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Sample records for lbl aecr source

  1. Improvements on the LBL AECR source

    SciTech Connect

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

    1995-04-01

    Performance of the LBL AECR source was improved by simultaneously heating the plasma with microwaves of 10 and 14 GHz (two-frequency heating). Plasma stability was improved.and the ion charge state distribution shifted to higher charge state. Production of high charge state ions was increased a factor of 2 to 5 or higher for the very heavy ions such as bismuth and uranium, as compared to the case of single-frequency (14 GHz) heating. Fully stripped argon ions at intensity I {ge} 5 enA were directly identified by the AECR charge state analyzing system for the first time. High charge state ion beams of bismuth and uranium produced by the source were injected into the 88-Inch Cyclotron. After acceleration to energies greater than 6 MeV/nucleon, the extracted beam intensities were 1{times}10{sup 6}pps or higher for Bi{sup 50+,51+} and {sup 238}U{sup 52+,53+}. Tests in the AECR source have also shown Al{sub 2}O{sub 3} coating is an effective coating and a better method than the electron gun for providing cold electrons to the ECR plasma. The AECR source will be upgraded to raise its magnetic field strengths to obtain better plasma confinement and enhanced production of hi ah charge state heavy ions.

  2. Performance of the LBL AECR source at various frequencies

    SciTech Connect

    Xie, Z.Q.; Lyneis, C.M.; Lundgren, S.A.; Collins, D.

    1992-07-01

    To study the effects of frequency on an electron cyclotron resonance (ECR) ion source, the LBL Advanced ECR ion source (designed to operate at 14 GHz) has been tested at 6.4, 10, and 14 GHz with one plasma chamber (ID = 6.0 cm), a permanent sextuple magnet (``closed sextuple``) with a field strength of 0.84 Tesla at the chamber wall, and no radial vacuum pumping. Pure oxygen was used as the running gas for a fair comparison. The source was tested as a single stage, as well as with cold electron injection using an electron gun in place of a conventional microwave-driven first stage. Higher frequency, with a higher axial magnetic field to ensure a closed ECR zone for electron heating, does give better performance. As demonstrated before, at each frequency electron injection led to about a factor of two increase in the high charge state oxygen beam intensity. The 14 GHz performance of the AECR source with the closed sextuple magnet was compared to the ``slotted sextuple`` (a plasma chamber with radial pumping slots of 7.0-cm dia and a weaker magnet of 0.64 Tesla at the chamber wall). Results show that a stronger sextuple magnet alone does not automatically improve the source performance.

  3. Performance of the LBL AECR source at various frequencies

    SciTech Connect

    Xie, Z.Q.; Lyneis, C.M.; Lundgren, S.A.; Collins, D.

    1992-07-01

    To study the effects of frequency on an electron cyclotron resonance (ECR) ion source, the LBL Advanced ECR ion source (designed to operate at 14 GHz) has been tested at 6.4, 10, and 14 GHz with one plasma chamber (ID = 6.0 cm), a permanent sextuple magnet ( closed sextuple'') with a field strength of 0.84 Tesla at the chamber wall, and no radial vacuum pumping. Pure oxygen was used as the running gas for a fair comparison. The source was tested as a single stage, as well as with cold electron injection using an electron gun in place of a conventional microwave-driven first stage. Higher frequency, with a higher axial magnetic field to ensure a closed ECR zone for electron heating, does give better performance. As demonstrated before, at each frequency electron injection led to about a factor of two increase in the high charge state oxygen beam intensity. The 14 GHz performance of the AECR source with the closed sextuple magnet was compared to the slotted sextuple'' (a plasma chamber with radial pumping slots of 7.0-cm dia and a weaker magnet of 0.64 Tesla at the chamber wall). Results show that a stronger sextuple magnet alone does not automatically improve the source performance.

  4. Beam acceleration in the LBL 88-inch cyclotron with injection from the AECR source

    SciTech Connect

    Clark, D.J.; Lyneis, C.M.; Xie, Zuqi.

    1991-05-01

    The new Advanced ECR (AECR) source is being developed for the 88-Inch Cyclotron at Lawrence Berkeley Laboratory. It operates at 14.5 GHz, compared to 6.4 GHz for the present LBL ECR source. An electron gun injects electrons into the plasma chamber to increase the production of high charge state ions. The first AECR beams were injected into the cyclotron in June of 1990 and since then a variety of ion species from the AECR have been accelerated, including beams from oxygen at 32 MeV/u to bismuth at 4.6 MeV/u. A Xe{sup 32+} beam of 1054 MeV or 8 MeV/u was accelerated. 4 refs., 3 figs., 2 tabs.

  5. Preliminary performance of the LBL AECR

    SciTech Connect

    Lyneis, C.M.; Xie, Zuqi; Clark, D.J.; Lam, R.S.; Lundgren, S.A.

    1990-11-01

    The AECR source, which operates at 14 GHz, is being developed for the 88-Inch Cyclotron at Lawrence Berkeley Laboratory. The AECR has been under source development since December 1989, when the mechanical construction was completed. The first AECR beams were injected into the cyclotron in June of 1990 and since then a variety of ion species from the AECR have been accelerated. The cyclotron recently accelerated {sup 209}Bi{sup 38+} to 954 MeV. An electron gun, which injects 10 to 150 eV electrons into the plasma chamber of the AECR, has been developed to increase the production of high charge state ions. With the electron gun the AECR has produced at 10 kV extraction voltage 131 e{mu}A of O{sup 7+}, 13 e{mu}A of O{sup 8+}, 17 e{mu}A of Ar{sup 14+}, 2.2 e{mu}A of Kr{sup 25+}, 1 e{mu}A of Xe{sup 31+}, and 0.2 e{mu}A of Bi{sup 38+}. The AECR was also tested as a single stage source with a coating of SiO{sub 2} on the plasma chamber walls. This significantly improved its performance compared to no coating, but direct injection of electrons with the electron gun produced the best results. 5 refs., 6 figs., 4 tabs.

  6. Recent developments on ECR sources at LBL

    SciTech Connect

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

    1993-05-05

    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.

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

    SciTech Connect

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

    2011-07-01

    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.

  8. The LBL advanced light source

    SciTech Connect

    Jackson, A.; Chattopadhyay, S.; Keller, R.; Kim, C.; Nishimura, H.; Selph, F.; Zisman, M.

    1988-06-01

    The LBL Advanced Light Source (ALS) will be a third generation synchrotron radiation facility. It is based on a low emittance 1--2 GeV electron storage ring (natural radial emittance <10 nm-rad), optimized to produce extremely bright beams of electromagnetic radiation (in the energy range from a few eV to around one keV) from insertion devices known as undulators. The storage ring is fed from an injection system consisting of a 50 MeV linac and a 1.5 GeV, 1 Hz, booster synchrotron, which can fill the ring to its normal operating current (400 mA, multibunch, or 7.6 mA, single bunch) in a few minutes. As well as high brightness (which is a consequence of the very small electron beam emittance in the storage ring), the design emphasizes: picosecond timestructure, laserlike coherence properties, narrow bandwidth, and long beam lifetimes. The more familiar continuous synchrotron radiation spectrum will be available from bending magnets and from wiggler magnets. This paper gives a general description of the ALS and discusses some of the significant design issues associated with the low emittance storage ring that is required for this new facility. 7 refs., 6 figs., 2 tabs.

  9. Operating experience with the LBL ECR source

    SciTech Connect

    Lyneis, C.M.

    1987-12-01

    The overall performance of the LBL ECR source in providing beam for the 88-Inch Cyclotron has been excellent. However, during the past two years there have been some fluctuations in the peak performance, particularly for the highest charge states. Among the factors which influence the peak performance are coatings from solid feeds or gases such as SiH/sub 4/ or CO/sub 2/, changes in first stage output, and variation in outgassing rates on the wall. Modifications made to the source have also affected its performance. In the plasma chamber the screens between the sextupole bars were removed to lower its Q/sub 0/. When the 9.2 GHz klystron used to power the first stage failed, it was replaced by a 10.3 GHz klystron. Tests were also made using 6.4 GHz to drive both first and second stages. The source performance in these various configuration will be reviewed.

  10. Performance of the LBL ECR ion source

    SciTech Connect

    Lyneis, C.M.

    1984-10-01

    The LBL Electron Cyclotron Resonance (ECR) ion source in test operation since January 1984 has produced a wide variety of high charge state ion beams suitable for injection into the 88-Inch Cyclotron. Two recent developments have dramatically improved the capability of the ECR source. The first development was the production of metallic ions. The intensities of aluminum ions produced were 36, 22, 10, and .065 e..mu..A for charge states 6, 7, 8, and 11, respectively. Calcium ion intensities were 36, 31, 4.6, and 0.20 e..mu..A for charge states 8, 9, 12, and 14, respectively. The second development was the replacement of the sextupole magnet used in of all other high charge state ECR sources with an octupole structure. This modification resulted in a dramatic improvement in the intensities of the high charge state beams and a significant upward shift in the charge state distribution (C.S.D.). The ECR-octupole or OCTIGUN has produced 89, 52, 9, and 2.5 e..mu..A of Ar/sup 8,9,11,12+/ and 21, 10, and 0.34 e..mu..A of Kr/sup 10,14,18+/, respectively. For the high charge states of argon and krypton the improvement gained by using the octupole is typically a factor of 5 to 10.

  11. Vacuum ARC ion sources - activities & developments at LBL

    SciTech Connect

    Brown, I.

    1996-08-01

    The author describes work at LBL on the development and application of vacuum arc ion sources. Work has been done on vacuum spark sources - to produce very high charge states, studies of high charge states in magnetic field, hybrid ion source operation on metal/gas plasma, multipole operation, work on MEVVA V for implantation applications, development of broad beam sources, and removal of particles from the output of the source.

  12. The atomic physics facility at the LBL ECR Source

    SciTech Connect

    Clark, D.J.; Lyneis, C.M.; Prior, M.H.; Stokstad, R.G.; Chantrenne, S.; Egan, P.O.

    1989-04-01

    A low energy beam line facility for atomic and surface physics research has been added to the injection line of the ECR source at the LBL 88-Inch Cyclotron. Beams throughout the periodic table can be delivered to 3 beam line stations at energies up to 15 Q keV. Experiments using this facility include forbidden line emission from the ion beam, ion-atom collisions, merged electron-ion beams and sputtering by highly charged ions. 9 refs., 4 figs.

  13. Vacuum system for the LBL advanced light source (ALS)

    SciTech Connect

    Kennedy, K.

    1988-09-30

    A 1.5 to 1.9 GeV synchrotron light sources is being built at LBL. The vacuum system is designed to permit all synchrotron photons on the median plane to escape the electron channel and go into an antechamber through a 10 mm high slot. This slot offers effective RF isolation between the electron duct and the antechamber. All unused synchrotron photons within a few mrad of the median plane will be stopped by 96 nearly horizontal absorbers located in the antechamber. The gas, generated by the photons hitting the absorbers, will be directed down to reactive titanium surfaces.

  14. Recent developments of the LBL ECR ion source

    SciTech Connect

    Lyneis, C.M.

    1986-05-01

    The performance of the LBL ECR has improved significantly since January 85 when the last ECR Ion Source Workshop was held in Berkeley. The 88-Inch Cyclotron began regular operation with the ECR source just prior to the workshop. Since then about 80% of the cyclotron operating schedule has been with the ECR source. The light-ion filament source is used only for runs two or more shifts in length using proton, /sup 3/He, or alpha beams. Occasionally the polarized ion source is used. The heavy-ion PIG sources are not longer used. The operating experience with the Cyclotron+ECR has been highly successful in terms of reliability, stability, production of high charge state currents, and in the range of ions which can be produced. For example, a 32.5 MeV/u /sup 16/O/sup 8 +/ beam was developed and successfully used for a nuclear structure experiment. The 60 nA beam available from the cyclotron was more intense than the experiment could use. A 1.08 GeV /sup 36/Ar/sup 18 +/ beam was used to test the response of various scintillator materials to intermediate energy heavy ions. Three aspects of the LBL ECR source development are discussed. First, the installation of a new first stage cavity has resulted in improved source performance. Second, a number of metal ion beams have been developed and are used regularly for nuclear science experiments with the cyclotron. Third, the source performance has been compared to charge state distribution (CSD) calculations using a computer code.

  15. Progress on the LBL ECR heavy ion source

    SciTech Connect

    Clark, D.J.; Jongen, Y.; Lyneis, C.M.

    1984-04-01

    The LBL ECR ion source, which began test operation in January 1984, has already produced a variety of high charge state heavy ion beams of sufficient intensity for cyclotron operation, although actual use must wait for completion of the beam transport system. The source has produced 40 ..mu..A of O/sup 6 +/, 2 ..mu..A of O/sup 7 +/, 40 ..mu..A of Ar/sup 8 +/, and 0.20 ..mu..A of Ar/sup 12 +/. The source development has centered on optimizing source performance with modifications and parameter tuning. Future plans include construction of an SmCo/sub 5/ octupole structure, and testing of solid feed techniques. The construction of the beam transport line and calculations on center region geometry for heavy ion axial injection into the 88-Inch Cyclotron are also underway.

  16. Operation of the LBL ECR source injection system

    SciTech Connect

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

    1986-10-01

    The injection system for the LBL 88-Inch Cyclotron ECR source has been in operation since October 1984. It consists of 7 meters of horizontal beam line following the ECR source analyzing magnet, and 4 meters of vertical beam line down the axis of the cyclotron. Beams throughout the cyclotron energy range of 1 to 32 MeV/u, and particles from protons to xenon have been injected and accelerated in the cyclotron on 1st, 3rd, 5th and 7th harmonic modes. A non-scaling mode of operation is used in which a source voltage of about 10 kV is used for all beams. The overall transmission from source analyzing magnet to cyclotron external beam is typically 10%. The reliability and stability of the system has been excellent.

  17. Vacuum system for the LBL Advanced Light Source (ALS)

    SciTech Connect

    Kennedy, K.; Henderson, T.; Meneghetti, J. )

    1989-03-01

    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 the antechambers will be pumped by titanium sublimation pumps located directly under the absorbers. The electron channel and the antechamber are connected by a 10-mm-high slot that offers good electrodynamic isolation of the two chambers of frequencies affecting the store electron orbit. Twelve 10-meter-long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. Machining both the inside and outside of the vacuum chamber permits the use of complex and accurate surfaces. The use of thick plates allows flanges to be machined directly into the wall of each chamber, thus avoiding much welding. 1 ref., 3 figs.

  18. Vacuum system for the LBL advanced light source (ALS)

    SciTech Connect

    Kennedy, K.

    1988-05-01

    A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit all synchrotron photons on the median plane to escape the electron channel and go into an antechamber through a 10 mm high slot. This slot offers effective RF isolation between the electron duct and the antechamber. All unused synchrotron photons within a few mrad of the median plane will be stopped by 96 nearly horizontal absorbers located in the antechamber. The gas, generated by the photons hitting the absorbers, will be directed down to reactive titanium surfaces. Twelve 10 meter long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. The nominal wall thickness of the vacuum chamber is 40 mm, which makes it possible to machine a flange into the chamber without the use of welding. 5 refs., 5 figs.

  19. The LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron operating with an ECR source

    SciTech Connect

    Clark, D.J.

    1986-10-01

    The features and operation of the LBL 88-inch Cyclotron are described, including its ECR source, injection system, and the cyclotron center region. The beams that have been accelerated at the cyclotron are discussed. (LEW)

  20. Characterization of the plasma-switch interaction in the LBL HIF ion source

    SciTech Connect

    Hewett, D.W. ); Rutkowski, H.L. )

    1990-01-01

    A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.

  1. Characterization of the plasma-switch interaction in the LBL HIF ion source

    SciTech Connect

    Hewett, D.W. ); Rutkowski, H.L. )

    1990-12-10

    A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.

  2. Concept for a third generation ECR source at LBL

    SciTech Connect

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

    1995-04-01

    Although the Advanced Electron Cyclotron Resonance ion source has produced record high charge state beams and is now in operation with the 88-Inch Cyclotron, development of a third generation ECR source could provide major new research opportunities at the 88-Inch Cyclotron. Higher intensities for particles with mass greater than 150 and energies above the Coulomb barrier would improve experiments using deep inelastic reactions to produce neutron rich compound nuclei that can be studied with the Gammasphere detector or its successor. Very high intensities (several particle {mu}A from the cyclotron) for masses between 30 to 65 would greatly benefit the heavy element research. On the basis of on progress in ECR source development, a third generation ECR source with multiple-frequency microwave drives, enhanced magnetic mirror ratios and high secondary emission walls for additional cold electrons could extend the performance of the cyclotron into the areas described above and serve as a tool for ECR study.

  3. Insertion devices for the Advanced Light Source at LBL

    SciTech Connect

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

    1989-03-01

    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.

  4. Scientific program of the Advanced Light Source at LBL

    SciTech Connect

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

    1991-10-01

    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.

  5. H/sup -/ ion source scaling studies at LBL

    SciTech Connect

    Lietzke, A.F.; Hauck, C.A.

    1987-07-30

    Four experiments are reported: 1) Constant arc voltage operation was compared with constant arc current operation over a similar range of plasma density. The higher arc voltage required in the constant arc current operation produced more H/sup -/, but it was at the expense of an even larger increase in the accelerated electron current. 2) A comparison of different magnetic filter locations showed the highest accelerated H/sup -/ and the lowest e/sup -/ content at the closest filter location. 3) Beam-forming electrode aperture comparison for round apertures from 2mm to 10mm diameters and an 11 x 27mm oval slot showed a decreasing H/sup -/ and e/sup -/ with increasing aperture area. 4) Increasing accelerator voltage produced an increasing plasma potential and electron temperature and decreasing electron density in the exit chamber of the plasma source.

  6. H/sup -/ ion source scaling studies at LBL

    SciTech Connect

    Lietzke, A.F.; Hauck, C.A.

    1986-10-01

    Four experiments are reported. Constant arc voltage operation was compared with constant arc current operation over a similar range of plasma density. The higher arc voltage required in the constant arc current operation produced more H/sup -/, but it was at the expense of an even larger increase in the accelerated electron current. A comparison of different magnetic filter locations showed the highest accelerated H/sup -/ and the lowest e/sup -/ content at the closest filter location. Beam-forming electrode aperture comparison for round apertures from 2mm to 10mm diameters and a 11 x 27 mm oval slot showed a decreasing H/sup -/ and e/sup -/ with increasing aperture area. Increasing accelerator voltage produced an increasing plasma potential and electron temperature and decreasing electron density in the exit chamber of the plasma source.

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

    SciTech Connect

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

    1984-08-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1985-08-01

    Positive ion based neutral beam development has centered on the long pulse, advanced positive ion source (APIS). The APIS 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 NFTF-E Project. The test consisted of 500 beam shots with 80kV, 30 second deuterium. The results of LBL testing, in which the LBL APIS demonstrated that it would meet the requirements for MFTF-B 30 second sources are summarized. 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.

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

    SciTech Connect

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

    1986-12-01

    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.

  10. The production of beams from solid materials at the LBL ECR source

    SciTech Connect

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

    1988-09-01

    Two ovens are described for the feed of vapor from solid materials in the LBL ECR source. A low temperature oven, operating up to 700 /degree/ C, has been used for Li, Mg, P, K, Ca, Ti and Bi. A high temperature oven operating up to 2000/degree/C, has been used for Sc, Fe, Ni, Cu, Ag, La and Tb. At the 1 e..mu..A level the charge states from the oven beams are very close to those from gases. 4 refs., 5 figs., 2 tabs.

  11. An ECR heavy-ion source for the LBL 88-inch cyclotron

    SciTech Connect

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

    1983-08-01

    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 O/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.

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

    SciTech Connect

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

    1983-03-01

    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.

  13. The Advanced Light Source at the Lawrence Berkeley Laboratory (ALS, LBL)

    SciTech Connect

    Jackson, A.

    1990-08-01

    The Advanced Light Source (ALS), a national facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation, in the energy range from a few eV to 10 keV. The design is based on a 1-1.9 GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. In this paper we describe the main accelerator components of the ALS, the variety of insertion devices, the radiation spectra expected from these devices, and the complement of experiments that have been approved for initial operation, starting in April 1993.

  14. First operation of the LBL ERC ion source with the 88-inch cyclotron

    SciTech Connect

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

    1985-05-01

    The LBL ECR ion source and new injection system are now in regular operation with the 88-Inch Cyclotron supplying stable, reliable heavy ion beams for both nuclear physics and applied research. The ions accelerated to date cover the mass range from nitrogen to xenon, and the energy range of 3 to 27 MeV/nucleon. Overall transmission of up to 14% from source to external cyclotron beam has been obtained. A beam from solid material, magnesium, has been used successfully for an experimental run. The emittance has been measured, at 10 kV accelerating voltage, for a variety of ions and has been found to vary from 100..pi.. mm mrad for the low charge states to 20..pi.. mm mrad for high charge states, for about 50% of the beam. 10 refs., 1 fig., 2 tabs.

