreholes; (6) near the waste canisters, investigations of the geochemical-hydrological interaction of radionuclides in the fluids with the material lining fractures in the rock; (7) numerical modeling studies to examine the effects of a varying thermal field on the precipitation of otherwise soluble minerals and the resulting decrease of porosity that could reduce the migration of solutes by diminishing mass diffusivity and fluid flow; (8) investigation of the mechanical degradation of the walls of the waste canister boreholes due to thermomechanical stress changes, and to understand the mechanical response of the fractured rock to elevated temperatures. The major findings in each of these areas are summarized briefly below.

Not Available

1990-11-01

76

Combining magnetic shielding and cryopumping for a neutral beam source  

Microsoft Academic Search

Neutral beam sources similar to the designs executed by LBL for TFTR and for Doublet III require a substantial hydrogen pumping speed and careful magnetic shielding in order to optimize neutral beam production. A design which satisfies each requirement separately results in a design where the performance of both the magnetic shield and the cryopump is compromised by the requirement

J. Tanabe; M. A. Green

1979-01-01

77

Development of a high intensity 48Ca ion beam for the heavy element program  

SciTech Connect

A high intensity {sup 48}Ca ion beam has been developed at the 88 Inch Cyclotron for the synthesis of {sup 283}112 using the reaction {sup 238}U({sup 48}Ca, 3n). An ion beam intensity of {approx} 700 pnA was delivered on target, resulting in a total dose of 2 x 10{sup 18} ions over a six day period. Since {sup 48}Ca is a very expensive and rare isotope minimal consumption is essential. Therefore a new oven [1] and special tantalum liner [2] have been developed for the AECR-U ion source during the last year to improve the metal ion beam efficiency. Both the LBL ECR and the AECR-U ion sources are built with radial access. Six radial slots between the sextupole magnet bars provide additional pumping and easy access to the plasma chamber for ovens and feedthroughs. Two types of radial ovens have been used at LBNL in the past, operating at temperatures up to 2100 C.

Wutte, Daniela; Leitner, Mattheus; Lyneis, Claude

2002-02-02

78

Plasmodium falciparum synthetic LbL microparticle vaccine elicits protective neutralizing antibody and parasite-specific cellular immune responses.  

PubMed

Epitopes of the circumsporozoite (CS) protein of Plasmodium falciparum, the most pathogenic species of the malaria parasite, have been shown to elicit protective immunity in experimental animals and human volunteers. The mechanisms of immunity include parasite-neutralizing antibodies that can inhibit parasite motility in the skin at the site of infection and in the bloodstream during transit to the hepatocyte host cell and also block interaction with host cell receptors on hepatocytes. In addition, specific CD4+ and CD8+ cellular mechanisms target the intracellular hepatic forms, thus preventing release of erythrocytic stage parasites from the infected hepatocyte and the ensuing blood stage cycle responsible for clinical disease. An innovative method for producing particle vaccines, layer-by-layer (LbL) fabrication of polypeptide films on solid CaCO3 cores, was used to produce synthetic malaria vaccines containing a tri-epitope CS peptide T1BT comprising the antibody epitope of the CS repeat region (B) and two T-cell epitopes, the highly conserved T1 epitope and the universal epitope T. Mice immunized with microparticles loaded with T1BT peptide developed parasite-neutralizing antibodies and malaria-specific T-cell responses including cytotoxic effector T-cells. Protection from liver stage infection following challenge with live sporozoites from infected mosquitoes correlated with neutralizing antibody levels. Although some immunized mice with low or undetectable neutralizing antibodies were also protected, depletion of T-cells prior to challenge resulted in the majority of mice remaining resistant to challenge. In addition, mice immunized with microparticles bearing only T-cell epitopes were not protected, demonstrating that cellular immunity alone was not sufficient for protective immunity. Although the microparticles without adjuvant were immunogenic and protective, a simple modification with the lipopeptide TLR2 agonist Pam3Cys increased the potency and efficacy of the LbL vaccine candidate. This study demonstrates the potential of LbL particles as promising malaria vaccine candidates using the T1BT epitopes from the P. falciparum CS protein. PMID:23481177

Powell, Thomas J; Tang, Jie; Derome, Mary E; Mitchell, Robert A; Jacobs, Andrea; Deng, Yanhong; Palath, Naveen; Cardenas, Edwin; Boyd, James G; Nardin, Elizabeth

2013-02-26

79

Influence of LbL surface modification on oxygen cross-over in self-assembled thin composite membranes  

NASA Astrophysics Data System (ADS)

The paper is concerned with the investigation of oxygen transport in layer-by-layer (LbL) self assembly of polystyrene sulfonic acid sodium salt (PSS) and polyallylamine hydrochloride (PAH) on Nafion membrane depending on the number of deposited bilayers, ion type within the multilayers and temperature. It is observed from SEM analysis that the polyelectrolyte layers growth on each side of Nafion membrane regularly. The oxygen permeability (P) of (PAH-PSS) 20 is 691 cm 3/(m 2 day bar) at 25 °C while P of pristine Nafion is 2329 cm 3/(m 2 day bar) at the same temperature. This significant reduction (70.3%) in gas permeability can be explained by the formation of LbL multilayers which both restrict the mobility of gas through the polymer matrix and adjust gas solubility properties in conjunction with ion-dipole interaction between the polar phase of Nafion and the secondary ammonium groups of PAH. (PAH/PSS) 20-Na + and (PAH/PSS) 20-H + exhibit 64.4% and 52.3% reduction in oxygen permittivity at 25 °C in comparison with the pristine Nafion ®117, respectively, while the proton conductivities of these membranes are 106.9 and 136.9 mS/cm. Promisingly, it is found that the membrane selectivity values ( ?) of all multilayered membranes in both H + and Na + form are much higher than that of perfluorosulfonated ionomer. The thickness of deposited bilayers dominates the diffusion and solubility properties of oxygen through the composite membrane while the major effect of surface hydrophilicity is not observed on oxygen permeability.

Y?lmaztürk, Serpil; Ercan, Nevra; Deligöz, Hüseyin

2012-01-01

80

The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada  

SciTech Connect

The three-dimensional site-scale numerical model o the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km{sup 2} and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them; the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Submodels are used to investigate specific hypotheses and their importance before incorporation into the three-dimensional site-scale model. The primary objectives of the three-dimensional site-scale model are to: (1) quantify moisture, gas and heat flows in the ambient conditions at Yucca Mountain, (2) help in guiding the site-characterization effort (primarily by USGS) in terms of additional data needs and to identify regions of the mountain where sufficient data have been collected, and (3) provide a reliable model of Yucca Mountain that is validated by repeated predictions of conditions in new boreboles and the ESF and has therefore the confidence of the public and scientific community. The computer code TOUGH2 developed by K. Pruess at LBL was used along with the three-dimensional site-scale model to generate these results. In this paper, we also describe the three-dimensional site-scale model emphasizing the numerical grid development, and then show some results in terms of moisture, gas and heat flow.

Bodvarsson, G.; Chen, G.; Haukwa, C.; Kwicklis, E.

1995-12-31

81

Role of the Templating Approach in Influencing the Suitability of Polymeric Nanocapsules for Drug Delivery: LbL vs SC/MS.  

PubMed

Polymer nanocapsules play an increasingly important role for drug delivery applications. Layer-by-layer (LbL) templated synthesis has received the widest attention to fabricate polymer nanocapsules. However, for drug delivery applications, the LbL approach may not necessarily offer the optimum nanocapsules. We make the first attempt to compare the LbL approach with a more recently developed solid core/mesoporous shell (SC/MS) templated approach in context of their suitability for construction of sub-500 nm sized capsules for drug delivery applications. The nanocapsules of chitosan, poly(allylamine hydrochloride) (PAH), and poly(sodium 4-styrenesulfonate) (PSS) are fabricated using LbL and SC/MS templating approaches and loaded with curcumin, a model lipophilic anticancer drug. The influence of the templating approach on capsule aggregation, polymer loading, drug loading, cellular uptake, and therapeutic efficacy against MCF-7 breast cancer cells is compared in an effort to identify the most suitable fabrication method and polymer material for drug delivery applications. In combination, among different tested nanocapsules, chitosan nanocapsules fabricated using the SC/MS approach are found to be the most promising candidate that demonstrates the optimum cytotoxic efficiency and significant potential for drug delivery. PMID:23998648

Goethals, Emma C; Shukla, Ravi; Mistry, Vishal; Bhargava, Suresh Kumar; Bansal, Vipul

2013-09-17

82

Synchrotron light source data book  

SciTech Connect

The ''Synchrotron Light Source Data Book'' is as its name implies a collection of data on existing and planned synchrotron light sources. The intention was to provide a compendium of tools for the design of electron storage rings as synchrotron radiation sources. The slant is toward the accelerator physicist as other booklets such as the X-ray Data Booklet, edited by D. Vaughan (LBL PUB-490), address the 'use' of synchrotron radiation. It is hoped that the booklet serves as a pocket sized reference to facilitate back of the envelope type calculations. It contains some useful formulae in 'practical units' and a brief description of many of the existing and planned light source lattices.

Murphy, J.

1989-01-01

83

Analysis of the ion beam obtained from a small multicusp ion source  

Microsoft Academic Search

The small multicusp ion source developed at Lawrence Berkeley Laboratory (LBL) has been equipped with a low voltage ratio, single aperture extraction system. The influence of the potential of the plasma electrode and of a dipole filter field on the beam emittance are measured. A simple method to reduce hash is suggested. The aim of these investigations is to produce

K. Langbein; G. Riehl; H. Klein; K. N. Leung; S. R. Walther; R. Keller

1990-01-01

84

Enzyme-mediated amperometric biosensors prepared with the Layer-by-Layer (LbL) adsorption technique.  

PubMed

Glucose oxidase (GOD) has been immobilized in Layer-by-Layer (LbL) films, adsorbed alternately with poly(allylamine) hydrochloride (PAH) layers, onto an ITO substrate modified with a Prussian Blue (PB) layer. The ITO/PB/GOD-PAH heterostructures were tested in amperometric glucose biosensors, with a high sensitivity of 16 microA mmol(-1)lcm(-2) and a limit of detection of 0.20 mmoll(-1) being achieved. This high sensitivity is attributed to the ultrathin nature of the film in addition to the low operating potentials that could be used due to the efficient catalysis of H(2)O(2) produced in the enzymatic reaction in the presence of Prussian Blue. The biosensors are highly selective to glucose, as demonstrated by the lack of interference from possible interferents such as ascorbic and uric acids and acetominophen. The stability of the biosensors was checked by observing an almost constant sensitivity for a period of approximately 20 days, thus indicating a stable adsorption of GOD. PMID:15142594

Ferreira, Marystela; Fiorito, Pablo A; Oliveira, Osvaldo N; Córdoba de Torresi, Susana I

2004-07-15

85

Characterization and nanoindentation testing of thin ZrO 2 films synthesized using layer-by-layer (LbL) deposited organic templates  

Microsoft Academic Search

Thin organic LbL (layer-by-layer) films with negatively charged surface were used as templates for biomimetic deposition of ZrO2 on Si wafers by hydrolysis of Zr(SO4)2 solution. The as-deposited ceramic layers were fully amorphous and were composed of the mixture of zirconia and zirconium sulfate. During transmission electron microscopy (TEM) examination, the amorphous ZrO2 crystallized almost instantaneously to tetragonal (t) ZrO2

I. Zlotnikov; I. Gotman; E. Y. Gutmanas

2008-01-01

86

Advances in metal ion sources  

SciTech Connect

Beams of metallic ion species can be produced by the ECR (electron cyclotron resonance) ion source and by the MEVVA (metal vapor vacuum arc) ion source. Although the ECR source is fundamentally a gaseous ion source, metal ion beams can be produced by introducing metallic feed material into the plasma discharge using a number of techniques. The ion charge states can be very high, which is a significant advantage to most applications. The MEVVA ion source, on the other hand, is specifically a metal ion source. It has produced metallic ion beams from virtually all the solid metallic elements at a current of typically hundreds of milliamperes; the ions produced are in general multiply ionized, but not as highly stripped as those generated in the ECR source. Although the MEVVA source at present operates in a pulsed mode with a low duty cycle (less than or equal to 1%), work is in progress to increase the duty cycle significantly. In this paper the operation and performance of the LBL ECR and MEVVA ion sources, with respect to metal ion generation, are described.

Brown, I.G.

1988-05-01

87

A high charge state multicusp ion source  

SciTech Connect

Attempts have been made to generate high charge state ion beams by employing a multicusp plasma source. Three experimental investigations have been performed at Lawrence Berkeley Laboratory (LBL) and at Gesellschaft fuer Schwerionenforschung, Darmstadt (GSI) to study the charge state distributions and the emittance of the extracted beam. Results demonstrate that charge state as high as +7 can be obtained with argon or xenon plasmas. The brightness of a 11-mA xenon ion beam is found to be 26 A/({pi} mm mrad){sup 2}.

Leung, K.N.; Keller, R. (Accelerator and Fusion Research Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (US))

1990-01-01

88

A high charge state multicusp ion source  

SciTech Connect

Attempts have been made to generate high charge state ion beams by employing a multicusp plasma source. Three experimental investigations have been performed at LBL and at GSI to study the charge state distributions and the emittance of the extracted beam. Results demonstrate that charge state as high as +7 can be obtained with argon or xenon plasmas. The brightness of a 11 mA xenon ion beam is found to be 26 A/({pi}-mm-mrad){sup 2}. 6 refs., 6 figs.

Leung, K.N.; Keller, R.

1989-06-01

89

New conditioning procedure derived from operating experience with the Common Long-Pulse Ion Source  

Microsoft Academic Search

The DIII-D neutral beam system utilizes an 80 kV version of the Common Long-Pulse Ion Source designed by Lawrence Berkeley Laboratories (LBL) and originally built by RCA. Eight of these ion sources are mounted on four beamlines to provide a total of 20 MW of injected deuterium neutral power to the DIII-D tokamak. To support the DIII-D one-shift operation, neutral

B. G. Scoville; M. Madruga; R. M. Hong; J. C. Phillips

1993-01-01

90

Measurements of neutral beam species, impurities, spatial divergence, energy dispersion, pressure, and reionization for the TFTR (Tokamak Fusion Test Reactor) US Common Long Pulse Ion Source  

Microsoft Academic Search

Physical characteristics of TFTR neutral beams were measured during the first tests and initial operating experience with production TFTR US Common Long Pulse Ion Sources on beamlines in the TFTR experimental environment under actual user conditions. These measurements were performed with different power supply systems, controls, diagnostics, and operating methods compared to those used at LBL during the development phase.

H. W. Kugel; G. M. Gammel; L. R. Grisham; R. Kaita; J. H. Kamperschroer; R. A. Langley; C. W. Magee; S. S. Medley; T. J. Murphy; A. L. Roquemore; M. D. Williams

1988-01-01

91

XUV synchrotron optical components for the Advanced Light Source: Summary of the requirements and the developmental program  

SciTech Connect

We give a brief summary of the requirements for water cooled optical components for the Advanced Light Source (ALS), a third generation synchrotron radiation source under construction at Lawrence Berkeley Laboratory (LBL). Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from a finished water cooled copper alloy mirror will be used to demonstrate the state of the art in optical metrology with the Takacs Long Trace Profiler (LTP II).

McKinney, W.; Irick, S.; Lunt, D.

1992-07-01

92

New conditioning procedures derived from operating experience with the common DIII-D neutral beam ion source  

Microsoft Academic Search

The DIII-D neutral beam system utilizes an 80 kV version of the Common Long-Pulse Ion Source designed by Lawrence Berkeley Laboratories (LBL) and originally built by RCA. Eight of these ion sources are mounted on four beamlines to provide a total of 20 MW of injected deuterium neutral power to the DIII-D tokamak. To support the DIII-D one-shift operation, neutral

B. G. Scoville; M. Madruga; R.-M. Hong; J. C. Phillips

1993-01-01

93

Prototype testing for the US common long pulse neutral beam source  

SciTech Connect

The US positive ion neutral beam program has developed a single design, the Common Long Pulse Source (CLPS), which will provide multi-second beam heating for TFTR, MFTF-B and GA's Big D. Following competitive prototype testing, the LBL design was selected for industrialization because it could both meet the performance requirements of all three users, and fit within all space constraints. The LBL accelerator design is based on a slot type of aperture, with water cooled molybdenum grid tubes. The plasma generator is a magnetic bucket arc chamber, with multiple tungsten wire filaments. Beam test results are presented for the 10 x 40 cm prototype source with 80 kV and 120 kV gaps. The initial test results from the first 12 x 48 cm CLPS industrial plasma generator, made by RCA, are also presented.

Vella, M.C.; Anderson, O.A.; Berkner, K.H.; Chan, C.F.; Cooper, W.S.; Lietzke, A.F.; Owren, H.M.; Paterson, J.A.; Pincosy, P.A.; Pyle, R.V.

1985-11-01

94

Studies on the positive hydrogen ion production from a small multicusp source  

SciTech Connect

An rf driven ion source has been developed and tested at LBL for positive hydrogen ion production. Studies of this new source on ion species and current densities for a dc arc discharge are made in the 60-kV PSI ion source test stand and the results compared with those obtained using the rf discharge. This source, using both discharge modes, will be installed in the PSI Cockcroft--Walton preinjector to increase the 870-keV dc proton beam intensity from the present 8--10 mA operation to about 25 mA.

Olivo, M.; Mariani, E. (Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland)); Leung, K.N. (Lawrence Berkeley Laboratory (LBL), University of California, Berkeley, California 94720 (United States))

1994-04-01

95

WLS R&D for the detection of noble gas scintillation at LBL: seeing the light from neutrinos, to dark matter, to double beta decay  

NASA Astrophysics Data System (ADS)

Radiation detectors with noble gasses as the active medium are becoming increasingly common in experimental programs searching for physics beyond the standard model. Nearly all of these experiments rely to some degree on collecting scintillation light from noble gasses. The VUV wavelengths associated with noble gas scintillation mean that most of these experiments use a fluorescent material to shift the direct scintillation light into the visible or near UV band. We present an overview of the R&D program at LBL related to noble gas detectors for neutrino physics, double beta decay, and dark matter. This program ranges from precise measurements of the fluorescence behavior of wavelength shifting films, to the prototyping of large are VUV sensitive light guides for multi-kiloton detectors.

Gehman, V. M.

2013-09-01

96

ZnO nanowire array-templated LbL self-assembled polyelectrolyte nanotube arrays and application for charged drug delivery.  

PubMed

Vertically oriented and robust polyelectrolyte nanotube arrays with high density, large area and high uniformity were successfully grown on substrates by a ZnO nanowire array-templated layer-by-layer (LbL) self-assembly approach for the first time, and were further used to deliver charged drugs, showing that they not only possess pH-responsive loading property, but also significantly enhance the loading capacity and sustained release time. This work could be extended to fabricate polyelectrolyte nanotube arrays with different polyelectrolyte combinations, including weak polyelectrolyte/weak polyelectrolyte, weak polyelectrolyte/strong polyelectrolyte and strong polyelectrolyte/strong polyelectrolyte. With the great versatility to use various substrates and building blocks, the polyelectrolyte nanotube arrays may have great potential for broad applications such as biosensor arrays, bioreactor arrays and optoelectronics. PMID:23299408

Yuan, Weiyong; Lu, Zhisong; Liu, Jinping; Wang, Huili; Li, Chang Ming

2013-01-08

97

Survey and alignment of the Advanced Light Source in Berkeley  

NASA Astrophysics Data System (ADS)

The general survey and alignment concept for the Advanced Light Source (ALS) at LBL Berkeley [1] is based on a network of fixed monuments to which all component positions are referred. Observations include electronic distance measurements and direction sightings with electronic data capture; data are processed by a customized version of the computer code PC-GEONET [2] which provides raw data reduction, calculation of adjusted coordinates, and error analysis. Additionally, for local survey tasks the commercial software package ECDCS [3] is used. In this paper, the ALS survey and alignment strategy and techniques are presented and critically discussed; first experiences with alignment of the linac and booster components are described.

Keller, R.

1991-05-01

98

A 6.3 T Bend Magnet for the Advanced Light Source  

SciTech Connect

The Advanced Light Source (ALS) is a 1.5 to 1.9 GeV high-brightness electron storage ring operating at Lawrence Berkeley Laboratory (LBL) that provides synchrotron radiation for a large variety of users. It Is proposed to replace three of the thirty six 1.5T, one meter long bend magnets with very sbort high-field superconductlng (SC) dipoles. These magnets would provide bend-magnet synchrotron radiation to six bcamlines with a critical energy of at least 6 keV that is much better suited for protein crystallography and other small-sample x-ray diffraction and adsorption studies, than is currently available at the ALS. The magnet design is described, including coil, yoke, magnetic field analysis, and cyrostat. A prototype magnet is under construction at LBL.

Taylor, C.E.; Caspi, S.

1995-06-07

99

Tuning nanostructure of graphene oxide/polyelectrolyte LbL assemblies by controlling pH of GO suspension to fabricate transparent and super gas barrier films  

NASA Astrophysics Data System (ADS)

A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm3 m-2 day-1). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used.A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm3 m-2 day-1). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used. Electronic supplementary information (ESI) available: See DOI: 10.1039/c3nr02845c

Chen, Jung-Tsai; Fu, Ywu-Jang; An, Quan-Fu; Lo, Shen-Chuan; Huang, Shu-Hsien; Hung, Wei-Song; Hu, Chien-Chieh; Lee, Kueir-Rarn; Lai, Juin-Yih

2013-09-01

100

Applications of the MEVVA high current metal ion source  

SciTech Connect

A new kind of ion source has been developed in which a metal vapor vacuum arc (MEVVA) is used to produce the plasma from which the ion beam is extracted. The novel and exciting feature of this source is the very high metal ion beam current attainable. A total ion beam current of over 1 Ampere has been extracted from the embodiment of the concept that we're presently using, and this is not a limit of the method. The source was developed to upgrade the uranium ion beam intensity of the Bevatron, LBL's heavy ion synchrotron, for basic nuclear physics research. Other important applications include its use within the Heavy Ion Fusion research effort; for ion implantation; and for other basic research uses. In this paper the source is described briefly, its performance outlined, and its poential and limitations for a variety of applications is discussed.

Brown, I.G.

1986-08-01

101

Tuning nanostructure of graphene oxide/polyelectrolyte LbL assemblies by controlling pH of GO suspension to fabricate transparent and super gas barrier films.  

PubMed

A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm(3) m(-2) day(-1)). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used. PMID:23900571

Chen, Jung-Tsai; Fu, Ywu-Jang; An, Quan-Fu; Lo, Shen-Chuan; Huang, Shu-Hsien; Hung, Wei-Song; Hu, Chien-Chieh; Lee, Kueir-Rarn; Lai, Juin-Yih

2013-07-31

102

Advanced Light Source beam position monitor  

SciTech Connect

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.

Hinkson, J.

1991-10-28

103

An improved layer-by-layer self-assembly technique to generate biointerfaces for platelet adhesion studies: Dynamic LbL  

NASA Astrophysics Data System (ADS)

Layer-by-layer self-assembly (LbL) is a technique that generates engineered nano-scale films, coatings, and particles. These nanoscale films have recently been used in multiple biomedical applications. Concurrently, microfabrication methods and advances in microfluidics are being developed and combined to create "Lab-on-a-Chip" technologies. The potential to perform complex biological assays in vitro as a first-line screening technique before moving on to animal models has made the concept of lab on a chip a valuable research tool. Prior studies in the Biofluids Laboratory at Louisiana Tech have used layer-by-layer and in vitro biological assays to study thrombogenesis in a controlled, repeatable, engineered environment. The reliability of these previously established techniques was unsatisfactory for more complex cases such as chemical and shear stress interactions. The work presented in this dissertation was performed to test the principal assumptions behind the established laboratory methodologies, suggest improvements where needed, and test the impact of these improvements on accuracy and repeatability. The assumptions to be tested were: (1) The fluorescence microscopy (FM) images of acridine orange-tagged platelets accurately provide a measure of percent area of surface covered by platelets; (2) fibrinogen coatings can be accurately controlled, interact with platelets, and do not interfere with the ability to quantify platelet adhesion; and (3) the dependence of platelet adhesion on chemical agents, as measured with the modified methods, generally agrees with results obtained from our previous methods and with known responses of platelets that have been documented in the literature. The distribution of fibrinogen on the final LbL surface generated with the standard, static process (s-LbL) was imaged by tagging the fibrinogen with an anti-fibrinogen antibody bound to fluorescein isothiocyanate (FITC). FITC FM images and acridine orange FM images were taken sequentially at selected surface locations to generate a composite overlap of presumed platelet adhesion as a function of fibrinogen distribution. The method was unable to distinguish the surface from the adhered cells. The surface inhomogeneity and porosity retained a large amount of acridine orange stain, even in the absence of platelets, and components in the platelet-rich plasma (PRP) were found to fix acridine orange in a mode that fluoresced in the FITC imaging FM. Both of these problems obfuscated the platelet adhesion FM results when using s-LbL surfaces and acridine orange staining of platelets. A dynamic process (d-LbL) was developed in which a solution of the molecule to be layered was constantly washed over the surface, and was constantly mixed to maintain a more homogeneous distribution of solute relative to the surface during the layering process. The d-LbL surfaces were tested as described above, and found to reduce the size and number of regions of anomalous acridine orange pooling trapped by the surface, providing a greater consistency and reliability in identifying platelets. The improved surface was then used in a series of platelet adhesion experiments under static and dynamic flow conditions, and with and without the chemical additive L-arginine. The complex microcharmel system used in prior studies was replaced with a simpler system involving fewer nuisance variables for these tests. The tests were performed on both collagen and fibrinogen surfaces. Collagen has been used as a thrombogenic surface in multiple studies in the literature, but produces additional variables in thrombogenesis control that are avoided when fibrinogen is used. In these tests, fibrinogen was found to be as thrombogenic as collagen, and platelet coverage of both biointerfaces was reduced by L-arginine in a manner similar to previously reported work. The simpler system differed from the previous microchannel system in important factors: (1) It exposed the platelets to much lower shear stresses; (2) It introduced an oscillatory flow, which introduced a higher de

Lopez, Juan Manuel

104

Vacuum arc ion sources - micro to macro  

SciTech Connect

Vacuum arc ion sources provide a convenient tool for the production of intense beams of metal ions. The sources are relatively easy to construct and they can produce beams from all of the solid metals as well as of compounds, alloys and mixtures. We have made a number of different kinds of such sources over the course of our development work at LBL in the past decade, from very small {open_quote}thumb-size{close_quote} versions to a very large one with 50-cm diameter extractor. Beam current ranges from a few milliamperes up to almost 10 amperes and extraction voltage from about 1 kV to 100 kV. Multicathode versions have been made so that one can switch between metal ion species simply and quickly. Most of the sources have been operated in a repetitively pulsed mode, and we`ve tested a dc version also. Here we outline some construction features of the array of vacuum arc ion sources that we`ve developed and used, and describe their performance and limitations.

MacGill, R.A.; Dickinson, M.R.; Brown, I.G.

1995-08-01

105

Status of the MEVVA (Metal Vapor Vacuum Arc) high current metal ion source. [Metal Vapor Vacuum Arc  

SciTech Connect

The MEVVA (Metal Vapor Vacuum Arc) ion source that has been developed at LBL was reported on for the first time at the 1985 Particle Accelerator Conference (1). This source can produce hundreds of milliamperes of beam current of metal species from lithium up to uranium. In the period since then we have developed the source further, and this work is summarized here. We have now run the source with over 30 different beam species, and with an extraction voltage up to 110 kV. We have made and operated a miniature source, the MicroMEVVA. A multi-cathode version, in which one can switch rapidly between cathodes of different materials, has recently been constructed and tested. Applications of the source include: as a synchrotron ion source, as an ion source for heavy ion fusion, and for metallurgical ion implantation; we have done some preliminary work in these directions.

Brown, I.G.; Galvin, J.E.; MacGill, R.A.; Wright, R.T.

1987-03-01

106

The Advanced Light Source at Lawrence Berkeley Laboratory  

SciTech Connect

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL), scheduled to be operational in the spring of 1993 as a US Department of Energy national user facility, will be a next- generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide the world's brightest synchrotron radiation at photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes above 10 keV. These capabilities will support an extensive research program in a broad spectrum of scientific and technological areas in which XUV radiation is used to study and manipulate matter in all its varied gaseous, liquid, and solid forms. The ALS will also serve those interested in developing the fabrication technology for micro- and nanostructures, as well as characterizing them.

Robinson, A.L.; Perera, R.C.C.; Schlachter, A.S.

1991-10-01

107

The Advanced Light Source at Lawrence Berkeley Laboratory  

SciTech Connect

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL), scheduled to be operational in the spring of 1993 as a US Department of Energy national user facility, will be a next- generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide the world`s brightest synchrotron radiation at photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes above 10 keV. These capabilities will support an extensive research program in a broad spectrum of scientific and technological areas in which XUV radiation is used to study and manipulate matter in all its varied gaseous, liquid, and solid forms. The ALS will also serve those interested in developing the fabrication technology for micro- and nanostructures, as well as characterizing them.

Robinson, A.L.; Perera, R.C.C.; Schlachter, A.S.

1991-10-01

108

Operation of a magnetically filtered multicusp volume source  

SciTech Connect

The results of experimental studies on an optimized version of the Lawrence Berkeley Laboratory (LBL) volume source are presented. Negative ion yields and emittance data were obtained for operation with both H/sup -/ and D/sup -/ beams. At high arc power, H/sup -/ beam currents up to 10 mA with rms normalized emittances of 0.0080 ..pi...cm.mrad were obtained from a 6.3-mm-dia emission aperture. The yields of D/sup -/ beams were approximately half those of H/sup -/ beams, and the normalized emittances were 1.7 times smaller at the same current density. The results of these studies indicate that the present operation is limited by the extraction system rather than the ion source.

Stevens, R.R. Jr.; York, R.L.; Leung, K.N.; Ehlers, K.W.

1986-01-01

109

Transverse coupled-bunch feedback in the Advanced Light Source (ALS)  

SciTech Connect

In order to effectively control a large number of transverse coupled-bunch models in the LBL Advanced Light source (ALS) storage ring, a broad-band, bunch-by-bunch feedback system has been designed, and is beginning to undergo testing and commissioning. This paper addresses the major electronic components of the feedback system. In particular, the components described include: broad-band microwave position detection receivers, closed orbit offset signal rejection circuitry, and baseband quadrature processing circuitry. Initial commissioning results are also presented.

Barry, W.; Byrd, J.; Corlett, J.; Lambertson, G.R.; Lo, C.C.

1994-06-01

110

ZAP and its application to the optimization of synchrotron light source parameters  

SciTech Connect

The design of electron storage rings for the production of synchrotron radiation has become increasingly sophisticated in recent years. To assist in the optimization of such storage rings, a new, user-friendly code to treat the relevant collective phenomena, called ZAP, has been written at LBL. The code is designed primarily to carry out parameter studies of electron storage rings, although options for protons or heavy ions are included where appropriate. In this paper, we first describe the contents of the code itself, and then illustrate, via selected examples, how the collective effects treated by ZAP manifest themselves in the new generation of synchrotron light sources.

Zisman, M.S.

1987-03-01

111

Optimization of surface plasma sources for efficient production of negative ions with high emission current density  

NASA Astrophysics Data System (ADS)

The main mechanism of negative ion formation in a Surface Plasma Source (SPS) is secondary emission of sputtered and scattered particles accompanied by capture of electrons from the electrodes. In the first, pulsed, versions of the SPS, adding a small amount of cesium increased the emission current density for light ions up to 3.7 A/cm2 with a flat emitter and up to 8 A/cm2 after optimization of geometrical focusing. Since this power density was too high for DC operation, LBL developed a large volume SPS with a hot cathode discharge, a large emitter-emission aperture gap and low emission current density. The LBL type of SPS was used for some accelerators and for heavy negative ion production with emission current density of 10 mA/cm2. Researchers at Budker Institute of Nuclear Physics (BINP) developed a small SPS optimized for long time DC operation. In the BINP source, DC H- current up to 2.5 mA and heavy ion current up to 1 mA have been extracted from a 1 mm diameter aperture using an improved SPS that employs a hollow cathode discharge and spherical focusing of negative ions toward the emission aperture. This paper describes further optimization of this type source for production of negative ion beam with a high emission current density. .

Farrell, J. Paul; Dudnikov, V.; Dudnikova, G.

2001-12-01

112

COMBUSTION AREA SOURCES: DATA SOURCES  

EPA Science Inventory

The report identifies, documents, and evaluates data sources for stationary area source emissions, including solid waste and agricultural burning. rea source emissions of particulate matter, sulfur dioxide, oxides of nitrogen, reactive volatile organic compounds, and carbon monox...

113

COMBUSTION AREA SOURCES: DATA SOURCES  

EPA Science Inventory

The report identifies, documents, and evaluates data sources for stationary area source emissions, including solid waste and agricultural burning. Area source emissions of particulate matter, sulfur dioxide, oxides of nitrogen, reactive volatile organic compounds, and carbon mon...

114

Modeling in control of the Advanced Light Source  

SciTech Connect

A software system for control of accelerator physics parameters of the Advanced Light Source (ALS) is being designed and implemented at LBL. Some of the parameters we wish to control are tunes, chromaticities, and closed orbit distortions as well as linear lattice distortions and, possibly, amplitude- and momentum-dependent tune shifts. In all our applications, the goal is to allow the user to adjust physics parameters of the machine, instead of turning knobs that control magnets directly. This control will take place via a highly graphical user interface, with both a model appropriate to the application and any correction algorithm running alongside as separate processes. Many of these applications will run on a Unix workstation, separate from the controls system, but communicating with the hardware database via Remote Procedure Calls (RPCs).

Bengtsson, J.; Forest, E.; Nishimura, H.; Schachinger, L.

1991-05-01

115

LBNL 88-inch Cyclotron improvements  

Microsoft Academic Search

A number of recent improvements have been made in the Cyclotron, ECR sources and beam lines. An aluminum oxide wall coating in the AECR source produces more secondary electrons to increase high charge state ion production by 2-4 compared to electron injection. Development of simultaneous multiple frequency ECR heating with 10 and 14 GRz results in two ECR zones and

C. M. Lyneis; Z. Q. Xie; D. J. Clark

1996-01-01

116

Nonpoint Sources.  

ERIC Educational Resources Information Center

|Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)|

Browne, F. X.

1978-01-01

117

Optical sources  

Microsoft Academic Search

The principles of operation of the optical sources for fiber optic sensors are discussed, and their properties are described. Attention is given to the source requirements, the emission process, the electrical properties and drive circuitry, and the modulation behavior of semiconductor diode light sources. The device construction of LEDs and semiconductor diode lasers and their optical properties and operation are

A. M. Yurek; A. Dandridge

1988-01-01

118

Health Source  

Microsoft Academic Search

This review describes two health and medical reference databases on the EBSCOhost system from EBSCO publishing: Health Source: Consumer Edition and Health Source: Nursing\\/Academic Edition. The Consumer Edition is a diverse collection of consumer health information from magazines, reference books, and pamphlets. The Nursing\\/Academic Edition is an ideal source of scholarly journal articles on many medical specialties for nurses, allied

Patricia Mongelia

2004-01-01

119

Design considerations for a negative ion source for dc operation of high-power, multi-megaelectron-volt neutral beams  

SciTech Connect

A dc negative hydrogen and/or deuterium ion source is needed to produce high-power, high-energy neutral beams for alpha diagnostics and current drive applications in fusion devices. The favorable beam particle energy for such applications extends to 1.5 MeV/amu. Continuous-wave (cw) radiofrequency quadrupole (RFQ) accelerators have been proposed to accelerate negative ions efficiently to this energy range. In this paper, the desired beam properties for ion beams injected into cw RFQ accelerators are summarized. A number of candidate ion sources being developed at Culham, JAERI, LBL, and ORNL may prove useful for these applications. The properties of the Volume Ionization with Transverse Extraction (VITEX) ion sources being developed at ORNL are presented. Scaling such a dc ion source to produce ampere beams is discussed. 53 refs., 4 figs., 2 tabs.

Tsai, C.C.; Stirling, W.L.; Akerman, M.A.; Becraft, W.R.; Dagenhart, W.K.; Haselton, H.H.; Ryan, P.M.; Schechter, D.E.; Whealton, J.H.

1987-01-01

120

Ion source  

DOEpatents

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01

121

Neutron dose equivalents at the Advanced Light Source: Calculation using the MORSE code vs estimated values  

SciTech Connect

The Advanced Light Source (ALS) complex at the Lawrence Berkeley Laboratory (LBL) is surrounded by a mezzanine and auxiliary buildings. An important radiological problem is the neutron dose equivalent in nearby occupied areas and at the LBL site boundary. Both the direct and air-scattered (skyshine) components of the neutron dose equivalents are evaluated using the neutron transport code MORSE. The shielding was designed using an empirical method based on data scaled from a 1977 SLAC experiment and on a compilation of experimental and theoretical material relevant to shielding of electron accelerators. From the MORSE calculation, the total occupational dose equivalent rate in the center of the ALS mezzanine was found to be less than 1 mSv (100 mrem) per shift year (2000-hr), and the total environmental dose equivalent rate at the ALS boundary, 125 m from the storage-ring center, was found to be about 302 {mu}Sv (30 mrem) per year. A comparison of the dose equivalents shows that the calculated MORSE-code values agree well with those estimated by the empirical method. That is, dose equivalents obtained by the empirical methods are of the same order of magnitude as the corresponding MORSE values. 7 refs., 7 figs., 2 tabs.

Sun, Rai-Ko S.

1991-02-01

122

Synchrotron sources  

SciTech Connect

Synchrotron radiation is a very bright, broadband, polarized, pulsed source of electromagnetic radiation extending from the infrared to the x-ray region. Brightness, defined as flux per unit area per unit solid angle, is normally a more important quantity than flux or intensity, particularly in throughput limited applications which include those in which monochromators are used. The authors have attempted to compile the formulae needed to calculate the flux, brightness, polarization and power produced by the three standard storage ring synchrotron radiation sources: bending magnets, wigglers and undulators. Where necessary, these formulae have contained reference to the emittance of the electron beam, as well as to the electron beam size and its divergence. For all three type sources, the source phase space area, i.e. the spatial and angular extent of the effective (real) source, is a convolution of its electron and photon components.

Hulbert, S.L.

1999-12-13

123

A figure of merit for blazar-like source identification in the gamma-ray energy band  

SciTech Connect

The microwave to gamma-ray slope {alpha}{mu}{gamma} can be used as a viable figure of merit for blazar-like source identification in gamma-rays. Taking into account the constraints from the observed extragalactic gamma-ray background, one can estimate the maximum duty cycle allowed for a selected sample of low energy peaked (LBL) blazars, in order to be detectable for the nominal sensitivity values of AGILE and GLAST gamma-ray experiments. This work is based on the results of a recently derived blazar radio LogN-LogS obtained by combining several multi-frequency surveys. We present our estimates of duty cycle constraints applied on a sample composed by 146 high latitude and 74 medium latitude LBL blazars from the new WMAP3 yr catalog. Our results can be used as an indicator to identify good gamma-ray blazar candidates: sources with high values of duty cycle can in principle be detectable also in a ''steady'' state by AGILE and GLAST without over-predicting the extragalactic background.

Cavazzuti, Elisabetta; Pittori, Carlotta; Giommi, Paolo; Colafrancesco, Sergio [ASI Science Data Center, Via Galileo Galilei, 00044, Frascati, Roma (Italy)

2007-07-12

124

Collisional mechanisms in D/sup -/ beam sources for MFE experiments and reactors. Technical progress report, November 1, 1981-October 31, 1982  

SciTech Connect

This research program is designed to aid the development of D/sup -/ beam sources needed for the high energy neutral-beam heating of magnetic fusion energy (MFE) plasmas. Initially, the work was directed to predict the angular scattering in D/sup -/ beams produced from D/sup +/ by charge transfer in metal vapors. However, recently it has been redirected to provide information on the mechanisms that govern the behavior of direct extraction D/sup -/ ion sources, with immediate emphasis on the very promising Ehlers-Leung source at LBNL. The controlling mechanisms in these sources and some aspects of their behavior are only vaguely understood, and this work is designed to answer recent questions about several of these mechanisms. These results will then be incorporated into a modeling effort at LBL that will support future improvements in source design and operation.

Coggiola, M.J.; Peterson, J.R.

1982-12-15

125

Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider  

SciTech Connect

A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported.

Yu, S.; Goffeney, N.; Henestroza, E. [Lawrence Berkeley Lab., CA (United States)] [and others

1995-02-22

126

Sustainable Sources  

NSDL National Science Digital Library

Sustainable Sources is a web site that provides information for green builders and other individuals interested in green building. Their site includes a directory of green building professionals, information on greenbuilt homes that are on the market, pertinent events, books and articles, online discussions, and links to other sites. You can also access the Sustainable Building Source book which contains a wealth of information on all aspects of green building through this web site.

2008-11-28

127

NEUTRON SOURCES  

DOEpatents

A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

Richmond, J.L.; Wells, C.E.

1963-01-15

128

Neutron source  

DOEpatents

A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

Cason, J.L. Jr.; Shaw, C.B.

1975-10-21

129

NEUTRON SOURCE  

DOEpatents

A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

1959-01-13

130

Superluminal sources.  

PubMed Central

Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H0 and the deceleration parameter q0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities betaapp in the range 1-5 h-1, where h = H0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 10(22) m], occur with roughly equal frequency; higher values, up to betaapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The betaapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at gammab approximately 2 h-1 and a tail up to at least gammab approximately 10 h-1. There appears to be a clearly rising upper envelope to the betaapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources.

Vermeulen, R C

1995-01-01

131

Nonlinear Source -  

Microsoft Academic Search

Specific economic sectors or source regions emit a wide variety of air pollutants which influence climate and air quality. This includes emissions of greenhouse gases, chemical species which affect the oxidation capacity of the atmosphere and the concentrations of ozone and methane, and aerosol particles or aerosol precursors. Regional climate respectively weather controls transport and removal of pollutants, chemical transformation

S. Kinne; J. Feichter; S. Rast; I. Bey; G. Folberth; L. Pozzoli; S. Kloster; P. Stier

2007-01-01

132

Energy Sources  

NSDL National Science Digital Library

In this activity, the teacher demonstrates several different types of energy, and assigns a research report topic for small groups of students. Suggestions are provided to tailor the assignment to different age groups. The lesson also contains definitions of many different energy sources and types.

1995-01-01

133

Energy Sources  

NSDL National Science Digital Library

This interactive website for students discusses both renewable and nonrenewable resources. It also discusses electricity and hyrdogen energy in depth. Furthermore, it provides a link to recent energy source statistics which can help students to identify the United States dependency on imports such as petroleum and natural gas.

2009-01-01

134

ION SOURCE  

DOEpatents

An ion source is presented capable of producing ions of elements which vaporize only at exceedingly high temperatures, i.e.,--1500 degrees to 3000 deg C. The ion source utilizes beams of electrons focused into a first chamber housing the material to be ionized to heat the material and thereby cause it to vaporize. An adjacent second chamber receives the vaporized material through an interconnecting passage, and ionization of the vaporized material occurs in this chamber. The ionization action is produced by an arc discharge sustained between a second clectron emitting filament and the walls of the chamber which are at different potentials. The resultant ionized material egresses from a passageway in the second chamber. Using this device, materials which in the past could not be processed in mass spectometers may be satisfactorily ionized for such applications.

Bell, W.A. Jr.; Love, L.O.; Prater, W.K.

1958-01-28

135

ION SOURCE  

DOEpatents

An ion source is described and comprises an arc discharge parallel to the direction of and inside of a magnetic field. an accelerating electrode surrounding substantially all of the discharge except for ion exit apertures, and means for establishing an electric field between that electrode and the arc discharge. the electric field being oriented at an acute angle to the magnetic field. Ions are drawn through the exit apertures in the accelrating electrcde in a direction substantially divergent to the direction of the magnetic field and so will travel in a spiral orbit along the magnetic field such that the ions will not strike the source at any point in their orbit within the magnetic field.

Blue, C.W.; Luce, J.S.

1960-07-19

136

MUON SOURCES.  

SciTech Connect

A full high energy muon collider may take considerable time to realize. However, intermediate steps in its direction are possible and could help facilitate the process. Employing an intense muon source to carry out forefront low energy research, such as the search for muon-number non-conservation, represents one interesting possibility. For example, the MECO proposal at BNL aims for 2 x 10{sup {minus}17} sensitivity in their search for coherent muon-electron conversion in the field of a nucleus. To reach that goal requires the production, capture and stopping of muons at an unprecedented 10{sup 11} {mu}/sec. If successful, such an effort would significantly advance the state of muon technology. More ambitious ideas for utilizing high intensity muon sources are also being explored. Building a muon storage ring for the purpose of providing intense high energy neutrino beams is particularly exciting.We present an overview of muon sources and example of a muon storage ring based Neutrino Factory at BNL with various detector location possibilities.

PARSA,Z.

2001-02-16

137

An RF driven H{sup {minus}} source and a low energy beam injection system for RFQ operation  

SciTech Connect

An RF driven H{sup {minus}} source has been developed at LBL for use in the Superconducting Super Collider (SSC). To date, an H{sup {minus}} current of {approx}40 mA can be obtained from a 5.6-cm-diam aperture with the source operated at a pressure of about 12 m Torr and 50 kW of RF power. In order to match the accelerated H{sup {minus}} beam into the SSC RFQ, a low-energy H{sup {minus}} injection system has been designed. This injector produces an outgoing H{sup {minus}} beam free of electron contamination, with small radius, large convergent angle and small projectional emittance.

Leung, K.N.; Bachman, D.A.; Chan, C.F.; McDonald, D.S.

1992-12-31

138

LBL Perspective on statistical database management  

SciTech Connect

The purpose of this document is to present a collective view of our research to outside researchers in statistical database management to facilitate communication and exchange of ideas in this new and exciting area. Two papers are in the General category, Arie Shoshani's survey of statistical database management research problems and John L. McCarthy et al.'s description of SEEDIS, a statistical database management system developed in CSAM. In User Interface, we selected Paul Chan and Arie Shoshani's paper on SUBJECT, a system that offers a directory driven interface to statistical data, and Harry K.T. Wong and Ivy Kuo's paper on GUIDE, a system using graphical user interface to complex databases for non-expert users. The SUBJECT paper describes some powerful modelling primitives for statistical summary data. In addition to the description of the system, the GUIDE paper also discusses the reasons why the current query systems fail to provide satisfactory interface to complex databases. The paper by Fred Gey describes the problems of data definitions of large statistical databases, citing real situations from the 1980 US Census data as examples. Deane Merrill's paper discusses more specific problems of handling statistical summary data, with emphasis on the problem and his solution of summary data aggregation and disaggregation. Peter Krep's paper describes a data model called semantic core model which contains useful modelling primitives for representing other semantic constructs. Modelling statistical databases is one of the major motivations of this work. The requirements of modelling metadata of statistical databases are given a thorough treatment in John L. McCarthy's paper.

Wong, H.K.T. (ed.)

1982-12-01

139

Operating instructions for LBL radon measurement facilities  

SciTech Connect

This manual is intended for users of the radon-measuring facilities of the Radon Project of the Building Ventilation and Indoor Air Quality Program at Lawrence Berkeley Laboratory. The manual comprises three parts. Part 1 sets out the steps involved in collecting, transferring, and counting radon. Part 2 describes the calibration of the transfer system and of the Lucas cells in the counting system. Part 3 outlines the maintenance procedures for the facility.

Ingersoll, J.G.

1980-06-01

140

Appropriate Energy Technology Library bibliography. [LBL  

Microsoft Academic Search

Lawrence Berkeley Laboratory discovered the need for a library of books dealing with technologies on a smaller scale than that of customary laboratory projects. These books introduce researchers to the inventive and ecology-conscious thinking (in its various social and cultural milieus) that lies behind the drive for small-scale self-reliance. The introduction explains the philosophy behind the library, the browsing system

1979-01-01

141

New conditioning procedure derived from operating experience with the Common Long-Pulse Ion Source  

NASA Astrophysics Data System (ADS)

The DIII-D neutral beam system utilizes an 80 kV version of the Common Long-Pulse Ion Source designed by Lawrence Berkeley Laboratories (LBL) and originally built by RCA. Eight of these ion sources are mounted on four beamlines to provide a total of 20 MW of injected deuterium neutral power to the DIII-D tokamak. To support the DIII-D one-shift operation, neutral beams must be readied in a relatively short period of time each day, typically one hour. During non-operating periods conditioning time for the ion sources is limited, due to the costs of associated support services and the need to perform corrective and preventive maintenance. The experience gained over a six year period resulted in finely tuned procedures for the conditioning and operation of these ion sources. Recently, an ion source was conditioned which had been accidentally filled with water for several days, resulting in surface corrosion and deconditioning of the grids and surfaces. The method of successful recovery along with data, experience and procedures derived this event and normal operations are detailed and discussed.

Scoville, B. G.; Madruga, M.; Hong, R. M.; Phillips, J. C.

1993-10-01

142

New conditioning procedure derived from operating experience with the Common Long-Pulse Ion Source  

SciTech Connect

The DIII-D neutral beam system utilizes an 80 kV version of the Common Long-Pulse Ion Source designed by Lawrence Berkeley Laboratories (LBL) and originally built by RCA. Eight of these ion sources are mounted on four beamlines to provide a total of 20 MW of injected deuterium neutral power to the DIII-D tokamak. To support the DIII-D one-shift operation, neutral beams must be readied in a relatively short period of time each day, typically one hour. During non-operating periods conditioning time for the ion sources is limited, due to the costs of associated support services and the need to perform corrective and preventive maintenance. The experience gained over a six year period has resulted in finely tuned procedures for the conditioning and operation of these ion sources. Recently, an ion source was conditioned which had been accidentally filled with water for several days, resulting in surface corrosion and deconditioning of the grids and surfaces. The method of successful recovery along with data, experience and procedures derived this event and normal operations will be detailed and discussed.

Scoville, B.G.; Madruga, M.; Hong, R.M.; Phillips, J.C.

1993-10-01

143

Primary and Secondary Sources  

NSDL National Science Digital Library

Use these links to learn more about primary and secondary sources. 1. Explore the links below to learn about primary and secondary sources. When you have finished, you should be able to: Tell the difference between primary and secondary sources. Give at least three examples of primary sources and three examples of secondary sources. Explain why primary sources are important in research. Examples of Primary Sources Examples of Primary and Secondary Sources on the Same Topic Genres/Formats of Primary Sources 2. ...

Bates, Albion M.

2010-01-23

144

Advanced Light Source: Users` Handbook  

SciTech Connect

The ALS Users` Handbook is designed to help you prepare for your visit to the ALS, to assist you in getting your experiments underway, and to act as a resource to the facilities and services available at the ALS and LBL. We hope it encompasses ``what you need to know`` to make your stay at the ALS productive and enjoyable. The handbook contains six sections. Sections 1 and 2 explain how to become a user of the ALS and contain important information users need to know before arriving at the ALS. All ALS users are encouraged to read this part of the handbook well in advance of their planned visit to the ALS. Sections 3 and 4 describe general information about organizational structure and access to the ALS, and describe the facilities and describe the facilities and services offered at the ALS an LBL. Section 5 lists some fun things to see and do in the Berkeley area including museums, parks, and sports facilities. Section 6 contains reference information.

Not Available

1994-10-01

145

Multicusp ion sources (invited)  

Microsoft Academic Search

During the last decade, different types of multicusp ion sources, such as high current, high concentration H+, H+2, or N+ ion sources, negative ion sources, radio-frequency-driven sources, and high charge state ion sources have been developed at the Lawrence Berkeley Laboratory. This article reviews the history of the research and development of these ion sources and their applications.

K. N. Leung

1994-01-01

146

Links Between Z Sources and Atoll Sources  

NASA Astrophysics Data System (ADS)

It is known that the Z and atoll sources are two typical types of neutron-star sources in low mass X-ray binaries (LMXBs), which present very different Q-? relations of lower kHz QPOs. We propose that the Z and atoll sources are two different phases in the evolutionary track of neutron star in LMXBs, instead of two types of distinct sources.

Wang, Joan Jing; Chang, Hsiang-Kuang

2013-02-01

147

Atomicity via source-to-source translation  

Microsoft Academic Search

We present an implementation and evaluation of atomicity (also known as software transactions) for a dialect of Java. Our imple- mentation is fundamentally different from prior work in three re- spects: (1) It is entirely a source-to-source translation, producing Java source code that can be compiled by any Java compiler and run on any Java Virtual Machine. (2) It can

Benjamin Hindman; Dan Grossman

2006-01-01

148

Measurements of plasma bremsstrahlung and plasma energy density produced by electron cyclotron resonance ion source plasmas  

NASA Astrophysics Data System (ADS)

The goal of this dissertation was to gain an understanding on the relative importance of microwave power, neutral pressure, and magnetic field configuration on the behavior of the hot electrons within an Electron Cyclotron Resonance Ion Source (ECRIS) plasma. This was carried out through measurement of plasma bremsstrahlung with both NaI(Tl) (hv > 30 keV) and CdTe (2 keV < hv < 70 keV) x-ray detectors, and through measurement of the plasma energy density with a diamagnetic loop placed around the plasma chamber. We also examined the anisotropy in x-ray power by simultaneously measuring the x-ray spectra in two orthogonal directions: radially and axially, using NaI(Tl) detectors. We have seen that for a 6.4 GHz ECRIS, both the x-ray power produced by confined electrons and the plasma energy density behave logarithmically with microwave power. The x-ray flux created by electrons lost from the plasma, however, does not saturate. Thus, the small increase in plasma density that occurred at high microwave powers (> 150 W on a 6.4 GHz ECRIS) was accompanied by a large increase in total x-ray power. We suggest that the saturation of x-ray power and plasma energy density was due to rf-induced pitch-angle scattering of the electrons. X-ray power and plasma energy density were also shown to saturate with neutral pressure, and to increase nearly linearly as the gradient of the magnetic field in the resonance zone was decreased. All of these findings were in agreement with the theoretical models describing ECRIS plasmas. We have discussed the use of a diamagnetic loop as a means of exploring various plasma time scales on a relative basis. Specifically, we focused much of our attention on studying how changing ion source parameters, such as microwave power and neutral pressure, would effect the rise and decay of the integrated diamagnetic signal, which can be related to plasma energy density. We showed that increasing microwave power lowers the e-fold times at both the leading edge and the trailing edge of the microwave pulse. Microwave power, however, had almost no impact on the ignition times of the plasma. The plasma energy density e-fold times were insensitive to both neutral pressure and magnetic field setting. Neutral pressure, however, had a dramatic effect on the time of first appearance of the diamagnetic signal ("plasma ignition time"). In addition to neutral pressure, ignition times were also a function the relative abundance of electrons in the plasma chamber at the beginning of a microwave pulse. In all instances, the rise time of the integrated diamagnetic signal was seen to be faster than the decay time. By comparing the unintegrated diamagnetic signal to the ratio of reflected to forward microwave power we theorized that the initial, exponential rise in the diamagnetic signal at the leading edge of a microwave pulse was due to rapid changes in both the average electron energy and density. During the slowly decaying portion of the diamagnetic loop signal, only the hot tail of the electron population was increasing. This theory was supported by time resolved, low energy x-ray measurements that showed that the period of rapid change of the ratio of reflected to forward microwave power coincided with a rapid change in average photon energy. We have also showed that x-rays production in an ECRIS plasma was highly anisotropic, with radial x-ray counts being much greater than axial x-ray counts. This was shown to be true for both the "ECR" (operating at 6.4 GHz) and the higher performance "AECR-U" (operating at 14 GHz). Based on this, we can make the qualitative statement that the electron energy was also highly anisotropic, with a much larger perpendicular energy than parallel energy. The degree of anisotropy was shown to increase with the operating frequency of the ion source. This increase was most likely attributable to the higher power density and greater confinement associated with higher performance machines, and implies that superconducting ECRIS operating at very high freq

Noland, Jonathan David

149

Craft Information Sources  

Microsoft Academic Search

A brief history of the development of the craft movement and the American Craft Council is given. Sources of information on craft include: major authorities in the field; major bibliographic sources; book reviewing sources; reference tools; periodicals and indices; major exhibitions and catalogs; craft artists; craft organizations; databases; educational sources; business sources; how to locate craft fairs and galleries; major

Mary Dodge Hujsak

1994-01-01

150

NSLS source development laboratory.  

National Technical Information Service (NTIS)

The National Synchrotron Light Source (NSLS) has initiated an ambitious project to develop fourth generation radiation sources. To achieve this goal, the Source Development Laboratory (SDL) is building on the experience gained at the NSLS, and at the high...

I. Ben-Zvi E. Blum E. D. Johnson

1995-01-01

151

Multicusp ion sources (invited)  

Microsoft Academic Search

During the last decade, different types of multicusp ion sources, such as high current, high concentration H[sup +], H[sup +][sub 2], or N[sup +] ion sources, negative ion sources, radio-frequency-driven sources, and high charge state ion sources have been developed at the Lawrence Berkeley Laboratory. This article reviews the history of the research and development of these ion sources and

K. N. Leung

1994-01-01

152

The marine seismic source  

SciTech Connect

The contents of this book are: Underlying physics and concepts; Source arrays and directivity; Interaction and wavefield determination; Practical aspects of wavefield stability; Source signature deconvolution; and Index.

Gregg, P.; Hatton, L.

1986-01-01

153

Monitoring the source monitoring.  

PubMed

The hypothesis that the retrieval of correct source memory cues, those leading to a correct source attribution, increases confidence, whereas the retrieval of incorrect source memory cues, those leading to a source misattribution, decreases confidence was tested. Four predictions were derived from this hypothesis: (1) confidence should be higher for correct than incorrect source attribution except; (2) when no source cues are retrieved; (3) only the source misattributions inferred from the retrieval of incorrect source cues will be rated with low confidence; and (4) the number of source cues retrieved, either correct or incorrect, will affect the confidence in the source attributions. To test these predictions, participants read two narratives from two witnesses to a bank robbery, a customer and a teller. Then, participants completed a source monitoring test with four alternatives, customer, teller, both, or neither, and rated their confidence in their source attribution. Results supported the first three predictions, but they also suggested that the number of correct source monitoring cues retrieved did not play a role in the monitoring of the accuracy of the source attributions. Attributions made from the recovery of incorrect source cues could be tagged as dubious or uncertain, thus leading to lowered confidence irrespective of the number of incorrect source cues or whether another correct source cue was also recovered. This research has potential applications for eyewitness memory because it shows that confidence can be an indicator of the accuracy of a source attribution. PMID:23553316

Luna, Karlos; Martín-Luengo, Beatriz

2013-04-04

154

Sources from shading  

Microsoft Academic Search

The authors assume a Lambertian shading model with unknown light source directions. It is shown that information on the occluding boundary puts strong constraints on the light source directions. For a small number of light sources, from sufficiently different directions, additional information from intensity extrema will be sufficient to determine the source directions. If there are two, or three, views

Yihing Yang; A. Yuille

1991-01-01

155

Familiarity in source memory.  