  15. First operation of the LBL ECR ion source with the 88-inch cyclotron

    SciTech Connect

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

    1985-10-01

    The LBL ECR ion source and new injection system are now in regular operation with the 88-Inch Cyclotron supplying stable, reliable heavy ion beams for both nuclear physics and applied research. The ions accelerated to date cover the mass range from nitrogen to xenon, and the energy range of 3 to 27 MeV/nucleon. Overall transmission of up to 14% from source to external cyclotron beam has been obtained. A beam from solid material, magnesium, has been used successfully for an experimental run. The emittance has been measured, at 10 kV accelerating voltage, for a variety of ions and has been found to vary from 100..pi.. mm mrad for the low charge states to 20..pi.. mm mrad for high charge states, for about 50% of the beam.

  16. Dynamic response analysis of the LBL Advanced Light Source synchrotron radiation storage ring

    SciTech Connect

    Leung, K.

    1993-05-01

    This paper presents the dynamic response analysis of the photon source synchrotron radiation storage ring excited by ground motion measured at the Lawrence Berkeley Laboratory advanced light source building site. The high spectral brilliance requirement the photon beams of the advanced light source storage ring specified displacement of the quadrupole focusing magnets in the order of 1 micron in vertical motion.There are 19 magnets supported by a 430-inch steel box beam girder. The girder and all magnets are supported by the kinematic mount system normally used in optical equipment. The kinematic mount called a six-strut magnet support system is now considered as an alternative system for supporting SSC magnets in the Super Collider. The effectively designed and effectively operated six-strut support system is now successfully operated for the Advanced Light Source (ALS) accelerator at the Lawrence Berkeley Laboratory. This paper will present the method of analysis and results of the dynamic motion study at the center of the magnets under the most critical excitation source as recorded at the LBL site.

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

    SciTech Connect

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

    1989-06-01

    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.

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

    SciTech Connect

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

    1990-01-01

    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 diam 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 downtime. 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 MEVVA V were fabricated using a particularly simple technique, and they are clamped into position and can thus be changed simply and quickly. The electrical system used to drive the arc is particularly simple and incorporates several attractive features. In this article we review and describe a number of the mechanical and electrical design features that have been developed for these sources.

  19. The magnet lattice of the LBL 1-2 GeV Synchrotron Radiation Source

    SciTech Connect

    Jackson, A.

    1987-03-01

    This paper describes the magnet chosen for the LBL 1-2 GeV Synchrotron Radiation Source. The structure has a circumference of 196.8 m, with 12 dispersion free straight sections that can accommodate insertion devices up to 5 m long. The achromatic arcs that connect these straight sections feature combined function (gradient) bending magnets. Utilization of three such magnets in the so-called three-bend-achromat (TBA) arrangement, has several beneficial effects: (1) it reduces the amplitude of the vertical beta-function in the bending magnets, thereby minimizing the required aperture; (2) it changes the damping partition number in such a way as to reduce the natural emittance; and (3) it produces separation of the beta-functions such that relatively low sextupole strengths are sufficient for chromatic correction. The result is a structure with very low emittance (4 nm-rad at 1.5 GeV) that is correctable with only two families of sextupoles while maintaining excellent chromatic properties and acceptable dynamic aperture. In this paper we describe the details of the storage ring and discuss the characteristic features of the lattice.

  20. Characteristics of the negative ion beam extracted from an LBL multicusp volume source

    SciTech Connect

    Debiak, T.W.; Solensten, L.; Sredniawski, J.J.; Ng, Y.C.; Heuer, R. )

    1990-01-01

    This work encompasses a study of the beam position, profile, and emittance of a Lawrence Berkeley Lab (LBL) multicusp volume source. The study includes a comparison of different extraction geometries with single- and multiple-hole apertures. Our work is currently based on single-gap extraction and acceleration. These experiments are the first of a planned series of studies with various extractor geometries. The beam profile full width at half-maximum ranged from 5.7 to 10.2 mm at a position 69 mm from the emission aperture. Measurements of profile and position in the vertical direction indicate that the beam is significantly bent in the direction expected due to the field of the electron separation magnet. Phase space contour plots in the horizontal plane have been obtained for circular extraction apertures with a diameter of 1.0 and 2.0 mm, and a multiple-hole aperture with an overall diameter of 2.46 mm. Emittances were calculated to be as low as 0.0010 {pi} cm mrad for the 1-mm aperture and 0.0014 {pi} cm mrad for the 2-mm aperture. Emittances are not reported for the multiple-hole aperture due to the shape of the phase space contours; however, analysis of the data is in progress to provide a meaningful comparison of the single-hole and multiple-hole beam characteristics.

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

    SciTech Connect

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

    1989-08-01

    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 utilizing Nd-Fe-B permanent magnet material and Vanadium Permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is with permanent magnet rotators. The supports structure features a 4-post configuration, a rigid base with 3 kinematic floor supports and 2 rigid 5 m long backing beams that fit within the 2.4 m high accelerator enclosure. The drive system is computer controlled utilizing a stepper motor and shaft encode coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps. 5 figs., 1 tab.

  2. Operational performance of the LBL 88-inch cyclotron with an ECR (Electron Cyclotron Resonance) source

    SciTech Connect

    Lyneis, C.M.

    1986-10-01

    The 88-Inch Cyclotron began regular operation with the ECR (Electron Cyclotron Resonance) source in January 1985. Since then about 80% of the cyclotron operating schedule has been with the ECR source. The light-ion filament source is used only for runs two or more shifts in length using proton, deuteron, /sup 3/He, or alpha beams. Occasionally the polarized ion source is used. The heavy-ion PIG sources are no longer used. The operating experience with the Cyclotron + ECR has been highly successful in terms of reliability, stability, production of high charge state currents, and range of ions which can be produced. The performance of the Cyclotron + ECR has steadily improved since regular operation began. The improvement is a result of better source performance, better stability and tuning of the injection line, and better cyclotron tuning. Development of the ECR source has resulted in improved high charge state performance and a greater variety of ion species. The LBL ECR now produces 14 ..mu..A of O/sup 7 +/, 1 ..mu..A of O/sup 8 +/, 72 ..mu..A of Ar/sup 9 +/, 1.4 ..mu..A of Ar/sup 14 +/, 5 ..mu..A of I/sup 25 +/, and .009 ..mu..A of I/sup 30 +/. Metal ions from Mg, K, and Ca are produced in the ECR using an oven to inject vapor into the plasma chamber. Operation with the oven is quite stable and frequently requires no adjustment during runs lasting several days. Beams of F, Si, S, and Ti have been produced using various compounds as gases or solids with the oven. The overall transmission from source analyzing magnet to cyclotron external beam is typically 2 to 10% with a maximum of 17%. As a result of the improved source performance and transmission a wide variety of new beams can be produced. For example, a 32.5 MeV/u /sup 16/O/sup 8 +/ beam and /sup 48/Ca/sup 11 +/ beams with energy from 200 to 350 MeV have been used for nuclear physics experiments. A 1.08 GeV /sup 36/Ar/sup 18 +/ beam was used to test the response of various scintillator materials to intermediate energy heavy ions.

  3. High performance single stage operation of the LBL ECR and the design of an advanced ECR ion source

    SciTech Connect

    Lyneis, C.M.

    1988-09-01

    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 nitrogen, oxygen, and argon. The critical parameter for this mode appears to be conditioning the plasma chamber walls with a coating of SiO/sub 2/. Various models to explain this effect will be discussed along with implications for ECR ion source design. A new Advanced ECR ion source which will operate at 14 GHz is being designed for the 88-Inch Cyclotron. Construction is scheduled to begin in the fall of 1988 and test operation should begin in the fall of 1989. The design includes hollow core copper wire solenoids, iron yoke, a Nd-Fe-B sextupole, radial pumping, and access to the plasma chamber. 8 refs., 4 figs., 1 tab.

  4. First experimental results from IBM/TENN/TULANE/LLNL/LBL undulator beamline at the advanced light source

    SciTech Connect

    Jia, J.J.; Callcott, T.A. ); Yurkas, J.; Ellis, A.W.; Himpsel, F.J. ); Samant, M.G.; Stoehr, J. ); Ederer, D.L. ); Carlisle, J.A.; Hudson, E.A.; Terminello, L.J. ); Shuh, D.K.; Perera, R.C.C. )

    1995-02-01

    The IBM/TENN/TULANE/LLNL/LBL Beamline 8.0 at the advanced light source combining a 5.0 cm, 89 period undulator with a high-throughput, high-resolution spherical grating monochromator, provides a powerful excitation source over a spectral range of 70--1200 eV for surface physics and material science research. The beamline progress and the first experimental results obtained with a fluorescence end station on graphite and titanium oxides are presented here. The dispersive features in K emission spectra of graphite excited near threshold, and found a clear relationship between them and graphite band structure are observed. The monochromator is operated at a resolving power of roughly 2000, while the spectrometer has a resolving power of 400 for these fluorescence experiments.

  5. Injection system design for the LBL (Lawrence Berkeley Laboratory) 1-2 GeV synchrotron radiation source

    SciTech Connect

    Selph, F.; Jackson, A.; Zisman, M.S.

    1987-03-01

    The injection system for the LBL 1 to 2 GeV Synchrotron Radiation Source is designed to provide an electron beam of 400 mA at 1.5 GeV to the storage ring in a filling time of less than 5 minutes. An alternate mode of operation requires that 7.6 mA be delivered to one, or a few rf bunches in the storage ring. To accomplish these tasks, a high intensity electron gun, a 50 MeV electron linac, and a 1.5 GeV booster synchrotron are used. The performance requirements of the injector complex are summarized. The electron gun and subharmonic buncher, linac design, and linac to booster and booster to storage ring transport are discussed as well as the booster synchrotron. (LEW)

  6. Low emittance 0.8A K{sup +} ion source for the LBL Induction Linac System Experiment (ILSE)

    SciTech Connect

    Eylon, S.; Henestroza, E.; Chupp, W.W.; Yu, S.

    1993-05-01

    A high current injector for heavy ion fusion presently under construction at Lawrence Berkeley Laboratory requires large sources of up to 17 an in diameter and total potassium ion current of 790 mA with a low normalized transverse emittance of less than 0.5 mm-mr. A 1 in. diameter hot alumina silicate (zeolite) source was fabricated and tested in the injector setup of SBTE, an existing facility at LBL. Initial measurements showed a maximum space charge limited ion current of 95 mA. The corresponding density of 19 mA/cm{sup 2} was limited by the source diode optics and not be the source emission. The density required for the high current injector is 4 mA/cm{sup 2}. The normalized emittance was measured to be 0.06 mm-mrad, corresponding to a transverse temperature of 0.2 eV. Non-destructive life tests showed that the source can be operated under continuous operating conditions of the high current injector for more than a month (twenty eight-hour days, with 1 {mu}s long pulses at 1 Hz). D.C. destructive life tests showed that {approximately}30% of the total stored K can be ionized and extracted, allowing, in principle, for years of operation for the high current injector. Furthermore, we shall describe the extension of the fabricating technique to large diameter sources (up to 17 cm) and report on measured ion emission performance, measured surface temperature uniformity and heating power considerations.

  7. 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

    Jackson, A.; Nishimura, H.

    1987-03-01

    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)

  8. The LBL (Lawrence Berkeley Laboratory) 1-2 GeV synchrotron radiation source

    SciTech Connect

    Cornacchia, M.

    1987-03-01

    A description is presented of the conceptual design of the 1 to 2 GeV Synchrotron Radiation Source proposed for construction at Lawrence Berkeley Laboratory. This facility is designed to produce ultraviolet and soft x-ray radiation. The accelerator complex consists of an injection system (linac plus booster synchrotron) and a low-emittance storage ring optimized for insertion devices. Eleven straight sections are available for undulators and wigglers, and up to 48 photon beam lines may ultimately emanate from bending magnets. Design features of the radiation source are the high brightness of the photon beams, the very short pulses (tens of picoseconds), and the tunability of the radiation.

  9. The LBL 1-2 GeV synchrotron radiation source

    SciTech Connect

    Selph, F.B.

    1987-06-01

    The design of the 1 to 2 GeV Synchrotron Radiation Source to be built at the Lawrence Berkeley Laboratory is described. The goal of this facility is to provide very high brightness photon beams in the ultraviolet and soft x-ray regions. The photon energy range to be served is from 0.5 eV to 10 keV, with the brightest beams available in the 1 eV to 1 keV interval. For time-resolved experiments, beam pulses of a few tens of picoseconds will be available. Emphasis will be on the use of undulators and wigglers to produce high quality, intense beams. Initially, four of the former and one of the latter devices will be installed, with six long straight sections left open for future installations. In addition, provision is being made for 48 beamlines from bending magnets. The storage ring is optimized for operation at 1.5 GeV, with a maximum energy of 1.9 GeV. The injection system includes a 1.5 GeV booster synchrotron for full energy injection at the nominal operating energy of the storage ring. Filling time for the maximum storage ring intensity of 400 mA is about 2 minutes, and beam lifetime will be about 6 hours. Attention has been given to the extraordinary requirements for beam stability, and to the need to independently control photon beam alignment. Typical rms beam size in insertion regions is 201 ..mu..m horizontal, and 38 ..mu..m vertical. The manner in which this design achieves very high spectral brightness from undulators and wigglers, while maintaining a modest value for the beam current, will be described. Primarily, this requires that the design of the lattice, the arrangement of bending magnets, focusing quadrupoles and straight sections, be done with this in mind.

  10. LBL computing newsletter

    SciTech Connect

    Not Available

    1985-07-01

    The LBL Computing Newsletter for July, 1985 summarizes information relating to the use of LBL computing facilities. Topics covered include 8600 VMS printers, electronic mail, CSA2, DECnet and several other systems. A section on personal computers is included which discusses discounts on computers and software.

  11. LBL computing newsletter

    SciTech Connect

    Not Available

    1985-02-01

    The LBL Computing Newsletter for February, 1985 summarizes information relating the the use of LBL computing facilities. Topics covered include terminals and screen management on VAX/VMS V 4.0, UNIX, Berkeley ISP and modems. A section on personal computers is included.

  12. News from LBL

    SciTech Connect

    Furman, M.A.

    1994-01-26

    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.

  13. RFQ development at LBL

    SciTech Connect

    Staples, J.

    1984-01-01

    LBL's interest in RFQ accelerators goes back to 1978. We have developed, constructed and operated a heavy ion machine that is the central part of an upgrade project in which our old proton injector linac is converted to a light ion injector system. We are now designing a second heavy ion RFQ linac which will be used at CERN for the injection of light ions into the PS complex. Other RFQ accelerators are under study for possible additional projects. LBL has pioneered new techniques, such as the vane mounting and adjusting mechanism, and the electrical shorting rings which stabilize the cavity field distribution. In conjunction with INS, Tokyo, a new design procedure has been derived, optimized for low current, heavy ion RFQ's which results in a short, efficient structure. LBL has had considerable operational experience with an Alvarez structure operated at high gradients for several years. As the operational characteristics of an RFQ improve dramatically with surface field, our experience with this operation and its implications for future RFQ linacs is discussed. 12 references.

  14. Calibration results of the ebit medium-energy flat-field spectrometer using the LBL advanced light source

    SciTech Connect

    Lepson, J K; Beiersdorfer, P; Brown, G V; Chen, H; Gullikson, E M; Schneider, M B; Utter, S B; Wong, K L

    2001-01-17

    The relative instrument response function of a flat-field grating extreme ultraviolet spectrometer was determined using the ALS synchrotron source in the wavelength region 40-200 {angstrom}. Details of the calibration procedure and results are given in the report.

  15. RFQ development at LBL

    SciTech Connect

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

    1982-11-01

    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.

  16. RFQ development at LBL

    SciTech Connect

    Abbott, S.; Brodzik, D.; Gough, R.A.; Howard, D.; Lancaster, H.; Mac Gill, R.; Rovanpera, S.; Schneider, H.

    1983-04-01

    The radio frequency quadrupole (RFQ) 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.

  17. LBL industry review

    SciTech Connect

    Benoit, D. )

    1993-01-01

    This is a general summary of a meeting on March 16, 1993 of the LBL Industry Review Panel on Exploration and Reservoir Technology. It met in three subpanels to consider (1) exploration for new discoveries (2) mapping reservoir properties and monitoring production/injection (3) well testing, reservoir simulation, and predicting future reservoir performance. This very brief meeting only allowed very broad coverage of concerns. There is a growing commercial development of liquid based geothermal reservoirs, and they are encountering problems for which they are asking for research dollars. This will probably cause a shift in research spending as there is a limited number of dollars available, and the vapor based Geysers has received most funding to this point. All three panels felt the need to see more case studies, whether they reached positive or negative conclusions. This may be forthcoming as consolidation in the industry is reducing the need to shield information from competitors.

  18. Beam Dynamics Activities and Plans at LBL

    SciTech Connect

    Chattopadhyay, S.

    1988-07-01

    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.

  19. Multi-beam injector development at LBL

    SciTech Connect

    Rutkowski, H.L.; Faltens, A.; Brodzik, D.A.; Johnson, R.M.; Pike, C.D.; Vanecek, D.L. ); Humphries, S. Jr. ); Meyer, E.A. ); Hewett, D.W. )

    1990-06-01

    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.

  20. 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

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

    1989-03-01

    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.

  1. Calculation of collective effects and beam lifetimes for the LBL (Lawrence Berkeley Laboratory) 1-2 GeV synchrotron radiation source

    SciTech Connect

    Chattopadhyay, S.; Zisman, M.S.

    1987-03-01

    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 1-2 GeV storage ring. In addition, we estimate the growth times for both longitudinal and transverse coupled bunch instabilities. Bunch lengths of about 20 ps should be obtainable and intrabeam scattering emittance growth is small. For a limiting undulator gap of 1 cm and residual gas pressure of 1n Torr, the beam lifetime is about 5 hours in the single-bunch mode; in the multibunch mode, lifetimes in excess of 6 hours are expected. These results indicate that all performance goals for the facility should be achievable.

  2. Electron Injector Studies at LBL

    SciTech Connect

    Kim, C.H.

    1990-06-01

    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.

  3. Emittance measurements on the LBL ECR source

    SciTech Connect

    Clark, D.J.

    1987-11-01

    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.

  4. Multiple beam induction linac research at LBL

    SciTech Connect

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

    1990-06-01

    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.

  5. Review of technical program and progress. LBL geothermal exploration technology development program, FY 1982

    SciTech Connect

    Goldstein, N.E.

    1982-01-01

    The objectives, method of approach, main program elements, and progress through FY 1982 for Geothermal Exploration Technology Program at LBL are reviewed. Current tasks include controlled-source electromagnetic research, seismological research, magnetotelluric research, and electromagnetic technique evaluation and numerical modeling.

  6. Neutral beam development at LBL/LLNL

    SciTech Connect

    Pyle, R.V.

    1980-10-01

    In a joint program LBL and LLNL are developing and testing neutral beam injection systems based on the acceleration of positive ions, for application in the 80- to 160-keV range on MFTF-B, D III, TFTR/TFM, ETF, MNS, etc. A conceptual design of a 160 keV injection system for the German ZEPHYR project is in progress. For applications at energies above about 200 keV, positive-ion-based system efficiencies are unacceptably low for most applications, and so negative-ion-based systems are being developed also.

  7. Status of LBL/LLNL FEL (free electron laser) research for two beam accelerator applications

    SciTech Connect

    Hopkins, D.B.; Sessler, A.M.

    1989-03-01

    We review the status of free electron laser (FEL) research being conducted at LBL and LLNL as part of a broader program of research on two beam accelerators (TBAs). Induction accelerator-driven FELs for use as power sources for high-gradient accelerators are discussed, along with preliminary cost estimates for this type of power source. Finally, a promising new version of an FEL/TBA is described. 25 refs., 1 fig., 3 tabs.

  8. Guidelines for generators of hazardous chemical waste at LBL and Guidelines for generators of radioactive and mixed waste at LBL

    SciTech Connect

    Not Available

    1991-07-01

    The purpose of this document is to provide the acceptance criteria for the transfer of hazardous chemical, radioactive, and mixed waste to Lawrence Berkeley Laboratory's (LBL) Hazardous Waste Handling Facility (HWHF). These guidelines describe how a generator of wastes can meet LBL's acceptance criteria for hazardous chemical, radioactive, and mixed waste. 9 figs.