PubMed

Familiarity and recollection are thought to be separate processes underlying recognition memory. Event-related potentials (ERPs) dissociate these processes, with an early (approximately 300-500ms) frontal effect relating to familiarity (the FN400) and a later (500-800ms) parietal old/new effect relating to recollection. It has been debated whether source information for a studied item (i.e., contextual associations from when the item was previously encountered) is only accessible through recollection, or whether familiarity can contribute to successful source recognition. It has been shown that familiarity can assist in perceptual source monitoring when the source attribute is an intrinsic property of the item (e.g., an object's surface color), but few studies have examined its contribution to recognizing extrinsic source associations. Extrinsic source associations were examined in three experiments involving memory judgments for pictures of common objects. In Experiment 1, source information was spatial and results suggested that familiarity contributed to accurate source recognition: the FN400 ERP component showed a source accuracy effect, and source accuracy was above chance for items judged to only feel familiar. Source information in Experiment 2 was an extrinsic color association; source accuracy was at chance for familiar items and the FN400 did not differ between correct and incorrect source judgments. Experiment 3 replicated the results using a within-subjects manipulation of spatial vs. color source. Overall, the results suggest that familiarity's contribution to extrinsic source monitoring depends on the type of source information being remembered. PMID:22789677

Mollison, Matthew V; Curran, Tim

2012-07-10

156

Point Pollution Sources Dimensioning  

Microsoft Academic Search

In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height

Georgeta CUCULEANU

2011-01-01

157

THE CHANDRA SOURCE CATALOG  

SciTech Connect

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public Advanced CCD Imaging Spectrometer imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents {approx}<30''. The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports scientific analysis using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1{sigma} uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of {approx}<1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a source is detected.

Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G.; Grier, John D.; Hain, Roger M.; Harbo, Peter N.; He Xiangqun; Karovska, Margarita; Kashyap, Vinay L. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Davis, John E.; Houck, John C. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Hall, Diane M., E-mail: ievans@cfa.harvard.ed [Northrop Grumman, 60 Garden Street, Cambridge, MA 02138 (United States)

2010-07-15

158

Program improvement by source to source transformation  

Microsoft Academic Search

We treat a program as an object of manipulation, determine items of program constancy, and simplify the program based on the constancy. Some motivation for program manipulation is presented, along with two examples of “higher level optimization” written in an Algol-like language. A collection of program transformations and a model of the compilation process in terms of source-to-source transformations are

David B. Loveman

1976-01-01

159

Combustive Sound Source.  

National Technical Information Service (NTIS)

This thesis describes a unique type of low frequency underwater sound source, the Combustive Sound Source (CSS). The fundamental operating principle of CSS is the following: Electrolysis of water produces hydrogen and oxygen gas, which is a combustible mi...

P. S. Wilson

1994-01-01

160

Synchrotron Radiation Sources  

ScienceCinema

The fundamental basis of synchrotron radiation will be presented in an easy to follow historically based perspective. The development of modern high brightness sources will be illustrated and a view given of the potential for coherent sources in the future.

161

iSource  

NSDL National Science Digital Library

iSource, the Web presence of the magazine iSource, is dedicated to supply chain solutions. The site features short daily news stories written by the iSource.com editorial staff along with several in-depth articles. Also included are video archived presentations from the iSource 100 Summit. While the Website serves mainly as a teaser for the print version of the magazine, it does cover important supply chain information.

162

Familiarity in Source Memory  

PubMed Central

Familiarity and recollection are thought to be separate processes underlying recognition memory. Event-related potentials (ERPs) dissociate these processes, with an early (approximately 300–500 ms) frontal effect relating to familiarity (the FN400) and a later (500–800 ms) parietal old/new effect relating to recollection. It has been debated whether source information for a studied item (i.e., contextual associations from when the item was previously encountered) is only accessible through recollection, or whether familiarity can contribute to successful source recognition. It has been shown that familiarity can assist in perceptual source monitoring when the source attribute is an intrinsic property of the item (e.g., an object’s surface color), but few studies have examined its contribution to recognizing extrinsic source associations. Extrinsic source associations were examined in three experiments involving memory judgments for pictures of common objects. In Experiment 1, source information was spatial and results suggested that familiarity contributed to accurate source recognition: the FN400 ERP component showed a source accuracy effect, and source accuracy was above chance for items judged to only feel familiar. Source information in Experiment 2 was an extrinsic color association; source accuracy was at chance for familiar items and the FN400 did not differ between correct and incorrect source judgments. Experiment 3 replicated the results using a within-subjects manipulation of spatial vs. color source. Overall, the results suggest that familiarity’s contribution to extrinsic source monitoring depends on the type of source information being remembered.

Mollison, Matthew V.; Curran, Tim

2012-01-01

163

Investigating Primary Source Literacy  

ERIC Educational Resources Information Center

Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind "primary source literacy". The study also evaluated students' strengths and weaknesses when conducting primary source research. (Contains 3…

Archer, Joanne; Hanlon, Ann M.; Levine, Jennie A.

2009-01-01

164

CALUTRON ION SOURCE  

Microsoft Academic Search

An ion source is described wherein a portion of the filament serving as ; a cathode for the arc is protected from the effects of non-ionized particles ; escaping from the ionizing mechanism. In the described ion source, the source ; block has a gas chamber and a gas passage extending from said gas chamber to two ; adjacent faces

Brobeck

1959-01-01

165

ION SOURCE FOR CALUTRONS  

Microsoft Academic Search

An improvement is presented in ion sources of the type employed in ; calutron devices. The described ion source has for its inventive contribution ; the incorporation of a plate-like cathode having the general configuration of a ; polygon including a given number of apices. When a polyphase source of current ; has a phase connected to each of the

Tolmie

1958-01-01

166

CALUTRON ION SOURCE  

Microsoft Academic Search

An improvement is described in ion source mechanisms whereby the source ; structure is better adapted to withstanid the ravages of heat, erosion, and ; deterioration concomitant with operation of an ion source of the calutron type. ; A pair of molybdenum plates define the exit opening of the arc chamber and are in ; thermal contact with the walls

Lofgren

1959-01-01

167

Markovian source separation  

Microsoft Academic Search

A maximum likelihood (ML) approach is used to separate the instantaneous mixtures of temporally correlated, independent sources with neither preliminary transformation nor a priori assumption about the probability distribution of the sources. A Markov model is used to represent the joint probability density of successive samples of each source. The joint probability density functions are estimated from the observations using

S. Hosseini; C. Jutten; Dinh Tuan Pham

2003-01-01

168

High current ion sources  

Microsoft Academic Search

The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be high', while in another area a current of 10 Amperes could low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely

1989-01-01

169

DC source assemblies  

DOEpatents

Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

Campbell, Jeremy B; Newson, Steve

2013-02-26

170

Z-source inverter  

Microsoft Academic Search

This paper presents an impedance-source (or impedance-fed) power converter (abbreviated as Z-source converter) and its control method for implementing DC-to-AC, AC-to-DC, AC-to-AC, and DC-to-DC power conversion. The Z-source converter employs a unique impedance network (or circuit) to couple the converter main circuit to the power source, thus providing unique features that cannot be obtained in the traditional voltage-source (or voltage-fed)

Fang Zheng Peng

2003-01-01

171

Neuromagnetic source reconstruction  

SciTech Connect

In neuromagnetic source reconstruction, a functional map of neural activity is constructed from noninvasive magnetoencephalographic (MEG) measurements. The overall reconstruction problem is under-determined, so some form of source modeling must be applied. We review the two main classes of reconstruction techniques-parametric current dipole models and nonparametric distributed source reconstructions. Current dipole reconstructions use a physically plausible source model, but are limited to cases in which the neural currents are expected to be highly sparse and localized. Distributed source reconstructions can be applied to a wider variety of cases, but must incorporate an implicit source, model in order to arrive at a single reconstruction. We examine distributed source reconstruction in a Bayesian framework to highlight the implicit nonphysical Gaussian assumptions of minimum norm based reconstruction algorithms. We conclude with a brief discussion of alternative non-Gaussian approachs.

Lewis, P.S.; Mosher, J.C. [Los Alamos National Lab., NM (United States); Leahy, R.M. [University of Southern California, Los Angeles, CA (United States)

1994-12-31

172

Source and replica calculations  

SciTech Connect

The starting point of the Hiroshima-Nagasaki Dose Reevaluation Program is the energy and directional distributions of the prompt neutron and gamma-ray radiation emitted from the exploding bombs. A brief introduction to the neutron source calculations is presented. The development of our current understanding of the source problem is outlined. It is recommended that adjoint calculations be used to modify source spectra to resolve the neutron discrepancy problem.

Whalen, P.P.

1994-02-01

173

Dynamic radioactive particle source  

SciTech Connect

A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

2012-06-26

174

Rf power sources  

SciTech Connect

This paper covers RF power sources for accelerator applications. The approach has been with particular customers in mind. These customers are high energy physicists who use accelerators as experimental tools in the study of the nucleus of the atom, and synchrotron light sources derived from electron or positron storage rings. This paper is confined to electron-positron linear accelerators since the RF sources have always defined what is possible to achieve with these accelerators. 11 refs., 13 figs.

Allen, M.A.

1988-05-01

175

ION SOURCE FOR CALUTRONS  

DOEpatents

An improvement is presented in ion sources of the type employed in calutron devices. The described ion source has for its inventive contribution the incorporation of a plate-like cathode having the general configuration of a polygon including a given number of apices. When a polyphase source of current has a phase connected to each of the apices, the cathode is heated and rendered electron emissive. This particular cathode configuration is of sturdy construction and provides unuform emission over a considerable area.

Tolmie, J.R.

1958-09-16

176

Pulsed spallation neutron sources  

SciTech Connect

This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

Carpenter, J.M. [Argonne National Lab., IL (United States). Intense Pulsed Neutron Source Div.

1996-05-01

177

SOURCE WATER ASSESSMENT GUIDANCE  

EPA Science Inventory

Provides guidance to primacy agencies and public water systems (PWS) for implementation of assessments of hydrogeologic sensitivity and source water fecal contamination under the Ground Water Rule (GWR)....

178

Improved ion source  

DOEpatents

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species,

Leung, K.N.; Ehlers, K.W.

1982-05-04

179

Lithium power sources  

NASA Astrophysics Data System (ADS)

The theoretical and applied aspects of the development of lithium power sources are examined. The characteristics of lithium power sources with liquid and solid cathode materials are analyzed, and their performance is evaluated as a function of the discharge regime and temperature. The discussion also covers the electrochemical kinetics of the lithium electrode, inorganic and organic electrolytes, primary and secondary lithium power sources, and medium-temperature storage batteries of the system lithium/iron sulfides. Particular attention is given to the existing and prospective applications of lithium power sources of various kinds.

Kedrinskii, Il'ia A.; Dmitrenko, Vasilii E.; Grudianov, Igor'i.

180

Mechanical baseline design of the common long pulse source for the neutral beam systems of TFTR, Doublet III-D, and MFTF-B  

SciTech Connect

The Common Long Pulse Source (CLPS) is designed to meet the differing long pulse neutral beam requirements of TFTR, Doublet III-D, and MFTF-B. The mechanical baseline design to meet these requirements is described along with supporting engineering data collected during the testing of the prototype LBL 10 x 40 Long Pulse Accelerator (LPA) and the Long Pulse Plasma Source (LPS). The CLPS is a scaled up design of the LPA and LPS and can be configured for 120 keV, 70 A D/sub 2/ non-focused, and, 80 keV, 80 A H/sub 2/ or 50 A D/sub 2/ with a 10 m focal length. The two configurations use identical major components, such as accelerator grids, supporting structures, insulators and plasma sources. Ion beam optics are analytically modeled and the results are presented along with the electric field gradients and thermal calculations for various components. A low technology plasma source back plate electron dump design has been adopted. A full scale model of CLPS was constructed, and the baseline design has been transferred to industry. 7 refs., 5 figs.

Paterson, J.A.; Chan, C.F.; Fong, M.Y.; Koehler, G.W.; Sullivan, J.S.; Wells, R.P.; Yee, D.P.

1985-11-01

181

Radiation Source Replacement Workshop  

SciTech Connect

This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

2010-12-01

182

New laser source technology.  

PubMed

Over the past 5 to 8 years several new laser sources have been developed as a result of R & D efforts stimulated by a growing number of laser applications. Four families of new devices-semiconductor diod laser arrays, free electron lasers, rare gas halide excimer sources, and several new tunable solid-state lasers-show particular promise. PMID:17744663

Christensen, C P

1984-04-13

183

Open Source Vision  

ERIC Educational Resources Information Center

Increasingly, colleges and universities are turning to open source as a way to meet their technology infrastructure and application needs. Open source has changed life for visionary CIOs and their campus communities nationwide. The author discusses what these technologists see as the benefits--and the considerations.

Villano, Matt

2006-01-01

184

Linear light source reflectometry  

Microsoft Academic Search

This paper presents a technique for estimating the spatially-varying reflectance properties of a surface based on its appearance during a single pass of a linear light source. By using a linear light rather than a point light source as the illuminant, we are able to reliably observe and estimate the diffuse color, specular color, and specular roughness of each point

Andrew Gardner; Chris Tchou; Tim Hawkins; Paul E. Debevec

2003-01-01

185

EEG source imaging  

Microsoft Academic Search

Objective: Electroencephalography (EEG) is an important tool for studying the temporal dynamics of the human brain's large-scale neuronal circuits. However, most EEG applications fail to capitalize on all of the data's available information, particularly that concerning the location of active sources in the brain. Localizing the sources of a given scalp measurement is only achieved by solving the so-called inverse

Christoph M. Michel; Micah M. Murray; Göran Lantz; Sara Gonzalez; Laurent Spinelli; Rolando Grave de Peralta

2004-01-01

186

New Source Performance Standards  

ERIC Educational Resources Information Center

|This feature article outlines the concept and procedures followed in establishing performance standards for new emission sources and summarizes the standards that have been established to date. Five source catagories are enumerated: fossil fuel-fired steam generators, municipal incinerators, Portland cement plants, nitric acid plants, and…

Jenkins, Richard E.; McCutchen, Gary D.

1972-01-01

187

PORTABLE SOURCE OF RADIOACTIVITY  

DOEpatents

A portable source for radiogiaphy or radiotherapy is described. It consists of a Tl/sup 170/ or Co/sup 60/ source mounted in a rotatable tungsten alloy plug. The plug rotates within a brass body to positions of safety or exposure. Provision is made for reloading and carrying the device safely. (T.R.H.)

Goertz, R.C.; Ferguson, K.R.; Rylander, E.W.; Safranski, L.M.

1959-06-16

188

Equivariant adaptive source separation  

Microsoft Academic Search

Source separation consists of recovering a set of independent signals when only mixtures with unknown coefficients are observed. This paper introduces a class of adaptive algorithms for source separation that implements an adaptive version of equivariant estimation and is henceforth called equivariant adaptive separation via independence (EASI). The EASI algorithms are based on the idea of serial updating. This specific

Jean-françois Cardoso; Beate Hvam Laheld

1996-01-01

189

Using Primary Source Documents.  

ERIC Educational Resources Information Center

|Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)|

Mintz, Steven

2003-01-01

190

Two Source Interference  

NSDL National Science Digital Library

This resource illustrates double slit interference patterns of 2D wave fronts. The waves from two point sources are shown propagating outward, with interference fringes shown on a surface. The wavelength of the waves can be changed, as can the source separation and relative phase.

Group, Kansas S.; Zollman, Dean A.

2004-03-10

191

Energy Sources and Development.  

ERIC Educational Resources Information Center

|This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with energy sources and development. Its objective is for the student to be able to discuss energy sources and development related to the historical perspective, biological development, current aspects, and future expectations…

Crank, Ron

192

Creating Open Source Conversation  

ERIC Educational Resources Information Center

|Darien Library, where the author serves as head of knowledge and learning services, launched a new website on September 1, 2008. The website is built with Drupal, an open source content management system (CMS). In this article, the author describes how she and her colleagues overhauled the library's website to provide an open source content…

Sheehan, Kate

2009-01-01

193

Fugitive Dust: Nonpoint Sources  

Microsoft Academic Search

Fugitive dust is a relatively new term for an old problem. Simply put, fugitive dust is a type of nonpoint source air pollution — small airborne particles that do not originate from a specific point such as a gravel quarry or grain mill. Fugitive dust originates in small quantities over large areas. Significant sources include unpaved roads, agricultural cropland and

John H. Ferguson; H. Willard Downs; Donald L. Pfost

194

Source Region EMP Calculations.  

National Technical Information Service (NTIS)

Source region EMP and close-in coupling calculations were performed in support of a source region EMP simulation experiment performed in the AURORA flash x-ray environment. Calculations were performed of the photon transport and electron transport to obta...

W. L. Chadsey E. R. Parkinson V. W. Pine

1975-01-01

195

Alternative energy sources VII  

Microsoft Academic Search

This book presents the papers given at a conference on the economic aspects of renewable energy sources. Topics considered at the conference included socio-economic factors affecting energy source development, an economic evaluation of solar thermal energy systems, energy planning and management, alternative energy in developing countries, energy conservation, environmental policy, and energy education.

Veziroglu

1985-01-01

196

Alternative energy sources III  

Microsoft Academic Search

This book is based upon the 3rd Clean Energy Research Institute International Conference on Alternative Energy Sources. It provides coverage on the latest advances and developments in the scientific and technical search for energy sources with reduced health and environmental hazards. Topics covered in this book include solar energy; ocean thermal energy; wind energy; geothermal power; hydropower; nuclear breeders and

Veziroglu

1983-01-01

197

Energy Sources and Use  

NSDL National Science Digital Library

This lesson will help students to distinguish between renewable and nonrenewable sources of energy, investigate a variety of renewable energy resources and compare the benefits and drawbacks of each. Students will use internet resources to investigate and compare alternative sources of energy. It is presumed that students have some basic prior understanding of the concept of energy.

198

Leading Education Reference Sources.  

ERIC Educational Resources Information Center

|This annotated bibliography focuses on, but is not limited to, reference sources on education found in the library at St. Bonaventure University, New York. The ERIC database leads the list of leading education reference sources. Also mentioned are the "Thesaurus of ERIC Descriptors" and the Academic Index (InfoTrak) computer system. Other…

Spencer, Michael D.

199

Radioisotopic heat source  

DOEpatents

Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

Jones, G.J.; Selle, J.E.; Teaney, P.E.

1975-09-30

200

Peristaltic ion source  

SciTech Connect

Conventional ion sources generate energetic ion beams by accelerating the plasma-produced ions through a voltage drop at the extractor, and since it is usual that the ion beam is to propagate in a space which is at ground potential, the plasma source is biased at extractor voltage. For high ion beam energy the plasma source and electrical systems need to be raised to high voltage, a task that adds considerable complexity and expense to the total ion source system. The authors have developed a system which though forming energetic ion beams at ground potential as usual, operates with the plasma source and electronics at ground potential also. Plasma produced by a nearby source streams into a grided chamber that is repetitively pulsed from ground to high positive potential, sequentially accepting plasma into its interior region and ejecting it energetically. They call the device a peristaltic ion source. In preliminary tests they`ve produced nitrogen and titanium ion beams at energies from 1 to 40 keV. Here they describe the philosophy behind the approach, the test embodiment that they have made, and some preliminary results.

Brown, I.G.; Anders, A.; Anders, S.; Dickinson, M.R.; MacGill, R.A.

1995-08-01

201

MEG source detection revisited  

NASA Astrophysics Data System (ADS)

Magnetoencephalography (MEG) is a multi-channel imaging technique. It uses an array composed of a large number of Superconducting Quantum Interference Device (SQUID) to measure the magnetic fields produced by the primary electric currents inside the brain. The measured spatio-temporal magnetic fields are then used to estimate the locations and strengths of these electric currents, often known as MEG sources. The estimated quantities are finally superimposed with the images generated by magnetic resonance imaging (MRI). The combination of information from MEG and MRI forms the magnetic source image (MSI). A great variety of signal processing and modeling techniques such as Inverse problem, Subspace approach, Independent component analysis (ICA) method, and Beamforming (BF) are used to estimate these sources. The first three approaches require the number of sources be detected a priori. Several shortcomings exist in the currently used methods for detecting the source number. First, the source detection is completed only after - not before - MSI is generated. Secondly, the detection methods are somewhat subjective. In order to provide a solution to the problem of detecting MEG source number for all these approaches, a novel method is developed. The covariance matrix of MEG measurements over all channels is decomposed into the signal and the noise subspaces. The number of sources is shown to be equal to the dimension of the signal subspace. The selection of this dimension is translated into a problem of determining the order of the underlying statistics. This statistical identification is resolved by using Information theoretic criteria which are derived based on Kullback-Leibler divergence. Because the method utilizes originally acquired MEG measurements and implemented before magnetic source images are generated, it is an entirely data-driven approach, more efficient, and less likely to be subjective.

Lei, Tianhu; Roberts, Timothy P. L.

2010-03-01

202

Biographical Sources for Astronomers  

NASA Astrophysics Data System (ADS)

This paper describes the different types of published sources for biographical data from the history of astronomy - well known ones like encyclopaedias, biographical dictionaries, and obituaries, as well as less known ones like membership directories of societies, annual reports, and lists of solar-system nomenclature. Also online sources such as web pages and databases are considered. Existing bio-bibliographies are discussed and a new "Biographical Index of Astronomy" (BIA) is introduced. It lists biographical and bio-bibliographical sources for more than 16,000 persons.

Dick, Wolfgang R.

2006-12-01

203

Multiaperture negative ion source  

NASA Astrophysics Data System (ADS)

The long-pulse multiaperture surface-plasma source with negative ion production on a cesiated grid is under construction at Budker Institute. The ion source includes RF plasma driver, an expansion chamber with multicusp magnetic filed, an external magnetic filter and a four-electrode ion-optical system for beam extraction and acceleration. The projected parameters of the ion source are: beam current 1.5 A, beam energy 120 keV, pulse duration 100 s, RF power in plasma 40 kW, hydrogen filling pressure < 0.5 Pa, e/H- ratio 1:1, H- ions emission current density 30 mA/cm2.

Belchenko, Yu. I.; Gorbovsky, A. I.; Ivanov, A. A.; Konstantinov, S. G.; Sanin, A. L.; Shikhovtsev, I. V.; Tiunov, M. A.

2013-02-01

204

Ultracold Electron Source  

NASA Astrophysics Data System (ADS)

We propose a technique for producing electron bunches that has the potential for advancing the state-of-the-art in brightness of pulsed electron sources by orders of magnitude. In addition, this method leads to femtosecond bunch lengths without the use of ultrafast lasers or magnetic compression. The electron source we propose is an ultracold plasma with electron temperatures down to 10 K, which can be fashioned from a cloud of laser-cooled atoms by photoionization just above threshold. Here we present results of simulations in a realistic setting, showing that an ultracold plasma has an enormous potential as a bright electron source.

Claessens, B. J.; van der Geer, S. B.; Taban, G.; Vredenbregt, E. J. D.; Luiten, O. J.

2005-10-01

205

Pulsed ion beam source  

DOEpatents

An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.

Greenly, John B. (Lansing, NY)

1996-01-01

206

Gadolinium-153 line sources  

PubMed

The technology for Gd-153 line source production has been developed at SSC RIAR. The source active core is made of Al-Gd2O3 composition by means of one of the following ways: either collecting pressed pellets or filling the source body with the composition followed by sintering. The composition is prepared by gadolinium salt thermal destruction on aluminium particles. The method allows setting gadolinium mass fraction (from 0.02 to 6%) with high accuracy and uniformity of distribution in the composition volume of more than 95%. PMID:11003528

Lebedev; Gordeev; Karelin; Gavrilov

2000-10-01

207

CALUTRON ION SOURCE  

DOEpatents

An improvement is described in ion source mechanisms whereby the source structure is better adapted to withstanid the ravages of heat, erosion, and deterioration concomitant with operation of an ion source of the calutron type. A pair of molybdenum plates define the exit opening of the arc chamber and are in thermal contact with the walls of the chamber. These plates are maintained at a reduced temperature by a pair of copper blocks in thermal conducting contact therewith to form subsequent diverging margins for the exit opening.

Lofgren, E.J.

1959-02-17

208

Microfabricated diffusion source  

DOEpatents

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Oborny, Michael C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

2008-07-15

209

PULSED ION SOURCE  

DOEpatents

An ion source is described adapted for pulsed operation and producing copious quantities of ions with a particular ion egress geometry. The particular source construction comprises a conical member having a conducting surface formed of a metal with a gas occladed therein and narrow non-conducting portions hereon dividing the conducting surface. A high voltage pulse is applied across the conducting surface or producing a discharge across the surface. After the gas ions have been produced by the discharge, the ions are drawn from the source in a diverging conical beam by a specially constructed accelerating electrode.

Ford, F.C.; Ruff, J.W.; Zizzo, S.G.; Cook, B.

1958-11-11

210

Alternative fuel information sources  

SciTech Connect

This short document contains a list of more than 200 US sources of information (Name, address, phone number, and sometimes contact) related to the use of alternative fuels in automobiles and trucks. Electric-powered cars are also included.

Not Available

1994-06-01

211

Contacts & Information Sources  

Cancer.gov

PLCO Background Information about PLCO Sponsoring Organization Participants/Eligibility PLCO Extended Follow-Up Etiology and Early Marker Studies Cancer Data Access System PLCO Publications Contacts & Information Sources PLCO participants who

212

National Synchrotron Light Source  

ScienceCinema

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

213

Alternatives to Source Reduction.  

National Technical Information Service (NTIS)

Source reduction means reducing waste before it's created. This can be accomplished by reducing the amount of material designed into a product, and by using recyclable alternative materials wherever possible. An area overlooked as a target for waste reduc...

R. Carstens

1990-01-01

214

Calibration of Radioactive Sources  

NASA Astrophysics Data System (ADS)

All detector systems for the measurement of radioactivity in the different fields of applications need to be calibrated in terms of efficiency with radioactive sources of known activities and of known radionuclides. This is true for the measurement of environmental radioactivity, activities of sources for medical applications, or activities in the field of nuclear industry and nuclear research. It is the task of National Metrology Institutes (NMIs) and Calibration Laboratories to calibrate radioactive sources in terms of activity and to provide activity standards appropriate to the special needs of their customers. This chapter describes the methods to calibrate the activity of radioactive materials, the different types of calibration sources, and the wayto establish the traceability and international comparability of activity standards.

Arnold, Dirk; Janßen, Herbert

215

Bayesian Radiation Source Localization  

SciTech Connect

Locating illicit radiological sources using gamma ray or neutron detection is a key challenge for both homeland security and nuclear nonproliferation. Localization methods using an array of detectors or a sequence of observations in time and space must provide rapid results while accounting for a dynamic attenuating environment. In the presence of significant attenuation and scatter, more extensive numerical transport calculations in place of the standard analytical approximations may be required to achieve accurate results. Numerical adjoints based on deterministic transport codes provide relatively efficient detector response calculations needed to determine the most likely location of a true source. Probabilistic representations account for uncertainty in the source location resulting from uncertainties in detector responses, the approximations that are used, and the potential for nonunique solutions. A Bayesian approach improves on previous likelihood methods for source localization by allowing the incorporation of all available information to help constrain solutions.

Jarman, Kenneth D.; Miller, Erin A.; Wittman, Richard S.; Gesh, Christopher J.

2011-07-01

216

Calcium source (image)  

MedlinePLUS

Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

217

Pharmacists' Drug Information Sources.  

National Technical Information Service (NTIS)

As part of the Pharmacists Manpower Information Project, pharmacists were asked to denote their frequency of use of five sources of drug information. There were 127,303 respondents representing over 90% of the national population of registered pharmacists...

L. A. Morris D. E. Knapp C. A. Rodowskas W. M. Dickson

1975-01-01

218

METHANE: INDUSTRIAL SOURCES  

EPA Science Inventory

The chapter provides qualitative information on the magnitude of industrial sources of methane and, where possible, provides information to allow the reader to quantify methane emissions. One difficulty in quantifying methane emissions from industry is the inconsistent treatment ...

219

Topology, Holes and Sources  

NASA Astrophysics Data System (ADS)

The Aharonov-Bohm effect is often called "topological." But it seems no more topological than magnetostatics, electrostatics or Newton-Poisson gravity (or just about any radiation, propagation from a source). I distinguish between two senses of "topological."

Afriat, Alexander

2013-03-01

220

Tunable marine seismic source  

SciTech Connect

The disclosed device is a marine seismic source which emits a constantly varying FM signal in the 10 to 100 H /SUB z/ range. The seismic source utilizes an adjustable length cantilever spring rotatably attached to stiff acoustic radiators, which create a signal in the water. Varying the length of the cantilever spring as a function of the frequency will permit the device to be continuously tuned for maximum power output.

Mifsud, J. F.

1985-12-10

221

The NLC positron source  

SciTech Connect

A baseline design for the NLC positron source based on the existing SLC positron system is described. The proposed NLC source consists of a dedicated S-band electron accelerator, a conventional positron production and capture system utilizing a high Z target and an adiabatic matching device, and an L-band positron linac. The invariant transverse acceptance of the capture system is 0.06 m{center_dot}rad, ensuring an adequate positron beam intensity for the NLC.

Tang, H.; Kulikov, A.V.; Clendenin, J.E.; Ecklund, S.D.; Miller, R.A.

1995-05-01

222

Dual Sourcing Strategies  

Microsoft Academic Search

Sourcing strategies that employ operational hedging can reduce the risk of operating in low-cost countries. This article examines\\u000a the sourcing strategy of toy-maker Mattel. Like the high technology industry, toys suffer from many supply chain ailments\\u000a including short product life, rapid product turnover, and seasonal demand. Coupled with long supply lines and potential political\\u000a and economic turmoil in Asia, toymakers

M. Eric Johnson

223

Hubble Source Catalog  

NASA Astrophysics Data System (ADS)

We have created an initial catalog of objects observed by the WFPC2 and ACS instruments on the Hubble Space Telescope (HST). The catalog is based on observations taken on more than 6000 visits (telescope pointings) of ACS/WFC and more than 25000 visits of WFPC2. The catalog is obtained by cross matching by position in the sky all Hubble Legacy Archive (HLA) Source Extractor source lists for these instruments. The source lists describe properties of source detections within a visit. The calculations are performed on a SQL Server database system. First we collect overlapping images into groups, e.g., Eta Car, and determine nearby (approximately matching) pairs of sources from different images within each group. We then apply a novel algorithm for improving the cross matching of pairs of sources by adjusting the astrometry of the images. Next, we combine pairwise matches into maximal sets of possible multi-source matches. We apply a greedy Bayesian method to split the maximal matches into more reliable matches. We test the accuracy of the matches by comparing the fluxes of the matched sources. The result is a set of information that ties together multiple observations of the same object. A byproduct of the catalog is greatly improved relative astrometry for many of the HST images. We also provide information on nondetections that can be used to determine dropouts. With the catalog, for the first time, one can carry out time domain, multi-wavelength studies across a large set of HST data. The catalog is publicly available. Much more can be done to expand the catalog capabilities.

Lubow, S.; Budavári, T.

2013-10-01

224

Energy Sources in Laparoscopy  

Microsoft Academic Search

\\u000a Traditional monopolar and bipolar electrosurgeries remain very useful in laparoscopic surgery. The need for meticulous hemostasis\\u000a and the tedium of vessel ligation in advanced cases has propelled the development of new energy source devices, which have\\u000a proven to be remarkably helpful in both laparoscopic and open surgery. Energy sources in the form of argon beam coagulation,\\u000a ultrasonic coagulation, and bipolar

Ajita S. Prabhu; B. Todd Heniford

225

Magnetron sputtering source  

DOEpatents

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

1994-08-02

226

Review of measurement at accelerators and application to dosimetry calibration.  

National Technical Information Service (NTIS)

Multisphere spectrometers have been used widely to determine neutron spectra and other related quantities from various radiation sources. At Lawrence Berkeley Laboratory (LBL), the multisphere spectrometer has taken measurements at different LBL accelerat...

R. K. S. Sun

1991-01-01

227

HIGH VOLTAGE ION SOURCE  

DOEpatents

A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

Luce, J.S.

1960-04-19

228

Single-photon sources  

NASA Astrophysics Data System (ADS)

The article surveys the state of the art in the design, development and application of devices for deterministically generating single photons on demand. Both the defined function and requisite form of such ‘single-photon’ sources are explained in detail. Their attributes and characteristics, in particular the photon-counting statistics of the light that they generate, are presented in conjunction with the experimental apparatus (most notably the Hanbury-Brown and Twiss interferometer) for measuring them. Promising applications of single-photon sources within quantum key distribution, quantum information processing, as well as metrology and fundamental tests of quantum mechanics, are described. The utility and relative advantages of single-photon sources vis-á-vis more conventional sources of light are explained in terms of application-specific requirements and the respective abilities of different sources to fulfil them. The article collects, classifies and sorts the most significant work towards realizing practical single-photon sources to date. Though emanating from a diverse set of technological disciplines, with different research and application objectives in mind, the relative advantages and drawbacks of each approach are assessed, to give the reader a broad yet coherent and critical review of a rapidly developing research front.

Oxborrow, Mark; Sinclair, Alastair G.

2005-05-01

229

Pulsed ion beam source  

DOEpatents

An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

Greenly, J.B.

1997-08-12

230

Electricity from Worldwide Energy Sources  

Microsoft Academic Search

The aim of this article is to investigate electricity production from energy sources. Electricity, which is a secondary energy source, can be generated from the conversion of other sources of energy, such as coal, natural gas, oil, nuclear power, and other natural sources, which are called primary sources. Much of the growth in new electricity demand is expected to come

Mustafa Balat

2006-01-01

231

Sealed source peer review plan  

Microsoft Academic Search

Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management

Alexander Feldman; Lee Leonard; Ron Burns

2009-01-01

232

Workshop on detectors for third-generation synchrotron sources: Proceedings  

SciTech Connect

The aims of the workshop were (1) to acquaint APS users with current R and D being carried out on detectors, (2) to identify new detector systems possible during the next five years, (3) to identify new detectors theoretically possible in the future, (4) to stimulate interactions between user groups and detector developers, and (5) to obtain recommendations from expert panels on technical issues needing resolution. Development of detectors at ESRF, Spring-8, BNL, CERN and LBL are included.

NONE

1994-12-01

233

Dual source heat pump  

DOEpatents

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

1982-01-01

234

Information sources in engineering  

SciTech Connect

This book was designed to serve as a guide to the wide range of sources of information used by engineers. The first part of this research tool describes the major primary and secondary sources for information (including online systems) that are relevant to all engineering disciplines. The second part provides the same information for each of the 19 specific engineering disciplines, with each chapter being written by an expert in the particular branch of engineering. This new edition of a work previously published under the title Use of Engineering Literature has been completely re-written with a new team of contributors. There is greater emphasis on disciplines basic to all engineering areas, e.g., fluid mechanics, thermodynamics, and materials science. Recent developments covered include robotics, CAD/CAM systems, renewable energy sources, and the use of online systems for information retrieval.

Anthony, L.J.

1985-01-01

235

Astrophysics Source Code Library  

NASA Astrophysics Data System (ADS)

The Astrophysics Source Code Library (ASCL), founded in 1999, is a free on-line registry for source codes of interest to astronomers and astrophysicists. The library is housed on the discussion forum for Astronomy Picture of the Day (APOD) and can be accessed at http://ascl.net. The ASCL has a comprehensive listing that covers a significant number of the astrophysics source codes used to generate results published in or submitted to refereed journals and continues to grow. The ASCL currently has entries for over 500 codes; its records are citable and are indexed by ADS. The editors of the ASCL and members of its Advisory Committee were on hand at a demonstration table in the ADASS poster room to present the ASCL, accept code submissions, show how the ASCL is starting to be used by the astrophysics community, and take questions on and suggestions for improving the resource.

Allen, A.; DuPrie, K.; Berriman, B.; Hanisch, R. J.; Mink, J.; Teuben, P. J.

2013-10-01

236

INEEL Source Water Assessment  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 mi2 and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL’s drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey’s Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency’s Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a thick vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL’s Source Water Assessment. Of the INEEL’s 12 public water systems, three systems rated as low susceptibility (EBR-I, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will protect the INEEL’s public water systems yet not too conservative to inhibit the INEEL from carrying out its missions.

Sehlke, Gerald

2003-03-01

237

Intense fusion neutron sources  

SciTech Connect

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 10{sup 15}-10{sup 21} neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 10{sup 20} neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

Kuteev, B. V. [Russian Research Centre Kurchatov Institute (Russian Federation); Goncharov, P. R.; Sergeev, V. Yu. [St. Petersburg State Polytechnic University (Russian Federation); Khripunov, V. I. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-04-15

238

CALUTRON ION SOURCE  

DOEpatents

The construction of an ion source is descrtbed wherein a uniform and elongated arc is established for employment in a calutron. The novel features of the . source include the positioning of a cathode at one end of an elongated extt slit of an arc chamber. and anode electrodes defintng the longitudinal margins of the exit opening. When the exit slit is orientated in a parallel relation to a magnetic field, the arc extends in the direction of the magnetic field along and between the anode electrodes, which are held at a positsve potential with respect to the cathode.

Oppenheimer, F.

1958-08-19

239

Download Mozilla Source  

NSDL National Science Digital Library

Netscape offers its browser source code at its Mozilla.org (discussed in the Feburary 27, 1998 Scout Report) site. The compressed code is available for Macintosh, Unix, and Windows operating systems, and is between 8.8 and 11.9 Mb. Netscape strongly points out that this is source code, not executable programs, that it is of use to developers only, and that it "will be unstable." More information about the code, as well as selected build instructions, can be obtained at the site.

1998-01-01

240

River Sources and Stories  

NSDL National Science Digital Library

In this lesson students learn about the differences in precipitation levels and elevation in the regions of the Nile and its source rivers (the White Nile and the Blue Nile) and will be able to explain the importance of the source rivers to civilization in Egypt. They use the MapMachine, an online atlas, and create elevation zones and precipitation maps of Africa. As they create each map, they compare it with their outline maps to answer some questions that will allow them to compare the physical characteristics of different regions and to understand the significance of one region to an adjoining area.

241

Milliwatt generator heat source  

NASA Astrophysics Data System (ADS)

All LANL hardware requirements were met during the reporting period as scheduled. Lot 12 of T-111 alloy sheet and Lot 8 of yttrium platelets were procured to meet future WR production needs. The GEND IP schedule requirements for 49 fueled MC2893 heat sources were met. Pressure burst surveillance activities continued to be conducted in accordance with SNLA document BB328965. Final results of evaluations of two pressure-burst capsules were normal, suggesting that the corresponding heat sources should be in good condition. The hardware production period ended with an overall hardware process yield of 98.4%.

Mershad, E. A.

1984-03-01

242

FABRICATION OF NEUTRON SOURCES  

DOEpatents

A method is presented for preparing a neutron source from polonium-210 and substances, such as beryllium and boron, characterized by emission of neutrons upon exposure to alpha particles from the polonium. According to the invention, a source is prepared by placing powdered beryllium and a platinum foil electroplated with polonium-2;.0 in a beryllium container. The container is sealed and then heated by induction to a temperature of 450 to 1100 deg C to volatilize the polonium off the foil into the powder. The heating step is terminated upon detection of a maximum in the neutron flux level.

Birden, J.H.

1959-04-21

243

OLED area illumination source  

DOEpatents

The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

Foust, Donald Franklin (Scotia, NY); Duggal, Anil Raj (Niskayuna, NY); Shiang, Joseph John (Niskayuna, NY); Nealon, William Francis (Gloversville, NY); Bortscheller, Jacob Charles (Clifton Park, NY)

2008-03-25

244

Alternative Energy Sources  

NSDL National Science Digital Library

Created by Work-Ready Electronics, a project of the Advanced Technological Education program, this module introduces students to the most common alternative energy sources that they may encounter in electronic work including fuel cells, solar power, and ultracapacitors. The module includes course materials covering each of these alternative energy sources along with three "Knowledge Probes" which provide an opportunity for students to master the objectives of the module. By clicking on "Learning Resources" at the top of the page, users will also find supplemental learning activities and additional resources for practice and research. The module also includes a glossary of terms and a notebook function.

2008-09-09

245

SOLE SOURCE AQUIFER BOUNDARY DATA  

EPA Science Inventory

There are 7 polygons representing 6 individual sole source aquifer boundaries and one streamflow source area in California, Arizona, and Nevada. Various efforts were combined to create the final product, which represents the Federal Register boundary description. Sole source aqu...

246

Californium source transfer  

SciTech Connect

In early 1995, the receipt of four sealed californium-252 sources from Oak Ridge National Lab was successfully accomplished by a team comprised of Radiological Engineering, Radiological Operations and Health Physics Instrumentation personnel. A procedure was developed and walked-down by the participants during a Dry Run Evolution. Several special tools were developed during the pre-planning phases of the project which reduced individual and job dose to minimal levels. These included a mobile lifting device for attachment of a transfer ball valve assembly to the undercarriage of the Cannonball Carrier, a transfer tube elbow to ensure proper angle of the source transfer tube, and several tools used during emergency response for remote retrieval and handling of an unshielded source. Lessons were learned in the areas of contamination control, emergency preparedness, and benefits of thorough pre-planning, effectiveness of locally creating and designing special tools to reduce worker dose, and methods of successfully accomplishing source receipt evolutions during extreme or inclement weather.

Wallace, C.R.

1995-12-31

247

Single-photon sources  

Microsoft Academic Search

The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical

Brahim Lounis; Michel Orrit

2005-01-01

248

The advanced neutron source  

Microsoft Academic Search

The Advanced Neutron Source (ANS), slated for construction start in 1994, will be a multipurpose neutron research laboratory serving academic and industrial users in chemistry, biology, condensed matter physics, nuclear and fundamental physics, materials science and engineering, and many other fields. It will be centered on the world`s highest flux neutron beam reactor, operating at 330 MW, with careful design

Hayter

1994-01-01

249

BNL Sources Development Laboratory  

SciTech Connect

The NSLS has a long-standing interest in providing the best possible synchrotron radiation sources for its user community, and hence, has recently established the Source Development Laboratory (SDL) to pursue research into fourth generation synchrotron radiation sources. A major element of the program includes development of a high peak power FEL meant to operate in the vacuum ultraviolet. The objective of the program is to develop the source, and experimental technology together to provide the greatest impact on UV science. The accelerator under construction for the SDL consists of a high brightness RF photocathode electron gun followed by a 230 MeV short pulse linac incorporating a magnetic chicane for pulse compression. The gun drive laser is a wide bandwidth Ti: Sapphire regenerative amplifier capable of pulse shaping which will be used to study non- linear emittance compensation. Using the compressor, 1 nC bunches with a length as small as 50 {mu}m sigma (2 kA peak current) are available for experiments. In this paper we briefly describe the facility and detail our plans for utilizing the 10 m long NISUS wiggler to carry out single pass FEL experiments. These include a 1 {mu}m SASE demonstration, a seeded beam demonstration at 300 nm, and a High Gain Harmonic Generation experiment at 200 mn. The application of chirped pulse amplification to this type of FEL will also be discussed.

Ben-Zvi, I.; Graves, W.; Heese, R.; Johnson, E.D.; Krinsky, S.; Yu, L.H.

1997-01-01

250

Tandem Terminal Ion Source  

SciTech Connect

OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the {sup 7}Be({gamma}){sup 8}B experiment. Most of the runs used {sup 1}H{sup +} at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used {sup 2}H{sup +} at terminal voltage of 1.4 MV. The other run used {sup 4}He{sup +} at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal.

None

2000-10-23

251

Chemical Plume Source Localization  

Microsoft Academic Search

This paper addresses the problem of estimating a likelihood map for the location of the source of a chemical plume using an autonomous vehicle as a sensor probe in a fluid flow. The fluid flow is assumed to have a high Reynolds number. Therefore, the dispersion of the chemical is dominated by turbulence, resulting in an intermittent chemical signal. The

Shuo Pang; Jay A. Farrell

2006-01-01

252

Oceanography Information Sources 70.  

ERIC Educational Resources Information Center

|This booklet lists oceanography information sources in the first section under industries, laboratories and departments of oceanography, and other organizations which can provide free information and materials describing programs and activities. Publications listed in the second section include these educational materials: bibliographies, career…

Vetter, Richard C.

253

Broadband seismic energy source  

SciTech Connect

A vibratory seismic energy source capable of generating significant energy over a broad frequency band is described. The vibrating baseplate and associated structure are designed to have minimum weight while still retaining sufficient structural integrity to permit the use of high actuator forces. This, coupled with a large reaction mass results in the generation of significant energy levels in the earth at high frequencies.

Bedenbender, J.W.; Weber, R.M.

1981-03-03

254

Open Source in Education  

ERIC Educational Resources Information Center

Educational institutions have rushed to put their academic resources and services online, beginning the global community onto a common platform and awakening the interest of investors. Despite continuing technical challenges, online education shows great promise. Open source software offers one approach to addressing the technical problems in…

Lakhan, Shaheen E.; Jhunjhunwala, Kavita

2008-01-01

255

Dual Wavelength Light Sources.  

National Technical Information Service (NTIS)

This is a report on research directed toward the development of a coal mine methanometer. The project encompassed two tasks. The first was a study conducted to determine if room-temperature injection lasers could be used as the source for a DIAL methanome...

R. T. Boos W. D. Egan R. A. Elliot R. K. DeFreeze

1985-01-01

256

Open Source Software Development.  

National Technical Information Service (NTIS)

This article examines and reviews what is known so far about free/open source software development (FOSSD). FOSSD is not the same as software engineering as that is portrayed in common textbooks. Instead, it is a complementary approach to address the many...

W. Scacchi

2011-01-01

257

Source Cellphone Identification  

Microsoft Academic Search

In this paper, we focus on blind source cell-phone identification problem. The main idea is that proprietary interpolation algorithm (involved due to the structure of color filter array [CFA]) leaves footprints in the form of correlations across adjacent bit planes of images. For this purpose, we explore a set of binary similarity measures, image quality measures and higher order wavelet

Oya Çeliktutan; I. Avcibas; B. Sankur; N. P. Ayerden; C. Capar

2006-01-01

258

Automated Source Depth Estimation  

Microsoft Academic Search

Source depth estimation is a key process in the discrimination of earthquakes and explosions for nuclear treaty monitoring. The lack of observable depth phases does not mean an event occurred at or near the surface. Shallow events can have closely spaced depth phases that are imperceptible to human analysts and regional events are often complicated by the simultaneous arrival of

W. N. Junek; J. R. Nieves; R. C. Kemerait; M. T. Woods; J. P. Creasey

2007-01-01

259

Selective ion source  

DOEpatents

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

Leung, K.N.

1996-05-14

260

Selective ion source  

DOEpatents

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01

261

Oceanography Information Sources 70.  

ERIC Educational Resources Information Center

This booklet lists oceanography information sources in the first section under industries, laboratories and departments of oceanography, and other organizations which can provide free information and materials describing programs and activities. Publications listed in the second section include these educational materials: bibliographies, career…

Vetter, Richard C.

262

Identifying EGRET Sources.  

National Technical Information Service (NTIS)

This project was awarded funding from the CGRO program to support ROSAT and ground-based observations of unidentified sources from data obtained by the EGRET instrument on the Compton Gamma-Ray Observatory. The critical items in the project are the indivi...

E. Schlegel

2002-01-01

263

World nonrenewable energy sources  

Microsoft Academic Search

The latest estimates are given for proven world reserves of nonrenewable energy sources, which includes coal, natural gas, natural gas liquids, crude and shale oil, bitumens, and uranium oxide. The data represents a reconciliation of figures obtained by recognized agencies. Tables summarize both proved and currently recoverable estimates and projections of remaining recoverable reserves. These two categories are then broken

1977-01-01

264

Alternative Energy Sources.  

National Technical Information Service (NTIS)

On this meeting it had been reported about the applicability and feasibility of techniques using renewable energy sources like solar energy, biomass particular wood fuels, geothermal energy and wind and techniques how to derive fuels from wastes e.g. pyro...

1982-01-01

265

Sources of Model Error  

NSDL National Science Digital Library

This undergraduate meteorology tutorial from Texas A&M University describes the common sources of weather forecasting computer model error, ways to identify model error, and how to correct a forecast for some simple types of error. Model sensitivity to parameterization and topography are covered.

Nielsen-Gammon, John

1996-01-01

266

MICROBIAL SOURCE TRACKING  

EPA Science Inventory

Fecal contamination of waters used for recreation, drinking water, and aquaculture is an environmental problem and poses significant human health risks. The problem is often difficult to correct because the source of the contamination cannot be determined with certainty. Run-of...

267

Biotechnology Information Sources  

Microsoft Academic Search

Biotechnology has experienced rapid growth in the past three years. A host of new books, journals, databases, dictionaries and directories have been published to satisfy the information needs of scientific, regulatory, legal and marketing personnel. The biotechnology literature is discussed in this paper under its general, business, scientific, regulatory and patent aspects. Major sources are highlighted in the text, with

Julie M. Neway

1988-01-01

268

Free open source software  

NSDL National Science Digital Library

This site offers open source software for the fields of civil and environmental engineering. Their mission statement is "to provide an online web directory for civil & environmental engineering." Nicely organized, the site is a valuable asset for anyone interested in this subject area.

2008-10-15

269

Fourth Generation Light Sources  

NASA Astrophysics Data System (ADS)

Concepts and designs are now being developed at laboratories around the world for light sources with performance levels that exceed present sources, including the very powerful and successful third generation synchrotron radiation sources that have come on line in the past few years. Workshops (M. Cornacchia and H. Winick (eds), Workshop on Fourth Generation Light Sources, Feb. 24-27, 1992, SSRL Report 92/02) (J.-L. Laclare (ed), ICFA Workshop on Fourth Generation Light Sources, Jan. 22-25, 1996, ESRF Report) have been held to review directions for future sources. A main thrust is to increase the brightness and coherence of the radiation using storage rings with lower electron-beam emittance or free-electron lasers (FELs). In the infra-red part of the spectrum very high brightness and coherence is already provided by FEL user facilities driven by linacs and storage rings. It now appears possible to extend FEL operation to the VUV, soft X-ray and even hard X-ray spectral range, to wavelengths down to the angstrom range, using high energy linacs equipped with high-brightness rf photoinjectors and bunch-length compressors. R&D to develop such sources is in progress at BNL, DESY, KEK, SLAC and other laboratories. In the absence of mirrors to form optical cavities, short wavelengths are reached in FEL systems in which a high peak current, low-emittance electron beam becomes bunch-density modulated at the optical wavelength in a single pass through a long undulator by self-amplified spontaneous emission (SASE); i.e.; startup from noise. A proposal to use the last kilometer of the three kilometer SLAC linac (the first two kilometers will be used for injection to the PEP II B-Factory) to provide 15 GeV electron beams to reach 1.5 Angstroms by SASE in a 100 m long undulator is in preparation.

Winick, Herman

1997-05-01

270

Fourth generation light sources  

SciTech Connect

Concepts and designs are now being developed at laboratories around the world for light sources with performance levels that exceed present sources, including the very powerful and successful third generation synchrotron radiation sources that have come on line in the past few years. Workshops, have been held to review directions for future sources. A main thrust is to increase the brightness and coherence of the radiation using storage rings with lower electron-beam emittance or free-electron lasers (FELs). In the infra-red part of the spectrum very high brightness and coherence is already provided by FEL user facilities driven by linacs and storage rings. It now appears possible to extend FEL operation to the VUV, soft X-ray and even hard X-ray spectral range, to wavelengths down to the angstrom range, using high energy linacs equipped with high-brightness rf photoinjectors and bunch-length compressors. R&D to develop such sources is in progress at BNL, DESY, KEK, SLAC and other laboratories. In the absence of mirrors to form optical cavities, short wavelengths are reached in FEL systems in which a high peak current, low-emittance electron beam becomes bunch-density modulated at the optical wavelength in a single pass through a long undulator by self-amplified spontaneous emission (SASE); i.e.; startup from noise. A proposal to use the last kilometer of the 3 kilometer SLAC linac (the first 2 kilometers will be used for injection to the PEP II B-Factory) to provide 15 GeV electron beams to reach 1.5 {angstrom} by SASE in a 100 m long undulator is in preparation.

Winick, H.

1997-05-01

271

M lbl Kit elblez Kit Melblez Kit for Ocular Melanoma  

Center for Biologics Evaluation and Research (CBER)

Text Version... 10 Clinical Perspective Richard Alexander, MD, FACS Page 11. ... itt • Permanent discontinuation if persistent toxicity > grade 2 eight weeks after PHP ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

272

Optimizing proton therapy at the LBL medical accelerator. Final report  

SciTech Connect

This Grant has marked the beginning of a multi-year study process expected to lead to design and construction of at least one, possibly several hospital-based proton therapy facilities in the United States.

Alonso, J.

1992-03-01

273

Optimizing proton therapy at the LBL medical accelerator  

SciTech Connect

This Grant has marked the beginning of a multi-year study process expected to lead to design and construction of at least one, possibly several hospital-based proton therapy facilities in the United States.

Alonso, J.

1992-03-01

274

LBL Magnetic-Measurements Data-Acquisition System  

NASA Astrophysics Data System (ADS)

A real time data acquisition system (DAS) for magnetic measurements was developed. The design objective was for a system that was versatile, portable, modular, expandable, quickly and easily reconfigurable both in hardware and software, and inexpensive. All objectives except the last were attained. An LSI 11/23 microcomputer is interfaced to a clock calendar, printer, CRT control terminal, plotter with hard copy, floppy and hard disks, GPIB, and CAMAC buses. Off the shelf hardware and software were used where possible. Operational capabilities include: (1) measurement of high permeability materials; (2) harmonic error analysis of superconducting dipoles and rare earth cobalt and conventional quadrupole magnets; and (3) 0.1% accuracy x-y mapping with Hall probes. Results are typically presented in both tabular and graphical form during measurements.

Green, M. I.; Nelson, D. H.

1983-03-01

275

LBL continuous bench-scale liquefaction unit, operation and results  

Microsoft Academic Search

A bench-scale continuous liquefaction unit (CLU) is now fully operational. The CLU is a flexible system capable of examining feedstocks introduced in slurry form by various liquefying techniques. It is the only continuous biomass liquefaction unit currently in use. Emphasis has been on the liquefaction of aqueous slurries (about 20% organics) of prehydrolyzed Douglas fir wood, without recycle, under the

C. Figueroa; L. L. Schaleger; H. G. Davis

1981-01-01

276

Progress report on LBL's numerical modeling studies on Cerro Prieto  

SciTech Connect

An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.

Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.

1989-04-01

277

Terahertz sources and detectors  

NASA Astrophysics Data System (ADS)

Through the support of the US Army Research Office we are developing terahertz sources and detectors suitable for use in the spectroscopy of chemical and biological materials as well as for use in imaging systems to detect concealed weapons. Our technology relies on nonlinear diodes to translate the functionality achieved at microwave frequencies to the terahertz band. Basic building blocks that have been developed for this application include low-noise mixers, frequency multipliers, sideband generators and direct detectors. These components rely on planar Schottky diodes and integrated diode circuits and are therefore easy to assemble and robust. They require no mechanical tuners to achieve high efficiency and broad bandwidth. This paper will review the range of performance that has been achieved with these terahertz components and briefly discuss preliminary results achieved with a spectroscopy system and the development of sources for imaging systems.

Crowe, Thomas W.; Porterfield, David W.; Hesler, Jeffrey L.; Bishop, William L.; Kurtz, David S.; Hui, Kai

2005-05-01

278

Mars Spark Source Prototype  

NASA Astrophysics Data System (ADS)

The Mars Spark Source Prototype (MSSP) hardware has been developed as part of a proof of concept system for the detection of trace metals such as lead, cadmium, and arsenic in Martian dusts and soils. A spark discharge produces plasma from a soil sample and detectors measure the optical emission from metals in the plasma that will allow their identification and quantification. Trace metal measurements are vital for the assessment of the potential toxicity of the Martian environment for human exploration. The current method of X-ray fluorescence can yield concentrations only of major species. Other instruments are incompatible with the volume, weight, and power constraints for a Mars mission. The instrument will be developed primarily for use in the Martian environment, but would be adaptable for terrestrial use in environmental monitoring. This paper describes the Mars Spark Source Prototype hardware, the results of the characterization tests, and future plans for hardware development.

Eichenberg, Dennis J.; Lindamood, Glenn R.; Weiland, Karen J.; VanderWal, Randall L.

1999-10-01

279

Evaluated Teletherapy Source Library  

SciTech Connect

The Evaluated Teletherapy Source Library (ETSL) is a system of hardware and software that provides for maintenance of a library of useful phase space descriptions (PSDs) of teletherapy sources used in radiation therapy for cancer treatment. The PSDs are designed to be used by PEREGRINE, the all-particle Monte Carlo dose calculation system. ETSL also stores other relevant information such as monitor unit factors (MUFs) for use with the PSDs, results of PEREGRINE calculations using the PSDs, clinical calibration measurements, and geometry descriptions sufficient for calculational purposes. Not all of this information is directly needed by PEREGRINE. It also is capable of acting as a repository for the Monte Carlo simulation history files from which the generic PSDs are derived.

Cox, L.J.; Schach Von Wittenau, A.E.

2000-02-22

280

Voltage controlled current source  

DOEpatents

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01

281

Alternative energy sources  

NASA Astrophysics Data System (ADS)

Renewable energy sources and their potential contribution for solving energy needs are presented. Centralized supply technologies include those alternative fuels derived from biomass using solar energy, (supplying 57% of the energy supply in some countries), and those using directly collected solar energy to manufacture a fuel. Fuel utilization effects can be doubled by using combined heat and power stations, and other major sources include wind, wave, tidal, and solar. In terms of local supply technology, wood burning appliances are becoming more popular, and methane is being used for heating and to fuel spark ignition engines. Geothermal low temperature heating exists worldwide at a capacity of 7.2 GW, supplying heat, particularly in Hungary, parts of the U.S.S.R., and Iceland, and a geothermal research program has been established in the United States. Sweden has a potential hydroelectric capacity of 600 MW, and the United States has a 100 GW capacity. Many of these technologies are already cost effective.

Todd, R. W.

1982-04-01

282

Filtered cathodic arc source  

DOEpatents

Disclosed is a continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45{degrees} to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

Falabella, S.; Sanders, D.M.