  9. SSC Quadrupole Magnet Performance at LBL

    SciTech Connect

    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

    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.

  10. The LBL magnetic measurements data acquisition system

    SciTech Connect

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

    1983-08-01

    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: measurement of high permeability materials, harmonic error analysis of superconducting dipoles and rare earth cobalt (REC) and conventional quadrupole magnets, and 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.

  11. Status of LBL/LLNL FEL (free electron laser) research for two beam accelerator applications

    SciTech Connect

    Hopkins, D.B.; Sessler, A.M.

    1988-11-01

    For this workshop, we review the status of free electron laser (FEL) research being conducted at LBL and LLNL as part of a broader program of research on two beam accelerators (TBAs). We discuss measurements made on high power 35 and 138 GHz FELs and their problem areas. Experience with 35 GHz accelerator section fabrication is summarized. Induction accelerator-driven FELs for use as power sources for high-gradient accelerators are discussed, along with preliminary cost estimates for this type of power source. Finally, a promising new version of an FEL/TBA is discussed. 22 refs., 7 figs., 5 tabs.

  12. Transient Beam Dynamics in the LBL 2 MV Injector

    SciTech Connect

    Henestroza, E; Grote, D

    1999-12-07

    A driver-scale injector for the Heavy Ion Fusion Accelerator project has been built at LBL. This machine has exceeded the design goals of high voltage (> 2 MV), high current (> 0.8 A of K{sup +}) and low normalized emittance (< 1 {pi} mm-mr). The injector consists of a 750 keV gun pre-injector followed by an electrostatic quadrupole accelerator (ESQ) which provides strong (alternating gradient) focusing for the space-charge dominated beam, and simultaneously accelerates the ions to 2 MeV. A matching section is being built to match the beam to the electrostatic accelerator ELISE. The gun preinjector, designed to hold up to 1 MV with minimal breakdown risks, consists of a hot aluminosilicate source with a large curved emitting surface surrounded by a thick ''extraction electrode''. During beam turn-on the voltage at the source is biased from a negative potential, enough to reverse the electric field on the emitting surface and avoid emission, to a positive potential to start extracting the beam; it stays constant for about 1 {micro}s, and is reversed to turn-off the emission. Since the Marx voltage applied on the accelerating quadrupoles and the main pre-injector gap is a long, constant pulse (several {micro}s), the transient behavior is dominated by the extraction pulser voltage time profile. The transient longitudinal dynamics of the beam in the injector was simulated by running the Particle in Cell codes GYMNOS and WARP3d in a time dependent mode. The generalization and its implementation in WAIW3d of a method proposed by Lampel and Tiefenback to eliminate transient oscillations in a one-dimensional planar diode will be presented.

  13. Linear collider research and development at SLAC, LBL and LLNL

    SciTech Connect

    Mattison, T.S.

    1988-10-01

    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.

  14. Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL

    SciTech Connect

    Not Available

    1991-09-01

    In part one of this document the Governing Documents and Definitions sections provide general guidelines and regulations applying to the handling of hazardous chemical wastes. The remaining sections provide details on how you can prepare your waste properly for transport and disposal. They are correlated with the steps you must take to properly prepare your waste for pickup. The purpose of the second part of this document is to provide the acceptance criteria for the transfer of radioactive and mixed waste to LBL's Hazardous Waste Handling Facility (HWHF). These guidelines describe how you, as a generator of radioactive or mixed waste, can meet LBL's acceptance criteria for radioactive and mixed waste.

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

    SciTech Connect

    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. ); Senf, S. . Stanford Synchrotron Radiation Lab.)

    1989-08-01

    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.

  16. Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL. Revision 2

    SciTech Connect

    Not Available

    1993-10-01

    The purpose of this document is to provide the acceptance criteria for the transfer of hazardous chemical waste to LBL`s Hazardous Waste Handling Facility (HWHF). Hazardous chemical waste is a necessary byproduct of LBL`s research and technical support activities. This waste must be handled properly if LBL is to operate safely and provide adequate protection to staff and the environment. These guidelines describe how you, as a generator of hazardous chemical waste, can meet LBL`s acceptance criteria for hazardous chemical waste.

  17. A detailed examination of the LBL infiltration model using the mobile infiltration test unit

    SciTech Connect

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

    1983-06-01

    The LBL infiltration model is a simplified method for combining weather information with air tightness to calculate residential air infiltration. In this report, the authors 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, the authors 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 added in quadrature, 3) that wind-induced infiltration can be represented by averaging the values for three typical aspect ratios, and 4) that wind-induced infiltration can be represented by averaging the values for all wind directions. The authors use 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, and the scatter is a measure of the ability of a model to track short-term fluctuations in infiltration rate.) The authors 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 overprediction (bias = 11%, 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%.

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

    SciTech Connect

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

    1983-07-01

    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%.

  19. Reservoir technology research at LBL addressing geysers issues

    SciTech Connect

    Lippmann, M.J.; Bodvarsson, G.S.

    1990-04-01

    The Geothermal Technology Division of the Department of Energy is redirecting a significant part of its Reservoir Technology funding to study problems now being experienced at The Geysers. These include excessive pressure drawdown and associated decline in well flow rates, corrosion due to high chloride concentration in the produced steam and high concentration of noncondensible gases in some parts of the field. Lawrence Berkeley Laboratory (LBL) is addressing some of these problems through field, laboratory and theoretical studies. 11 refs., 6 figs.

  20. Initial operation of the LBL heavy ion RFQ

    SciTech Connect

    Staples, J.; Gough, R.; Schneider, H.; Zajec, E.

    1983-08-01

    The LBL heavy ion RFQ accelerator, a 200 MHz structure that accelerates an ion with q/A greater than or equal to 1/7 from 8.4 to 200 keV/n, has now passed all its acceptance tests. This machine is unique in several respects: it uses coupling rings between vanes to stablize the azimuthal field distribution, it incorporates a vane mounting system that simplifies vane alignment, it uses no end tuners or power distribution manifold, and it needs only one rf feed loop. The beam performance of this machine is reported in this paper.

  1. The LBL/AGMEF/JSU El Yunque Environmental Research Initiative

    SciTech Connect

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

    1989-03-01

    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 eastern end of Puerto Rico offers a unique site to study atmospheric processes relevant to current national and international concerns regarding global climate modification. Based on this review, a Puerto Rico El Yunque Intensive Summer Research Campaign is proposed. 6 refs.

  2. TPX Sb3SN Conductor Testing at LBL

    SciTech Connect

    Lietzke, A.F.; Scanlan, R.

    1995-07-01

    Two wire lengths (one from Supercon and one from IGC) were delivered for testing at the LBL Short-Sample Test Facility. Several samples of each wire-type were wound onto forms and reacted according to the requested prescriptions. Leads and voltage-tap wires were carefully attached after reaction according to standard LBL short-sample test procedures. Testing of some of the samples has been completed. Liquid helium immersion (4.2K) data was gathered over a limited range of magnetic fields (5-10T). Additional gas-cooled data was collected over a range of temperatures (1.8-14 K). Testing was interrupted when the test-magnet's persistent-switch-heater failed. Good sample-to-sample and retest repeatability was observed for the 4.2K data when it was checked. Temperature measruements on the Supercon samples used CGR's and revealed a disappointing, non-repeatable (pressure-dependent) temperature offset for the gas-cooled measurements. They also observed a systematic dependence upon magnetic-field strength. Changing to a second CGR did not help. The IGC sample used a Cernox-type resistor which showed negligible magnetic and pressure dependencies. Testing is expected to resume when the magnet is repaired.

  3. Design and operation of the LBL heavy ion RFQ linac

    SciTech Connect

    Gouch, R.A.

    1984-05-01

    LBL has designed and tested a heavy ion RFQ linac for ions in the mass range of 1 to 40. Designed as part of a preinjector package for synchrotron applications, it is a low duty factor device, operating at 200 MHz with maximum surface fields as high as 28 MV/meter. It is a loop-driven, four vane structure employing several innovative design concepts. These include an exit matcher section, to ensure efficient capture by a following Alvarez linac; advanced mechanical design features, to ensure accurate positioning of the vane pole-tips; and vane coupling rings, to ensure field stabilization and balance. This RFQ has been used on a test bench to accelerate a variety of ions as heavy as silicon, with charge to mass ratios as low as 1/7. Results of the initial operation show that the structure meets all of the design performance criteria, and that it holds promise for a long lifetime of simple and reliable service. This RFQ linac will soon be incorporated into the Bevatron operations program as part of th 200 MHz injector upgrade. A further application of this same RFQ design is in the dedicated Heavy Ion Medical Accelerator presently under study at LBL. Details of the design, construction and testing of the RFQ linac are given.

  4. Enhanced performance of the LBL/SNLL leaky EBIS: Evidence for cooling of trapped heavy ions

    SciTech Connect

    Schmieder, R.W.; Bisson, C.L. )

    1990-01-01

    The LBL/SNLL EBIS has been operated as a leaky electron beam ion source (EBIS), i.e., with continuous gas leaks and continuous extraction of the ions. Under normal conditions the charge-state distributions are determined by the extraction from the trap; recombination with the residual gas is negligible. A simple rate equation model of the charge-state distributions shows clear evidence that heavy ions (Xe) reach higher charge states than expected, while light residual gas ions (C,N,O) reach lower charge states. This is taken as evidence that ion-ion collisional cooling and heating of these ions results in enhanced trapping of the heavy ions, due to the presence of the residual gas.

  5. Plasma production for the 50 MeV plasma lens experiment at LBL

    SciTech Connect

    Leemans, W.; van der Geer, B.; de Loos, M.; Conde, M.; Govil, R.; Chattopadhyay, S.

    1994-06-01

    The Center for Beam Physics at LBL has constructed a Beam Test Facility (BTF) housing a 50 MeV electron beam transport line, which uses the linac injector from the Advanced Light Source, and a terawatt Ti:Al{sub 2}O{sub 3} laser system. The linac operates at 50 MeV and generates 15 ps long electron bunches containing a charge of up to 2 nC. The measured unnormalized beam emittance is 0.33 mm-mrad. These parameters allow for a comprehensive study of focusing of relativistic electron beams with plasma columns, in both the overdense and underdense regime (adiabatic and tapered lenses). A study of adiabatic and/or tapered lenses requires careful control of plasma density and scale lengths of the plasma. We present experimental results on the production of plasmas through resonant two-photon ionization, with parameters relevant to an upcoming plasma lens experiment.

  6. 75 FR 64691 - Information Collection; Land Between The Lakes (LBL) Communication Effectiveness Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... co-op advertising and tourism promotions, as well as LBL's own Web site. The Forest Service is... regional tourism industry. To accomplish these goals, LBL will utilize a voluntary survey provided to... technological collection techniques or other forms of information technology. All comments received in...

  7. The 50 MeV Beam Test Facility at LBL

    SciTech Connect

    Leemans, W.; Behrsing, G.; Kim, K.J.; Krupnick, J.; Matuk, C.; Selph, F.; Chattopadhyay, S.

    1993-05-01

    A new beam line, expected to be built by September 1993, will transport the 50 MeV electron beam from the ALS LINAC into an experimental area to support various R&D activities in the Center for Beam Physics at LBL. A variety of experiments are planned involving the interaction of such a relativistic electron beam with plasmas (plasma focusing), laser beams (generation of femtosecond X-ray pulses) and electromagnetic cavities (Crab cavities etc....). The beam line is designed using the measured emittance and Twiss parameters of the ALS linac. It accommodates the different requirements of the various experiments on the electron beam properties (charge, energy, pulse length) and on the handling of the beam before and after the interaction point. Special attention has also been given to incorporate diagnostics for measuring the beam properties (such as the electron energy, bunch length and charge) needed in the interpretation of the experiments.

  8. Electron beam transport for the LBL IR-FEL

    SciTech Connect

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

    1992-07-01

    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.

  9. Scientific and statistical data management research at LBL

    SciTech Connect

    Olken, F.; Rotem, D.; Shoshani, A.; Wong, H.

    1986-06-01

    This paper is a review of scientific and statistical data management research at LBL in recent years in the areas of: logical modeling and user interfaces, database operators, and physical organization and access methods. In the area of logical modeling and user interfaces we discuss: SUBJECT, a system for organizing multi-dimensional data, GUIDE, a graphical query system, and logical modeling of temporal data. In database operators we discuss sampling from relational databases, and transposition of compressed data. In the area of physical DB organization and access methods we discuss: header data compression, rearrangement of data arrays to enhance data compression, batched interpolation search, bit transposed file organization, techniques for controlling overflow from multi-dimensional data structures (e.g. grid files), and data structures for temporal data. 31 refs., 7 figs., 1 tab.

  10. A fragment separator at LBL for beta-NMR experiment

    SciTech Connect

    Matsuta, K.; Ozawa, A.; Nojiri, Y.; Minamisono, T.; Fukuda, M.; Kitagawa, A.; Ohtsubo, T.; Momota, S.; Fukuda, S.; Matsuo, Y.; Takechi, H.; Minami, I.; Sugimoto, K.; Tanihata, I.; Omata, K.; Shimoura, S.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.

    1992-03-01

    The Beam 44 fragment separator was built at the Bevalac of LBL for NMR studies of beta emitting nuclei. {sup 37}K, {sup 39}Ca, and {sup 43}Ti fragments originating from {sup 40}Ca and {sup 46}Ti primary beams were separated by the separator for NMR studies on these nuclei. Nuclear spin polarization was created in {sup 39}Ca and {sup 43}Ti using the tilted foil technique (TFT), and the magnetic moment of {sup 43}Ti was deduced. Fragment polarization was measured for {sup 37}K and {sup 39}Ca emitted to finite deflection angles. The Beam 44 fragment separator in combination with a proper polarization technique, such as TFT or fragment polarization, has been very effective for such NMR studies.

  11. LBL/Industry fractured reservoir performance definition project

    SciTech Connect

    Benson, S.M.

    1995-04-01

    One of the problems facing the petroleum industry is the recovery of oil from heterogeneous, fractured reservoirs and from reservoirs that have been partially depleted. In response to this need, several companies, notably British Petroleum USA, (BP) and Continental Oil Company (CONOCO), have established integrated reservoir description programs. Concurrently, LBL is actively involved in developing characterization technology for heterogeneous, fractured rock, mainly for DOE`s Civilian Nuclear Waste Program as well as Geothermal Energy programs. The technology developed for these programs was noticed by the petroleum industry and resulted in cooperative research centered on the petroleum companies test facilities. The emphasis of this work is a tightly integrated interdisciplinary approach to the problem of characterizing complex, heterogeneous earth materials. In this approach we explicitly combine the geologic, geomechanical, geophysical and hydrologic information in a unified model for predicting fluid flow. The overall objective is to derive improved integrated approaches to characterizing naturally fractured gas reservoirs.

  12. LBL residential energy model an improved policy analysis tool

    SciTech Connect

    McMahon, J.E.

    1987-01-01

    Energy consumption in residences accounts for 20% of total energy and 35% of electricity used in the United States today. Over time, the amount of energy consumed to provide a particular service will change. The mix of fuels consumed also changes; recently, households have increased their electricity consumption and decreased consumption of fossil fuels. For these reasons, an understanding of the components of residential energy consumption is important to utility companies and government policy makers. This article describes the development of the LBL Residential Energy Model to provide improved policy analysis at the end-use level. The major improvements include:representation of recent equipment efficiency trends; new techniques for forecasting future appliance efficiencies and annual appliance replacements; and extension of the model to include heat-pump space-conditioning systems. The resulting forecasts give improved agreement with recently reported energy consumption and provide lower estimates of future energy consumption.

  13. Automatic tuning of the LBL superhilac third injector transport line

    SciTech Connect

    Pines, H.

    1983-08-01

    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 technique is the calculation of beam transverse 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.

  14. Guidelines for Waste Accumulation Areas (WAAs) at LBL. Revision 1

    SciTech Connect

    Not Available

    1994-06-01

    The purpose of this document is to set conditions for establishing and containing areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes for up to 90 days in quantities greater than 55 gallons (208 liters) of hazardous waste, one quart (0.946 liter) of extremely hazardous waste, or one quart (0.946 liter) of acutely hazardous waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs, constructing a WAA, storing waste in a WAA, operating and maintaining a WAA, and responding to spills in a WAA.

  15. Use of Silicon Photomultiplier in LBL Cosmic Tay Detector

    NASA Astrophysics Data System (ADS)

    Osornio, Leo

    2012-10-01

    During a summer internship program at Hartnell Community College our team successfully constructed two complementary cosmic ray experiments. The first employed NIM electronic modules the second constructed as per specifications of a circuit board designed by the Berkeley Lab Cosmic Ray Telescope Project (http://cosmic.lbl.gov/). During the following summer at Lawrence Berkeley National Laboratory, we worked on optimizing the performance of a group of Berkeley Lab Detector and developed tools to measure its performance. The next phase was exploring whether Silicon Photomultiplier (SiPM) can be used to replace the phototube of the Berkeley Detector. Data will be presented from both summers including the dependence of the cosmic ray flux on the separation and polar angle of scintillator paddles, as well as the results from our SiPM tests. Finally, I will include prospects for curriculum development using the cosmic ray experiments.

  16. AUV Positioning Method Based on Tightly Coupled SINS/LBL for Underwater Acoustic Multipath Propagation.

    PubMed

    Zhang, Tao; Shi, Hongfei; Chen, Liping; Li, Yao; Tong, Jinwu

    2016-01-01

    This paper researches an AUV (Autonomous Underwater Vehicle) positioning method based on SINS (Strapdown Inertial Navigation System)/LBL (Long Base Line) tightly coupled algorithm. This algorithm mainly includes SINS-assisted searching method of optimum slant-range of underwater acoustic propagation multipath, SINS/LBL tightly coupled model and multi-sensor information fusion algorithm. Fuzzy correlation peak problem of underwater LBL acoustic propagation multipath could be solved based on SINS positional information, thus improving LBL positional accuracy. Moreover, introduction of SINS-centered LBL locating information could compensate accumulative AUV position error effectively and regularly. Compared to loosely coupled algorithm, this tightly coupled algorithm can still provide accurate location information when there are fewer than four available hydrophones (or within the signal receiving range). Therefore, effective positional calibration area of tightly coupled system based on LBL array is wider and has higher reliability and fault tolerance than loosely coupled. It is more applicable to AUV positioning based on SINS/LBL. PMID:26978361

  17. AUV Positioning Method Based on Tightly Coupled SINS/LBL for Underwater Acoustic Multipath Propagation

    PubMed Central

    Zhang, Tao; Shi, Hongfei; Chen, Liping; Li, Yao; Tong, Jinwu

    2016-01-01

    This paper researches an AUV (Autonomous Underwater Vehicle) positioning method based on SINS (Strapdown Inertial Navigation System)/LBL (Long Base Line) tightly coupled algorithm. This algorithm mainly includes SINS-assisted searching method of optimum slant-range of underwater acoustic propagation multipath, SINS/LBL tightly coupled model and multi-sensor information fusion algorithm. Fuzzy correlation peak problem of underwater LBL acoustic propagation multipath could be solved based on SINS positional information, thus improving LBL positional accuracy. Moreover, introduction of SINS-centered LBL locating information could compensate accumulative AUV position error effectively and regularly. Compared to loosely coupled algorithm, this tightly coupled algorithm can still provide accurate location information when there are fewer than four available hydrophones (or within the signal receiving range). Therefore, effective positional calibration area of tightly coupled system based on LBL array is wider and has higher reliability and fault tolerance than loosely coupled. It is more applicable to AUV positioning based on SINS/LBL. PMID:26978361

  18. User's guide for the ENGNOTE database system for LBL engineering notes: Version 1. 2

    SciTech Connect

    Konrad, A.

    1986-07-30

    The ENGNOTE database was implemented at the request of the Mechanical Engineering Department for management of LBL engineering notes. It was converted from an LBL BKY program called ARDIE which was supported on the CDC 7600 in batch mode. The user interface was printed listings. In contrast, the current ENGNOTE database is interactive, though printed listings are easily produceable. ENGNOTE is implemented using the SPIRES database management system, a product of Stanford University, support by LBL on the U.C. Berkeley campus IBM 3090 computer. There is no practical limit to the number of records which may be contained in the database.

  19. LBL Magnetic-Measurements Data-Acquisition System

    SciTech Connect

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

    1983-03-01

    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.

  20. Capabilities and usage of the LBL low background counting facilities

    SciTech Connect

    Smith, A.R.; McDonald, R.J.; Hurley, D.L.; Norman, E.B.

    1993-10-01

    Many current experiments in nuclear and particle physics and numerous environmental characterization studies involve measurements of minute levels of radioactivity. These experiments require that radiation detectors be operated in the lowest possible background environment. A low background counting facility has been in operation since the early 1960`s at LBL. Recently, an even lower background facility was established under the Oroville dam. Gamma-ray counting is performed with large NaI or germanium detectors depending upon the particular application. Using a large (115% {open_quotes}efficiency{close_quotes}) n-type high-purity germanium detector at Oroville, we have established detection limits for kilogram-size samples of approximately 30 ppt (parts per trillion by weight) for the equilibrium U-series, 150 ppt for the equilibrium Th-series, and 50 ppb for potassium. Recent examples of projects which have used these facilities include the Sudbury Neutrino Observatory, a dark matter search, and measurements of radioactivities produced in the Long Duration Exposure Facility satellite. A description of these facilities and results obtained for some of these projects will be presented.

  1. Spray-assisted layer-by-Layer (LbL) assembly of anisotropic materials

    NASA Astrophysics Data System (ADS)

    de, Souvik; Suarez Martinez, Pilar; Kavarthapu, Avanti; Lutkenhaus, Jodie

    2015-03-01

    Layer-by-layer (LbL) assembly has gained tremendous interest as it allows one to incorporate a large variety of molecules with nano-scale precision and very good reproducibility. In addition to charged polymers, the technique has become extremely popular to fabricate tailor-made thin films containing anisotropic nanomaterials (e.g., graphene oxide sheets). The challenge is that a standard protocol to fabricate ``all-polyelectrolyte'' LbL films may not necessarily give rise to satisfactory film growth when applied to LbL assembly where one of the adsorbing components is an anisotropic nanomaterial. Therefore, in this contribution, we combine polymers and anisotropic nanomaterials via dip- and spray-assisted LbL assembly and investigate the effect of charge density, exfoliation, concentration etc. of the components on the growth behavior and the film quality. The end result is a conformal, pin-hole free coating on model substrates (glass, silicon, metal) over a large area.

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

    SciTech Connect

    Schroeder, L.S.

    1984-11-01

    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)

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

    SciTech Connect

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

    1980-03-01

    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).

  4. Production of exotic beams at the LBL 88-Inch Cyclotron by the ISOL method

    SciTech Connect

    Not Available

    1990-04-01

    The Users of the LBL 88-Inch Cyclotron are preparing a proposal to produce exotic, i.e., radioactive beams. The facility will consist of a high-current 30 MeV cyclotron to generate the radioactive nuclei, an ECR source that can be coupled to different production targets, and the 88-Inch Cyclotron to accelerate the radioactive ions. Thus, the basic concept is that of the double cyclotron system pioneered at Louvain-la-Neuve, although the initial emphasis will be on producing a variety of light proton-rich beams at energies up to 10 MeV/A. At this workshop we wish to outline what is being planned, to invite comments and suggestions, and, especially, to encourage participation. We believe that this facility will be an important step toward establishing the scientific and technical basis for a National High Intensity Facility. This can be achieved through active participation by members of the radioactive beam (RB) community in (1) experiments with high quality radioactive beams of moderate intensity and, (2) R D on high beam-power targets and highly efficient ion sources. 5 refs., 4 figs.

  5. Requirements and design of a high stable infrared free electron laser at LBL

    SciTech Connect

    Kim, K.J.; Berz, M.; Chattopadhyay, S.; Gough, R.; Kim, C.; Kung, A.H.; Xie, M. ); Edighoffer, J. ); Stein, W. )

    1990-06-01

    An infrared free electron laser (IRFEL) is being designed for the Chemical Dynamics Research Laboratory (CDRL) at LBL. The FEL is based on a 50 MeV RF linac operating in synchronization to the Advanced Light Source (ALS), and will produce intense (100 {mu}J per micropulse), narrow bandwidth (narrower than 0.1%) radiation between 3 {mu} and 50 {mu}. In the design, we pay particular attention to the FEL stability issues and require that the fluctuations in electron beam energy and in timing be less than 0.05% and 0.1 ps, respectively. The FEL spectrum can then be stabilized to about 10{sup {minus}3}, or if grating is used, to 10{sup {minus}4}. We discuss various sources of fluctuations in the gun, the bunchers and the accelerator sections, as well as the feedback and feedforward schemes to reduce these fluctuations. The accelerator structure is chosen to be of the side coupled, standing wave type for easier control. The beam transport is made isochronous to avoid the coupling between the energy and the timing fluctuations. 9 refs., 2 figs.

  6. Design overview of a highly stable infrared free electron laser at LBL

    SciTech Connect

    Kim, K.J.; Berz, M.; Chattopadhyay, S.; Gough, R.; Kim, C.; Kung, A.H.; Xie, M. ); Edighoffer, J. ); Stein, W. )

    1990-11-01

    An infrared free electron laser (IRFEL) is being designed for the Chemical Dynamics Research Laboratory (CDRL) at LBL. The FEL is based on a 50 MeV RF linac operating in synchronization to the Advanced Light Source (ALS), and will produce intense (100 {mu}J per micropulse), narrow bandwidth (narrower than 0.1%) radiation between 3 {mu} and 50 {mu}. In the design, we pay particular attention to the FEL stability issues and require that the fluctuations in electron beam energy and in timing be less then 0.05% and 0.1 ps respectively. The FEL spectrum can then be stabilized to about 10{sup {minus}3}, or if grating is used, to 10{sup {minus}4}. We discuss various sources of fluctuations in the gun, the bunchers and the accelerator sections, as well as the feedback and feedforward schemes to reduce these fluctuations. The accelerator structure is chosen to be of the side coupled, standing wave type for easier control. The beam transport is made isochronous to avoid the coupling between the energy and the timing fluctuations. 12 refs., 1 fig.

  7. pH-indicators doped polysaccharide LbL coatings for hazardous gases optical sensing.

    PubMed

    Mironenko, A Yu; Sergeev, A A; Voznesenskiy, S S; Marinin, D V; Bratskaya, S Yu

    2013-01-30

    Sensitive layer-by-layer (LbL) coatings for optical detection of gaseous NH(3) and HCl were prepared by self-assembly of oppositely charged polysaccharides (chitosan and λ-carrageenan) followed by doping LbLs with pH-sensitive dyes - bromothymol blue (BTB) and Congo red (CR). It has been shown that CR, being an amphoteric dye, diffuses into LbL films regardless of the charge of the outermost polyelectrolyte layer, and the dye loading increases linearly with the LbL film thickness, whereas BTB diffuses into LbL films only when the outermost layer is positively charged, and linearity between dye loading and film thickness holds only up to 8-12 double layers (DLs) deposited. Formation of dye-doped LbL coatings at the surface of K(+)/Na(+) ion-exchanged glass has allowed fabrication of composite optical waveguide (OWG) gas sensor for detection of ammonia and hydrochloric acid vapors. The response time of BTB-doped composite OWG for ammonia detection was below 1s, and the detection limit was below 1 ppm. CR-doped OWG sensors have shown high sensitivity to HCl vapor but slow relaxation time (up to several hours for 12 DL LbL films). PMID:23218366

  8. Measurement of frequency response of LBL stochastic cooling arrays for TeV-I storage rings

    SciTech Connect

    Goldberg, D.A.; Lambertson, G.R.; Voelker, F.; Shalz, L.

    1985-05-01

    Lawrence Berkeley Laboratory (LBL) has developed electrodes for the stochastic cooling system which is used in the anti-proton source in TeV-I at Fermilab. The electrodes are in the form of a pair of stripline couplers or loops, the elements of which are mounted on opposite sides of the beam. We have made two different couplers of similar design, the one to operate in the frequency range 1-2 GHz, the other, 2-4 GHz. We have made two different types of measurements; the one involving the response of a single loop pair to a wire signal simulating the beam signal; the other, the response of a 16 loop-pair array to an actual beam. Both sets of measurements were made in the frequency domain, and both involved taking both the so-called sum and difference responses, in which the signals from the two elements of the loop pair are added and subtracted, respectively. The former response shows little variation as the beam or wire is displaced from the midplane of the loop-pair; the latter exhibits a roughly linear variation with displacement, and is used to detect the position variation of the particles in cooling systems. In general, the beam and wire measurements were found to be in excellent agreement.

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

    PubMed

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

    2012-05-29

    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 μm 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

  10. LBL structured chitosan-layered silicate intercalated composites based fibrous mats for protein delivery.

    PubMed

    Li, Wei; Xu, Ruifen; Zheng, Liangqun; Du, Jing; Zhu, Yuli; Huang, Rong; Deng, Hongbing

    2012-11-01

    Organic rectorite (OREC) was used to prepare intercalated composites with chitosan. The negatively charged cellulose acetate (CA) fibrous mats were modified with multilayers of the positively charged chitosan or chitosan-OREC intercalated composites and the negatively charged bovine serum albumin (BSA) via electrostatic layer-by-layer (LBL) self-assembly technique. The morphology and protein delivery properties of the resultant samples were investigated by regulating the number of deposition bilayers, the outermost layer and the composition of coating bilayers. The thickness of LBL films coated CA mats increased as the number of bilayers was increased and OREC was added. X-ray photoelectron spectroscopy indicated that chitosan and OREC were deposited on CA fibers. Small angle X-ray diffraction patterns showed that OREC was intercalated by chitosan. The in vitro BSA encapsulation and release experiments demonstrated that OREC could affect the degree of protein loading capacity and release efficiency of the LBL films coating. PMID:22944430

  11. [Application of PBL method and LBL method in the teaching of Acupuncutre and Moxibustion].

    PubMed

    Li, Jing; Lu, Jin; Ruan, Zhizhong

    2015-08-01

    In order to improve teaching lever and explore teaching approach, the feasibility study on the combination of the problembased learning method CPBL) and the lecture-based learning method (LBL) was conducted in the teaching of Acupuncture and Moxibustion. The 2010 undergraduates in the major of clinical integrated Chinese and western medicine of five years were randomized into a PBL and LBL group and a LEL group. In the first semester, according to the basic teaching requirement, LBL was used to accomplish the teaching of basic theory. In the internship teaching section, the different teaching method was applied. In the PBL and LEL group, PEL was used, and in the LBL group, LBL was given. At the end of semester, the examination results of the theory learning and medical cases learning were evaluated. The questionnaire was summarized in the teachers and students. The final examination result of theory learning was not different significantly between the two groups (P >0. 05), but the result of medical cases learning in the PEL and LEL group was better than that in LEL group (84. 4710. 72 vs 76. 009. 97, P<0. 05). The questionnaire for the students and teachers indicated that the result of PEL and LEL combined method was higher than that of LEL method (86. 278. 36 vs 56. 0014. 59, P< 0. 01; 45. 893. 68 vs 36. 616. 41, P<0. 0l), indicating that the combined method of PBL and LEL is feasible in teaching of Acupuncture and Moxibustion and the teaching outcome is superior to the simple LBL, which provides the new approach to the teaching reform. PMID:26571905

  12. Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL. Revision 1

    SciTech Connect

    Not Available

    1991-09-01

    In part one of this document the Governing Documents and Definitions sections provide general guidelines and regulations applying to the handling of hazardous chemical wastes. The remaining sections provide details on how you can prepare your waste properly for transport and disposal. They are correlated with the steps you must take to properly prepare your waste for pickup. The purpose of the second part of this document is to provide the acceptance criteria for the transfer of radioactive and mixed waste to LBL`s Hazardous Waste Handling Facility (HWHF). These guidelines describe how you, as a generator of radioactive or mixed waste, can meet LBL`s acceptance criteria for radioactive and mixed waste.

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

    SciTech Connect

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

    1992-03-24

    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.

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

    SciTech Connect

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

    1992-03-01

    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.

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

    SciTech Connect

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

    1982-03-01

    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.

  16. A new VME-based, multi-processor data acquisition station for the LBL Bevalac

    SciTech Connect

    McParland, C.

    1987-08-01

    A new VME-based multi-processor data acquisition station has been developed for use at several LBL Bevalac facilities. This system acquires and manipulates data from multiple CAMAC crates and transmits them via Ethernet to a central VAX facility for taping. Overall architecture is discussed and major hardware and software components are described.

  17. Beam-beam studies for the proposed SLAC/LBL/LLNL B Factory

    SciTech Connect

    Furman, M.A.

    1991-05-01

    We present a summary of beam-beam dynamics studies that have been carried out to date for the proposed SLAC/LBL/LLNL B Factory. Most of the material presented here is contained in the proposal's Conceptual Design Report, although post-CDR studies are also presented. 15 refs., 6 figs., 2 tabs.

  18. Comparison of measured and predicted infiltration using the LBL infiltration model

    SciTech Connect

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

    1984-02-01

    The LBL infiltration model was developed in 1980; since that time many simultaneous measurements of infiltration and weather have been made allowing comparison of predictions with measured infiltration. This report presents the LBL model as it currently exists and summarizes infiltration measurements and corresponding predictions. These measurements include both long-term and short-term data taken in houses with climates ranging from the mild San Fransisco bay area to the more extreme mid-west. This data also provides a database for comparison with other infiltration models and provides a starting point for the determination of the accuracy and precision of air infiltration models. In this report we have presented the LBL infiltration model and have used field data to validate it. For short-term measurements the model predicts to within 20% for well defined environments (e.g. the MITU trailer) and slightly higher for other situations. The long-term (one week) average infiltration is accurate to 7%; in the Owens-Corning houses the long-term average error increases to up to 15%. A detailed examination of the LBL model using data from Mobile Infiltration Test Unit was used to probe the model and suggest areas for future research. 13 refs., 12 figs., 14 tabs.

  19. Spatio-temporal control of LbL films for biomedical applications: from 2D to 3D

    PubMed Central

    Monge, Claire; Almodóvar, Jorge; Boudou, Thomas; Picart, Catherine

    2015-01-01

    Introduced in the 90’s by Prof Moehwald, Lvov and Decher, the layer-by-layer (LbL) assembly of polyelectrolytes has become a popular technique to engineer various types of objects such as films, capsules and free standing membranes, with an unprecedented control at the nanometer and micrometer scales. The LbL technique allows to engineer biofunctional surface coatings, which may be dedicated to biomedical applications in vivo but also to fundamental studies and diagnosis in vitro. Initially mostly developed as 2D coatings and hollow capsules, the range of complex objects created by the LbL technique has greatly expanded in the past 10 years. In this review, our aim was to highlight the recent progress in the field of LbL films for biomedical applications and discuss the various ways to control spatially and temporally the biochemical and mechanical properties of multilayers. In particular, we will discuss three major developments of LbL films: 1) the new methods and templates to engineer LbL films and control cellular processes from adhesion to differentiation, 2) the major ways to achieve temporal control by chemical, biological and physical triggers and, 3) the combinations of LbL technique, cells and scaffolds for repairing 3D tissues, including cardio-vascular devices, bone implants and neuro-prosthetic devices. PMID:25627563

  20. Overview of current radon and radon daughter research at LBL

    SciTech Connect

    Not Available

    1983-01-01

    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.

  1. Recent development of the LBL/USGS site-scale model of Yucca Mountain, Nevada

    SciTech Connect

    Bodvarsson, G.S.; Aunzo, Z.; Chen, Gang

    1995-12-01

    The three-dimensional site-scale model of Yucca Mountain has been under development by Lawrence Berkeley Laboratory and U.S. Geological Survey (LBL/USGS) over the last four years. The model has been used to evaluate moisture flow within Yucca Mountain for different assumed infiltration patterns and for various assumed hydrological conditions and properties of faults. This model is under constant development as new data may require grid modifications or extensions as new wells are drilled and information from the Exploratory Studies Facility (ESF) become available. Recent development of the model include calibrations against observed gas and temperature data, incorporation of the ESF into the numerical grid, and the areal extension of the model in all directions to include data from nearby wells and for studies of water infiltration into nearby faults such as the Solitario Canyon fault. This paper summarizes these recent developments of the LBL/USGS site-scale model.

  2. Volume H/sup -/ ion production experiments at LBL

    SciTech Connect

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

    1983-11-01

    H/sup -/ ions formed by volume processes have been extracted from a multicusp ion source. It is shown that a permanent magnet filter together with a small positive bias voltage on the plasma grid can produce a very significant reduction in electron drain as well as a sizable increase in H/sup -/ ions available for extraction. A further reduction in electron current is achieved by installing a pair of small magnets at the extraction aperture. An H/sup -/ ion current density of 38 mA/cm/sup 2/ was obtained with a discharge current of approximately 350 A. Different techniques to increase the H/sup -/ ion yield have also been investigated.

  3. Volume H/sup -/ ion production experiments at LBL

    SciTech Connect

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

    1984-03-01

    H/sup -/ ions formed by volume processes have been extracted from a multicusp ion source. It is shown that a permanent magnet filter together with a small positive bias voltage on the plasma grid can produce a very significant reduction in electron drain as well as a sizable increase in H/sup -/ ions available for extraction. A further reduction in electron current is achieved by installing a pair of small magnets at the extraction aperture. An H/sup -/ ion current density of 38 mA/cm/sup 2/ was obtained with a discharge current of approximately 350 A. Different techniques to increase the H/sup -/ ion yield have also been investigated.

  4. Production of lepton pairs at the LBL Bevelac

    SciTech Connect

    Roche, G.

    1989-06-01

    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.

  5. Survey and Alighment for the ALS Project at LBL Berkeley

    SciTech Connect

    Keller, R.; Lauritzen, T.; Friedsam, H.; /SLAC

    2005-08-12

    The Advanced Light Source (ALS), now under construction at Lawrence Berkeley Laboratory, is a synchrotron radiation source of the third generation designed to produce extremely bright photon beams in the UV and soft X-ray regions. Its main accelerator components are a 1-1.9 GeV electron storage ring with 196.8 m circumference and 12 super-periods, a 1.5 GeV booster synchrotron with 75.0 m circumference and 4 super-periods, and a 50 MeV linac, as shown in Fig. 1. The storage ring has particularly tight positioning tolerances for lattice magnets and other components to assure the required operational characteristics. The general survey and alignment concept for the ALS is based on a network of fixed monuments installed in the building floor, to which all component positions are referred. Measurements include electronic distance measurements and separate sightings for horizontal and vertical directions, partially with automated electronic data capture. Most of the data processing is accomplished by running a customized version of PC-GEONET. It provides raw data storage, data reduction, and the calculation of adjusted coordinates, as well as an option for error analysis. PC-GEONET has also been used to establish an observation plan for the monuments and calculate their expected position accuracies, based on approximate coordinates. Additionally, for local survey tasks, the commercial software package ECDS is used. In this paper, the ALS survey and alignment strategy and techniques are presented and critically discussed. First experiences with the alignment of the linac and booster components are described.

  6. The architecture and biological performance of drug-loaded LbL nanoparticles.

    PubMed

    Morton, Stephen W; Poon, Zhiyong; Hammond, Paula T

    2013-07-01

    Layer-by-Layer (LbL) nanoparticles are an emerging class of therapeutic carriers that afford precise control over key design parameters that facilitate improved drug and carrier pharmacokinetics, and enhanced molecular-targeting capabilities. This paper advances the development of these systems by establishing them as drug carriers, with the means to control drug release in a systemic environment and retard particle clearance from circulation, promoting improved biodistribution of the drug-containing system. Using dual-fluorescent tracking in vivo, this work establishes a robust means of screening libraries of LbL systems generated, affording simultaneous resolution over persistence and biodistribution of both the drug and carrier following systemic administration of a single particle formulation. Employing a PLGA drug-containing core as a substrate for LbL deposition, a range of coated systems were fabricated to investigate the abilities of these films to stabilize drug for delivery as well as to improve the pharmacokinetics of both the drug and carrier. Significant reductions in liver accumulation were observed for different formulations of the layered architectures within the first 30 min of systemic circulation. LbL architectures diminished liver localization of the surrogate drug, cardiogreen, by 10-25% ID/g relative to native PLGA nanoparticles and modulated carrier accumulation in the liver >50% ID/g. Further, enhanced persistence of the drug was observed with the coated systems, significantly increasing the drug half-life from 2 to 3 min for free drug and 1.87 h for the uncoated core to 4.17 h and 4.54 h for the coated systems. These systems provide an exciting, modular platform that improves the pharmacokinetic properties of the therapeutic, reduces bolus release of drug from nanoparticles, and enhances the safety and circulation half-life of the drug in vivo, proving them to be highly clinically-relevant and a promising approach for future development of molecularly-targeted and combination therapeutics. PMID:23618629

  7. The Architecture and Biological Performance of Drug-Loaded LbL Nanoparticles

    PubMed Central

    Morton, Stephen; Poon, Zhiyong; Hammond, Paula

    2014-01-01

    Layer-by-Layer (LbL) nanoparticles are an emerging class of therapeutic carriers that afford precise control over key design parameters that facilitate improved drug and carrier pharmacokinetics, and enhanced molecular-targeting capabilities. This paper advances the development of these systems by establishing them as drug carriers, with the means to control drug release in a systemic environment and retard particle clearance from circulation, promoting improved biodistribution of the drug-containing system. Using dual-fluorescent tracking in vivo, this work establishes a robust means of screening libraries of LbL systems generated, affording simultaneous resolution over persistence and biodistribution of both the drug and carrier following systemic administration of a single particle formulation. Employing a PLGA drug-containing core as a substrate for LbL deposition, a range of coated systems were fabricated to investigate the abilities of these films to stabilize drug for delivery as well as to improve the pharmacokinetics of both the drug and carrier. Significant reductions in liver accumulation were observed for different formulations of the layered architectures within the first 30 minutes of systemic circulation. LbL architectures diminished liver localization of the surrogate drug, cardiogreen, by 10–25% ID/g relative to native PLGA nanoparticles and modulated carrier accumulation in the liver >50% ID/g. Further, enhanced persistence of the drug was observed with the coated systems, significantly increasing the drug half-life from 2–3 minutes for free drug and 1.87h for the uncoated core to 4.17h and 4.54h for the coated systems. These systems provide an exciting, modular platform that improves the pharmacokinetic properties of the therapeutic, reduces bolus release of drug from nanoparticles, and enhances the safety and circulation half-life of the drug in vivo, proving them to be highly clinically-relevant and a promising approach for future development of molecularly-targeted and combination therapeutics. PMID:23618629

  8. Summary of the Argonne Measurements of the LBL Prototype Pickup Characteristics

    SciTech Connect

    Konecny, R.; Kramer, S.; Mtingwa, S.; Simpson, J.; Suddeth, D.