1992-12-31

283

Open Source Development Network  

NSDL National Science Digital Library

"A collection of Internet technology and software sites," provides daily IT news in nine subjects, including AppleWatch, HardwareWatch, Internet-Watch, JavaWatch, and MicrosoftWatch, among others. Sources include InfoWorld, Computer News Daily, Interactive Week, Wired, Techwire, and ZDNNews, among others. The key to this site is the way it repackages and organizes already existing news, allowing the user to follow all aspects of IT news from one place.

1998-01-01

284

The European Spallation Source  

SciTech Connect

The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.

2011-03-01

285

Energy source book  

Microsoft Academic Search

The most up-to-date information obtainable on every aspect of the U.S. energy situation and the government's energy programs is detailed in this book. It presents analyses of the Administration's plans and newly enacted legislation, detailed forecasts of energy supplies through 1990, potential energy source alternatives, good industrial energy use and conservation data. Following a discussion of the National Energy Plan

A. McRae; J. L. Dudas; H. Rowland

1977-01-01

286

Alternatives to source reduction  

SciTech Connect

Source reduction means reducing waste before it`s created. This can be accomplished by reducing the amount of material designed into a product, and by using recyclable alternative materials wherever possible. An area overlooked as a target for waste reduction is the ordinary corrugated box. According to the Fibre Box Association, 20 million tons of corrugated were produced in 1989, about half of which was recycled.

Carstens, R.

1990-11-01

287

The advanced neutron source  

SciTech Connect

The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge in the late 1990's. The centerpiece of the ANS will be a steady-state research reactor of unprecedented thermal neutron flux ({phi}{sub th} {approx} 8 {times} 10{sup 19} m{sup {minus}2} {center dot}s{sup {minus}1}) accompanied by extensive and comprehensive equipment and facilities for neutron-based research.

Raman, S.; Hayter, J.B.

1990-01-01

288

World nonrenewable energy source  

Microsoft Academic Search

In this report, up-to-date estimates are presented for world proven reserves, remaining recoverable resources, annual production rates, and cumulative production of the non-renewable energy sources: coal, natural gas, crude oil, natural gas liquids, syncrude from oil shale and tar sands, and uranium oxide. Life indexes are also presented for the world fossil fuels for several annual growth rates. Data are

1979-01-01

289

Estimation of neutron dose equivalent at the mezzanine of the Advanced Light Source and the laboratory boundary using the ORNL program MORSE  

SciTech Connect

To investigate the radiation effect of neutrons near the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory (LBL) with respect to the neutron dose equivalents in nearby occupied areas and at the site boundary, the neutron transport code MORSE, from Oak Ridge National Laboratory (ORNL), was used. These dose equivalents result from both skyshine neutrons transported by air scattering and direct neutrons penetrating the shielding. The ALS neutron sources are a 50-MeV linear accelerator and its transfer line, a 1.5-GeV booster, a beam extraction line, and a 1.9-GeV storage ring. The most conservative total occupational-dose-equivalent rate in the center of the ALS mezzanine, 39 m from the ALS center, was found to be 1.14 X 10(-3) Sv y-1 per 2000-h occupational year, and the total environmental-dose-equivalent rate at the ALS boundary, 125 m from the ALS center, was found to be 3.02 X 10(-4) Sv y-1 per 8760-h calendar year. More realistic dose-equivalent rates, using the nominal (expected) storage-ring current, were calculated to be 1.0 X 10(-4) Sv y-1 and 2.65 X 10(-5) Sv y-1 occupational year and calendar year, respectively, which are much lower than the DOE reporting levels.

Sun, R.K. (Lawrence Berkeley Lab., CA (USA))

1990-12-01

290

Estimation of neutron dose equivalent at the mezzanine of the Advanced Light Source and the laboratory boundary using the ORNL program MORSE.  

PubMed

To investigate the radiation effect of neutrons near the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory (LBL) with respect to the neutron dose equivalents in nearby occupied areas and at the site boundary, the neutron transport code MORSE, from Oak Ridge National Laboratory (ORNL), was used. These dose equivalents result from both skyshine neutrons transported by air scattering and direct neutrons penetrating the shielding. The ALS neutron sources are a 50-MeV linear accelerator and its transfer line, a 1.5-GeV booster, a beam extraction line, and a 1.9-GeV storage ring. The most conservative total occupational-dose-equivalent rate in the center of the ALS mezzanine, 39 m from the ALS center, was found to be 1.14 X 10(-3) Sv y-1 per 2000-h "occupational" year, and the total environmental-dose-equivalent rate at the ALS boundary, 125 m from the ALS center, was found to be 3.02 X 10(-4) Sv y-1 per 8760-h calendar year. More realistic dose-equivalent rates, using the nominal (expected) storage-ring current, were calculated to be 1.0 X 10(-4) Sv y-1 and 2.65 X 10(-5) Sv y-1 occupational year and calendar year, respectively, which are much lower than the DOE reporting levels. PMID:2228611

Sun, R K

1990-12-01

291

Intense neutron source  

SciTech Connect

A ScD/sub 2/ target film 5 x 10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10'' /s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1 x 10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the more complicated duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. = 60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

Walko, R.J.; Brainard, J.P.; Riedel, A.A.; O'Hagan, J.B.; Bacon, F.M.

1982-01-01

292

Intense neutron source  

SciTech Connect

A ScD/sub 2/ target film 5x10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10/sup 11//s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1x10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the high pressure duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. =60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

Walko, R.J.; Bacon, F.M.; Brainard, J.P.; O'Hagan, J.B.; Riedel, A.A.

1983-04-01

293

Seismic source parameters  

SciTech Connect

The use of information contained on seismograms to infer the properties of an explosion source presents an interesting challenge because the seismic waves recorded on the seismograms represent only small indirect, effects of the explosion. The essential physics of the problem includes the process by which these elastic waves are generated by the explosion and also the process involved in propagating the seismic waves from the source region to the sites where the seismic data are collected. Interpretation of the seismic data in terms of source properties requires that the effects of these generation and propagation processes be taken into account. The propagation process involves linear mechanics and a variety of standard seismological methods have been developed for handling this part of the problem. The generation process presents a more difficult problem, as it involves non-linear mechanics, but semi-empirical methods have been developed for handling this part of the problem which appear to yield reasonable results. These basic properties of the seismic method are illustrated with some of the results from the NPE.

Johnson, L.R.

1994-06-01

294

Coded source neutron imaging  

SciTech Connect

Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100 m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100um and 10um aperture hole diameters show resolutions matching the hole diameters.

Bingham, Philip R [ORNL; Santos-Villalobos, Hector J [ORNL

2011-01-01

295

A useful infrared source.  

PubMed

Reliable Inconel-sheathed cartridge heaters rated at hundreds or thousands of watts have been in use for many years. Miniature heaters have been manufactured, having axial leads, which when treated with an emissive coating meet or exceed Globar emissivities in the ir. Free-air temperatures approximating 800 degrees C have been obtained for power inputs of 10 W, while temperatures as high as 1150 degrees C are possible for short lifetimes, e.g., 10 h, at power dissipations of 24 W or more. Sources can be designed to operate from d or ac power with higher voltages and lower currents depending upon physical size limitations, resulting in simplified power supply problems. Although voltages from 12 V to 230 V are practical for larger units, the sources described below operated at 1060 degrees C from a nominal 1.07 A at 18.7 V d for apower consumption of 20 W variable continuously about this value. The small dimensions of these sources compare favorably to those of a 0.5-W electronic resistor. The present units are cylindrical, 1 cm long x 4 mm diam. The construction of smaller units is possible bt difficult under present state-of-the-art limitations. PMID:20057526

Carlon, H R

1966-08-01

296

Acoustic source localization.  

PubMed

In this article different techniques for localizing acoustic sources are described and the advantages/disadvantages of these techniques are discussed. Some source localization techniques are restricted to isotropic structures while other methods can be applied to anisotropic structures as well. Some techniques require precise knowledge of the direction dependent velocity profiles in the anisotropic body while other techniques do not require that knowledge. Some methods require accurate values of the time of arrival of the acoustic waves at the receivers while other techniques can function without that information. Published papers introducing various techniques emphasize the advantages of the introduced techniques while ignoring and often not mentioning the limitations and weaknesses of the new techniques. What is lacking in the literature is a comprehensive review and comparison of the available techniques; this article attempts to do that. After reviewing various techniques the paper concludes which source localization technique should be most effective for what type of structure and what the current research needs are. PMID:23870388

Kundu, Tribikram

2013-06-30

297

Calibration Sources for CRIRES  

NASA Astrophysics Data System (ADS)

We report on our efforts to provide high accuracy wavelength calibration to the scientific observations with the Cryogenic High-Resolution IR Echelle Spectrograph (CRIRES), ESO's new high resolution (R?100,000) infrared (IR) spectrograph at the VLT. In order to provide reliable and accurate wavelength standards for CRIRES the European Southern Observatory (ESO), in collaboration with the Space Telescope European Co-ordinating Facility (ST-ECF) and the National Institute of Standards and Technology (NIST), embarked on a project to establish Th-Ar wavelength standards in the 950nm to 5000nm operating range of CRIRES. Based on current findings we conclude that Th-Ar hollow cathode lamps hold the promise of becoming a standard source for wavelength calibration for near IR astronomy, providing a high density of sharp well-characterized emission lines with the ease and efficiency of operation of a commercial discharge lamp. In addition, and for use at wavelengths larger than 2200, we have established a gas cell filled with N2O as a calibration source based on existing data from NIST. Both sources were extensively tested during CRIRES commissioning runs and both are now being used for routine operations of the instrument.

Kerber, F.; Seifahrt, A.; Bristow, P.; Nave, G.; Käufl, H. U.; Rosa, M. R.; Sansonetti, C. J.; Siebenmorgen, R.; Smette, A.

298

Open-Source GIS  

SciTech Connect

The components making up an Open Source GIS are explained in this chapter. A map server (Sect. 30.1) can broadly be defined as a software platform for dynamically generating spatially referenced digital map products. The University of Minnesota MapServer (UMN Map Server) is one such system. Its basic features are visualization, overlay, and query. Section 30.2 names and explains many of the geospatial open source libraries, such as GDAL and OGR. The other libraries are FDO, JTS, GEOS, JCS, MetaCRS, and GPSBabel. The application examples include derived GIS-software and data format conversions. Quantum GIS, its origin and its applications explained in detail in Sect. 30.3. The features include a rich GUI, attribute tables, vector symbols, labeling, editing functions, projections, georeferencing, GPS support, analysis, and Web Map Server functionality. Future developments will address mobile applications, 3-D, and multithreading. The origins of PostgreSQL are outlined and PostGIS discussed in detail in Sect. 30.4. It extends PostgreSQL by implementing the Simple Feature standard. Section 30.5 details the most important open source licenses such as the GPL, the LGPL, the MIT License, and the BSD License, as well as the role of the Creative Commons.

Vatsavai, Raju [ORNL; Burk, Thomas E [University of Minnesota; Lime, Steve [Minnesota Department of Natural Resources

2012-01-01

299

Ferroelectric electron beam sources  

SciTech Connect

Ferroelectric materials offer the possibility of compact electron sources, with modest requirements to initiate the emission process. We are studying such sources as possible injectors for microwave generation. The source consists of a polarized ferroelectric ceramic disk with silver electrodes coated on both faces. The front electrode consists of a periodic grid created by etching the silver to expose a line pattern of ceramic. This electrode functions as the cathode in a planar diode geometry with an accelerating gap adjustable from 0.1 to 5 cm. A rapid change in the polarization state of the ceramic is achieved by applying a 1{endash}2 kV, 150 ns pulse between the electrodes of the ferroelectric. Early work used a coaxial cable to maintain an anode potential of up to 1 kV across the A{endash}K gap. The emitted electron current was measured as a function of the gap spacing and the anode potential. The current varies linearly with the anode voltage, up to 1 kV, for gaps {much_gt}10 mm, and typically exceeds the Child-Langmuir current density by at least two orders of magnitude. Current densities in excess of 70 A/cm{sup 2} have been measured. More recent work has used a 300 ns pulse forming network to apply a potential of up to 15 kV at the anode. Results of emittance and scaling measurements under these conditions are reported. {copyright} 1995 {ital American Institute of Physics}.

Flechtner, D.; Flechtner, D.; Ivers, J.D.; Kerslick, G.S.; Nation, J.A.; Schaechter, L.; Zhang, G. [Laboratory of Plasma Studies and School of Electrical Engineering, Cornell University, Ithaca, New York 14853 (United States)

1995-06-01

300

Coded source neutron imaging  

NASA Astrophysics Data System (ADS)

Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100?m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100?m and 10?m aperture hole diameters show resolutions matching the hole diameters.

Bingham, Philip; Santos-Villalobos, Hector; Tobin, Ken

2011-02-01

301

NON-POINT SOURCE POLLUTION  

EPA Science Inventory

Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

302

Online Sources of Competitive Intelligence.  

ERIC Educational Resources Information Center

|Presents an approach to using online sources of information for competitor intelligence (i.e., monitoring industry and tracking activities of competitors); identifies principal sources; and suggests some ways of making use of online databases. Types and sources of information and sources and database charts are appended. Eight references are…

Wagers, Robert

1986-01-01

303

Source Monitoring in Alzheimer's Disease  

ERIC Educational Resources Information Center

|Source monitoring is the process of making judgments about the origin of memories. There are three categories of source monitoring: reality monitoring (discrimination between self- versus other-generated sources), external monitoring (discrimination between several external sources), and internal monitoring (discrimination between two types of…

El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

2012-01-01

304

A universal finite memory source  

Microsoft Academic Search

An irreducible parameterization for a finite memory source is constructed in the form of a tree machine. A universal information source for the set of finite memory sources is constructed by a predictive modification of an earlier studied algorithm-Context. It is shown that this universal source incorporates any minimal data-generating tree machine in an asymptotically optimal manner in the following

Marcelo J. Weinberger; Jorma J. Rissanen; Meir Feder

1995-01-01

305

Refurbishing tritium contaminated ion sources  

Microsoft Academic Search

Extended tritium experimentation on TFTR has necessitated refurbishing Neutral Beam Long Pulse Ion Sources (LPIS) which developed operational difficulties, both in the TFTR Test Cell and later, in the NE Source Refurbishment Shop. Shipping contaminated sources off-site for repair was not permissible from a transport and safety perspective. Therefore, the NE source repair facility was upgraded by relocating fixtures, tooling,

K. E. Wright; R. H. Carnevale; B. E. McCormack; T. Stevenson; A. von Halle

1995-01-01

306

Online Sources of Competitive Intelligence.  

ERIC Educational Resources Information Center

Presents an approach to using online sources of information for competitor intelligence (i.e., monitoring industry and tracking activities of competitors); identifies principal sources; and suggests some ways of making use of online databases. Types and sources of information and sources and database charts are appended. Eight references are…

Wagers, Robert

1986-01-01

307

Commonly used earthquake source models  

NASA Astrophysics Data System (ADS)

Several important earthquake source models that have been extensively used in seismological research and earthquake prediction are presented and discussed. A new fault source model is used to explain the earthquake focal mechanism solution and tectonic stress field, which play a crucial role in earthquake initiation and preparation. The elastodynamic-dislocation theory is demonstrated which provides the theoretical background of most earthquake source models. Important earthquake source models reviewed here include the double-force-couple point-source model, the circular-shear dislocation model, the finite moving-source model, the Brune model, and the spherical explosive source model.

Liu, Wenlong; Liu, Yucheng

2012-11-01

308

H sup minus ion sources  

SciTech Connect

A review is given of H{sup {minus}} ion sources, with the emphasis on sources of use for accelerator applications. A brief description is given of magnetron, multicusp/converter, Penning and volume H{sup {minus}} ion sources. Operating parameters for examples of the various type sources are presented, and then some comparisons among the sources are made. 37 refs., 1 fig., 3 tabs.

Alessi, J.G.

1991-01-01

309

BERNAS ION SOURCE DISCHARGE SIMULATION  

SciTech Connect

The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Bemas ion source is the wide used ion source for ion implantation industry. The new simulation code was developed for the Bemas ion source discharge simulation. We present first results of the simulation for several materials interested in semiconductors. As well the comparison of results obtained with experimental data obtained at the ITEP ion source test-bench is presented.

RUDSKOY,I.; KULEVOY, T.V.; PETRENKO, S.V.; KUIBEDA, R.P.; SELEZNEV, D.N.; PERSHIN, V.I.; HERSHCOVITCH, A.; JOHNSON, B.M.; GUSHENETS, V.I.; OKS, E.M.; POOLE, H.J.

2007-08-26

310

On non-radiating sources  

NASA Astrophysics Data System (ADS)

Following the analysis by P.E. Doak on the radiating (active) and non-radiating (reactive) parts of a source distribution and their effect on the identification of sources, this paper discusses the possible structure of non-radiating sources, i.e., of sources which produce a null field outside the source region. It is shown that these sources can be of three types, two of them only with arbitrary time dependence. In this case, the non-radiating sources are forcibly formed by the difference of two source distributions which generate, outside the region limited by the sources in question, the same field. In the type discussed by Doak, one source distribution encircles the other and cancelation is attained as a global effect. In the other, emphasized by Ffowcs Williams, the two source distributions are superimposed and cancelation is produced locally. The latter type of non-radiating source is discussed in detail, it being shown that, while they do not represent physical sources, they provide valuable information on non-radiating effects. The third type refers to single frequency sources and involves a particular match of wavelength, geometry and source strength distribution so that the acoustic energy gets trapped inside the source region. Of these three types of non-radiating sources, only the first one—that focused by Doak—can influence the identification of the active part of a source distribution from measurements made outside the source region. Evanescent waves, associated with a purely reactive field, are also discussed. It is pointed out that evanescent waves obtained in the decomposition of the field of a vibrating body of finite extent, although useful for representing certain aspects of the field, do not exist physically. Aspects affecting the identification of sources are also briefly tackled.

Musafir, Ricardo E.

2013-08-01

311

Visuoperceptual deficits in letter-by-letter reading?  

Microsoft Academic Search

A longstanding and controversial issue concerns the underlying mechanisms that give rise to letter-by-letter (LBL) reading: while some researchers propose a prelexical, perceptual basis for the disorder, others postulate a postlexical, linguistic source for the problem. To examine the nature of the deficit underlying LBL reading, in three experiments, we compare the performance of seven LBL readers, matched control participants

Rachel H. Mycroft; Marlene Behrmann; Janice Kay

2009-01-01

312

Efficient terahertz photoconductive source  

NASA Astrophysics Data System (ADS)

The photoconductive method is one of the oldest methods for the generation of THz room temperature operated THz electromagnetic waves. The THz photoconductive source has operated at a lower power level in the order of hundreds of nW. In addition, the energy conversion of optical to THz efficiency has remained extremely low. One of the most efficient THz photoconductive sources is a trap-enhanced field (TEF) effect source. The field is measured to contain more than 90% of the total DC bias within the first 5 mum of an 80 mum gap between the electrodes reaching kV/cm with only a modest bias. The overall THz power, however, has remained low, due to its rapid saturation. To date, there has been a limited understanding of the TEF effect. In this thesis, a more detailed experimental investigation of TEF effect current transport and field distribution based on annealing is presented to explain some of the underlining physics of TEF effect. A spatially extended line excitation is introduced to effectively reduce the screening effect while still exploiting the TEF region to maintain high efficiency and reach the muW regime. The record efficiency reached by this method is demonstrated. An experimental demonstration with a numerical analysis of the line excitation is presented. The spectral analysis of both a point and a line excitation demonstrate that the line excitation spectrum is not only comparable to that of the point excitation, but also extends the range of useful lower frequency content. To further improve the THz efficiency, the line excitation THz array is investigated.

Kim, Joong Hyun

313

SYNCHROTRON RADIATION SOURCES  

SciTech Connect

Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

HULBERT,S.L.; WILLIAMS,G.P.

1998-07-01

314

Semiconductor quantized voltage source.  

PubMed

We realize and investigate an all-semiconductor quantized voltage source which generates quantized output voltages V(out) = f(h/e) linked only to two fundamental constants, the electron's charge e and Planck's constant h, and to an applied excitation frequency f. The device is based on an integrated quantized circuit of a single-electron pump operated at pumping frequency f and a quantum Hall device monolithically integrated in series. Robust output voltages up to several ?V are generated, which are expected to be scalable by orders of magnitude using present technology. The device might open a new route towards the closure of the quantum metrology triangle. PMID:23006195

Hohls, F; Welker, A C; Leicht, Ch; Fricke, L; Kaestner, B; Mirovsky, P; Müller, A; Pierz, K; Siegner, U; Schumacher, H W

2012-07-31

315

LLSDC Legislative Source Book  

NSDL National Science Digital Library

The Law Librarians' Society of Washington, D.C. recently announced that they have placed online a series of unique informational documents and links of interest to law librarians and government researchers. Compiled by LLSDC's Legislative Research Special Interest Section, much of the material was previously available in print, but is gathered together online for the first time. Titles include Establishing Persistent Links to Thomas and GPO Access Documents, GPO Congressional Publication Releases (weekly listings), Internet and Online Sources of Legislative and Regulatory Information, Quick Links to House and Senate Committee Documents and Hearings, and the Union List of Legislative Documents, 1994, 3rd. edition.

316

BirdSource  

NSDL National Science Digital Library

Associated with the Audubon Society and the Cornell Laboratory of Ornithology, BirdSource is a Web site that allows Web users to participate in bird conservation and data gathering. By participating in bird identification and counts, citizens can help ornithologists determine species distribution and ranges. In addition to maps showing results from several public bird surveys, the site contains a great deal on identifying birds, conservation articles, and information for attracting birds to your feeder. This is a well rounded and attractive site for the bird enthusiast that offers data gathering opportunities throughout the year.

317

Pbar Source Group summary  

SciTech Connect

Maxium antiproton accumulation rates have been investigated. A scheme is outlined which would accumulate more than 7E8 pbars/s ina form suitable for a peak luminosity of more than 0.5E33 /(s*cm**2) in a single SSC ring. This scheme utilizes only moderate extrapolations of present technology. Each of the stages in the accumulation process has been investigated in some detail with the same calculational tools as have been used in the CERN and Fermilab pbar sources. The results of these calculations and possibilities for improvements are discussed.

Johnson, R.P.; Simpson, J.

1984-01-01

318

Variable leak gas source  

DOEpatents

A variable leak gas source and a method for obtaining the same which includes filling a quantity of hollow glass micro-spheres with a gas, storing said quantity in a confined chamber having a controllable outlet, heating said chamber above room temperature, and controlling the temperature of said chamber to control the quantity of gas passing out of said controllable outlet. Individual gas filled spheres may be utilized for calibration purposes by breaking a sphere having a known quantity of a known gas to calibrate a gas detection apparatus.

Henderson, Timothy M. (Ann Arbor, MI); Wuttke, Gilbert H. (Ann Arbor, MI)

1977-01-01

319

Point radiographic source characterization  

SciTech Connect

A study was undertaken to find the optimal conditions for generating x rays using a high-power frequency-doubled Nd laser pulse for x-ray backlighting application. More than 30 laser shots on the Lawrence Livermore National Laboratory JANUS Research Laser system have been studied. The following specific questions are addressed: (a) X-ray yield dependence on the laser parameters: (i) temporal pulse width and (ii) focusing conditions. (b) X-ray source size versus target dimensions by using a tungsten wire with various diameters. (c) Influence of background plasma on the x-ray yield from the wire using 25- m wires surrounded by plastic.

Zigler, A.; Lee, R.W.; Kilkenny, J.D.; Kolbe, G.; Nathel, H.

1987-09-01

320

The European Spallation Source  

SciTech Connect

In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

2011-04-20

321

Flipper energy source  

NASA Astrophysics Data System (ADS)

A flipper energy source for generating electricity includes a flipper or fin having an opening for engaging a foot and a body portion extending therefrom. The body portion includes fluid displacing surfaces which are adapted to be moved through the fluid for creating a propelling force via the movement. Such movement causes stress to be created on the surfaces of the body portion. The device further includes a piezoelectric element for converting the stress into electric power. The electric power thus generated is conditioned for use in powering electrical devices such as lighting, communications devices, battery rechargers, photography equipment, and sonar transducers.

Demarco, James

1995-01-01

322

A femtosecond neutron source  

NASA Astrophysics Data System (ADS)

The possibility of using the ultrashort ion bunches produced by circularly polarized laser pulses to drive a source of fusion neutrons with sub-optical cycle duration is discussed. A two-sided irradiation of a deuterated thin foil target produces two counter-moving ion bunches, whose collision produces an ultrashort neutron burst. Using particle-in-cell simulations and analytical modeling, it is calculated that, for intensities of a few 1019 W cm-2, more than 103 neutrons per Joule may be producedwithin a time shorter than one femtosecond. Another scheme based on a layered deuterium-tritium target is outlined.

Macchi, A.

2006-03-01

323

New Developments with H- Sources  

SciTech Connect

Existing spallation neutron source upgrades, planned spallation neutron sources, and high-energy accelerators for particle physics place demanding requirements on the H- sources. These requirements ask for increased beam currents and duty factor (df) while generally maintaining state-of-the art H- source emittance. A variety of H- sources are being developed to address these challenges. These include volume sources with and without the addition of cesium for enhanced H- production, increased df cesiated H- Penning and magnetron sources, and cesiated surface converter H- sources. Research on surface films of tantalum metal for enhanced volume H- production is also being studied. Innovative plasma production techniques to address the longer df requirement without sacrificing H- source reliability and lifetime will be reviewed. The physical bases, the goals, and perceived challenges will be discussed.

Sherman, Joseph D.; Rouleau, Gary [Los Alamos National Laboratory, Los Alamos, NM87545 (United States)

2003-08-26

324

Inductive source induced polarization  

NASA Astrophysics Data System (ADS)

Induced polarization (IP) surveys are commonly performed to map the distribution of electrical chargeability that is a diagnostic physical property in mineral exploration and in many environmental problems. Although these surveys have been successful in the past, the galvanic sources required for traditional IP and magnetic IP (MIP) surveys prevent them from being applied in some geological settings. We develop a new methodology for processing frequency domain EM data to identify the presence of IP effects in observations of the magnetic fields arising from an inductive source. The method makes use of the asymptotic behaviour of the secondary magnetic fields at low frequency. A new quantity, referred to as the ISIP datum, is defined so that it equals zero at low frequencies for any frequency-independent (non-chargeable) conductivity distribution. Thus, any non-zero response in the ISIP data indicates the presence of chargeable material. Numerical simulations demonstrate that the method can be applied even in complicated geological situations. A 3-D inversion algorithm is developed to recover the chargeability from the ISIP data and the inversion is demonstrated on synthetic examples.

Marchant, David; Haber, Eldad; Oldenburg, Douglas W.

2013-02-01

325

DreiserWebSource  

NSDL National Science Digital Library

Designed and maintained by the Annenberg Rare Book and Manuscript Library Collection at the University of Pennsylvania, the DreiserWebSource website brings together a host of written ephemera, original essays, and electronic texts related to the life and writings of Theodore Dreiser, the prominent American author. While the site doesn't have a formal search engine, the material is divided into four primary sections: Correspondence & Texts, Scholarly Essays, Reference Sources, and Still and Moving images. The Correspondence & Texts section is a delight unto itself, as it contains a host of digitized correspondence between Dreiser and colleagues over several decades and a special section dedicated to his ground-breaking novel, Sister Carrie. Along with several editions of the complete novel there are several essays about the novel's composition and historical context, along with a virtual exhibition curated by Nancy M. Shawcross from the Rare Book & Manuscript Library at Penn. The site also includes a rare 3-minute silent film of Dreiser from 1938 at Mt. Kisco, New York, taken by Robert Elias.

326

Spallation neutron source (SNS)  

NASA Astrophysics Data System (ADS)

The Spallation Neutron Source [1], located at Oak Ridge, TN, is a state-of-the-art neutron-scattering facility presently under construction as a collaborative effort of six national laboratories. The facility is comprised of a high-power particle-accelerator system, a liquid-mercury target-moderator system, and a suite of world-class scientific instruments. One-ms-long negative-hydrogen-ion (H-) pulses are produced by an ion source. The ion beam is accelerated to 185 MeV by normal conducting (NC) linear accelerator (linac) cavities, and further accelerated to 1 GeV by a superconducting linac [2]. The acceleration is accomplished by means of niobium superconducting radiofrequency (SRF) cavities that operate at 2.1K. The linac beam is stacked in a compressor ring, and 695-ns-long pulses are extracted onto the target at a 60-Hz rate. Neutrons are produced by spallation in the mercury, and their energy is moderated to useable levels, in part by supercritical hydrogen moderators. The simultaneous performance goals of more than one MW of initial proton beam power, 95% facility availability, and the desire for hands-on maintenance capability in the accelerator complex place significant demands on the performance and operational reliability of the technical and conventional systems. An overview of the SNS facility, including its purpose, major components, and a summary of the present status is presented, with particular emphasis on the superconducting linac and the cryogenic moderators. .