    1984-08-14

    During the past year the authors have conducted a series of tests on the LBL prototype 1-2 GHz and 2-4 GHz stochastic cooling electrodes at Argonne Chemistry Division's electron LINAC. The electrode geometries are illustrated in Figures 1 and 2. Using the test electron beam, the 16-loop arrays were operated as beam current pickups and their sum and difference mode coupling impedances were measured.

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

    SciTech Connect

    Jackson, A.

    1988-05-01

    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.

  10. Status of the SLAC/LBL/LLNL B-factory and the BABAR detector

    SciTech Connect

    Oddone, P.

    1994-10-01

    After a brief introduction on the physics reach of the SLAC/LBL/LLNL Asymmetric B-Factory, the author describes the status of the accelerator and the detector as of the end of 1994. At this time, essentially all major decisions have been made, including the choice of particle identification for the detector. The author concludes this report with the description of the schedule for the construction of both accelerator and detector.

  11. Biomimetic LBL structured nanofibrous matrices assembled by chitosan/collagen for promoting wound healing.

    PubMed

    Huang, Rong; Li, Wangzhou; Lv, Xiaoxing; Lei, Zhanjun; Bian, Yongqian; Deng, Hongbing; Wang, Hongjun; Li, Jinqing; Li, Xueyong

    2015-06-01

    This paper reports the fabrication of biomimetic nanofibrous matrices via co-electrospinning of polycaprolactone (PCL)/cellulose acetate (CA) and layer-by-layer self-assembly (LBL) of positively charged chitosan (CS) and negatively charged Type Ⅰ collagen on the nanofibrous matrix. FE-SEM images indicate that the average fiber diameter increased from 392 to 541 nm when the coating bilayers varied from 5 to 20.5. Besides, the excellent biocompatibility and enhanced attachment and spreading of normal human dermal fibroblasts (NHDFs) of prepared nanofibrous mats are confirmed by MTT and SEM results. Furthermore, the LBL structured (CS/collagen)n nanofibrous mats greatly improve the cell migration in vitro, promote re-epithelialization and vascularization in vivo, and up-regulate the expression of collagen Ⅳ and α-tubulin, as well as the Integrin β1 and phosphorylation of focal adhesion kinase (FAK) at Tyr-397. The levels of expressed protein are significantly enhanced with increasing coating bilayers via immunohistochemistry and western blotting analyses. Collectively, these results suggest that the LBL structured biomimetic nanofibrous matrices may enhance cell migration and further promote the skin regeneration by up-regulating the secretion of ECM protein and triggering Integrin/FAK signaling pathway, which demonstrate the potential use of the nanofibrous mats to rapidly restore the structural and functional properties of wounded skin. PMID:25890707

  12. Bimodal Tumor-Targeting from Microenvironment Responsive Hyaluronan Layer-by-Layer (LbL) Nanoparticles

    PubMed Central

    2015-01-01

    Active targeting of nanoscale drug carriers can improve tumor-specific delivery; however, cellular heterogeneity both within and among tumor sites is a fundamental barrier to their success. Here, we describe a tumor microenvironment-responsive layer-by-layer (LbL) polymer drug carrier that actively targets tumors based on two independent mechanisms: pH-dependent cellular uptake at hypoxic tumor pH and hyaluronan-directed targeting of cell-surface CD44 receptor, a well-characterized biomarker for breast and ovarian cancer stem cells. Hypoxic pH-induced structural reorganization of hyaluronan-LbL nanoparticles was a direct result of the nature of the LbL electrostatic complex, and led to targeted cellular delivery in vitro and in vivo, with effective tumor penetration and uptake. The nanoscale drug carriers selectively bound CD44 and diminished cancer cell migration in vitro, while co-localizing with the CD44 receptor in vivo. Multimodal targeting of LbL nanoparticles is a powerful strategy for tumor-specific cancer diagnostics and therapy that can be accomplished using a single bilayer of polyamine and hyaluronan that, when assembled, produce a dynamic and responsive cell–particle interface. PMID:25100313

  13. Bimodal tumor-targeting from microenvironment responsive hyaluronan layer-by-layer (LbL) nanoparticles.

    PubMed

    Dreaden, Erik C; Morton, Stephen W; Shopsowitz, Kevin E; Choi, Jae-Hyeok; Deng, Zhou J; Cho, Nam-Joon; Hammond, Paula T

    2014-08-26

    Active targeting of nanoscale drug carriers can improve tumor-specific delivery; however, cellular heterogeneity both within and among tumor sites is a fundamental barrier to their success. Here, we describe a tumor microenvironment-responsive layer-by-layer (LbL) polymer drug carrier that actively targets tumors based on two independent mechanisms: pH-dependent cellular uptake at hypoxic tumor pH and hyaluronan-directed targeting of cell-surface CD44 receptor, a well-characterized biomarker for breast and ovarian cancer stem cells. Hypoxic pH-induced structural reorganization of hyaluronan-LbL nanoparticles was a direct result of the nature of the LbL electrostatic complex, and led to targeted cellular delivery in vitro and in vivo, with effective tumor penetration and uptake. The nanoscale drug carriers selectively bound CD44 and diminished cancer cell migration in vitro, while co-localizing with the CD44 receptor in vivo. Multimodal targeting of LbL nanoparticles is a powerful strategy for tumor-specific cancer diagnostics and therapy that can be accomplished using a single bilayer of polyamine and hyaluronan that, when assembled, produce a dynamic and responsive cell-particle interface. PMID:25100313

  14. Preparation of Simulated LBL Defects for Round Robin Experiment

    SciTech Connect

    Gerczak, Tyler J.; Baldwin, Charles A.; Hunn, John D.; Montgomery, Fred C.

    2015-12-01

    A critical characteristic of the TRISO fuel design is its ability to retain fission products. During reactor operation, the TRISO layers act as barriers to release of fission products not stabilized in the kernel. Each component of the TRISO particle and compact construction plays a unique role in retaining select fission products, and layer performance is often interrelated. The IPyC, SiC, and OPyC layers are barriers to the release of fission product gases such as Kr and Xe. The SiC layer provides the primary barrier to release of metallic fission products not retained in the kernel, as transport across the SiC layer is rate limiting due to the greater permeability of the IPyC and OPyC layers to many metallic fission products. These attributes allow intact TRISO coatings to successfully retain most fission products released from the kernel, with the majority of released fission products during operation being due to defective, damaged, or failed coatings. This dominant release of fission products from compromised particles contributes to the overall source term in reactor; causing safety and maintenance concerns and limiting the lifetime of the fuel. Under these considerations, an understanding of the nature and frequency of compromised particles is an important part of predicting the expected fission product release and ensuring safe and efficient operation.

  15. Scintillator characterization using the LBL Pulsed X-ray Facility

    SciTech Connect

    Moses, W.W.; Derenzo, S.E.; Weber, M.J.; Blankespoor, S.C.; Ho, M.H.; West, A.C.

    1994-10-01

    The authors have developed a bench-top pulsed x-ray system for measuring scintillation properties of compounds in crystal or powdered form. The source is a light-excited x-ray tube that produces 40 x-ray photons (mean energy 18.5 keV) per steradian in each 100 ps fwhm pulse. The repetition rate is adjustable from 0 to 10{sup 7} pulses per second. The fluorescent emanations from the x-ray excited samples are detected with either a sapphire-windowed microchannel plate photomultiplier tube (spectral range 150--650 nm, transit time jitter 40 ps fwhm) or a quartz windowed GaAs(Cs) photomultiplier tube (spectral range 160--930 nm, transit time jitter 4 ns fwhm). Decay time spectra are acquired using a TDC Havina 40 ps fwhm resolution over a 84 ms dynamic range. A computer controlled monochromator can be inserted into the optical path to measure the emission spectrum or wavelength resolved decay time spectrum. A computer controlled sample changer allows up to 64 samples to be measured without intervention.

  16. The LBL (Lawrence Berkeley Laboratory) multiple beam experiments

    SciTech Connect

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

    1987-03-01

    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.

  17. Investigating the Impact of Land between the Lakes (LBL) and Land Use/Land Cover Change on Precipitation Patterns

    NASA Astrophysics Data System (ADS)

    Degu, A. M.; Hossain, F.

    2012-12-01

    Large dams/reservoirs as open water surface and as a mechanism of triggering land use/land cover changes in their vicinity have impacted local climate and extreme precipitation patterns as study show. Urbanization, agricultural development, and forestation are some of the Land Use/Land Cover Changes (LULCC) that are result of development of large dams/reservoirs. Thus creating heterogeneities. It is believed that such heterogeneities bring about a boundary of different air masses that triggers convection due to differential heating as well as variation in soil moisture. One such heterogeneities is of the Land Between the Lakes (LBL). LBL is an inland peninsula formed by Lake Kentucky on Tennessee River and Lake Barkley on Cumberland River in Western Kentucky. The development of the two lakes brought about an area of 680 sq.km forest cover. The LBL renders unique land use/land cover heterogeneities with in a shorter distance providing open water for evaporation and forest for evapotranspiration. Reports as well as a preliminary investigation of nearby weather radar data showed storms dying out as it approaches the inland peninsula and gaining strength east of LBL. The storm exhibits a wave like strength, attenuating before LBL and gaining strength after. The purpose of this study mainly is to investigate the impact of LBL and in general LULCC on precipitation in the area. In this study the following specific scientific question will be addressed a. Has the development of LBL modified precipitation in the region? b. Which LULCC predominately affects storm formation? Summer radar reflectivity data from Paducah, KY station along with North America Regional Reanalysis (NARR) geopotential height and wind direction data will be analyzed for identification of LBL effect precipitation and synoptic effect precipitation, respectively. A Weather Research and Forecasting Model (WRF) will be setup to investigate what land use/land cover predominately modifies precipitation in the region.

  18. The LBL advanced light source (ALS) transverse coupled-bunch feedback system---Recent commissioning results

    SciTech Connect

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

    1995-05-05

    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. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

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

    SciTech Connect

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

    1994-10-01

    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.

  20. Status of the SLAC/LBL/LLNL B-Factory and the BaBar detector

    SciTech Connect

    Oddone, P.

    1994-08-01

    The primary motivation of the Asymmetric B-Factory is the study of CP violation. The decay of B mesons and, in particular, the decay of neutral B mesons, offers the possibility of determining conclusively whether CP violation is part and parcel of the Standard Model with three generations of quarks and leptons. Alternatively, the authors may discover that CP violation lies outside the present framework. In this paper the authors briefly describe the physics reach of the SLAC/LBL/LLNL Asymmetric B-Factory, the progress on the machine design and construction, the progress on the detector design, and the schedule to complete both projects.

  1. Beam dynamics and vane geometry in the LBL heavy ion RFQ

    SciTech Connect

    Staples, J.

    1983-08-01

    The LBL Heavy Ion RFQ accelerator, presently undergoing acceptance tests, extends the application of the RFQ principle to charge-to-mass ratios considerably less than one. In this design the aperture is very small compared to the operating wavelength, causing a large capacitive loading of the structure and also in a high sensitivity of the field configuration of the structure to vane alignment. A structure has been derived that eases the vane alignment procedure and reduces the sensitivity to vane misalignment. The selection of the vane cross section facilitates machining and eventual frequency trimming.

  2. Effect of manufacturing errors on field quality of the LBL SSC dipoles

    SciTech Connect

    Meuser, R.B.

    1984-01-01

    A method is developed for determining the field aberrations resulting from specific kinds of manufacturing errors. This method is applied to the 40-mm i.d. dipoles under consideration at LBL, and also to similar ones with 30 and 50 mm i.d. The method is also applied to the CBA and Doubler/Saver magnets and the results compared with the measurements. The results obtained by this method are also compared with those obtained by assigning identical errors to the positions of the edges of all the coil sectors.

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

    SciTech Connect

    Goldhaber, G.

    1992-06-01

    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.

  4. LBL/JSU/AGMUS science consortium annual report, FY 1991--1992

    SciTech Connect

    Not Available

    1992-12-31

    In 1983, a formal Memorandum of Understanding joined the Ana G. Mendez University System (AGMUS), Jackson State University (JSU), and the Lawrence Berkeley Laboratory (LBL) in a consortium designed to advance the science and technology programs of JSU and AGMUS. This is the first such collaboration between a Hispanic university system, a historically Black university, and a national laboratory. The goals of this alliance are basic and direct: to develop and effect a long-term, comprehensive program that will enable the campuses of AGMUS and JSU to provide a broad, high-quality offering in the natural and computer sciences, to increase the number of minority students entering these fields, and to contribute to scientific knowledge and the federal government`s science mission through research. This report documents the progress toward these goals and includes individual success stories. The LBL/JSU/AGMUS Science Consortium has developed plans for utilizing its program successes to help other institutions to adopt or adapt those elements of the model that have produced the greatest results. Within the five-year plan formulated in 1990 are eight major components, each with defining elements and goals. These elements have become the components of the Science Consortium`s current plan for expansion and propagation.

  5. Europium phosphomolybdate and osmium metallopolymer multi-functional LbL films: redox and electrocatalytic properties.

    PubMed

    Fernandes, Diana M; Vos, Johannes G; Freire, Cristina

    2014-04-15

    Hybrid multilayer films composed by osmium metallopolymer [Os(bpy)2(PVP)10Cl]Cl (Os-poly) and europium phosphomolybdate, K₁₁[Eu(III)(PMo₁₁O₃₉)₂] (Eu(PMo11)2), were prepared using the electrostatic layer-by-layer (LbL) self-assembly method. The film build-up, monitored by electronic spectroscopy, showed a regular stepwise growth indicating a strong interaction between layers. The XPS measurements corroborated the successful fabrication of the hybrid films with the Os-poly/Eu(PMo11)2 composition. SEM images revealed a completely covered surface with a highly roughened texture. Electrochemical characterisation of films by cyclic voltammetry revealed three Mo-based reduction processes (Mo(VI)→Mo(V)) in the potential range between -0.4 and 0.1 V and one Os reduction process (Os(III)→Os(II)) at ≈0.270 V. The cyclic voltammograms of two electroactive probes, [Fe(CN)₆](3-/4-) and [Ru(NH₃)₆](3+/2+) on {Os-poly/Eu(PMo11)2}n modified electrodes revealed redox mediation between film and the probes. Furthermore, the {Os-poly/Eu(PMo11)2}n multilayer films also showed excellent Mo-based electrocatalytic activity towards reduction of nitrite and iodate, confirming the multi-functional properties of the hybrid europium phosphomolybdate - osmium metallopolymer LbL films. PMID:24559710

  6. Layer-by-Layer (LBL) Self-Assembled Biohybrid Nanomaterials for Efficient Antibacterial Applications.

    PubMed

    Wu, Yuanhao; Long, Yubo; Li, Qing-Lan; Han, Shuying; Ma, Jianbiao; Yang, Ying-Wei; Gao, Hui

    2015-08-12

    Although antibiotics have been widely used in clinical applications to treat pathogenic infections at present, the problem of drug-resistance associated with abuse of antibiotics is becoming a potential threat to human beings. We report a biohybrid nanomaterial consisting of antibiotics, enzyme, polymers, hyaluronic acid (HA), and mesoporous silica nanoparticles (MSNs), which exhibits efficient in vitro and in vivo antibacterial activity with good biocompatibility and negligible hemolytic side effect. Herein, biocompatible layer-by-layer (LBL) coated MSNs are designed and crafted to release encapsulated antibiotics, e.g., amoxicillin (AMO), upon triggering with hyaluronidase, produced by various pathogenic Staphylococcus aureus (S. aureus). The LBL coating process comprises lysozyme (Lys), HA, and 1,2-ethanediamine (EDA)-modified polyglycerol methacrylate (PGMA). The Lys and cationic polymers provided multivalent interactions between MSN-Lys-HA-PGMA and bacterial membrane and accordingly immobilized the nanoparticles to facilitate the synergistic effect of these antibacterial agents. Loading process was characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray diffraction spectroscopy (XRD). The minimal inhibition concentration (MIC) of MSN-Lys-HA-PGMA treated to antibiotic resistant bacteria is much lower than that of isodose Lys and AMO. Especially, MSN-Lys-HA-PGMA exhibited good inhibition for pathogens in bacteria-infected wounds in vivo. Therefore, this type of new biohybrid nanomaterials showed great potential as novel antibacterial agents. PMID:26192024

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

    PubMed Central

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

    2012-01-01

    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 1μm. 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 Ω·m and 3.80×10−6 Ω·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

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

    SciTech Connect

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

    1992-07-01

    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.

  9. Automatic tuning of the LBL SuperHILAC third-injector transport line

    SciTech Connect

    Pines, H.

    1983-03-01

    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.

  10. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL.

    PubMed

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-01-01

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV. PMID:26729120

  11. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL

    PubMed Central

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-01-01

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV. PMID:26729120

  12. Inverse modeling as a step in the calibration of the LBL-USGS site-scale model of Yucca Mountain

    SciTech Connect

    Finsterle, S.; Bodvarsson, G.S.; Chen, G.

    1995-05-01

    Calibration of the LBL-USGS site-scale model of Yucca Mountain is initiated. Inverse modeling techniques are used to match the results of simplified submodels to the observed pressure, saturation, and temperature data. Hydrologic and thermal parameters are determined and compared to the values obtained from laboratory measurements and conventional field test analysis.

  13. First results for 960 A. MeV /sup 238/U on /sup 238/U in the LBL streamer chamber

    SciTech Connect

    Fung, S.H.; Beavis, D.; Gorn, W.; Keane, D.; Liu, Y.H.; Poe, R.T.; VanDalen, G.; Vient, M.

    1984-11-15

    We report preliminary results for uranium on uranium collisions at the LBL streamer chamber facility, at the maximum Bevalac incident energy. Global event parameters are compared with results for Ar on KCl in the same energy region, and with intranuclear cascade model predictions. We also report results of temperature fits to negative pion spectra.

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

    SciTech Connect

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

    1989-03-01

    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.

  15. LBL/UCSB /sup 76/Ge double beta decay experiment: first results

    SciTech Connect

    Goulding, F.S.; Cork, C.P.; Landis, D.A.; Luke, P.N.; Madden, N.W.; Malone, D.F.; Pehl, R.H.; Smith, A.R.; Caldwell, D.O.; Eisberg, R.M.

    1984-10-01

    A paper given at the IEEE Nuclear Science Symposium last year presented the scientific justification for this experiment and discussed the design of the detector system. At the present time two of the dual detector systems (i.e., four out of a final total of eight detectors) are operating in the complete active/passive shield in the low background laboratory at LBL. Early results (1620 h) of an experiment using two detectors yield a limit of 4 x 10/sup 22/ years (68% confidence) for the half life of the neutrinoless double beta decay (..beta beta../sub o nu/) of /sup 76/Ge. Although this experiment was carried out above ground, the result approaches those achieved by other groups in deep underground laboratories. Based on studies of the origins of background in our system, we hope to reach a limit of 3 x 10/sup 23/ years (or more) in a two month/four detector experiment to be carried out soon in an underground facility.