White, Marion M.; SNS Project

2002-05-01

327

Lacustrine petroleum source rocks  

SciTech Connect

This book is a proceedings volume from a 1985 symposium sponsored by the Geological Society of London and the International Geological Correlation Program Project No. 219 (Comparative lacustrine sedimentology in space and time). That meeting set the tone for subsequent IGCP No. 219 symposia, where sedimentary, petroleum, and structural geologists, as well as geochemists and paleontologists, have grappled with important problems in lake geology. The 1985 meeting on lacustrine source rocks considered the following questions: (1) How can we develop more refined methods for interpreting depositional environments from lake deposits and fossils , (2) What limnologic, sedimentologic, and tectonic conditions are most conducive to the production and accumulation of organic matter in lakes , (3) What diagenetic changes affect organic-rich sediments after deposition , and (4) How can questions 2 and 3 be best evaluated from the stratigraphic record As a group, lakes are extremely productive ecosystems. Marine environments that would be ranked as high productivity systems are only moderately productive by lacustrine standards. Even with energy transfer rates of less than a few percent from the primary producers to the sediment, lacustrine mudrocks can be extremely rich in organic matter. The major limitations of lacustrine source rocks are not lithologic but limitations of scale (both spatial and temporal). How, in the middle of a continent, do you get a hole in the ground that is both big enough and long-lasting enough to generate significant quantities of hydrocarbons

Fleet, A.J.; Kelts, K.; Talbot, M. (eds.)

1988-01-01

328

Earthquake Source Mechanics  

NASA Astrophysics Data System (ADS)

The past 2 decades have seen substantial progress in our understanding of the nature of the earthquake faulting process, but increasingly, the subject has become an interdisciplinary one. Thus, although the observation of radiated seismic waves remains the primary tool for studying earthquakes (and has been increasingly focused on extracting the physical processes occurring in the “source”), geological studies have also begun to play a more important role in understanding the faulting process. Additionally, defining the physical underpinning for these phenomena has come to be an important subject in experimental and theoretical rock mechanics.In recognition of this, a Maurice Ewing Symposium was held at Arden House, Harriman, N.Y. (the former home of the great American statesman Averill Harriman), May 20-23, 1985. The purpose of the meeting was to bring together the international community of experimentalists, theoreticians, and observationalists who are engaged in the study of various aspects of earthquake source mechanics. The conference was attended by more than 60 scientists from nine countries (France, Italy, Japan, Poland, China, the United Kingdom, United States, Soviet Union, and the Federal Republic of Germany).

329

Source partitioning using stable isotopes: coping with too many sources  

Microsoft Academic Search

Stable isotopes are increasingly being used as tracers in environmental studies. One application is to use isotopic ratios to quantitatively determine the proportional contribution of several sources to a mixture, such as the proportion of various pollution sources in a waste stream. In general, the proportional contributions of n+1 different sources can be uniquely determined by the use of n

Donald L. Phillips; Jillian W. Gregg

2003-01-01

330

Tunable CMOS Constant Current Source.  

National Technical Information Service (NTIS)

A constant current source has been designed which makes use of on chip electrically erasable memory to adjust the magnitude and temperature coefficient of the output current. The current source includes a voltage reference based on the difference between ...

D. Thelen

1991-01-01

331

Radioisotope Sources of Electric Power.  

National Technical Information Service (NTIS)

The basic principles of operation of radioisotope current sources for various purposes are summarized. Structural diagrams of contemporary radioisotope thermoelectric generators are surveyed. Methods of obtaining radioisotope sources of thermal energy are...

G. M. Fradkin V. M. Kodyukov

1973-01-01

332

HYDROCARBON POLLUTANTS FROM STATIONARY SOURCES  

EPA Science Inventory

The report gives results of a study of hydrocarbon pollutants from stationary sources. Early in the study, readily available information was assembled on stationary sources of hydrocarbon emissions and effluents. Information was also obtained on process descriptions, operating pa...

333

Submergible marine seismic source  

SciTech Connect

A marine seismic source employs a cylindrical gas exploder adapted to be supported from a surface vessel in a submerged state adjacent a marine bottom. The force of expanding gases within the exploder applies a thrust along the exploder longitudinal axis to a ground contact member operatively interconnected with the exploder to produce a seismic signal. The energy producing force is reacted by piston means within the exploder interconnected rigidly with a large area external water interacting disk. The mass of the reaction piston-disk system is sufficiently great so that the slow moving disk experiences viscous damping in the water and thus generates no significant undesirable secondary seismic signal in the water. The exploder may be oriented horizontally for maximum generation of shear waves or inclined at an acute angle to the vertical for generation of a combination of shear waves and compressional waves.

Airhart, T.P.

1980-08-26

334

Multiple source heat pump  

DOEpatents

A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

Ecker, Amir L. (Duncanville, TX)

1983-01-01

335

Hazardous solvent source reduction  

SciTech Connect

This book is written for the managers, production leaders, and operations staff tasked with the job of eliminating hazardous cleaning solvents from their workplace. Information regarding the location, evaluation, and implementation of environmentally preferred cleaning technologies is offered for a broad range of applications. These include: removal of grease and grime from a piece of equipment during maintenance, cleaning small parts before assembly, defluxing printed circuit boards and assemblies, and stripping paint from field vehicles and aircraft. Moving beyond the limits of source reduction alone, this book provides complete information on the planning, staffing, and execution of a pollution prevention program, alternative and in-use cleaner testing, waste recycling and treatment, air emission control, replacement system design, and system economics. For the environmental specialist, this book helps to bridge the gap between regulatory requirements and shop-floor constraints.

Callahan, M.S.; Green, B.

1995-09-01

336

Spark source infrared fluorometry  

NASA Astrophysics Data System (ADS)

The application of our development of 750 nm excitation from an argon-hydrogen filled spark source to time-resolved fluorescence probe studies of lipid membranes and inverse micelles is reported. The laser dye IR-140 was studied using the single-photon counting technique both in a lipid membrane of L-(alpha) dipalmitoylphosphatidylcholine (DPPC) and in sodium sulfosuccinic acid bis (2-ethylhexyl) ester (AOT) in iso-octane. In DPPC a dramatic change in the fluorescence behavior of IR-140 is observed between the gel and liquid crystalline phases. In inverse micelles of AOT an increase in the intensity of the peak fluorescence emission and a decrease in fluorescence lifetime is noticed on increasing the water content.

Hungerford, Graham; Birch, David J.; Imhof, Robert E.

1992-04-01

337

Semiconductor surface plasmon sources.  

PubMed

Surface-plasmon polaritons (SPPs) are propagating electromagnetic modes bound at a metal-dielectric interface. We report on electrical generation of SPPs by reproducing the analogue in the near field of the slit-doublet experiment, in a device which includes all the building blocks required for a fully integrated plasmonic active source: an electrical generator of SPPs, a coupler, and a passive metallic waveguide. SPPs are generated upon injection of electrical current, and they are then launched at the edges of a passive metallic strip. The interference fringes arising from the plasmonic standing wave on the surface of the metallic strip are unambiguously detected with apertureless near-field scanning optical microscopy. PMID:20867196

Babuty, A; Bousseksou, A; Tetienne, J-P; Doyen, I Moldovan; Sirtori, C; Beaudoin, G; Sagnes, I; De Wilde, Y; Colombelli, R

2010-06-04

338

Arsenic pollution sources.  

PubMed

Arsenic is a widely dispersed element in the Earth's crust and exists at an average concentration of approximately 5 mg/kg. There are many possible routes of human exposure to arsenic from both natural and anthropogenic sources. Arsenic occurs as a constituent in more than 200 minerals, although it primarily exists as arsenopyrite and as a constituent in several other sulfide minerals. The introduction of arsenic into drinking water can occur as a result of its natural geological presence in local bedrock. Arsenic-containing bedrock formations of this sort are known in Bangladesh, West Bengal (India), and regions of China, and many cases of endemic contamination by arsenic with serious consequences to human health are known from these areas. Significant natural contamination of surface waters and soil can arise when arsenic-rich geothermal fluids come into contact with surface waters. When humans are implicated in causing or exacerbating arsenic pollution, the cause can almost always be traced to mining or mining-related activities. Arsenic exists in many oxidation states, with arsenic (III) and (V) being the most common forms. Similar to many metalloids, the prevalence of particular species of arsenic depends greatly on the pH and redox conditions of the matrix in which it exists. Speciation is also important in determining the toxicity of arsenic. Arsenic minerals exist in the environment principally as sulfides, oxides, and phosphates. In igneous rocks, only those of volcanic origin are implicated in high aqueous arsenic concentrations. Sedimentary rocks tend not to bear high arsenic loads, and common matrices such as sands and sandstones contain lower concentrations owing to the dominance of quartz and feldspars. Groundwater contamination by arsenic arises from sources of arsenopyrite, base metal sulfides, realgar and orpiment, arsenic-rich pyrite, and iron oxyhydroxide. Mechanisms by which arsenic is released from minerals are varied and are accounted for by many (bio)geochemical processes: oxidation of arsenic-bearing sulfides, desorption from oxides and hydroxides, reductive dissolution, evaporative concentration, leaching from sulfides by carbonate, and microbial mobilization. Arsenic enrichment also takes place in geothermally active areas; surface waters are more susceptible than groundwater to contamination in the vicinity of such geothermal systems, and evidence suggests that increased use of geothermal power may elevate risks of arsenic exposure in affected areas. Past and current mining activities continue to provide sources of environmental contamination by arsenic. Because gold- and arsenic-bearing minerals coexist, there is a hazard of mobilizing arsenic during gold mining activities. The Ashanti region of central Ghana currently faces this as a real risk. Historical arsenic contamination exists in Cornwall, UK; an example of a recent arsenic pollution event is that of Ron Phibun town in southern Thailand, where arsenic-related human health effects have been reported. Other important sources of arsenic exposure include coal burning in Slovakia, Turkey, and the Guizhou Province of China; use of arsenic as pesticides in Australia, New Zealand, and the US; and consumption of contaminated foodstuffs (China) and exposure to wood preserving arsenicals (Europe and North America). PMID:18982996

Garelick, Hemda; Jones, Huw; Dybowska, Agnieszka; Valsami-Jones, Eugenia

2008-01-01

339

Migration Information Source  

NSDL National Science Digital Library

As a publication of the Migration Policy Institute, the Migration Information Source "provides fresh thought, authoritative data from numerous global organizations and governments, and global analysis of international migration and refugee trends." Their well-organized homepage offers policy briefs, "Spotlight" features (including a recent one on Indian immigrants in the United States), and information about their ongoing projects. Policy makers and scholars will love the "Immigration Data Hub" area. Here they can get valuable data on state responses to immigrations, the top global destinations for Irish immigrants, as well as historical immigration data. Visitors can also use the "US in Focus" area to find out about specific immigration trends throughout the country, with a special focus on policy issues affecting states and urban areas. The site is rounded out by an RSS feed, a press room of recent news releases, and a glossary of terms.

340

Pulsed light sources  

SciTech Connect

This book summarizes the findings of research on the physical and technical characteristics of pulsed discharges in gases and on the implementation of such discharges in pulsed light sources. Gas-discharge flashlamps are described. Topics considered include the electrical breakdown of gas at nearatmospheric pressures, high-current pulsed discharge with an expanding channel, pulsed discharge of the quasi-stationary type, phenomena at electrodes, the radiation characteristics of flashlamps, the load characteristics of flashlamps, the operating characteristics of flashlamps, the industrial production of flashlamps, circuit diagrams of flashlamps and the main circuit elements, and the interaction of radiation pulses with detectors. This book is necessary because the correct use of existing types of flashlamps, work toward developing new types of flashlamps, and the solution of new problems by using such flashlamps require a knowledge of the physical processes that occur in them and the relationship between their technical characteristics and their design data and power-supply parameters.

Marshak, I.S.

1984-01-01

341

Moving Image Source  

NSDL National Science Digital Library

If you enjoy films, you will probably be delighted to learn about the Moving Image Source website. Created by the people at the Museum of the Moving Image, the site contains interviews and articles with film critics, filmmakers, and other commentators. The site contains four primary areas: "Articles", "Calendar", "Dialogues", and "Research Guide." The "Articles" area contains guided tours through Jean-Luc Godard's "Film Socialisme", the virtual visions of Marco Brambilla, and the many faces of Catherine Deneuve. The archives of these articles date back to 2008, and visitors can also search this collection by author. The "Dialogues" area contains audio files of conversations with film figures like Michael Caine, Amy Ryan, Terry Gilliam, and David O. Russell. The site is rounded out by the "Research Guide" area, which includes helpful links to sites that deal with film criticism, scoring, history, and technology.

342

Source modification special study  

SciTech Connect

One of the major issues that must be addressed during the evaluation of the efficiency of tailings embankment designs for compliance with groundwater standards is the estimation of source concentrations and the change in these concentrations with time. Because any effort to predict concentrations of contaminants in the uppermost aquifer requires a source concentration, data from these analyses are essential. Thetechnical approach of this study was twofold. The first approach was to investigate the rates of natural flushing of contaminants. Two sets of tailings samples were collected at two sites on the Old Rifle tailings pile at the Rifle UMTRA Project site in Colorado. One set of samples was collected at a site where the lower portion of the profile is continuously inundated with water and the other set was collected in anarea that only receives water from precipitation. The tailings samples were refluxed in strong acid (nitric acid) and the leachate was analyzed for hazardous constituents. The results of this investigation indicate that many of the hazardous constituents have been leached from the tailings at the wet site and that there has been little redistribution of elemental hazardous constituents at the dry site. The second approach involved a laboratory investigation of contaminant removal from tailings by doubly distilled water and two lixiviants. Tailings samples from the Gunnison, Colorado, UMTRA Project site were subjected to leaching by doubly distilled water, and by the lixiviants sodium bicarbonate and disodium ethylenediaminetetraacetic acid. The resulting data were tabulated and plotted with concentration as a function of pore volume. Evaluation of the data indicates that pore fluids should show a decrease in concentration after very few pore volumes of liquid have eluted through the tailings. It is also demonstrated that lixiviants significantly increase the solubility and rate of elution of all of the hazardous constituents.

Not Available

1989-04-01

343

Off line ion source terminal  

NASA Astrophysics Data System (ADS)

The off-line ion source (OLIS) terminal provides beams from stable isotopes to ISAC (see Fig. 1) experiments as well as for accelerator commissioning and for pilot beams for radioactive beam experiments. The OLIS terminal (see Fig. 2) is equipped with a microwave driven cusp source for single and double charge ions, a surface ion source for low energy spread alkali beams, and a multi-charge ion source.

Jayamanna, K.

2013-10-01

344

Ion source development at GSI  

Microsoft Academic Search

Different ion sources are used at GSI to match the requirements for specific tasks at the accelerator. At the standard injector a Penning ionization gauge ion source is used (design ion U10+, m\\/q<24, 1 emA). Further development of this source is mainly aiming at an increase of the extractable currents and an increase of the lifetime of the source. The

P. Spädtke; J. Bossler; H. Emig; K. D. Leible; C. Mühle; H. Reich; H. Schulte; K. Tinschert

1998-01-01

345

Many Meanings of Open Source.  

National Technical Information Service (NTIS)

The term Open Source is widely applied to describe some software development methodologies. This paper does not provide a judgment on the open source approach, but exposes the fact that simply stating that a project is open source does not provide a preci...

C. Gacek T. Lawrie B. Arief

2002-01-01

346

Ion sources for cyclotron applications  

SciTech Connect

The use of a multicusp plasma generator as an ion source has many advantages. The development of both positive and negative ion beams based on the multicusp source geometry is presented. It is shown that these sources can be operated at steady state or cw mode. As a result they are very suitable for cyclotron operations.

Leung, K.N.; Bachman, D.A.; McDonald, D.S.; Young, A.T.

1992-07-01

347

Transuranic sealed source recovery project.  

PubMed

If you have transuranic sealed sources (239Pu, 238Pu, or 241Am) that have no potential for recycle or commercial disposal, the Off Site Source Recovery Project at LANL can assist in recovering the sealed sources from your facility to a DOE storage site. PMID:11669192

Tompkins, J A; Pearson, M W

2001-11-01

348

Sine Wave Constant Current Source.  

National Technical Information Service (NTIS)

A sine wave constant current source of 133 Hz frequency is described. The source can give up to 10 mA rms constant current with a max. voltage of about 2.5 V rms. Long term current stability is better than + or - 0.01 percent. The source frequency can be ...

R. Chaudhry

1982-01-01

349

Ion dynamics in helicon sources.  

SciTech Connect

Recent experiments have demonstrated that ion dominated phenomena, such as the lower hybrid resonance, can play an important role in helicon source operation. In this work, we review recent ion heating measurements and the role of the slow wave in heating ions at the edge of helicon. sources. We also discuss the relationship between parametrically driven waves and ion heating near the rf antenna in helicon sources. Recent measurements of parallel and rotational ion flows in helicon sources have important implications for particle confinement, instability growth, and helicon source operation. In this work we present new measurements of ion flows and summarize the important features of the flows.

Kline, J. L. (John L.); Balkey, M. M. (Matthew M.); Keiter, P. A. (Paul A.); Scime, Earl E.; Keesee, Anne M.; Sun, X.; Harding R.; Compton, C.; Boivin, R. F.; Zintl, M. W.

2002-01-01

350

Radioactive source recovery program responses to neutron source emergencies  

SciTech Connect

Recovery of neutron sources containing Pu{sup 239} and Be is currently taking place at Los Alamos National Laboratory. The program was initiated in 1979 by the Department of Energy (DOE) to dismantle and recover sources owned primarily by universities and the Department of Defense. Since the inception of this program, Los Alamos has dismantled and recovered more than 1000 sources. The dismantlement and recovery process involves the removal of source cladding and the chemical separation of the source materials to eliminate neutron emissions. While this program continues for the disposal of {sup 239}Pu/Be sources, there is currently no avenue for the disposition of any sources other than those containing Pu{sup 239}. Increasingly, there have been demands from agencies both inside and outside the Federal Government and from the public to dispose of unwanted sources containing {sup 238}Pu/Be and {sup 241}Am/Be. DOE is attempting to establish a formal program to recover these sources and is working closely with the Nuclear Regulatory Commission (NRC) on a proposed Memorandum of Understanding to formalize an Acceptance Program. In the absence of a formal program to handle {sup 238}Pu/Be and {sup 241}Am/Be neutron sources, Los Alamos has responded to several emergency requests to receive and recover sources that have been determined to be a threat to public health and safety. This presentation will: (1) review the established {sup 239}Pu neutron source recovery program at Los Alamos, (2) detail plans for a more extensive neutron source disposal program, and (3) focus on recent emergency responses.

Dinehart, S.M.; Hatler, V.A.; Gray, D.W.; Guillen, A.D. [and others

1997-04-01

351

Radiation sources working group summary  

SciTech Connect

The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, components technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigation, and phenomena that impact source design such as fatigue in resonant structures due to RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations.

Fazio, M.V.

1998-12-31

352

LISA and Capture Sources  

NASA Astrophysics Data System (ADS)

LISA is a joint ESA/NASA mission to detect and observe gravitational waves. It is designed to register the change in distance between free-falling reference points to picometer accuracy, allowing to measure the effect of gravitational waves created by the coalescence of massive black holes almost anywhere in the universe, stellar mass black holes and neutron stars spiraling into massive black holes in other galaxies at intermediate distances, and tightly orbiting binary stars in our galaxy. LISA will be able to detect gravitational waves from coalescing massive black holes to redshifts of z ˜ 10 and higher, allowing an unprecedented view into the early stages of galaxy formation. The signals from the many million binary stars in our galaxy yield information about the evolution and the morphology of our galaxy, giving a view of the population of binary stars unobstructed by dust. Among the most challenging, yet scientifically interesting sources are the captures of a small massive object by massive black holes where the mass ratio exceeds 1,000. Those events, named extreme mass ratio inspirals (EMRI), create very complex waveforms and allow to test general relativity to very high precision. LISA has been recently confirmed as a candidate for the L1 mission in ESA's Cosmic Vision program and is foreseen to be launched in the 2018 time frame.

Jennrich, Oliver

353

Spallation neutron source saddle antenna H- ion source project  

NASA Astrophysics Data System (ADS)

In this project we are developing an H- source which will synthesize the most important developments in the field of negative ion sources to provide high current, high brightness, good lifetime, high reliability, and high power efficiency. We describe two planned modifications to the present spallation neutron source external antenna source in order to increase the plasma density near the output aperture: (1) replacing the present 2 MHz plasma-forming solenoid antenna with a 13 MHz saddle-type antenna and (2) replacing the permanent multicusp magnetic system with a weaker electromagnet.

Dudnikov, Vadim; Johnson, Rolland P.; Dudnikova, Galina; Stockli, Martin; Welton, Robert

2010-02-01

354

Spallation neutron source saddle antenna H- ion source project.  

PubMed

In this project we are developing an H(-) source which will synthesize the most important developments in the field of negative ion sources to provide high current, high brightness, good lifetime, high reliability, and high power efficiency. We describe two planned modifications to the present spallation neutron source external antenna source in order to increase the plasma density near the output aperture: (1) replacing the present 2 MHz plasma-forming solenoid antenna with a 13 MHz saddle-type antenna and (2) replacing the permanent multicusp magnetic system with a weaker electromagnet. PMID:20192379

Dudnikov, Vadim; Johnson, Rolland P; Dudnikova, Galina; Stockli, Martin; Welton, Robert

2010-02-01

355

Constricted glow discharge plasma source  

DOEpatents

A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

2000-01-01

356

Directivity of railway noise sources  

NASA Astrophysics Data System (ADS)

In the Harmonoise project the description of vertical and horizontal directivities of railway noise sources has been required. Other features of the source description are sound power level spectra in one-third octave bands as a function of speed and the physical location of the different sound sources. Based on systematic investigations methods to measure and to determine the directivities of railway noise sources are presented in this paper. The determination of the directivity of rolling noise is discussed in detail. For the directivities of traction noise and aerodynamic noise the discussion is more analytical because of limited access to relevant data. For each type of main railway noise source, i.e. rolling noise, traction noise and aerodynamic noise, default directivity functions are proposed for the use in the source description of railway noise. These default directivity functions will be subject to revisions when more accurate data become available.

Zhang, Xuetao; Jonasson, Hans G.

2006-06-01

357

Source credibility and syllogistic reasoning  

Microsoft Academic Search

Two experiments examined whether a source credibility effect would be observed for a syllogistic reasoning task. In the experiments,\\u000a people were given two statements, presented as the results from a survey, followed by a conclusion that was supposedly made\\u000a by one of two sources. In Experiment 1, one of the sources was described as honest and the other as dishonest,

David E. Copeland; Kris Gunawan; Nicole J. Bies-Hernandez

2011-01-01

358

Positron sources for Linear Colliders  

SciTech Connect

Positron beams have many applications and there are many different concepts for positron sources. In this paper, only positron source techniques for linear colliders are covered. In order to achieve high luminosity, a linear collider positron source should have a high beam current, high beam energy, small emittance and, for some applications, a high degree of beam polarization. There are several different schemes presently being developed around the globe. Both the differences between these schemes and their common technical challenges are discussed.

Gai Wei; Liu Wanming [Argonne National Laboratory, 9700 S Cass Ave, Argonne, IL, 60439 (United States)

2009-09-02

359

The institutionalization of Open Source  

Microsoft Academic Search

Using concepts of neoinstitutional economics, such as transaction cost economics, institutional economics, property rights\\u000a theory, and information economics, the development of the Open Source movement is investigated. Following the evolution of\\u000a institutions in Open Source, it is discussed what the comparative institutional advantages of this model are. The conclusion\\u000a is that it is the institutional framework of Open Source, not

Robert A. Gehring

2006-01-01

360

Miniature x-ray source  

Microsoft Academic Search

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode,

James E. Trebes; Perry M. Bell; Ronald B. Robinson

2000-01-01

361

The SIAM Photon Source  

NASA Astrophysics Data System (ADS)

A short history of the SIAM Photon Source in Thailand is described. The facility is based on the 1 GeV storage ring obtained from the SORTEC consortium in Japan. After a redesign to include insertion straight sections it produced the first light in December 2001 and the first beam line became operational in early 2002. Special difficulties appear when a synchrotron light facility is obtained by donation, which have mostly to do with the absence of human resource development that elsewhere is commonly accomplished during design and construction. Additional problems arise by the distance of a developing country like Thailand from the origin of technical parts of the donation. A donation does not provide time to generate local capabilities or include in the technical design locally obtainable parts. This makes future developments, repairs and maintenance more time consuming, difficult and expensive than it should be. In other cases, parts of components are proprietary or obsolete or both which requires redesign and engineering at a time when the replacement part should be available to prevent stoppage of operation. The build-up of a user community is very difficult, especially when the radiation spectrum is confined to the VUV regime. Most of scientific interest these days is focused on the x-ray regime. Due to its low beam energy, the SIAM storage ring did not produce useful x-ray intensities and we are therefore in the midst of an upgrade to produce harder radiation. The first step has been achieved with a 20% increase of energy to 1.2 GeV. This step shifts the critical photon energy of bending magnet radiation from 800 eV to 1.4 keV providing useful radiation up to 7 keV. A XAS-beam line has been completed in 2005 and experimentation is very active by now. The next step is to install a 6.4 T wavelength shifter by the end of 2006 resulting in a critical photon energy of 6.15 keV. Further upgrades are planed for the comming years.

Pairsuwan, Weerapong

2007-01-01

362

Disintegrins from hematophagous sources.  

PubMed

Bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. Here we review the literature on salivary disintegrins and their targets. Disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. In hematophagous animals, most disintegrins described so far have been discovered in the salivary gland of ticks and leeches. A limited number have also been found in hookworms and horseflies, and none identified in mosquitoes or sand flies. The vast majority of salivary disintegrins reported display a RGD motif and were described as platelet aggregation inhibitors, and few others as negative modulator of neutrophil or endothelial cell functions. This notably low number of reported disintegrins is certainly an underestimation of the actual complexity of this family of proteins in hematophagous secretions. Therefore an algorithm was created in order to identify the tripeptide motifs RGD, KGD, VGD, MLD, KTS, RTS, WGD, or RED (flanked by cysteines) in sialogenins deposited in GenBank database. The search included sequences from various blood-sucking animals such as ticks (e.g., Ixodes sp., Argas sp., Rhipicephalus sp., Amblyommasp.), tabanids (e.g., Tabanus sp.), bugs (e.g., Triatoma sp., Rhodnius prolixus), mosquitoes (e.g., Anopheles sp., Aedes sp., Culex sp.), sand flies (e.g., Lutzomyia sp., Phlebotomus sp.), leeches (e.g., Macrobdella sp., Placobdella sp.) and worms (e.g., Ancylostoma sp.). This approach allowed the identification of a remarkably high number of novel putative sialogenins with tripeptide motifs typical of disintegrins (>450 sequences) whose biological activity remains to be verified. This database is accessible online as a hyperlinked worksheet and displays biochemical, taxonomic, and gene ontology aspects for each putative disintegrin. It is also freely available for download (right click with the mouse) at links http://exon.niaid.nih.gov/transcriptome/RGD/RGD-Peps-WEB.xlsx (web version) and http://exon.niaid.nih.gov/transcriptome/RGD/RGD-sialogenins.zip (stand alone version). PMID:22778902

Assumpcao, Teresa C F; Ribeiro, José M C; Francischetti, Ivo M B

2012-04-26

363

Coaxial microwave neutron interrogation source  

NASA Astrophysics Data System (ADS)

A compact neutron generator is being developed based on a novel coaxial dipole permanent magnet electron cyclotron resonance (ECR) ion source. The ion source is capable of generating a high fraction of atomic ion species and can operate at low pressure. Multiple deuterium ion (D+) beamlets are extracted from the plasma ion source and accelerated to a beam-loaded titanium target creating 2.4 MeV neutrons as a result of the D-D fusion reaction at the target surface. This paper describes the design of the ECR-based neutron generator as well as reports on preliminary simulation and experimental results of the ion source performance.

Johnson, Will; Antolak, Arlyn; Leung, Ka-Ngo; Raber, Tom

2011-09-01

364

ION SOURCE UNIT FOR CALUTRON  

DOEpatents

An improvement in the mounting arrangement for an ion source within the vacuum tank of a calutron device is reported. The cathode and arc block of the source are independently supported from a stem passing through the tank wall. The arc block may be pivoted and moved longitudinally with respect to the stem to thereby align the arc chamber in the biock with the cathode and magnetic field in the tank. With this arrangement the elements of the ion source are capable of precise adjustment with respect to one another, promoting increased source efficiency.

Sloan, D.H.; Yockey, H.P.; Schmidt, F.H.

1959-04-14

365

Neutron imaging of radioactive sources  

NASA Astrophysics Data System (ADS)

Isotopic neutron sources have been available for more than six decades. At the Atomic Institute in Vienna, operating a 250 kW TRIGA reactor, different neutron sources are in use for instrument calibration and fast neutron applications but we have only little information about their construction and densities. The knowledge of source design is essential for a complete MCNP5 modeling of the experiments. Neutron radiography (NR) and neutron tomography (NT) are the best choices for the non-destructive inspection of the source geometry and homogeneity. From the transmission analysis we gain information about the shielding components and the densities of the radio-isotopes in the cores. Three neutron sources, based on (alpha, n) reaction, have been investigated, two 239PuBe sources and one 241AmBe source. In the NR images the internal structure was clearly revealed using high-resolving scintillation and imaging plate detectors. In one source tablet a crack was detected which causes asymmetric neutron emission. The tomography inspection of strong absorbing materials is more challenging due to the low beam intensity of 1.3x105 n/cm2s at our NT instrument, and due to the beam hardening effect which requires an extension of reconstruction software. The tomographic inspection of a PuBe neutron source and appropriate measures for background and beam hardening correction are presented.

Hameed, F.; Karimzadeh, S.; Zawisky, M.