  16. Steam stripping of oil shale wastewaters. LBL/SEEHRL steam stripper: design, operation, and maintenance manual

    SciTech Connect

    Sakaji, R.H.; Persoff, P.; Daughton, C.G.

    1984-08-01

    Steam stripping is the most often proposed means of treating oil shale wastewaters for the removal of ammonia and carbon dioxide. The removal of organic carbon generally is not an objective. This manual compares current steam stripper design theory with actual operating data reported in the literature and concludes that discrepancies exist between theory and actual practice. Although this manual is by no means a complete literature review on the more detailed subject of mass transfer, references are provided so that the reader can explore the subject material more closely. The primary intent of the manual is to give the operator a brief overview of the chemical and physical principles underlying the steam stripping process. Sufficient information is provided so that the operator can understand how the LBL/SEEHRL experimental-scale steam stripper was designed to be operated. Start-up procedures are detailed, and modifications required to improve performance are presented. Included are notes outlining periodic maintenance procedures for mechanical parts, protocols for the reduction of data, notes on the methods of chemical analysis, and the calculations used for mass balances. 66 references, 16 figures, 21 tables.

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

    SciTech Connect

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

    1983-10-01

    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.

  18. Effect of nano clay platelets and DNA on controlling the H-dimer of oxazine 4 perchlorate (OX4) in LbL film

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, J.; Hussain, S. A.; Bhattacharjee, D.

    2014-09-01

    Oxazine 4 perchlorate (OX4) forms dimer even in aqueous solution. In layer-by-layer (LbL) film of OX4, dimeric sites predominate over monomeric sites. This results in the quenching of fluorescence intensity. This communication reports a study of the control of H-dimer of OX4 in LbL film by incorporating nano clay platelets. Influence of deoxyribonucleic acid molecules in controlling the H-dimeric sites of Ox4 in the LbL film has also been studied. UV-Vis absorption spectroscopic technique has been employed to study this effect. Atomic force microscopic image confirms the presence of nano clay platelets in the LbL film.

  19. Development of LBL PhoSNOX combined NO sub x /SO sub 2 treatment process

    SciTech Connect

    Chang, S.G.; Littlejohn, D.; Liu, D.

    1991-04-01

    The LBL PhoSNOX process is a new advanced flue gas treatment process with the potential for removing more than 95% of both NO{sub x} and SO{sub 2} from flue gas. The initial idea of the process was conceived in 1987. The process uses yellow phosphorus (P{sub 4}) to induce the oxidation of insoluble NO to NO{sub 2}. P{sub 4} reacts with flue gas O{sub 2} to produce ozone which selectively oxidizes NO to NO{sub 2}. Subsequently, NO{sub 2} and SO{sub 2} are removed from flue gas by dissolution into an aqueous alkaline solution/slurry. P{sub 4} is converted to a desirable commercial by-product, phosphoric acid, as a result of this interaction. During the past year, parametric studies of the NO removal efficiency and the P/NO stoichiometric ratio were carried out with the 20 cfm bench-scale system. The parameters studied included the concentrations of NO in flue gas and P{sub 4} in spraying liquors. The fate of NO{sub x}, SO{sub 2}, and P{sub 4} was investigated. Computer modelings of the NO{sub x} and SO{sub 2} removal efficiencies and chemistry of nitrogen-sulfur compounds in scrubbing liquors were performed. A revised process configuration was proposed, and a mass balance of nitrogen, sulfur and phosphorus was made. An updated process economical evaluation was performed by George Lee of Bechtel Corporation. A safety evaluation was conducted by FMC. Pilot plant tests involving Bechtel Corp. and FMC were planned. 6 refs., 5 figs., 1 tab.

  20. Femtosecond x-ray generation through 90{degree} Thomson scattering: Status of the LBL experiment

    SciTech Connect

    Leemans, W.; Schoenlein, R.; Chin, A.; Glover, E.; Conde, M.; Chattopadhyay, S.; Kim, K.; Shank, C.V.

    1995-06-01

    Scattering of femtosecond laser pulses off a low energy relativistic electron beam at 90{degree} offers the possibility to generate ultrashort X-ray pulses. Experiments are under preparation in the Beam Test Facility of the Center for Beam Physics at LBL to demonstrate the generation and detection of such pulses. The experiments involve a relativistic electron beam (tunable from 25{endash}50 MeV) with a bunch length of 10 ps containing 1-2 nC, and an ultra short pulse (50{endash}200 fs), high peak power ({approx_gt}2 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. The electron beam, focused down to about a 50 {mu}m waist size intersects the focused laser beam at 90{degree}. The laser field acts as an electromagnetic undulator with strength {ital K} (quiver velocity of an electron normalized to the speed of light) for the relativistic electron beam, generating radiation up-shifted by 2 {gamma}{sup 2}/(1+{ital K}{sup 2}/2) and a pulse length given by the overlapped interaction length in time of the laser beam and the electron beam. Here {gamma} is the usual Lorentz factor. Wavelength tuning will be accomplished in the experiment by generating wiggler strengths on the order of one as well as by electron beam energy tuning. For a 50 MeV electron beam and a laser beam focused to an intensity on the order of 10{sup 16} W/cm{sup 2}, we expect 10{sup 5} photons at 0.4 A (10{percent} bandwidth) in a cone angle of 6 mrad in a 170 fs pulse. {copyright} 1995 {ital American Institute of Physics}.

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

    SciTech Connect

    Not Available

    1990-11-01

    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.

  2. Femtosecond X-ray generation through 90{sup o} Thomson scattering: Status of the LBL experiment

    SciTech Connect

    Leemans, W.; Schoenlein, R.; Chin, A.; Glover, E.; Conde, M.; Chattopadhyay, S.; Kim, K.J.; Shank, C.V.

    1994-11-01

    Scattering of femotosecond laser pulses off a low energy relativistic electron beam at 90{sup o} offers the possibility to generate ultrashort X-ray pulses. Experiments are under preparation in the Beam Test Facility of the Center for Beam Physics at LBL to demonstrate the generation and detection of such pulses. The experiments involve a relativistic electron beam (tunable from 25-50 MeV) with a bunch length of 10 ps containing 1-2 nC, and an ultra short pulse (50-200 fs), high peak power (>2 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. The electron beam, focused down to about a 50 {mu}m waist size intersects the focused laser beam at 90{sup o}. The laser field acts as an electromagnetic undulator with strength K (quiver velocity of an electron normalized to the speed of light) for the relativistic electron beam, generating radiation up-shifted by 2{gamma}{sup 2}/(1+K{sup 2}/2) and a pulse length given by the overlapped interaction length in time of the laser beam and the electron beam. Here {gamma} is the usual Lorentz factor. Wavelength tuning will be accomplished in the experiment by generating wiggler strengths on the order of one as well as by electron beam energy tuning. For a 50 MeV electron beam and a laser beam focused to an intensity on the order of 10{sup 16} W/cm{sup 2}, the authors expect 10{sup 5} photons at 0.4 {angstrom} (10% bandwidth) in a cone angle of 6 mrad in a 170 fs pulse.

  3. Proceedings of the 10th international workshop on ECR ion sources

    SciTech Connect

    Meyer, F W; Kirkpatrick, M I

    1991-01-01

    This report contains papers on the following topics: Recent Developments and Future Projects on ECR Ion Sources; Operation of the New KVI ECR Ion Source at 10 GHz; Operational Experience and Status of the INS SF-ECR Ion Source; Results of the New ECR4'' 14.5 GHz ECRIS; Preliminary Performance of the AECR; Experimental Study of the Parallel and Perpendicular Particle Losses from an ECRIS Plasma; Plasma Instability in Electron Cyclotron Resonance Heated Ion Sources; The Hyperbolic Energy Analyzer; Status of ECR Source Development; The New 10 GHz CAPRICE Source; First Operation of the Texas A M ECR Ion Source; Recent Developments of the RIKEN ECR Ion Sources; The 14 GHz CAPRICE Source; Characteristics and Potential Applications of an ORNL Microwave ECR Multicusp Plasma Ion Source; ECRIPAC: The Production and Acceleration of Multiply Charged Ions Using an ECR Plasma; ECR Source for the HHIRF Tandem Accelerator; Feasibility Studies for an ECR-Generated Plasma Stripper; Production of Ion Beams by using the ECR Plasmas Cathode; A Single Stage ECR Source for Efficient Production of Radioactive Ion Beams; The Single Staged ECR Source at the TRIUMF Isotope Separator TISOL; The Continuous Wave, Optically Pumped H{sup {minus}} Source; The H{sup +} ECR Source for the LAMPF Optically Pumped Polarized Ion Source; Present Status of the Warsaw CUSP ECR Ion Source; An ECR Source for Negative Ion Production; GYRAC-D: A Device for a 200 keV ECR Plasma Production and Accumulation; Status Report of the 14.4 GHZ ECR in Legnaro; Status of JYFL-ECRIS; Report on the Uppsala ECRIS Facility and Its Planned Use for Atomic Physics; A 10 GHz ECR Ion Source for Ion-Electron and Ion-Atom Collision Studies; and Status of the ORNL ECR Source Facility for Multicharged Ion Collision Research.

  4. Transparent Conductors from Carbon Nanotubes LBL-Assembled with Polymer Dopant with π-π Electron Transfer

    SciTech Connect

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

    2011-01-01

    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 π-π interactions was identified for this system. It leads to a conductivity of 1.1 × 10⁵ S/m at 66 wt % loadings of SWNT. This is better than other polymer/SWNT composites and translates into surface conductivity of 920 Ω/⟂ 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/m³, respectively, and exceed corresponding parameters of all similar TCs. The cumulative figure of merit, ΠTC, which included the critical failure strain relevant for flexible electronics, was ΠTC = 0.022 and should be compared to ΠTC = 0.006 for commercial ITO. Further optimization is possible using stratified nanoscale coatings and improved doping from the macromolecular LBL components.

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

    PubMed

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

    2011-05-18

    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 π-π 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 Ω/◻ 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

  6. Transparent Conductors from Carbon Nanotubes LBL-Assembled with Polymer Dopant with π-π Electron Transfer

    PubMed Central

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

    2011-01-01

    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 π-π 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, ΠTC, which included the critical failure strain relevant for flexible electronics, was ΠTC = 0.022 and should be compared to ΠTC = 0.006 for commercial ITO. Further optimization is possible using stratified nanoscale coatings and improved doping from the macromolecular LBL components. PMID:21524068

  7. LBL PhoSNOX process for combined removal of SO sub 2 and NO sub x from flue gas

    SciTech Connect

    Chang, S.G. ) Lee, G.C. )

    1992-02-01

    The addition of yellow phosphorus in wet scrubbing systems can result in the high efficiency simultaneous removal of SO{sub 2} and NO{sub x} from flue gas. Yellow phosphorus reacts with O{sub 2} to produce O{sub 3} which selectively oxidizes NO to NO{sub 2}. Subsequently, NO{sub 2} and SO{sub 2} are removed from flue gas by dissolution into an aqueous alkaline solution/slurry, where they are converted to ammonium sulfate and gypsum. Yellow phosphorus is oxidized to yield a desirable commercial by-product, phosphoric acid. This new technology has been tested jointly by LBL and Bechtel at LBL with a 20 cfm bench-scale scrubbing absorber. The test results indicated that greater than 90% NO removal efficiency could be achieved with an L/G{gt}60 (gal/min)/(1,000 cu ft/min) for NO concentrations ranging from 60 to 600 ppm. A stoichiometric ratio, P/NO, as low as 0.6 has been achieved. Economic projections for the PhoSNOX process have been made based on a conceptual process configuration. The estimated costs compare favorably with the SCR for high removal and are competitive with urea injection processes for low levels of NO{sub x} removal. FMC has conducted a safety study of the process and concluded that the potential safety hazards of yellow phosphorus can be avoided if proper precautions are taken.

  8. Improving the connection between wood and cement using LBL nanocoating to create a lightweight, eco-friendly structural material

    NASA Astrophysics Data System (ADS)

    Bejo, L.; Major, B.; Csoka, L.; Hantos, Z.; Karacsonyi, Zs

    2016-04-01

    Structural elements made out of cement bonded wood may be an excellent alternative to flammable organic bonded composite beams, and CO2 intensive, heavy and nonrenewable reinforced concrete. Unfortunately, preliminary studies showed that a sufficient load-bearing performance is difficult to achieve. Improving the compatibility of cement and wood by LbL nanocoating may be a significant step towards creating viable cement bonded wood load bearing elements. The study involved creating multi layer nanocoating on the surface of poplar veneer using various polyelectrolyte combinations and numbers of treatment cycles, and testing the withdrawal resistance of the samples from a cement matrix. PDDA-PSS treatment was found to form increasingly uniform coating on the surface of wood, while the results were less straightforward for PAH-PSS. Both types and all levels of treatment caused dramatic improvement in load withdrawal resistance. The best result - a more than tenfold improvement - was achieved by at least 10 cycles of PDDA-PSS treatment. PAH-PSS treatment yielded a somewhat more modest improvement, which was already evident after five treatment cycles. The results point to the excellent potential of LbL nanocoating for creating cement bonded structural wood based composite materials.

  9. Immobilization of lutetium bisphthalocyanine in nanostructured biomimetic sensors using the LbL technique for phenol detection.

    PubMed

    Fernandes, Edson Giuliani R; Brazaca, Lais C; Rodríguez-Mendez, Maria Luz; Saja, Jose Antonio de; Zucolotto, Valtencir

    2011-08-15

    This study describes the development of amperometric sensors based on poly(allylamine hydrochloride) (PAH) and lutetium bisphthalocyanine (LuPc(2)) films assembled using the Layer-by-Layer (LbL) technique. The films have been used as modified electrodes for catechol quantification. Electrochemical measurements have been employed to investigate the catalytic properties of the LuPc(2) immobilized in the LbL films. By chronoamperometry, the sensors present excellent sensitivity (20 nA μM(-1)) in a wide linear range (R(2)=0.994) up to 900 μM and limit of detection (s/n=3) of 37.5 × 10(-8)M for catechol. The sensors have good reproducibility and can be used at least for ten times. The work potential is +0.3 V vs. saturated calomel electrode (SCE). In voltammetry measurements, the calibration curve shows a good linearity (R(2)=0.992) in the range of catechol up to 500 μM with a sensitivity of 90 nA μM(-1) and LD of 8 μM. PMID:21704506

  10. A study on the interactions of cationic porphyrin with nano clay platelets in Layer-by-Layer (LbL) self assembled films

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, J.; Banik, Soma; Hussain, S. A.; Bhattacharjee, D.

    2015-07-01

    In the present communication, interaction of tetracationic porphyrin, 5,10,15,10-tetrakis (1-methyl-4-pyrindino) porphyrin tetra (p-toluenesulfonate) (TMPyP) with anionic nano clay platelets laponite has been studied in aqueous clay dispersion and Layer-by-Layer (LbL) self assembled film. Electrostatic adsorption of TMPyP molecules on clay platelets resulted in the flattenening of meso-substituent groups which led to the development of a new adsorbed band in the UV-vis absorption spectra. J-band was also formed due to overlapped organizations of organo-clay hybrid molecules in the LbL film leading to J-aggregates. Atomic force microscopic (AFM) studies gave visual evidence of this favoured organization in the monolayer LbL film.

  11. Development of ion beams for space effects testing using an ECR ion source

    NASA Astrophysics Data System (ADS)

    Benitez, Janilee; Hodgkinson, Adrian; Johnson, Mike; Loew, Tim; Lyneis, Claude; Phair, Larry

    2013-04-01

    At LBNL's 88-Inch Cyclotron and Berkeley Accelerator Space Effects (BASE) Facility, a range of ion beams at energies from 1 to 55 MeV/nucleon are used for radiation space effects testing. By bombarding a component with ion beams the radiation component of the space environment can be simulated and single event effects (SEEs) determined. The performance of electronic components used in space flight and high altitude aircraft can then be evaluated. The 88- Inch Cyclotron is coupled to the three electron cyclotron resonance ion sources (ECR, AECR-U, VENUS). These ion sources provide a variety of ion species, ranging from protons to heavy ions such as bismuth, for these tests. In particular the ion sources have been developed to provide "cocktails", a mixture of ions of similar mass-to-charge ratio, which can be simultaneously injected into the cyclotron, but selectively extracted from it. The ions differ in both their linear energy transfer (LET) deposited to the part and in their penetration depth into the tested part. The current heavy ion cocktails available are the 4.5, 10, 16, and 30 MeV per nucleon.

  12. Development of ion beams for space effects testing using an ECR ion source

    SciTech Connect

    Benitez, Janilee; Hodgkinson, Adrian; Johnson, Mike; Loew, Tim; Lyneis, Claude; Phair, Larry

    2013-04-19

    At LBNL's 88-Inch Cyclotron and Berkeley Accelerator Space Effects (BASE) Facility, a range of ion beams at energies from 1 to 55 MeV/nucleon are used for radiation space effects testing. By bombarding a component with ion beams the radiation component of the space environment can be simulated and single event effects (SEEs) determined. The performance of electronic components used in space flight and high altitude aircraft can then be evaluated. The 88- Inch Cyclotron is coupled to the three electron cyclotron resonance ion sources (ECR, AECR-U, VENUS). These ion sources provide a variety of ion species, ranging from protons to heavy ions such as bismuth, for these tests. In particular the ion sources have been developed to provide {sup c}ocktails{sup ,} a mixture of ions of similar mass-to-charge ratio, which can be simultaneously injected into the cyclotron, but selectively extracted from it. The ions differ in both their linear energy transfer (LET) deposited to the part and in their penetration depth into the tested part. The current heavy ion cocktails available are the 4.5, 10, 16, and 30 MeV per nucleon.

  13. Arming embolic beads with anti-VEGF antibodies and controlling their release using LbL technology.

    PubMed

    Sakr, O S; Berndt, S; Carpentier, G; Cuendet, M; Jordan, O; Borchard, G

    2016-02-28

    Transarterial chemoembolization (TACE) is used to treat various types of hypervascular tumors such as hepatocellular carcinoma and renal cancer. However, embolization and blocking of blood vessels nourishing a tumor mass evokes an angiogenic response due to the secretion of vascular endothelial growth factor (VEGF), which results in the formation of new blood vessels and eventually limitation in therapeutic efficacy. The presented work investigates the feasibility of loading the clinically used embolic beads (DC Bead®) with Bevacizumab (BEV), an anti-VEGF antibody, and control its release kinetics via Layer-by-Layer (LbL) coating. This strategy has the aim to achieve high, localized and sustained concentrations of BEV at the tumor site and reduce drug exposure in the systemic circulation. High loading of BEV on lyophilized beads of about 76mg BEV/bead vial was achieved. LbL coating was carried out by depositing alternating layers of the biocompatible polymers alginate and poly-L-lysine. Coating was proven successful by monitoring the reversal of zeta potential after addition of each layer. Morphological changes of the bead surface before and after coating were illustrated using SEM imaging. Moreover, release profiles from different formulations were studied and results showed that optimizing the number of deposited layers effectively slows the release of BEV for three days. Activity of released BEV was studied in different 2D and 3D cell based assays. Released BEV fractions showed comparable activity to fresh BEV solution used as control after 3days. In conclusion, our results suggest the opportunity for loading anti-VEGF antibodies on commercially available embolic beads to increase the efficacy of TACE of hypervascular tumors. PMID:26780173

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

    SciTech Connect

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

    1995-12-31

    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.

  15. An infrared free electron laser system for the proposed Chemical Dynamics Research Laboratory at LBL based on a 500 MHz superconducting linac

    SciTech Connect

    Kim, K.J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-09-01

    We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10{sup {minus}4}.

  16. An infrared free electron laser system for the proposed Chemical Dynamics Research Laboratory at LBL based on a 500 MHz superconducting linac

    SciTech Connect

    Kim, K.J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-09-01

    We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10[sup [minus]4].

  17. Role of the templating approach in influencing the suitability of polymeric nanocapsules for drug delivery: LbL vs SC/MS.

    PubMed

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

    2013-10-01

    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

  18. An infrared free electron laser system for the proposed chemical dynamics research laboratory at LBL based on a 500 MHz superconducting linac

    NASA Astrophysics Data System (ADS)

    Kim, K.-J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1994-03-01

    We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10 -4.

  19. An infrared free electron laser system for the proposed Chemical Dynamics Research Laboratory at LBL based on a 500 MHz superconducting linac

    NASA Astrophysics Data System (ADS)

    Kim, K. J.; Byrns, R.; Chattopadhyay, S.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Leemans, W.; Staples, J.; Taylor, B.

    1992-09-01

    A design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL is described. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10(exp -4).