2008-08-01

366

A systematic study of source error in source mask optimization  

NASA Astrophysics Data System (ADS)

Source Mask Optimization (SMO) technique is an advanced RET with the goal of extending optical lithography lifetime by enabling low k1 imaging [1,2]. Most of the literature concerning SMO has so far focused on PV (process variation) band, MEEF and PW (process window) aspects to judge the performance of the optimization as in traditional OPC [3]. In analogy to MEEF impact for low k1 imaging we investigate the source error impact as SMO sources can have rather complicated forms depending on the degree of freedom allowed during optimization. For this study we use Tachyon SMO tool on a 22nm metal design test case. A free form and parametric source solutions are obtained using MEEF and PW requirements as main criteria. For each type of source, a source perturbation is introduced to study the impact on lithography performance. Based on the findings we conclude on the choice of freeform or parametric as a source and the importance of source error in the optimization process.

Alleaume, C.; Yesilada, E.; Farys, V.; Depre, L.; Arnoux, V.; Li, Zhipan; Trouiller, Y.; Serebriakov, A.

2010-09-01

367

The status of the spallation neutron source ion source  

SciTech Connect

The ion source for the spallation neutron source (SNS) is a radio-frequency, multicusp source designed to deliver 45 mA of H2 to the SNS accelerator with a pulse length of 1 ms and repetition rate of 60 Hz. A total of three ion sources have been fabricated and commissioned at Lawrence Berkeley National Laboratory and subsequently delivered to the SNS at the Oak Ridge National Laboratory. The ion sources are currently being rotated between operation on the SNS accelerator, where they are involved in ongoing efforts to commission the SNS LINAC, and the hot spare stand (HSS), where high-current tests are in progress. Commissioning work involves operating the source in a low duty-factor mode (pulse width {approx}200 ms and repetition rate {approx}5 Hz) for extended periods of time while the high-current tests involve source operation at full duty-factor of 6 percent (1 ms/60 Hz). This report discusses routine performance of the source employed in the commissioning role as well as the initial results o f high-current tests performed on the HSS.

Welton, R.F.; Stockli, M.P.; Murray, S.N.; Keller, R.

2003-09-11

368

The status of the spallation neutron source ion source  

NASA Astrophysics Data System (ADS)

The ion source for the spallation neutron source (SNS) is a radio-frequency, multicusp source designed to deliver 45 mA of H- to the SNS accelerator with a pulse length of 1 ms and repetition rate of 60 Hz. A total of three ion sources have been fabricated and commissioned at Lawrence Berkeley National Laboratory and subsequently delivered to the SNS at the Oak Ridge National Laboratory. The ion sources are currently being rotated between operation on the SNS accelerator, where they are involved in ongoing efforts to commission the SNS LINAC, and the hot spare stand (HSS), where high-current tests are in progress. Commissioning work involves operating the source in a low duty-factor mode (pulse width ~200 ?s and repetition rate ~5 Hz) for extended periods of time while the high-current tests involve source operation at full duty-factor of 6% (1 ms/60 Hz). This report discusses routine performance of the source employed in the commissioning role as well as the initial results of high-current tests performed on the HSS.

Welton, R. F.; Stockli, M. P.; Murray, S. N.; Keller, R.

2004-05-01

369

Localization of Brain Abnormal Signal Sources Using Blind Source Separation  

Microsoft Academic Search

An effective and simple algorithm for localization of abnormal sources of the EEG signals within the brain has been developed here. In this method the signals are separated first, then the estimated independent components are lowpass filtered and normalized. In the next stage the correlation values between the estimated sources and the electrode signals are measured. On the other hand

M. A. Latif; S. Sanei

2005-01-01

370

Sourcing homelessness: How journalists use sources to frame homelessness  

Microsoft Academic Search

This article describes a content and qualitative analysis of quotations from sources in Canadian newspaper items on homelessness. Experts dominate as sources on homelessness. Homeless people are not completely deprived of a voice, but are limited to the devalued voice of experience. Quotes from homeless people themselves promote a narrative of homelessness that marginalizes the people who experience it and

Barbara Schneider

2012-01-01

371

Thermal Management of Light Sources  

NASA Astrophysics Data System (ADS)

The primary task of light sources is illumination, i.e., the emission of visible radiation—light. However, depending on the generation principle, besides light, also heat will be dissipated to the surroundings. Traditional thermal light sources generate light by the electrical heating of a tungsten wire to temperatures of about 3000 K. Even at this high temperature, the majority of the emitted thermal radiation is within the long wavelength range of the spectrum, i.e., not in the visible range of the optical spectrum. Generation of light with discharge lamps is completely different and non-thermal; however, even in this case the electrodes are heated to temperatures well above 2000 K. Thus, discharge lamps also suffer from thermal problems. In the case of solid-state light sources, also non-thermal light sources, the driving electrical current causes heating of the device, for which the temperature is, or should usually be, below 420 K for proper operation. Contrary to thermal or discharge light sources, such relatively low temperatures of solid-state light sources prevent efficient cooling by thermal radiation, requiring convective or conductive cooling. However, for all mentioned light sources, the thermal management, i.e., the adjusting and maintaining of an optimum operation temperature are vital for the efficiency and lifetime of the light sources. This paper deals with the methods of generation and measurement of the thermal load in the respective light sources and discusses ways to optimize the efficiency and lifetime of such light sources. Also, some practical examples are given to emphasize the relevance of such thermal management for industry, pointing out the potential for future more energy-efficient light source concepts.

Hartmann, J.; Völker, Stephan

2011-01-01

372

Ion source choices - an h- source for the high intensity neutrino source  

SciTech Connect

The High Intensity Neutrino Source (HINS) program at Fermilab (formerly the Proton Driver) aims to develop a multi-mission linear accelerator (LINAC) capable of accelerate H{sup -} ions to 8 GeV. This paper touches on the ion source requirements for the HINS and discusses long pulse length testing of three ion sources which appear to have the capability of meeting these requirements.

Moehs, Douglas P.; /Fermilab; Welton, Robert F.; /SNS Project, Oak Ridge; Stockli, Martin P.; Peters, Jens; /DESY; Alessi, James; /Brookhaven

2006-08-01

373

Community Open Source Strategic Plan.  

National Technical Information Service (NTIS)

The Strategic Plan describes the goals and objectives of the Community Open Source Program for the next seven years. It builds on the half-century-plus heritage of Open Source Information providers and users in the Intelligence Community. The Plan project...

1995-01-01

374

Ultra-wideband source research  

Microsoft Academic Search

Ultra-wideband (UWB) microwave sources and antennas are of interest for a variety of applications such as transient radar, mine detection and unexploded ordnance (UXO) location and identification. Much of the current research is being performed at the Air Force Research Laboratory (AFRL) at Kirtland AFB, NM, USA. The approach to high power source development has included high pressure gas switching,

William D. Prather; Carl E. Baum; Jane M. Lehr; J. P. O'Loughlin; S. Tyo; J. S. H. Schoenberg; R. J. Torres; T. C. Tran; D. W. Scholfield; J. W. Burger; J. Gaudet

1999-01-01

375

The Open Source Acid Test  

Microsoft Academic Search

In the late 1970s, AT&T openly licensed the source code for its fledgling Unix operating system to universities and government research labs. This move got Bill Joy and Sun Microsystems started and resulted in several other famous open source product developments such as sendmail and BIND (Berkeley Internet Name Domain). Over the next two decades, Unix took root and became

Ted G. Lewis

1999-01-01

376

The DCU laser ion source  

Microsoft Academic Search

Laser ion sources are used to generate and deliver highly charged ions of various masses and energies. We present details on the design and basic parameters of the DCU laser ion source (LIS). The theoretical aspects of a high voltage (HV) linear LIS are presented and the main issues surrounding laser-plasma formation, ion extraction and modeling of beam transport in

P. Yeates; J. T. Costello; E. T. Kennedy

2010-01-01

377

News Sources and Media Bias  

Microsoft Academic Search

In this paper we investigate the relationship between news sources and media firms. Although empirically important, this channel for supply-driven media bias has not previously been analyzed in economics literature. We model the relationship as an informal contract based on trust and punishment, where a news source decides if and how much information to provide to a media firm. Strategic

Armando J. Garcia-Pires; Hans Jarle Kind; Lars Sørgard

2012-01-01

378

Hollow electrode plasma excitation source  

DOEpatents

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures. 5 figs.

Ballou, N.E.

1992-04-14

379

Digitally Controlled Thyristor Current Source  

Microsoft Academic Search

A digitally controlled current source, based on a 6-pulse thyristor bridge is described. When part of a larger system, the source is amenable to direct microprocessor control. Salient aspects of the design described here are a new method for zero voltage detection and the configuration and analysis of a digital proportional-integral (PI) controller. The paper gives the design procedure as

Guy Olivier; V. R. Stefanovic; Mohammed Akhtar Jamil

1979-01-01

380

Online Sources for Competitor Information.  

ERIC Educational Resources Information Center

|Competitor information gathering is a key aspect of business planning. Information can be collected from either published or unpublished sources. Unpublished information will often be verified based on material from published sources. Published information is more likely to be factual and includes financial, stockmarket, press, market and…

Weiss, Arthur

381

Belgium considers new energy sources  

Microsoft Academic Search

A new energy policy proposal is expected to emphasize the use of indigenous coal and other energy sources to replace Belgium's heavy reliance on natural gas and oil imports. Efforts to ensure gas supplies by diversifying supply sources were spurred by the dwindling gas fields in Holland and the demands of the Belgian chemical industry. An increase in nuclear energy

Traill

1978-01-01

382

Global sourcing trends in 2008  

Microsoft Academic Search

Purpose – The purpose of this paper is to collate Morrison & Foerster's view on the state of the global outsourcing market and their lawyers' experience with a wide range of sourcing projects in a number of geographic and sectoral markets. Design\\/methodology\\/approach – The global sourcing trends 2008 report is co-authored by Morrison & Foerster partners based in Europe, the

Jon Edgell; Gabriel E. Meister; Nigel Stamp

2008-01-01

383

MICROBIAL SOURCE TRACKING GUIDE DOCUMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

A significant percentage of surface waters I the U.S. do not meet the designated use criteria as determined by high densities of fecal indicator bacteria as set forth by the Clean Water Act. Both point and non-point sources contribute to water pollution. In contrast to point sources such as sewage...

384

Saturian kilometric radiation: Source locations  

Microsoft Academic Search

Using Voyager 1 and 2 Planetary Radio Astronomy data and reasonable assumptions about radiation beam geometry, we deduce the source locations of both polarization components of the Saturn kilometer-wavelength radiation. The resulting radio source footprints are at high latitudes north and south, and near the noon meridian. These footprints are compared with the surface locations of Saturn's UV aurorae, polar

M. L. Kaiser; M. D. Desch

1982-01-01

385

Evaluation of Longwall Dust Sources.  

National Technical Information Service (NTIS)

The major objective of this study was to define the relative contributions of various sources of respirable airborne dust on longwall faces. In order to define the contribution of various primary sources, continuous dust level data were recorded on five l...

J. Ludlow E. Marshall

1983-01-01

386

Alternative sources of gas supply  

Microsoft Academic Search

The alternative sources considered include imported liquefied natural gas, and substitute natural gas produced from oil, coal, oil shale, peat, and biomass. Data are included on fuel prices, electricity prices, environmental impacts, fossil fuel resources, and unconventional sources of natural gas. It is noted that some of the technologies to tap these resources are in early stages of development and

1978-01-01

387

Elevator for cobalt-60 source.  

National Technical Information Service (NTIS)

The elevator used for cobalt-60 source is a key device in the irradiation industry. It plays an important role in the safety and control of irradiation operation as well as the utilization rate of radiation source. From 1983 to 1986, Beijing Institute of ...

Z. Tang D. Liang

1990-01-01

388

Cretaceous source rocks in Pakistan  

SciTech Connect

Pakistan is located at the converging boundaries of the Indian, Arabian, and Eurasian plates. Evolution of this tectonic setting has provided an array of environmental habitats for deposition of petroleum source rocks and development of structural forms. The potential Cretaceous source rocks in Central and South Indus Basin are spread over an area of about 300,000 km[sup 2]. With 2% cutoff on Total Organic Carbon, the average source rock thickness is 30-50 m, which is estimated to have generated more than 200 billion bbl of oil equivalent. To date, production of more than 30,000 bbl of oil and about 1200 million ft[sup 3] of gas per day can be directly attributed to Cretaceous source. This basin was an area of extensional tectonics during the Lower to Middle Cretaceous associated with slightly restricted circulation of the sea waters at the north-western margin of Indian Plate. Lower Cretaceous source rocks (Sembar Formation) were deposited while the basin was opening up and anoxia was prevailing. Similarly Middle to Upper Cretaceous clastics were deposited in setting favorable for preservation of organic matter. The time and depth of burial of the Cretaceous source material and optimum thermal regime have provided the requisite maturation level for generation of hydrocarbons in the basin. Central Indus basin is characterized by Cretaceous source rocks mature for gas generation. However, in South Indus Basin Cretaceous source rocks lie within the oil window in some parts and have gone past it in others.

Kari, I.B. (Pakistan Petroleum Limited, Sindh (Pakistan))

1993-02-01

389

Cretaceous source rocks in Pakistan  

Microsoft Academic Search

Pakistan is located at the converging boundaries of the Indian, Arabian, and Eurasian plates. Evolution of this tectonic setting has provided an array of environmental habitats for deposition of petroleum source rocks and development of structural forms. The potential Cretaceous source rocks in Central and South Indus Basin are spread over an area of about 300,000 km[sup 2]. With 2%

Kari

1993-01-01

390

OPEN SOURCE SOFTWARE AND LIBRARIES  

Microsoft Academic Search

OPEN SOURCE AND ITS DEMOCRATIC PROMISE? Faced with the increased commodifi cation of information resources and ser- vices and the encroaching dominant logics of business\\/corporate culture, today's libraries are in search of innovative technological solutions to protect the free fl ow of ideas. In response to this situation, a growing segment of the library profession is promoting open source software

Ajit Pyati

2008-01-01

391

SOURCE ASSESSMENT: CHLORINATED HYDROCARBONS MANUFACTURE  

EPA Science Inventory

This report describes a study of air pollutants released during the manufacture of chlorinated hydrocarbons. The potential environmental effect of the source was evaluated using source severity, S, defined as the ratio of the maximum ground level concentration of an emission to t...

392

Experimental characterization of vibration sources  

Microsoft Academic Search

Mobility and impedance schemes are widely used in mechanical systems analysis to predict the effects of vibration sources on the system dynamics. This paper describes a systematic approach based on the mobility and impedance method for the characterization of vibration sources. The cases of elastic and rigid bodies are considered and analyzed. Guidelines for the design of the force and

Bortolino Saggin; Diego Scaccabarozzi; Irina Shatalina; Marco Tarabini

2012-01-01

393

Biomass as alternative energy source  

Microsoft Academic Search

The potential for biomass utilization as a source of fuel, petrochemicals and petroleum-sparing substances is reviewed. The choices for cultivating biomass, utilizing it directly as an energy source, and converting it to fuels are considered against the background of the principal metabolic pathways. Engineering options for the production of biomass derived fuels include the direct use of photosynthetic materials, the

Keenan

1982-01-01

394

ION SOURCE UNIT FOR CALUTRON  

Microsoft Academic Search

An improvement in the mounting arrangement for an ion source within the ; vacuum tank of a calutron device is reported. The cathode and arc block of the ; source are independently supported from a stem passing through the tank wall. ; The arc block may be pivoted and moved longitudinally with respect to the stem to ; thereby align

D. H. Sloan; H. P. Yockey; F. H. Schmidt

1959-01-01

395

Open Source Software in Industry  

Microsoft Academic Search

Many of today's most innovative products and solutions are developed on the basis of free and open source software (FOSS). Most of us can no longer imagine the world of software engineering without open source operating systems, databases, application servers, Web servers, frameworks, and tools. Brands such as Linux, MySQL, Apache, and Eclipse have shaped product and service development. They

Christof Ebert

2008-01-01

396

Current Controlled Current Source (CCCS)  

NSDL National Science Digital Library

This interactive website from professor James A. Svoboda of Clarkson University describes current controlled current source (CCCS). The interactive applet depicts a circuit that contains a Current Controlled Current Source (CCCS). The gain of the CCCS can be changed using the scroll bar.

Svoboda, James A.

2011-08-29

397

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

398

Regional source rock mapping using a source potential rating index  

SciTech Connect

A method has been developed to combine sediment thickness, organic carbon content, and thermal-maturity data from potential source rock units into a single mapable parameter that can be used to indicate areas of potential hydrocarbon generation. This parameter is computed by multiplying the average percent organic carbon by the effective source rock thickness of a formation. This yields a richness factor that is then multiplied by maturity scaling factors to give source potential ratings for oil and/or gas generation. The rating values can be combined with kerogen type data, if available, to refine these assessments of generating potential. The rating index can also be used with burial history curves and thermal-maturation modeling to look at source potential during geologic time. An example is given of the rating index mapping applied to the Bakken Formation in the Williston basin. The source potential rating index provides objective, semiquantitative measures by which the source potential of a single formation can be compared within an area, or by which the source potential of two or more formations can be compared in the same or different basins. In conjunction with structural analysis of a basin, the resulting maps can help the explorer explain known hydrocarbon accumulations, trace migration pathways, and point toward new areas for exploration.

Dembicki, H.; Pirkle, F.L.

1985-04-01

399

Ion source requirements for pulsed spallation neutron sources  

SciTech Connect

The neutron scattering community has endorsed the need for a high- power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor for a large class of experiments. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 KW source in the UK), and call for a high-current (approx. 100 mA peak) H{sup {minus}} source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The 1 to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. A workshop held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H{sup {minus}} source technologies, and identified necessary R&D efforts to bridge the gap.

Alonso, J.R.

1995-10-01

400

Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs  

NASA Astrophysics Data System (ADS)

We describe an online system for automated classification of X-ray sources, ClassX, and we present preliminary results of classification of the three major catalogs of ROSAT sources, ROSAT All-Sky Survey (RASS) Bright Source Catalog, RASS Faint Source Catalog, and WGACAT, into six class categories: stars, white dwarfs, X-ray binaries, galaxies, active galactic nuclei, and clusters of galaxies. ClassX is based on a machine-learning technology. It represents a system of classifiers, each classifier consisting of a considerable number of oblique decision trees. These trees are built as the classifier is ``trained'' to recognize various classes of objects using a training sample of sources of known object types. Each source is characterized by a preselected set of parameters, or attributes; the same set is then used as the classifier conducts classification of sources of unknown identity. The ClassX pipeline features an automatic search for X-ray source counterparts among heterogeneous data sets in online data archives using Virtual Observatory protocols; it retrieves from those archives all the attributes required by the selected classifier and inputs them to the classifier. The user input to ClassX is typically a file with target coordinates, optionally complemented with target IDs. The output contains the class name, attributes, and class probabilities for all classified targets. We discuss ways to characterize and assess the classifier quality and performance, and we present the respective validation procedures. On the basis of both internal validation and external verification, we conclude that the ClassX classifiers yield reasonable and reliable classifications for ROSAT sources and have the potential to broaden class representation significantly for rare object types.

McGlynn, T. A.; Suchkov, A. A.; Winter, E. L.; Hanisch, R. J.; White, R. L.; Ochsenbein, F.; Derriere, S.; Voges, W.; Corcoran, M. F.; Drake, S. A.; Donahue, M.

2004-12-01

401

Sealed source peer review plan  

SciTech Connect

Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR {section} 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements for the subject peer review.

Feldman, Alexander [Los Alamos National Laboratory; Leonard, Lee [RETIRED; Burns, Ron [CONTRACTOR

2009-01-01

402

Multi-source solar simulator using single light source  

DOEpatents

Methods, techniques and apparatus are described for adjusting the spectral irradiance characteristics of a light source. The invention is applicable to any light source and has many areas of utility. One example is for simulating solar light for use in testing efficiency of photovoltaic cells. Solar light at any point in the world can be simulated. Also, light having any desired wavelength (or combination of desired wavelengths) can be obtained from a single light source using the techniques and apparatus of the invention. 4 figs.

Emery, K.A.; Osterwald, C.R.

1989-08-17

403

Major System Source Evaluation and Selection Procedures.  

National Technical Information Service (NTIS)

source evaluation and selection, contracting requirements and procedures,Planning for source selection, initiating an acquisition, organization for source selection, functions of the source selection organization, evaluation criteria and standards, scorin...

1987-01-01

404

Plasma echo from moving sources  

SciTech Connect

A theory is derived for the plasma-wave echo from two moving plane sources oscillating at frequencies ..omega../sub 1/ and ..omega../sub 2/ in their proper frames of reference. The echo effect for sources which are moving at different but constant velocities is shown to be quite different from that for fixed sources. In particular, the electric field at a certain point arises only at a certain time. In accordance with the general property of echo effects, there is a large region between the sources and the observation point in which there is no electric field, and perturbations are carried from the sources to the observation point by Van Kampen waves. The signal depends on the distance between the sources. After the sources meet, the echo field E/sub E/ at a given point in space increases as a function of the time t in proportion to t/sup 1/2/ (..nu..<<1, where ..nu.. is the effective rate of collisions, ..nu -->..0).

Eidman, V.Y.

1981-05-01

405

International Data on Radiological Sources  

SciTech Connect

ABSTRACT The mission of radiological dispersal device (RDD) nuclear forensics is to identify the provenance of nuclear and radiological materials used in RDDs and to aid law enforcement in tracking nuclear materials and routes. The application of databases to radiological forensics is to match RDD source material to a source model in the database, provide guidance regarding a possible second device, and aid the FBI by providing a short list of manufacturers and distributors, and ultimately to the last legal owner of the source. The Argonne/Idaho National Laboratory RDD attribution database is a powerful technical tool in radiological forensics. The database (1267 unique vendors) includes all sealed sources and a device registered in the U.S., is complemented by data from the IAEA Catalogue, and is supported by rigorous in-lab characterization of selected sealed sources regarding physical form, radiochemical composition, and age-dating profiles. Close working relationships with global partners in the commercial sealed sources industry provide invaluable technical information and expertise in the development of signature profiles. These profiles are critical to the down-selection of potential candidates in either pre- or post- event RDD attribution. The down-selection process includes a match between an interdicted (or detonated) source and a model in the database linked to one or more manufacturers and distributors.

Martha Finck; Margaret Goldberg

2010-07-01

406

Source rock potential in Pakistan  

SciTech Connect

Pakistan contains two sedimentary basins: Indus in the east and Balochistan in the west. The Indus basin has received sediments from precambrian until Recent, albeit with breaks. It has been producing hydrocarbons since 1914 from three main producing regions, namely, the Potwar, Sulaisman, and Kirthar. In the Potwar, oil has been discovered in Cambrian, Permian, Jurassic, and Tertiary rocks. Potential source rocks are identified in Infra-Cambrian, Permian, Paleocene, and Eocene successions, but Paleocene/Eocene Patala Formation seems to be the main source of most of the oil. In the Sulaiman, gas has been found in Cretaceous and Tertiary; condensate in Cretaceous rocks. Potential source rocks are indicated in Cretaceous, Paleocene, and Eocene successions. The Sembar Formation of Early Cretaceous age appears to be the source of gas. In the Kirthar, oil and gas have been discovered in Cretaceous and gas has been discovered in paleocene and Eocene rocks. Potential source rocks are identified in Kirthar and Ghazij formations of Eocene age in the western part. However, in the easter oil- and gas-producing Badin platform area, Union Texas has recognized the Sembar Formation of Early Cretaceous age as the only source of Cretaceous oil and gas. The Balochistan basin is part of an Early Tertiary arc-trench system. The basin is inadequately explored, and there is no oil or gas discovery so far. However, potential source rocks have been identified in Eocene, Oligocene, Miocene, and Pliocene successions based on geochemical analysis of surface samples. Mud volcanoes are present.

Raza, H.A. (Hydrocarbon Development Institute of Pakistan, Islamabad (Pakistan))

1991-03-01

407

Spallation neutron source and other high intensity froton sources  

SciTech Connect

This lecture is an introduction to the design of a spallation neutron source and other high intensity proton sources. It discusses two different approaches: linac-based and synchrotron-based. The requirements and design concepts of each approach are presented. The advantages and disadvantages are compared. A brief review of existing machines and those under construction and proposed is also given. An R&D program is included in an appendix.

Weiren Chou

2003-02-06

408

The Chandra Source Catalog: Processing and Infrastructure  

Microsoft Academic Search

Chandra Source Catalog processing recalibrates each observation using the latest available calibration data, and employs a wavelet-based source detection algorithm to identify all the X-ray sources in the field of view. Source properties are then extracted from each detected source that is a candidate for inclusion in the catalog. Catalog processing is completed by matching sources across multiple observations, merging

Janet Evans; Ian N. Evans; Kenny J. Glotfelty; Roger Hain; Diane M. Hall; Joseph B. Miller; David A. Plummer; Panagoula Zografou; Francis A. Primini; Craig S. Anderson; Nina R. Bonaventura; Judy C. Chen; John E. Davis; Stephen M. Doe; Giuseppina Fabbiano; Elizabeth C. Galle; Danny G. Gibbs II; John D. Grier; Peter N. Harbo; John C. Houck; Margarita Karovska; Vinay L. Kashyap; Jennifer Lauer; Michael L. McCollough; Jonathan C. McDowell; Arik W. Mitschang; Douglas L. Morgan; Amy E. Mossman; Joy S. Nichols; Michael A. Nowak; Brian L. Refsdal; Arnold H. Rots; Aneta L. Siemiginowska; Beth A. Sundheim; Michael S. Tibbetts; David W. van Stone; Sherry L. Winkelman

2009-01-01

409

H- Ion Source Development for the National Spallation Neutron Source  

NASA Astrophysics Data System (ADS)

The ion source for the 1 MW National Spallation Neutron Source (NSNS) is required to provide 35 mA of H- beam current (1 ms pulses at 60 Hz) at 65 keV with a normalized rms emittance of less than 0.2 #185# mm mrad. The same ion source should be able to produce 70 mA of H- at 6% duty factor when the NSNS is upgraded to 2 MW of power. For this application, a radio-frequency driven, magnetically filtered multicusp source is now being developed at LBNL. In preliminary experiments with an existing ion source developed for the Superconducting Super Collider, 16 mA of H- ions were extracted at an accelerated voltage of 10 kV and an RF output power of 20 kW without cesium. The design of a new source equipped with a cesium dispenser-collar, a fast ion beam pre-chopper (rise times < 100 ns) and a strong permanent-magnet insert for electron deflection will be presented. [This research is sponsored by the Division of Materials Sciences, DOE, under contract DE-AC05-96OR22464 with Lockheed Martin Energy Research Corp.

Leitner, M.; Gough, R.; Leung, K. N.; Rickard, M.; Wengrow, A. B.; Williams, M. D.; Wutte, D.

1997-05-01

410

Three chamber negative ion source  

DOEpatents

It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

1983-11-10

411

Synchrotron radiation sources and research  

SciTech Connect

This is an introduction and a review of Synchrotron Radiation sources and the research performed using synchrotron radiation. I will begin with a brief discussion of the two principal uses of particle storage rings: for colliding beams (Collider) and for synchrotron radiation (Radiator). Then I will concentrate on discussions of synchrotron radiation topics, starting with a historical account, followed by descriptions of the features of the storage ring and the features of the radiation from the simplest source -- the bending magnet. I will then discuss the special insertion device sources -- wigglers and undulators -- and their radiations, and end with a brief general account of the research and other applications of synchrotron radiation.

Teng, L.C.

1995-12-31

412

Primary ion sources for EBIS  

SciTech Connect

This paper gives an introduction into the topic of primary ion sources that can be used to feed ions of normally solid elements into EBIS devices. Starting with a set of typical requirements for primary ion sources, some major types of ion generators are discussed first, with emphasis on their working principles rather than trying to give a fully representative listing of used and proposed generators. Beam-transport issues between primary ion source and EBIS are then examined, and generic characteristics of suitable beam-formation and transport systems are explained.

Keller, R.

2001-03-21

413

Contextual forgetting: Posthypnotic source amnesia  

Microsoft Academic Search

Notes that posthypnotic source amnesia (SA) involves recall of information recently learned during hypnosis without recollection of how the information was acquired. SA occurs when, posthypnotically, an S gives the correct answer to a question like, \\

Frederick J. Evans

1979-01-01

414

Current Controlled Voltage Source (CCVS)  

NSDL National Science Digital Library

This interactive website from professor James A. Svoboda of Clarkson University describes a circuit that contains a Current Controlled Voltage Source (CCVS). The gain of the CCVS can be changed using the scrollbar.

Svoboda, James A.

2012-12-17

415

Ion sources for medical accelerators  

SciTech Connect

Advanced injector systems for proton synchrotrons and accelerator-based boron neutron capture therapy systems are being developed at the Lawrence Berkeley National Laboratory. Multicusp ion sources, particularly those driven by radio frequency, have been tested for these applications. The use of a radio frequency induction discharge provides clean, reliable, and long-life source operation. It has been demonstrated that the multicusp ion source can provide good-quality positive hydrogen ion beams with a monatomic ion fraction higher than 90{percent}. The extractable ion current densities from this type of source can meet the injector requirements for both proton synchrotron and accelerator-based boron neutron capture therapy projects. {copyright} {ital 1998 American Institute of Physics.}

Barletta, W.A.; Chu, W.T.; Leung, K.N. [Lawrence Berkeley National Laboratory, University of California, Berkeley, California94720 (United States)

1998-02-01

416

Electrolyte salts for power sources  

DOEpatents

Electrolyte salts are disclosed for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts. 2 figs.