  20. Heavy ion development at the LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron

    SciTech Connect

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

    1989-05-01

    The 88-Inch Cyclotron produces a wide range of ions for basic and applied research. The 6.4 GHz ECR source has completely replaced the PIG source, giving higher charge states and higher cyclotron energies. The ECR source has produced ions of 34 elements, of which 28 have been accelerated in the cyclotron, using gases, and low and high temperature ovens. A higher frequency 14.5 GHz advanced ECR is now under construction. It will further increase the charge states and energies available. A conceptual design has been done for a superconducting ECR driven by a gyrotron at 28 GHz. 8 refs., 5 figs., 1 tab.

  1. Status of the UCSB-LBL /sup 76/Ge double beta decay experiment

    SciTech Connect

    Witherell, M.S.

    1983-01-01

    This paper describes an experiment to look for neutrinoless double beta decay in /sup 76/Ge which is now under construction. Eight large high-purity germanium detectors are surrounded by an active shield of sodium iodide. The problem of reducing background sources is discussed in some detail.

  2. SciDAC - The Scientific Data Management Center (http://sdmcenter.lbl.gov)

    SciTech Connect

    Ling Liu Calton Pu

    2005-06-20

    In SciDAC SDM project, the main assignment to the Georgia Institute of Technology team (according to the proposed work) is to develop advanced information extraction and information integration technologies on top of the XWRAP technology originated from Georgia Tech [LPH01]. We have developed XWRAPComposer technology to enable the XWRAP code generator to generate Java information wrappers that are capable of extraction of data from multiple linked pages. These information wrappers are used as gateways or adaptors for scientific information mediators to access and fuse interesting data and answering complex queries over a large collection of heterogeneous scientific information sources. Our accomplishments over the SciDAC sponsored years (July 2001 to July 2004) can be summarized along two dimensions. Technically, we have produced a number of major software releases and published over 30 research papers in both international conferences and international journals. The planned software releases include 1. Five Java wrappers and five WDSL-enabled wrappers for SDM Pilot scenarios, which were released in early 2003, 2. The XWRAPComposer toolkit (command line version) which was first released in late 2003 and then released in Summer 2004, 3. Five Ptolemy wrapper actors which were released first in Summer 2003, and then released again in Fall 2005. 4. The decomposable XWRAPComposer actor in Ptolemy, which we have made it available as open source in end of 2004 and tested it in early 2005.

  3. A der(11)t(4;11)(q21;p15) in a T-ALL/LBL patient.

    PubMed

    Colli, Sandra; Furforo, Lilian; Rojo Pisarello, Eduardo; Maidana, Marcela; Martín, Carlos; Bordone, Javier; Slavutsky, Irma

    2016-04-01

    Translocation t(4;11)(q21;p15) is a rare recurrent change associated to T-cell acute leukemia. In most cases, this alteration appears as the only abnormality or as part of a simple karyotype. In this report, we present the first case of T acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) with the unbalanced translocation der(11)t(4;11)(q21;p15) as part of a very complex karyotype with multiple chromosome abnormalities, most of them not previously described in the literature. FISH (fluorescence in situ hybridization) and spectral karyotype (HiSKY) analysis confirmed the presence of complex alterations. The patient, a 16-year-old male, showed poor response to treatment and short survival (11 months). A detailed review of previously reported cases with t(4;11)(q21;p15) is also provided. The description of this type of alterations may contribute to the identification of new molecular mechanism associated to neoplastic development. PMID:26883452

  4. User's guide for the DOE/GSA ADPE (Automated Data Processing Equipment) inventory database system at LBL: Version 1. 1

    SciTech Connect

    Konrad, A.

    1986-03-21

    The ADPE Inventory database system was implemented to enable LBL to meet GSA and DOE ADPE inventory reporting requirements and to meet its own ADP management needs. It makes use of the SPIRES database management system, an IBM-compatible PC, YTERM and RELAY software. Extensive use of SPIRES protocols and formats have been made in order to meet stringent GSA data formatting requirements. In so doing, much of the interactive user support has been provided in the user interface so that users need to know very little about technical detail of DOE/GSA reporting requirements and procedures and virtually nothing about SPIRES. This document provides a brief sketch of required tasks and how to accomplish them. It should be used in conjunction with the Automated Data Processing Equipment/Data System System Reference Manual, by DOE, which contains descriptions of the constraints on the values of each data element. Those constraints are not repeated in this manual and they may change from time to time.

  5. Preliminary development of the LBL/USGS three-dimensional site-scale model of Yucca Mountain, Nevada

    SciTech Connect

    Wittwer, C.; Chen, G.; Bodvarsson, G.S.; Chornack, M.; Flint, A.; Flint, L.; Kwicklis, E.; Spengler, R.

    1995-06-01

    A 3-D model of moisture flow within the unsaturated zone at Yucca Mountain is being developed at LBL in cooperation with USGS. This site-scale model covers an area of about 34 km{sup 2} and is bounded by major faults to the north, east, and west. The relatively coarse-grid model includes about 300 horizontal grid-blocks and 17 layers. Contour maps and isopach maps are presented defining different types of infiltration zones, and the spatial distribution of Tiva Canyon, Paintbrush, and Topopah Spring hydrogeological units. Matrix flow is approximated using the van Genuchten model, and the equivalent continuum approximation is used to account for fracture flow in the welded units. One-, two-, and three-dimensional simulations are conducted using the TOUGH2 computer program. Steady-state simulations are performed with various uniform and nonuniform infiltration rates; results are interpreted in terms of effect of fault characteristics on moisture flow distribution, and on the location and formation of preferential pathways.

  6. Micropatterned antibody-terminated nanocomposites (MANs) fabricated using layer-by-layer lift-off (LBL-LO) technique.

    PubMed

    Shaik, Jameel; Mills, David K

    2012-07-01

    Patterned functional biomolecular surfaces have been created using a wide range of fabrication methods for applications in cell-based studies, with the most common methods based on photolithography or soft lithography. In this study, a simple fabrication method combining photolithography, layer-by-layer (LbL) self-assembly, and photoresist lift-off (LO) was used to create spatially defined nanocomposite micropatterns of antibodies on polyelectrolyte-protein multilayer beds. The two components of the micropatterned surfaces consisted of an anti-CD44 rat monoclonal antibody atop a vitronectin-coated multilayer film and an anti-rat osteopontin (MPIIIB10(1)) anitibody atop a fibronectin-coated multilayer film. The micropatterned antibody-terminated nanocomposites (MANs) were characterized using bright field microscopy, surface profilometry, and atomic force microscopy. The results demonstrate that LbL-LO method can be successfully used to create patterns of proteins and antibodies in precise spatial arrangements. The MAN surfaces can be utilized in many bionanotechnology applications, including patterned cell cocultures or tricultures, cytotoxicity testing, drug screening, and biosensing. In addition, the general fabrication approach used in this study is applicable to other antibodies and other ligands. PMID:22544682

  7. Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

    PubMed

    Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

    2014-12-10

    In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating, endothelial cell viability was also promoted, which indicated that the heparin-mimicking multilayer coating might extend the application fields of polymeric membranes in biomedical fields. PMID:25375347

  8. Preliminary development of the LBL/USGS three-dimensional site-scale model of Yucca Mountain, Nevada

    USGS Publications Warehouse

    1995-01-01

    A three-dimensional model of moisture flow within the unsaturated zone at Yucca Mountain is being developed at Lawrence Berkeley Laboratory (LBL) in cooperation with the U.S. Geological Survey (USGS). This site-scale model covers and area of about 34 km2 and is bounded by major faults to the north, east and west. The model geometry is defined (1) to represent the variations of hydrogeological units between the ground surface and the water table; (2) to be able to reproduce the effect of abrupt changes in hydrogeological parameters at the boundaries between hyrdogeological units; and (3) to include the influence of major faults. A detailed numerical grid has been developed based on the locations of boreholes, different infiltration zones, hydrogeological units and their outcrops, major faults, and water level data. Contour maps and isopatch maps are presented defining different types of infiltration zones, and the spatial distribution of Tiva Canyon, Paintbrush, and Topopah Spring hydrogeological units. The grid geometry consists of seventeen non-uniform layers which represent the lithological variations within the four main welded and non-welded hydrogeological units. Matrix flow is approximated using the van Genuchten model, and the equivalent continuum approximation is used to account for fracture flow in the welded units. The fault zones are explicitly modeled as porous medium using various assumptions regarding their permeabilities and characteristic curves. One-, two-, and three-dimensional simulations are conducted using the TOUGH2 computer program. Steady-state simulations are performed with various uniform and non-uniform infiltration rates. The results are interpreted in terms of the effect of fault characteristics on the moisture flow distribution, and on location and formation of preferential pathways.

  9. Synchrotron light source data book

    SciTech Connect

    Murphy, J.

    1989-01-01

    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.

  10. Thermal and structural analysis of the LBL 10 x 40 cm long pulse accelerator and the 12 x 48 cm common long pulse accelerator for TFTR, doublet III-D, and MFTF-B

    SciTech Connect

    Wells, R.P.

    1985-11-01

    Stress and deflection of the grid rails of the existing, Lawrence Berkeley Laboratory (LBL) designed, 10 x 40 cm Long Pulse (neutral beam) Accelerator (40LPA) and the expanded 12 x 48 cm version, Common Long Pulse Source (CLPS), have been computed for a series of assumed heat load distributions. The combined stress from self-constraint of thermal expansion and rail holder reaction forces has been calculated. A simplification of the gradient grid rail holder was analyzed and was found to work as well or better than the original 40LPA design under the most probable operating conditions. Heat flux non-uniformity over the rail surface for both accelerator designs was estimated from 40LPA grid calorimetry data for arc and beam extraction operation. The extrapolated total heat load per rail for the CLPS was less than the 1.2 kW value used in this analysis. Under worst case assumptions, the maximum equivalent stress in any of the molybdenum grid rails was less than 20% of yield. For the anticipated heat load distribution on the gradient grid, the predicted deflection of the grid rail meets the 0.0457 mm position tolerance except under extremely non-uniform heat loads.

  11. Introduction to LBL graphics

    SciTech Connect

    Not Available

    1984-08-01

    The Computing Services Department supports a number of graphics software packages on the VAX machines, primarily on the IGM VAX. These packages will drive a large variety of different graphical devices, terminals (including various Tektronix terminals, the AED 512 color raster terminal, the IMLAC Series II vector list processor terminal and others), various styles of plotters and the DICOMED D48 film recorder. We are going to present to you the following graphic software packages: Tell-A-Graf, Cuechart, Tell-A-Plan, Data Connection, DI-3000, Contouring, Grafmaker (including Grafeasy), Grafmaster, Movie.BYU, Grafpac, IDDS, UGS/HPLOT/HBOOK, and SDL/SGL.

  12. Magnet power supplies for the Advanced Light Source

    SciTech Connect

    Jackson, L.T.; Lutz, I.C.

    1989-03-01

    The Lawrence Berkeley Laboratory (LBL) is building an Advanced Light Source (ALS) to produce synchrotron radiation. An electron linear accelerator, and a booster synchrotron are used to accelerate the electron beam to 1.5 GeV to fill the storage ring. This paper describes the power supplies used for the magnets in the booster and the storage ring and the interface requirements for computer control and monitoring the power supplies and magnet currents. 1 ref., 3 figs., 2 tabs.

  13. Effects of total pressure on non-grey gas radiation transfer in oxy-fuel combustion using the LBL, SNB, SNBCK, WSGG, and FSCK methods

    NASA Astrophysics Data System (ADS)

    Chu, Huaqiang; Gu, Mingyan; Consalvi, Jean-Louis; Liu, Fengshan; Zhou, Huaichun

    2016-03-01

    The effects of total pressure on gas radiation heat transfer are investigated in 1D parallel plate geometry containing isothermal and homogeneous media and an inhomogeneous and non-isothermal CO2-H2O mixture under conditions relevant to oxy-fuel combustion using the line-by-line (LBL), statistical narrow-band (SNB), statistical narrow-band correlated-k (SNBCK), weighted-sum-of-grey-gases (WSGG), and full-spectrum correlated-k (FSCK) models. The LBL calculations were conducted using the HITEMP2010 and CDSD-1000 databases and the LBL results serve as the benchmark solution to evaluate the accuracy of the other models. Calculations of the SNB, SNBCK, and FSCK were conducted using both the 1997 EM2C SNB parameters and their recently updated 2012 parameters to investigate how the SNB model parameters affect the results under oxy-fuel combustion conditions at high pressures. The WSGG model considered is the recently developed one by Bordbar et al. [19] for oxy-fuel combustion based on LBL calculations using HITEMP2010. The total pressure considered ranges from 1 up to 30 atm. The total pressure significantly affects gas radiation transfer primarily through the increase in molecule number density and only slightly through spectral line broadening. Using the 1997 EM2C SNB model parameters the accuracy of SNB and SNBCK is very good and remains essentially independent of the total pressure. When using the 2012 EM2C SNB model parameters the SNB and SNBCK results are less accurate and their error increases with increasing the total pressure. The WSGG model has the lowest accuracy and the best computational efficiency among the models investigated. The errors of both WSGG and FSCK using the 2012 EM2C SNB model parameters increase when the total pressure is increased from 1 to 10 atm, but remain nearly independent of the total pressure beyond 10 atm. When using the 1997 EM2C SNB model parameters the accuracy of FSCK only slightly decreases with increasing the total pressure.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    Thin organic LbL (layer-by-layer) films with negatively charged surface were used as templates for biomimetic deposition of ZrO 2 on Si wafers by hydrolysis of Zr(SO 4) 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 ZrO 2 crystallized almost instantaneously to tetragonal (t) ZrO 2 under the electron beam. The ≤110 nm thick as-deposited layers were crack-free and adhered well to the LbL surface. Annealing at 500 °C led to complete crystallization of amorphous ZrO 2 to nanocrystalline t-ZrO 2. Further heating to 900 °C resulted in transformation to monoclinic ZrO 2, complete removal of sulfur and twofold shrinkage of the ceramic layer thickness. Both the nanohardness and elastic modulus of the deposited zirconia layers were significantly improved following the heat treatments.

  15. Design of a superconducting linear accelerator for an Infrared Free Electron Laser of the proposed Chemical Dynamics Research Laboratory at LBL

    SciTech Connect

    Chattopadhyay, S.; Byrns, R.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Kim, K.J.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.

    1992-08-01

    An accelerator complex has recently been designed at LBL as part of an Infrared Free Electron Laser facility in support of a proposed Chemical Dynamics Research Laboratory. We will outline the choice of parameters and design philosophy, which are strongly driven by the demand of reliable and spectrally stable operation of the FEL for very special scientific experiments. The design is based on a 500 MHz recirculating superconducting electron linac with highest energy reach of about 60 MeV. The accelerator is injected with beams prepared by a specially designed gun-buncher system and incorporates a near-isochronous and achromatic recirculation line tunable over a wide range of beam energies. The stability issues considered to arrive at the specific design will be outlined.

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

    SciTech Connect

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

    1992-07-01

    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).

  17. XUV synchrotron optical components for the Advanced Light Source: summary of the requirements and the developmental program

    NASA Astrophysics Data System (ADS)

    McKinney, Wayne R.; Irick, Steven C.; Lunt, David L.

    1993-01-01

    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).

  18. 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)

    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

    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

  19. LBL neutralized beam focusing experiment

    SciTech Connect

    Krafft, G.A.; Kim, C.H.; Smith, L.

    1985-05-01

    An intense neutralized Cs/sup +1/ beam has been focused by an electrostatic polarization field induced by a solenoidal magnetic field of 10-25 gauss. This report describes the experiment and compares the results with the predictions of an analytic linearized fluid model and a particle-in-cell simulation which treats the motion of the warm electrons in detail.

  20. New collider scheme at LBL

    SciTech Connect

    Pugh, H.G.

    1984-07-01

    This paper presents current ideas from Berkeley concerning a possible new facility for studying the phase transition from hadronic matter to quark matter. The physics ideas have evolved over a period of more than five years, the VENUS concept for a 25 GeV/nucleon colliding beam facility having been presented in 1979. The concept for the Minicollider has been, like that of VENUS, the work of Hermann Grunder and Christoph Leemann.

  1. LBL's Pollution Instrumentation Comparability Program.

    ERIC Educational Resources Information Center

    McLaughlin, R. D.; And Others

    1979-01-01

    Contained are condensed excerpts from the Lawrence Berkeley Laboratory Survey of Instrumentation for Environmental Monitoring. The survey describes instrumentation used to analyze air and water quality, radiation emissions, and biomedical impacts. (BB)

  2. Advanced Light Source beam position monitor

    SciTech Connect

    Hinkson, J.

    1991-10-28

    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.

  3. Parameter studies of candidate lattices for the 1-2 GeV synchrotron radiation source

    SciTech Connect

    Zisman, M.S.

    1986-01-13

    This document discusses the implications of various collective phenomena on the required performance of candidate lattices for the LBL 1 to 2 GeV Synchrotron Radiation Source. The performance issues considered include bunch length, emittance growth, and beam lifetime. In addition, the possible use of the 1 to 2 GeV Synchrotron Radiation Source as a high-gain FEL is explored briefly. Generally, the differences between lattices are minor. It appears that the most significant feature distinguishing the various alternatives will be the beam lifetime.

  4. ECR (Electron Cyclotron Resonance) ion sources for cyclotrons

    SciTech Connect

    Lyneis, C.M.

    1986-10-01

    In the last decade ECR (Electron Cyclotron Resonance) ion sources have evolved from a single large, power consuming, complex prototype into a variety of compact, simple, reliable, efficient, high performance sources of high charge state ions for accelerators and atomic physics. The coupling of ECR sources to cyclotrons has resulted in significant performance gains in energy, intensity, reliability, and variety of ion species. Seven ECR sources are in regular operation with cyclotrons and numerous other projects are under development or in the planning stag. At least four laboratories have ECR sources dedicated for atomic physics research and other atomic physics programs share ECR sources with cyclotrons. An ECR source is now installed on the injector for the CERN SPS synchrotron to accelerate O/sup 8 +/ to relativistic energies. A project is underway at Argonne to couple an ECR source to a superconducting heavy-ion linac. Although tremendous progress has been made, the field of ECR sources is still a relatively young technology and there is still the potential for further advances both in source development and understanding of the plasma physics. The development of ECR sources is reviewed. The important physics mechanisms which come into play in the operation of ECR Sources are discussed, along with various models for charge state distributions (CSD). The design and performance of several ECR sources are compared. The 88-Inch Cyclotron and the LBL ECR is used as an example of cyclotron+ECR operation. The future of ECR sources is considered.

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

    NASA Astrophysics Data System (ADS)

    Lopez, Juan Manuel

    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 degree of variability in the adhesion than previously reported; (3) the previous work had not removed the acridine orange surface problems. Therefore, a direct comparison between results was not possible. The new d-LbL surface process was successful in testing the basic assumptions. Testing showed that the new process eliminated the anomalous acridine orange retention problem during fluorescence imaging. This improvement in fluorescence response meant that the FM results matched the platelet adhesion on plain glass slides and adhesion reported by others in microfluidic flows. The chemical additive responses behaved as expected, with an increase in L-arginine contributing to a decrease in thrombogenesis under dynamic conditions, but not under static conditions.

  6. 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

    SciTech Connect

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

    1988-06-01

    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. The set of diagnostics included water calorimetry, thermocouples, vacuum ionization gauges, photodiodes, neutron, gamma-ray and charged particle backscatter spectroscopy, and implantation/secondary ion mass spectroscopy. These systems were used to perform complementary measurements of neutral beam species, measurements were performed either in the neutralizer region, where the beam contained both ions and neutrals, or in the region of the output neutral beam. In general, consistent with estimates made during the LBL development phase. They can provide guidance for the optimization of TFTR neutral beam heating operations and the understanding of auxilliary heated TFTR plasmas. 21 refs., 28 figs., 2 tabs.

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

    SciTech Connect

    Zisman, M.S.

    1987-03-01

    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.

  8. 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...

  9. 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...

  10. First undulators for the Advanced Light Source

    SciTech Connect

    Hoyer, E.; Akre, J.; Chin, J.

    1993-05-01

    The first three undulators, each 4.6 m in length, for the Advanced Light source (ALS) at Lawrence Berkeley Laboratory (LBL), are near completion and are undergoing qualification tests before installation into the storage ring. Two devices have 5.0-cm period lengths, 89 periods, and achieve an effective field of 0.85 T at the 14 mm minimum magnetic gap. The other device has a period length of 8.0 cm, 55 periods, and an effective field of 1.2 T at the minimum 14 mm gap. Measurements on the first 5 cm period device show the uncorrelated field errors to be 0.23%, which is less than the required 0.25%. Measurements of gap control show reproducibility of {plus_minus}5 microns or better. The first vacuum chamber, 5.0 m long, is flat to within 0.53 mm over the 4.6 m magnetic structure section and a 4 x 10{sup -11} Torr pressure was achieved during vacuum tests. Device description, fabrication, and measurements are presented.