Doddapaneni, N.; Ingersoll, D.

1995-11-28

417

SOURCE ASSESSMENT: MAJOR BARIUM CHEMICALS  

EPA Science Inventory

This report summarizes data on air emissions from the production of major barium chemicals. Compounds studied include barium sulfide, barium carbonate, barium chloride, barium hydroxide, and barium sulfate. In order to evaluate potential environmental effects the source severity,...

418

Plasma Sound Source Basic Research.  

National Technical Information Service (NTIS)

This report investigates the phenomena of breakdown and initial arc formation of a plasma sound source. The prebreakdown phase is examined experimentally. A proton-hopping model is proposed that is qualitatively consistent with the data. A literature revi...

R. L. Rogers J. C. Espinosa D. L. Fisher A. M. Gleeson

1999-01-01

419

IN SITU ENHANCED SOURCE REMOVAL  

EPA Science Inventory

This html report describes and compares the performance of in situ technologies designed to accelerate the removal of organic contaminants from unconsolidated soils and aquifers. The research was conducted through the Enhanced Source Removal (ESR) Program within the Subsurface Pr...

420

Source Category Survey: Perlite Industry.  

National Technical Information Service (NTIS)

Background information is presented on the perlite industry for the purpose of determining the need for a new source performance standard (NSPS). The industry is surveyed and categorized by plant, process, and other factors. Information is presented on pr...

1980-01-01

421

Stand by electrical supply source  

SciTech Connect

A stand-by electrical energy source for equipment to be operated with substantially continuous current supply, comprising three components one of which is at least one electric rotary machine, another of which is a flywheel and the third of which is an auxiliary energy source. Planetary gearing is provided, comprising a central shaft on which is mounted a sun gear, a planet gear and a ring gear, each of the three components being connected with a respective one of these gears. Two of the three components are interconnected by a drive with an infinitely variable transmission. In one embodiment, the electric rotary machine is connected to the planet gear, the flywheel is connected to the sun gear and the auxiliary energy source is connected with the ring gear. In another embodiment, the electric rotary machine is connected to the sun gear, the flywheel is connected to the ring gear, and the auxiliary energy source is connected to the planet gear.

Mucsy, E.; Hoos, K.

1985-06-25

422

Electrolyte salts for power sources  

DOEpatents

Electrolyte salts for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts.

Doddapaneni, Narayan (10516 Royal Birkdale, NE., Albuquerque, NM 87111); Ingersoll, David (5824 Mimosa Pl., NE., Albuquerque, NM 87111)

1995-01-01

423

Multi-Source Image Analysis.  

National Technical Information Service (NTIS)

For the purposes of this study, multi-source image analysis is defined as the utilization of imagery from panchromatic photography, radar and thermal infrared systems for providing military geographic information. The imagery was limited to sets available...

D. D. Steller M. R. Mel D. J. Shiroma J. A. Sowma W. Muir

1979-01-01

424

Power Source Options for Communications.  

National Technical Information Service (NTIS)

It is difficult to grasp a more demanding power consumer than the military. The modern military has come to rely on increasingly complex communications/electronic equipment that require a dependable, lightweight, compact power source that has the ability ...

J. M. Farina

2005-01-01

425

Compressing Data by Source Separation  

NASA Astrophysics Data System (ADS)

We interpret source separation of hyperspectral data as a way of applying lossy compressing. In settings where datacubes can be interpreted as a linear combination of source spectra and their abundances and the number of sources is small, we try to quantify the trade-offs and the benefits of source separation and its implementation with non-negative source factorisation. While various methods to implement non-negative matrix factorisation have been used successfully for factoring hyperspectral images into physically meaningful sources which linearly combine to an approximation of the original image. This is useful for modelling the processes which make up the image. At the same time, the approximation opens up the potential for a significant reduction of the data by keeping only the sources and their corresponding abundances, instead of the original complete data cube. This presentation will try to explore the potential of the idea and also to establish limits of its use. Formally, the setting is as follows: we consider P pixels of a hyperspectral image which are acquired at L frequency bands and which are represented as a PxL data matrix X. Each row of this matrix represents a spectrum at a pixel with spatial index p=1..P; this implies that the original topology may be disregarded. Since we work under the assumption of linear mixing, the p-th spectrum, 1<=p<=P, can be expressed as a linear combination of r, 1<=r<=R, source spectra. Thus, X=AxS+E, E being an error matrix to be minimised, and X, A, and S only have non-negative entries. The rows of matrix S are the estimations of the R source spectra, and each entry of A expresses the contribution of the r-th component to the pixel with spatial index p. There are applications where we may interpret the rows of S as physical sources which can be combined using the columns of A to approximate the original data. If the source signals are few and strong (but not even necessarily meaningful), the data volume that has to be transmitted or looked at can be reduced significantly.

Schmidt, A.; Tréguier, E.; Schmidt, F.; Moussaoui, S.

2012-04-01

426

H- radio frequency source development at the Spallation Neutron Source.  

PubMed

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ?38 mA peak current in the linac and an availability of ?90%. H(-) beam pulses (?1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ?60 kW) of a copper antenna that has been encased with a thickness of ?0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ?99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ?75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance?installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ?100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence. PMID:22380234

Welton, R F; Dudnikov, V G; Gawne, K R; Han, B X; Murray, S N; Pennisi, T R; Roseberry, R T; Santana, M; Stockli, M P; Turvey, M W

2012-02-01

427

H- radio frequency source development at the Spallation Neutron Source  

NASA Astrophysics Data System (ADS)

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ~38 mA peak current in the linac and an availability of ~90%. H- beam pulses (~1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ~60 kW) of a copper antenna that has been encased with a thickness of ~0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ~99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ~75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ~100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, R. F.; Dudnikov, V. G.; Gawne, K. R.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Roseberry, R. T.; Santana, M.; Stockli, M. P.; Turvey, M. W.

2012-02-01

428

Farewell to direct source incompatibilism  

Microsoft Academic Search

Traditional theorists about free will and moral responsibility endorse the principle of alternative possibilities (PAP): an\\u000a agent is morally responsible for an action that she performs only if she can do or could have done otherwise. According to\\u000a source theorists, PAP is false and an agent is morally responsible for her action only if she is the source of that

Joseph Keim Campbell

2006-01-01

429

Radio sources with superluminal velocities  

Microsoft Academic Search

Observed variations concerning the brightness distributions in four extragalactic radio sources were so rapid that the apparent transverse velocity of expansion is greater than the velocity of light. The term superluminal is used to describe this phenomenon. A review is provided of the observations of superluminal expansions. Attention is given to four sources including three quasars (3C345, 3C273, and 3C279)

M. H. Cohen; R. P. Linfield; A. T. Moffet; G. A. Seielstad; K. I. Kellermann; D. B. Shaffer; I. I. K. Pauliny-Toth; E. Preuss; A. Witzel; J. D. Romney; R. T. Schilizzi; B. J. Geldzahler

1977-01-01

430

Novel Inductively Coupled Plasma Source  

Microsoft Academic Search

Plasma Research Laboratory, Dublin City University Novel Inductively Coupled Plasma Source A novel high-pressure, high-power-density-compatible plasma source is investigated. Possible applications include high brightness lightning, effluent abatement and chemical activation for downstream use. The systems comprises an inductively coupled rf antenna and plasma. The plasma housing chamber and plasma act as a secondary windings to the antenna. The design features

Andrew Rybin; Albert R. Ellingboe

2002-01-01

431

rf improvements for Spallation Neutron Source H- ion source.  

PubMed

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering approximately 38 mA H(-) beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. PMID:20192394

Kang, Y W; Fuja, R; Goulding, R H; Hardek, T; Lee, S-W; McCarthy, M P; Piller, M C; Shin, K; Stockli, M P; Welton, R F

2010-02-01

432

rf improvements for Spallation Neutron Source H- ion source  

NASA Astrophysics Data System (ADS)

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering ~38 mA H- beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier.

Kang, Y. W.; Fuja, R.; Goulding, R. H.; Hardek, T.; Lee, S.-W.; McCarthy, M. P.; Piller, M. C.; Shin, K.; Stockli, M. P.; Welton, R. F.

2010-02-01

433

Multilevel cascade voltage source inverter with seperate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

2002-01-01

434

Multilevel cascade voltage source inverter with seperate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01

435

Multilevel cascade voltage source inverter with separate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

Peng, F.Z.; Lai, J.S.

1997-06-24

436

Design parameters and source terms: Volume 3, Source terms  

SciTech Connect

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 11 refs., 9 tabs.

Not Available

1987-10-01

437

Sources.  

ERIC Educational Resources Information Center

|Presents print and non-print titles, other materials, and information for the following categories: Award Winning Books; Booklist Lists; Canadian Book Awards; Non-Book Awards; Searching the Internet; Picture Books for Older Students; Professional Books; New Reference Materials; Periodicals for Teacher Librarians; Feature Length Films; Margaret B.…

School Libraries in Canada, 2001

2001-01-01

438

Research on fusion neutron sources  

SciTech Connect

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19

439

Compton Sources of Electromagnetic Radiation  

SciTech Connect

When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

Geoffrey Krafft,Gerd Priebe

2011-01-01

440

Next Generation Spallation Neutron Sources  

NASA Astrophysics Data System (ADS)

Neutron Scattering Experiments are traditionally done at nuclear reactors where high neutron fluxes are available from fission inside the reactor core. Naturally these are cw sources, which makes a whole class of time resolved experiments difficult to perform. Pulsed neutron sources, based on the spallation of neutrons by impinging an intense proton beam on a high atomic number target material, have therefore generated a large interest ever since they were put into operation. So far the typical integrated neutron flux is one or two orders of magnitude smaller than in a reactor. With the Spallation Neutron Source (SNS*) at Oak Ridge National Lab and the Japanese Hadron Project (J-PARC) at JAERI in Japan two second generation facilities are under construction that will provide average neutron fluxes exceeding those of reactors and peak fluxes that will allow new science to be done. The European Spallation Source, a project that still is in the planning stage, would even go beyond that. The talk will start out with the existing Spallation Sources and give an overview about the two construction projects focusing on the SNS presently foreseen to be finished in 2006. * SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.

Holtkamp, Norbert

2004-05-01

441

Distributed Source Coding for Satellite Communications  

Microsoft Academic Search

Inspired by mobile satellite communications systems, we consider a source coding system which consists of multiple sources, multiple encoders, and multiple decoders. Each encoder has access to a certain subset of the sources, each decoder has access to certain subset of the encoders, and each decoder reconstructs a certain subset of the sources almost perfectly. The connectivity between the sources

Raymond W. Yeung; Zhen Zhang

1999-01-01

442

Solar power source for a lighting system  

Microsoft Academic Search

A solar recharged power supply circuit for a lighting system which circuit includes a rechargeable power source, a solar powered recharger connected to that rechargeable power source and which circuit prevents discharge of that rechargeable power source through the solar powered recharger during times when the recharger is inactive; prevents overcharging of that power source; prevents discharging that power source

1982-01-01

443

Stacee Observations of Extragalactic Sources  

NASA Astrophysics Data System (ADS)

The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a ground-based gamma-ray telescope employing the atmospheric Cherenkov technique. STACEE uses 64 large heliostats at a solar research facility near Albuquerque NM, USA, to achieve a gamma-ray energy threshold below traditional imaging telescopes. The full STACEE experiment started regular observations in October, 2001. An earlier version of the experiment using 48 heliostats took data between January and June of 2001. Here we report the results from STACEE observations of extragalactic sources in 2001 and 2002. The sources observed include the active galaxies Markarian 421, Markarian 501, 3C 66A, and W Comae. We also summarize our future observing plan in the context of measuring the absorbtion of high energy emission due to radiation fields at the source, or in intergalactic space.

Mukherjee, R.; Boone, L. M.; Bramel, D.; Covault, C. E.; Fortin, P.; Gingrich, D.; Hanna, D.; Hinton, J. A.; Mueller, C.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Schuette, D. R.; Williams, D. A.

2002-04-01

444

Materials for spallation neutron sources  

SciTech Connect

The Workshop on Materials for Spallation Neutron Sources at the Los Alamos Neutron Science Center, February 6 to 10, 1995, gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss areas in which work is needed, successful designs and use of materials, and opportunities for further studies. During the first day of the workshop, speakers presented overviews of current spallation neutron sources. During the next 3 days, seven panels allowed speakers to present information on a variety of topics ranging from experimental and theoretical considerations on radiation damage to materials safety issues. An attempt was made to identify specific problems that require attention within the context of spallation neutron sources. This proceedings is a collection of summaries from the overview sessions and the panel presentations.

Sommer, W.F.; Daemen, L.L. [comps.

1996-03-01

445

Safety of sealed source disposal  

NASA Astrophysics Data System (ADS)

The disposal of sealed sources from industrial irradiators usually includes reuse or recycling where feasible, and then long-term storage at a waste management facility until the sources have decayed to a level at which they can be disposed of as essentially non-radioactive waste. The space required for this storage, and the time needed, are small relative to the needs of the power reactor industry. All aspects of this process are well established and licensed by regulatory agencies. There have been no accidents related to this activity that are known to the author. Accidents have occurred related to other applications of sealed sources; the causes of these are discussed and found to be unrelated to the industrial irradiator application.

Martell, E. S.

2004-09-01

446

Source Detection with Interferometric Datasets  

NASA Astrophysics Data System (ADS)

The detection of sources in interferometric radio data typically relies on extracting information from images, formed by Fourier transform of the underlying visibility dataset, and CLEANed of contaminating sidelobes through iterative deconvolution. Variable and transient radio sources span a large range of variability timescales, and their study has the potential to enhance our knowledge of the dynamic universe. Their detection and classification involve large data rates and non-stationary PSFs, commensal observing programs and ambitious science goals, and will demand a paradigm shift in the deployment of next-generation instruments. Optimal source detection and classification in real time requires efficient and automated algorithms. On short time-scales variability can be probed with an optimal matched filter detector applied directly to the visibility dataset. This paper shows the design of such a detector, and some preliminary detection performance results.

Trott, Cathryn M.; Wayth, Randall B.; Macquart, Jean-Pierre R.; Tingay, Steven J.

2012-04-01

447

Miniature x-ray source  

DOEpatents

A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

2002-01-01

448

LIGHT SOURCE: Conceptual design of Hefei advanced light source  

NASA Astrophysics Data System (ADS)

The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

2009-06-01

449

SOURCE ASSESSMENT: PRIORITIZATION OF STATIONARY WATER POLLUTION SOURCES  

EPA Science Inventory

The report gives priority lists to aid in selecting specific sources of water effluents for detailed assessment. It describes the general water prioritization model, explains its implementation, and gives a detailed example of its use. It describes hazard factors that were develo...

450

Information Sources for Travel Decisions: Toward a Source Process Model  

Microsoft Academic Search

This article contributes to the study of information sour- cing behavior in the travel decision process. It focuses on the differences between information sourcing before and after a definite trip decision (characterized either by an irreversible choice with regard to destination or by a legal contract such as a reservation or purchase of one or multiple elements of a trip).

Thomas Bieger; Christian Laesser

2004-01-01

451

Modeling mobile source emissions in presence of stationary sources  

Microsoft Academic Search

The impact of oxides of nitrogen (NOx) emissions from motor vehicles to the air quality in city-state Singapore is analyzed using AIRVIRO, a regional scale dispersion model developed by the Swedish Meteorological and Hydrological Institute. In a predominantly urban location like Singapore, it is difficult to separate out the contribution of pollutants from mobile and point sources at different locations.

Preety Mukherjee; Shekar Viswanathan; Lim Cheng Choon

2000-01-01

452

SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA  

SciTech Connect

The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.

Jessie L. Bonner; Brian Stump; Mark Leidig; Heather Hooper; Xiaoning (David) Yang; Rongmao Zhou; Tae Sung Kim; William R. Walter; Aaron Velasco; Chris Hayward; Diane Baker; C. L. Edwards; Steven Harder; Travis Glenn; Cleat Zeiler; James Britton; James F. Lewkowicz

2005-09-30

453

The SLAC polarized electron source  

SciTech Connect

The SLAC polarized electron source employs a photocathode DC high voltage gun with a loadlock and a YAG pumped Ti:sapphire laser system for colliding beam experiments or a flash lamp pumped Ti:sapphire laser for fixed target experiments. It uses a thin, strained GaAs(100) photocathode, and is capable of producing a pulsed beam with a polarization of {ge}80% and a peak current exceeding 10 A. Its operating efficiency has reached 99%. The physics and technology of producing high polarization electron beams from a GaAs photocathode will be reviewed. The prospects of realizing a polarized electron source for future linear colliders will also be discussed.

Tang, H.; Alley, R.; Frisch, J. [and others

1995-06-01

454

Tikal obsidian: sources and typology  

SciTech Connect

The obsidian industry of Classic period Tikal, Guatemala, is discussed with regard to geological source determinations and behavioral typology. The potential of these two approaches for cultural reconstruction is greatly extended when they can supplement each other. Recent source determinations of obsidian artifacts from Tikal indicate (1) a behavioral link between locally-produced prismatic blades of Highland Guatemalan stone and ceremonial incised obsidians and eccentrics, and (2) a Central Mexican origin for a seemingly large portion of Tikal's obsidian projectile points and knives. 25 references, 3 figures, 5 tables.

Moholy-Nagy, H.; Asaro, F.; Stross, F.H.

1984-01-01

455

The JavaScript Source  

NSDL National Science Digital Library

The JavaScript Source contains hundreds of scripts which can be copied and used free of charge. Scripts are divided into categories such as Background Effects, Buttons, Cookies, and Forms. Included with each script is the description, file size, and contributor information. The JavaScript Source also provides several services beyond the collection. If you'd rather receive code in email, they will send it to you. A discussion forum is available. A free biweekly newsletter informs its subscribers of newly added scripts.

456

The UMLS Knowledge Source server.  

PubMed

The UMLS Knowledge Source server is an evolving tool for accessing information stored in the UMLS Knowledge Sources. The system architecture is based on the client-server paradigm wherein remote site users send their requests to a centrally managed server at the U.S. National Library of Medicine. The client programs can run on platforms supporting the TCP/IP communication protocol. Access to the system is provided through a command-line interface and through an Application Programming Interface. PMID:8591140

McCray, A T; Razi, A

1995-01-01

457

Changing Sources for Research Literature  

NASA Astrophysics Data System (ADS)

Including material published previously, I considered all the references listed in the January issues of Astronomy & Astrophysics and the Astrophysical Journal in decade intervals from 1952 to 2006. The results are that journal papers, preprints, and reviews are growing in the frequency in which they are cited, while observatory publications, private communications, theses, conference papers, and monographs are decreasing in cited frequency. The last two are surprising in view of the rapidly increasing numbers of conferences and monographs published annually. It appears that sources of information that are readily available on-line are greatly preferred over sources that are not available on the internet.

Abt, Helmut A.

458

Sensor/source electrometer circuit  

DOEpatents

A multiple decade electrometer circuit is claimed which can measure low input currents or act as a current source and is comprised of a microprocessor controlled digital to analog converters to derive individual decades. A plurality of decades are created by multiple D-A voltage sources which generate electrometer currents through scaled resistors. After a first series of decades of current are successively produced, the converters are 10 cycled to generate current through new resistors scaled to produce another series decades of current. In this manner, the electrometer circuit generates or senses a plurality of decades of current without significant scale change.

Hughes, W.J.

1991-12-31

459

40 CFR 52.12 - Source surveillance.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Source surveillance. 52.12 Section 52.12...Provisions § 52.12 Source surveillance. (a) Each subpart identifies the plan provisions for source surveillance which are disapproved,...

2013-07-01

460

40 CFR Source - Management (Section 319(h))  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Management (Section 319(h)) Source Nonpoint Source Protection of Environment ENVIRONMENTAL PROTECTION...percent of the approved work plan costs. Nonpoint Source-Management (Section 319(h...

2010-07-01

461

30 CFR 56.4500 - Heat sources.  

Code of Federal Regulations, 2010 CFR

... 1 2009-07-01 2009-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources...Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing combustion shall be...

2009-07-01

462

30 CFR 56.4500 - Heat sources.  

Code of Federal Regulations, 2010 CFR

... 1 2010-07-01 2010-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources...Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing combustion shall be...

2010-07-01

463

30 CFR 57.4500 - Heat sources.  

Code of Federal Regulations, 2010 CFR

... 1 2009-07-01 2009-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources...Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing combustion shall be...

2009-07-01

464

30 CFR 57.4500 - Heat sources.  

Code of Federal Regulations, 2010 CFR

... 1 2010-07-01 2010-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources...Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing combustion shall be...

2010-07-01

465

30 CFR 56.4500 - Heat sources.  

Code of Federal Regulations, 2013 CFR

... 1 2013-07-01 2013-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources...Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing combustion shall be...

2013-07-01

466

30 CFR 57.4500 - Heat sources.  

Code of Federal Regulations, 2013 CFR

... 1 2013-07-01 2013-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources...Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing combustion shall be...

2013-07-01

467

Economics of renewable and nonrenewable energy sources.  

National Technical Information Service (NTIS)

Nonrenewable sources are subject to intertemporal optimization. Electrical and renewable sources, which are exogenous, can be integrated and treated on nonrenewable sources. For typical conditions, the model predicts that prices will increase and flows wi...

G. H. Canavan

1991-01-01

468

Z-source inverter for UPS application  

Microsoft Academic Search

This project proposes an impedance-source inverter and its control method for implementing dc-to-ac, ac-to-dc, ac-to-ac, and dc-to-dc power conversion. The Z-source converter employs a unique impedance network to couple the converter main circuit to the power source. The Z-source converter overcomes the conceptual and theoretical barriers and limitations of the traditional voltage-source converter and current-source converter and provides a novel

R. Senthilkumar; R. Bharanikumar; J. Jerom

2007-01-01

469

Management of disused plutonium sealed sources  

Microsoft Academic Search

The Global Threat Reduction Initiative's (GTRI) Offsite Source Recovery Project (OSRP) has been recovering excess and unwanted radioactive sealed sources since 1999, including more than 2,400 Plutonium (Pu)-238 sealed sources and 653 Pu-239-bearing sources that represent more than 10% of the total sources recovered by GTRI\\/OSRP to date. These sources have been recovered from hundreds of sites within the United

Julia Rose Whitworth; Michael W Pearson; Cristy Abeyta

2010-01-01

470

Mini-conference on helicon plasma sources  

SciTech Connect

The first two sessions of this mini-conference focused attention on two areas of helicon source research: The conditions for optimal helicon source performance and the origins of energetic electrons and ions in helicon source plasmas. The final mini-conference session reviewed novel applications of helicon sources, such as mixed plasma source systems and toroidal helicon sources. The session format was designed to stimulate debate and discussion, with considerable time available for extended discussion.

Scime, E. E.; Keesee, A. M. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Boswell, R. W. [SP3, Australian National University, Canberra (Australia)

2008-05-15

471

Recent ion source development in China (invited)  

SciTech Connect

The recent development of various types of ion sources and their application in China is reviewed. Emphasis is given to new improvements of the electron cyclotron resonance ion source, MEVVA ion source, electron beam evaporation metal ion source, compact multicusp ion source, as well as compact negative ion sources with permanent magnets. Some of the new proposals are also presented. {copyright} {ital 1996 American Institute of Physics.}

Chen, C.; Zhao, W. [Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

1996-03-01

472

Solar power source for a lighting system  

SciTech Connect

A solar recharged power supply circuit for a lighting system which circuit includes a rechargeable power source, a solar powered recharger connected to that rechargeable power source and which circuit prevents discharge of that rechargeable power source through the solar powered recharger during times when the recharger is inactive; prevents overcharging of that power source; prevents discharging that power source below a predetermined level; and automatically connects and disconnects the lighting system to and from the rechargeable power source.

Rogers, W.E.

1982-02-02

473

Microseisms: Coastal and Pelagic Sources.  

National Technical Information Service (NTIS)

Wave-number frequency spectra of seismic background recordings from the large aperture seismic array (LASA) in eastern Montana have been used to study the source locations of different wave types in the frequency band from 40 to 500 m Hz. Microseisms in t...

R. A. Haubrich K. McCamy

1968-01-01

474

Maximum entropy light source placement  

Microsoft Academic Search

Several methods have been proposed to help the user to position lighting sources for a given view of a 3d-scene. In the first kind of methods the user defines a desired illumination through highlight and shadow locations for which the lighting system optimizes the light positions. The more automatic approaches are based on perceptual image metrics. [Marks et al. 1997

Stefan Gumhold

2002-01-01

475

Fission neutron source in Rome  

Microsoft Academic Search

A fission neutron source is operating in Rome at the ENEA Casaccia Research Center since 1971, consisting of a low power fast reactor named RSV-Tapiro. it is employed for a variety of experiments, including dosimetry, material testing, radiation protection and biology. In particular, application to experimental radiobiology includes studies of the biological action of neutrons in the whole-body irradiated animal,

Mario Coppola; V. di Majo; G. Ingrao; S. Rebessi; A. Testa

1997-01-01

476

Variability of Galactic Center Sources  

NASA Astrophysics Data System (ADS)

A broad range of accretion disk models with black hole masses appropriate to the Galactic Center {0.5-3.0 million solar masses} implies variability at the 2-25% level on time scales as short as 10 minutes. As the current literature provides only upper limits for the near-infrared counterpart to the radio source Sgr A*, this proposal endeavors to detect the source as well as observe its variability. An observed light-curve will test general relativistic predictions and will further constrain black hole models. We will search for source flickering by repeated imaging in broadband filters {F160W and F110M} and in [SiVI]. The F160W and F110M filters will provide the best forum for finding a continuum object and establishing its color. The extinction-corrected fluxes can then constrain accretion disk models. [SiVI] is associated with Active Galactic Nuclei, and requires very high densities and temperatures which one would expect in an accretion disk but not in any of the stellar sources in the field.

McCarthy, Donald

1997-12-01

477

Energy Source for Ball Lightning  

Microsoft Academic Search

It is shown that the EM radiation frequencies from external sources required to form ball lightning (according to the Kapitza theory) are emitted during the collision of charged water drops. Calculations show that a reasonable volume of nominally charged drop- lets will provide the energy necessary for the lightning ball, but a prohibitively large volume of ordinary rain drops is

W. H. Andersen

1965-01-01

478

Alternative Nitrogen Sources for Cotton  

Technology Transfer Automated Retrieval System (TEKTRAN)

Several alternative nitrogen (N) sources, rates of N, and amendments were evaluated at Prattville, Alabama, on cotton in 2008. Nitrogen rates reported are for sidedress application only. Dry urea produced the highest yield, averaging 1100 pounds lint per acre. Ammonia volatilization was measured fr...

479

Voltage Controlled Voltage Source (VCVS)  

NSDL National Science Digital Library

Hosted by Clarkson University, this applet demonstrates a circuit that contains a voltage controlled voltage source (VCVS). The gain may be modified using the scroll bar. Even though brief, this resource can be used in a variety of different technical education classrooms.

Dorf, Richard C.; Svoboda, James A.

2008-11-27

480

Voltage Controlled Current Source (VCCS)  

NSDL National Science Digital Library

Hosted by Clarkson University, this websited contains an applet which demonstrates a circuit that contains a voltage controlled current source (VCCS). The gain of the VCCS can be changed using the scrollbar. This simple resource is a nice representation for a technical education classroom.

Dorf, Richard C.; Svoboda, James A.

2008-11-27

481

Multiple source navigation signal generator  

Microsoft Academic Search

The paper presents a FPGA based digital VOR\\/LOC signal generator. It provides the composite signal, which consists of the particular signals of several predefined navigation sources - VOR beacons. Design of the generator is implemented into the two different FPGA DSP platforms.

Petr Bojda

2010-01-01

482

Multiple source navigation signal generator  

NASA Astrophysics Data System (ADS)

The paper presents a FPGA based digital VOR/LOC signal generator. It provides the composite signal, which consists of the particular signals of several predefined navigation sources - VOR beacons. Design of the generator is implemented into the two different FPGA DSP platforms.

Bojda, Petr

2010-06-01

483

Renewable energy sources for desalination  

Microsoft Academic Search

Renewable energy sources (RES) coupled to desalination offers a promising prospect for covering the fundamental needs of power and water in remote regions, where connection to the public electrical grid is either not cost effective or not feasible, and where the water scarcity is severe. Stand-alone systems for electricity supply in isolated locations are now proven technologies. Correct matching of

Eftihia Tzen; Richard Morris

2003-01-01

484

Ethanol: A Strategic Energy Source.  

National Technical Information Service (NTIS)

As an element of our energy security policy, the United States should encourage the development of alternative energy sources for future U.S. energy needs. The present administration cites our dependence on oil as one of our critical national weaknesses. ...

A. A. Wickham

2009-01-01

485

Future of small energy sources  

Microsoft Academic Search

Industrialization and the concept of economy of scale eliminated the use of many small energy sources and introduced the concept of centralized energy supplies. Small energy resources that can be used where they are produced now appear to have a role as the need for diversification and conservation becomes stronger. Three processes now underway are the expansion of formerly uneconomical

Barnea

1981-01-01

486

Deep space travel energy sources  

Microsoft Academic Search

Exploration of the planets beyond Mars and their surroundings is already planned. Astronomy researchers are citing important information that can be obtained with instrumented spacecraft that fly beyond the planets of our solar system. Spacecraft flying these missions need power for performing their functions and communicating with Earth stations. Sunlight in these zones is so weak that alternative energy sources

H. Oman

2003-01-01

487