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

    SciTech Connect

    Cavazzuti, Elisabetta; Pittori, Carlotta; Giommi, Paolo; Colafrancesco, Sergio

    2007-07-12

    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.

  12. 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

    Yu, S.; Goffeney, N.; Henestroza, E.

    1995-02-22

    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.

  13. Selection Sources.

    ERIC Educational Resources Information Center

    Kerby, Ramona

    2002-01-01

    Discusses library collection development by school library media specialists and describes selection sources for new books and materials; retrospective selection sources for materials published in preceding years; and an acquisition source. Provides an overview of the selection process and includes 10 suggestions for selection. (LRW)

  14. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    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)

  15. Laser sources and techniques for spectroscopy and dynamics

    SciTech Connect

    Kung, A.H.

    1993-12-01

    This program focuses on the development of novel laser and spectroscopic techniques in the IR, UV, and VUV regions for studying combustion related molecular dynamics at the microscopic level. Laser spectroscopic techniques have proven to be extremely powerful in the investigation of molecular processes which require very high sensitivity and selectivity. The authors approach is to use quantum electronic and non-linear optical techniques to extend the spectral coverage and to enhance the optical power of ultrahigh resolution laser sources so as to obtain and analyze photoionization, fluorescence, and photoelectron spectra of jet-cooled free radicals and of reaction products resulting from unimolecular and bimolecular dissociations. New spectroscopic techniques are developed with these sources for the detection of optically thin and often short-lived species. Recent activities center on regenerative amplification of high resolution solid-state lasers, development of tunable high power mid-IR lasers and short-pulse UV/VUV tunable lasers, and development of a multipurpose high-order suppressor crossed molecular beam apparatus for use with synchrotron radiation sources. This program also provides scientific and technical support within the Chemical Sciences Division to the development of LBL`s Combustion Dynamics Initiative.

  16. The LBL geothermal reservoir technology program

    SciTech Connect

    Lippmann, M.J.

    1991-03-01

    The main objective of the DOE/GD-funded Geothermal Reservoir Technology Program at Lawrence Berkeley Laboratory is the development and testing of new and improved methods and tools needed by industry in its effort to delineate, characterize, evaluate, and exploit hydrothermal systems for geothermal energy. This paper summarizes the recent and ongoing field, laboratory, and theoretical research activities being conducted as part of the Geothermal Reservoir Technology Program. 28 refs., 4 figs.

  17. Crystal preparation at LBL 1976 to 1986

    SciTech Connect

    Heppler, W.

    1989-05-01

    Soon after some progress had been made in understanding the structure of solids and the relation of structures to physical properties of solids, attention has turned to understanding the boundaries of bulk materials, their surfaces. Aside from the intrinsic interest of the subject, the motivations for this study are many because many chemical processes, such as corrosion, catalysis, and adhesion to name a few are limited to the surface of bulk materials. The natural starting point for such studies is oriented and polished single crystal surfaces, since these idealized terminations of the bulk are expected to present a minimal number of different surface atoms or chemical states to the outside world. This report is meant to be a quick guide for the uninitiated into the mysteries of crystal orienting, cutting and polishing. It is hoped that the worker can then avoid some of the many pitfalls along the way.

  18. Upgrades to the LBL lattice program

    SciTech Connect

    Staples, J.W. )

    1993-12-25

    The lATTICE synchrotron and transport system design code, dating from 1976 and currently running worldwide, is a friendly, interactive first-order design and analysis code with a rich graphics environment. The code is ideal for conceptualizing and designing beam optics systems quickly and intuitively. Recent additions to the code include a tracking module for determination of dynamic aperture and small amplitude tune shift including random element errors to 12-pole, automatic translation of lATTICE data files to input files into several other design codes for higher-order analysis, and additional graphics software. A companion code with the same data and command structure, qUICKtRAN, uses the full 6[times]6 [sigma]-matrix TRANSPORT formalism to include full phase plane mixing. The two official versions run on Sun and VAX platforms: the code is in Pascal.

  19. LBL Perspective on statistical database management

    SciTech Connect

    Wong, H.K.T.

    1982-12-01

    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.

  20. The LBL neutralized beam focusing experiment

    SciTech Connect

    Krafft, G.A.; Kim, C.H.; Smith, L.

    1985-10-01

    An intense neutralized Cs /SUP +l/ beam has been focused by an electrostatic polarization field induced by a solenoidal magnetic field of 10-25 gauss. This report describes the experiment and compares the results with the predictions of an analytic linearized fluid model and a particle-in-cell simulation which treats the motion of the warm electrons in detail.

  1. Operating instructions for LBL radon measurement facilities

    SciTech Connect

    Ingersoll, J.G.

    1980-06-01

    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.

  2. LBL resistivity studies at Cerro Prieto

    SciTech Connect

    Wilt, M.J.; Goldstein, N.E.; Razo, A.M.

    1980-01-01

    A series of dc resistivity studies were performed at the Cerro Prieto geothermal field. In the present study dipole-dipole resistivity data have been collected and two-dimensional modeling studies have been performed using these and existing Schlumberger data taken by the CFE. 10 refs.

  3. Ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    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.

  4. Synchrotron sources

    SciTech Connect

    Hulbert, S.L.

    1999-12-13

    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.

  5. Light Source

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

  6. NEUTRON SOURCES

    DOEpatents

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

    1963-01-15

    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)

  7. Neutron source

    DOEpatents

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

    1975-10-21

    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.

  8. ION SOURCE

    DOEpatents

    Leland, W.T.

    1960-01-01

    The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

  9. Crowd Sourcing.

    PubMed

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish. PMID:27039640

  10. NEUTRON SOURCE

    DOEpatents

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

    1959-01-13

    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.

  11. RADIATION SOURCES

    DOEpatents

    Brucer, M.H.

    1958-04-15

    A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

  12. Terahertz sources.

    PubMed

    Shumyatsky, Pavel; Alfano, Robert R

    2011-03-01

    We present an overview and history of terahertz (THz) sources for readers of the biomedical and optical community for applications in physics, biology, chemistry, medicine, imaging, and spectroscopy. THz low-frequency vibrational modes are involved in many biological, chemical, and solid state physical processes. PMID:21456861

  13. Superluminal sources.

    PubMed Central

    Vermeulen, R C

    1995-01-01

    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. PMID:11607604

  14. ION SOURCE

    DOEpatents

    Brobeck, W.M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from thc source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a varuum lock arrangement in conjunction with an arm for manipulating the bottle.

  15. ION SOURCE

    DOEpatents

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

    1960-07-19

    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.

  16. ION SOURCE

    DOEpatents

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

    1958-01-28

    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.

  17. Ion source

    DOEpatents

    Brobeck, W. M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from the source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a vacuum lock arrangement in conjunction with an arm for manipulating the bottle.

  18. Low-emittance uniform density Cs sup + sources for heavy ion fusion accelerators studies

    SciTech Connect

    Eylon, S.; Henestroza, E.; Garvey, T.; Johnson, R.; Chupp, W.

    1991-04-01

    Low-emittance (high-brightness) Cs{sup +} thermionic sources were developed for the heavy ion induction linac experiment MBE-4 at LBL. The MBE-4 linac accelerates four 10 mA beams from 200 ke V to 900 ke V while amplifying the current up to a factor of nine. Recent studies of the transverse beam dynamics suggested that characteristics of the injector geometry were contributing to the normalized transverse emissions growth. Phase-space and current density distribution measurements of the beam extracted from the injector revealed overfocusing of the outermost rays causing a hollow density profile. We shall report on the performance of a 5 mA scraped beam source (which eliminates the outermost beam rays in the diode) and on the design of an improved 10 mA source. The new source is based on EGUN calculations which indicated that a beam with good emissions and uniform current density could be obtained by modifying the cathode Pierce electrodes and using a spherical emitting surface. The measurements of the beam current density profile on a test stand were found to be in agreement with the numerical simulations. 3 refs., 6 figs.

  19. Radiation source

    DOEpatents

    Thode, Lester E.

    1981-01-01

    A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

  20. Brain protein deciphered at Advanced Light Source

    SciTech Connect

    2010-01-01

    This computer-generated model of a rat glutamate receptor is the first complete portrait of this important link in the nervous system. At the top of the Y-shaped protein, a pair of molecules splay outward like diverging prongs. The bottom section, which is embedded in a neuronal membrane, houses the ion channel. The resolution of this image is 3.6 angstroms per pixel, or just under four ten-billionths of a meter per image unit. http://newscenter.lbl.gov/feature-stories/2010/01/21/glutamate-receptor/

  1. Who goes there. A dialogue of questions and answers about benign hacking. [Securing access to computer from outside sources

    SciTech Connect

    Stevens, D.F.

    1987-04-01

    On August 23, 1986, it was noticed that the accounting files for one of LBL's computing systems failed to balance. On August 24, we received word that an unauthorized person was attempting entry into a US Navy computer from LBL. Preliminary investigation indicated that LBL was the victim of a benign hacker, where ''benign'' is used in the medical sense. It was thought that the perpetrator was a graduate student from a neighboring university, and that it would provide a useful object lesson to other such folk if he were caught and admonished. LBL therefore embarked upon a journey of detection and containment instead of prevention. That journey continues today, having led first across the country, then across the Atlantic. In the course of the journey we have gathered a number of observations that should be of interest to anyone running a computer with any connection to the outside world.

  2. An assessment of the effects of radiation on permanent magnet material in the ALS (Advanced Light Source) insertion devices

    SciTech Connect

    Hassenzahl, W.V.; Jenkins, T.M.; Namito, Y.; Nelson, W.R.; Swanson, W.P.

    1989-08-01

    Electrons that are lost from the beam during normal operation of a synchrotron radiation source and during a beam dump at the end of a run produce both ionizing radiation and neutrons. This radiation has the potential for damaging sensitive materials, in particular those that need to be very close to the beam. The wigglers and undulators for the Advanced Light Source (ALS) at LBL will use magnetic materials such as the very high performance neodymium-iron-boron, which will be as close as 1 cm away from the electron beam during operation. This material, which is preferred because of its high remanence, is known to be more sensitive to radiation than some other magnetic materials. Simple energy loss estimates and the EGS4 code were used to estimate the radiation levels in the ALS insertion devices in the regions of the magnetic materials. The radiation levels were estimated for both aluminum and stainless steel vacuum chambers to determine if one would provide significantly better shielding. We conclude that Nd-Fe-B can be used in the ALS insertion devices and that there is little difference in the radiation levels for aluminum and stainless vacuum vessels. 8 refs., 7 figs., 1 tab.

  3. Source Water Quality Monitoring

    EPA Science Inventory

    Presentation will provide background information on continuous source water monitoring using online toxicity monitors and cover various tools available. Conceptual and practical aspects of source water quality monitoring will be discussed.

  4. Artificial light sources.

    PubMed

    Anderson, T F

    1986-04-01

    A wide variety of artificial light sources exists for use in the diagnosis and treatment of photosensitivity disorders. A discussion of the advantages and disadvantages of these light sources (including gas discharge arcs, fluorescent lamps, and other apparatus) illustrates the importance of matching the emission spectrum of the light source, the spectral response of the radiometer, and the photobiologic action spectrum. Environmental and occupational exposure to artificial light sources may contribute to photosensitivity disorders. PMID:3955892

  5. Familiarity in Source Memory

    PubMed Central

    Mollison, Matthew V.; Curran, Tim

    2012-01-01

    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. PMID:22789677

  6. Extragalactic Radio Sources

    ERIC Educational Resources Information Center

    Kellerman, Kenneth I.

    1973-01-01

    Discusses new problems arising from the growing observational data through radio telescope arrays, involving the origin of radio sources, apparent superluminal velocities, conversion of radio sources to relativistic particles, and the nature of compact opaque and extended transparent sources. New physics may be needed to answer these cosmological…

  7. Aeroacoustic sources in phonation

    NASA Astrophysics Data System (ADS)

    Krane, Michael

    2010-11-01

    An analysis of the flow through a time-varying duct constriction is used to identify the primary aeroacoustic source mechanisms in human vocalization. The acoustic fields on either side of the constriction are matched using equations describing the flow through the constriction. The form of the resulting sound fields indicates that the primary source of sound is the unsteady aerodynamic drag due to separated flow, and that secondary sources arise from changes in glottis volume and the movement of the separation point. The source strengths are shown to depend on the incident sound field, calling into question the "source-filter" theory of voice production. A control volume analysis supports these results.

  8. DC source assemblies

    DOEpatents

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    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.

  9. Erosion/corrosion newsletter (excerpted from LBL--13840)

    SciTech Connect

    Levy, A.V.

    1982-08-01

    Research is reported on the following programs: erosion/corrosion wear, coal liquefaction alloy test, utilization of metals in oil shale retort components, and materials characterization in fossil fuel combustion products. (DLC)

  10. Proceedings of the first LBL workshop on statistical database management

    SciTech Connect

    Wong, H.K.T.

    1982-03-01

    The workshop on statistical database management was intended to serve as a forum in which users, system builders, and database researchers could exchange ideas on the applications, techniques, problems, and requirements of statistical database management. The term statistical databases refers to databases that represent statistical or summary information and that are used for statistical analysis. Typically, these databases contain quantitative information, such as population counts and combinations of descriptive information, and such as race and sex for each quantitative measure. Individual items from the workshop were prepared separately for the database.

  11. Wobbler dosimetry for the biomedical program at the LBL Bevalac

    SciTech Connect

    Chu, W.; McEvoy, M.; Nyman, M.; Renner, T.; Gonzales, B.; Singh, R.P.; Stradner, R.

    1985-05-01

    A system for measuring delivered dose and dose distributions has been developed for use with the wobbler beam delivery system. The system allows rapid termination of an irradiation when hardware of software monitors indicate the required dose has been delivered. In addition several safeguard systems are required by such an active system in event of a failure of the wobbler, associated electronic hardware or the computer. Computer graphic displays allow operator monitoring of the irradiation on a pulse by pulse basis. 1 ref., 5 figs.

  12. Wobbler dosimetry for the biomedical program at the LBL Bevalac

    SciTech Connect

    Chu, W.; Gonzales, B.; McEvoy, M.; Nyman, M.; Renner, T.; Singh, R.P.; Stradner, R.

    1985-10-01

    A system for measuring delivered dose and dose distributions has been developed for use with the wobbler beam delivery system. The system allows rapid termination of an irradiation when hardware of software monitors indicate the required dose has been delivered. In addition several safeguard systems are required by such an active system in event of a failure of the wobbler, associated electronic hardware or the computer. Computer graphic displays allow operator monitoring of the irradiation on a pulse by pulse basis.

  13. GSI-LBL plastic ball/wall spectrometer

    SciTech Connect

    Gustafsson, H.A.; Doss, K.G.R.; Gutbrod, H.H.; Kolb, B.; Ludewigt, B.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.

    1984-09-01

    For the high multiplicity events occurring in relativistics nuclear collisions an electronic 4..pi.. detector with particle identification has been built. It consists of 815 ..delta..E - E telescopes and 176 TOF telescopes covering 97% of 4..pi... Very good particle identification has been obtained for hydrogen and helium isotopes and also ..pi../sup +/ have been detected with high efficiency. This spectrometer was used at the Berkeley Bevalac to study the reactions Ca + Ca, Nb + Nb and Au + Au at energies between 0.15 and 1.05 GeV/nucleon. Various exclusive observables like the degree of thermalization, the multiplicity dependence of composite particle formation, and freeze-out densities are discussed. From global analyses the collective flow of nuclear matter has been deduced. A method of separating efficiently participant and spectator particles has been applied in order to disentangle the two collective effects: The side-splash of the participants and the bounce-off in the fragmentation region. 9 references, 11 figures.

  14. LBL/Industry Heterogeneous Reservoir Performance Definition Project

    SciTech Connect

    Benson, S.M.; Majer, E.L.; Long, J.C.S.

    1993-12-31

    In this paper the investigator discusses hydrologic and seismic characterization of a fractured limestone and shale/sandstone formations based on a set of interference test data and vertical seismic profile (VSP)/tomographic imaging. Numerical inversions have been carried to build conceptual models for the Ft. Riley formation based on ``equivalent discontinuum`` and ``variable aperture continuum`` approaches. The analysis suggests the following conclusions: Stochastic inverse approaches were successful in reproducing the transient pressure behavior at the pumping and observation wells and appear to be viable means for characterizing fractured formation. The conceptual models for the Ft. Riley formation derived based on both continuum as well as discontinuum approaches indicate presence of a preferential pathway between wells GW-2 and GW-5 to the north of well GW-3. An attempt was made to verify the conceptual models by predicting the build data during the test Pump 58. The field data was affected by rainfall; however, the conceptual models appear to generate the expected trend. Multi-component VSP is useful for determining fracture orientation. High frequency (up to 5000 hz) imaging of the subsurface is possible at moderate scales (few hundred meters). P-wave imaging of fractured rocks using traveltime and amplitude studies give useful information on fracture density, location, and orientation.

  15. High current heavy ion beam transport experiment at LBL

    SciTech Connect

    Chupp, W.; Faltens, A.; Hartwig, E.C.; Keefe, D.; Kim, C.H.; Pike, C.; Rosenblum, S.S.; Tiefenback, M.; Vanecek, D.; Warwick, A.I.

    1984-01-01

    Information on the current limit in a long quadrupole transport channel is required in designing an accelerator driver for an inertial confinement fusion system. Although a current transport limit was proposed by Maschke, quantitative estimates require a detailed knowledge of the stability of the beam. Analytic calculations based on the Kapchinskij-Vladimirskij (K-V) distribution function have identified transversely unstable modes, but particle simulations have shown that some of the K-V instabilities are benign, i.e., particles redistribute themselves in the 4-D transverse phase space, but the rms emittances do not grow. Some preliminary results of beam transport experiments were reported in the 1983 Particle Accelerator Conference in Santa Fe.

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

    SciTech Connect

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

    1989-04-01

    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.

  17. Optimizing proton therapy at the LBL medical accelerator. Final report

    SciTech Connect

    Alonso, J.

    1992-03-01

    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.

  18. Optimizing proton therapy at the LBL medical accelerator

    SciTech Connect

    Alonso, J.

    1992-03-01

    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.

  19. Markov information sources

    NASA Technical Reports Server (NTRS)

    Massey, J. L.

    1975-01-01

    A regular Markov source is defined as the output of a deterministic, but noisy, channel driven by the state sequence of a regular finite-state Markov chain. The rate of such a source is the per letter uncertainty of its digits. The well-known result that the rate of a unifilar regular Markov source is easily calculable is demonstrated, where unifilarity means that the present state of the Markov chain and the next output of the deterministic channel uniquely determine the next state. At present, there is no known method to calculate the rate of a nonunifilar source. Two tentative approaches to this unsolved problem are given, namely source identical twins and the master-slave source, which appear to shed some light on the question of rate calculation for a nonunifilar source.

  20. Neuromagnetic source reconstruction

    SciTech Connect

    Lewis, P.S.; Mosher, J.C.; Leahy, R.M.

    1994-12-31

    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.

  1. Opportunities for high aspect ratio micro-electro-magnetic-mechanical systems (HAR-MEMMS) at Lawrence Berkeley Laboratory

    SciTech Connect

    Hunter, S.

    1993-10-01

    This report contains viewgraphs on the following topics: Opportunities for HAR-MEMMS at LBL; Industrial Needs and Opportunities; Deep Etch X-ray Lithography; MEMS Activities at BSAC; DNA Amplification with Microfabricated Reaction Chamber; Electrochemistry Research at LBL; MEMS Activities at LLNL; Space Microsensors and Microinstruments; The Advanced Light Source; Institute for Micromaching; IBM MEMS Interests; and Technology Transfer Opportunities at LBL.

  2. Unveiling Unidentified Fermi Sources

    NASA Astrophysics Data System (ADS)

    Zhang, Lizhong; South Pole Telescope

    2016-01-01

    The Fermi γ-ray Space Telescope (Fermi) has surveyed the entire sky at the highest-energy band of the electromagnetic spectrum. The majority of Fermi sources have counterpart identifications from multi-wavelength large-area surveys, particularly in the radio and x-ray bands. However, around 35% of Fermi sources remain unidentified, a problem exasperated by the low resolution of the telescope. Understanding the nature of unidentified Fermi sources is one of the most pressing problems in γ-ray astronomy. The South Pole Telescope (SPT) has completed a survey covering a 2500 square degrees of the southern extragalactic sky with arcminute resolution at millimeter wavelengths. The mm wavelength is the most efficient means to identify blazars and unidentified Fermi sources. Our analysis shows that the SPT point source catalog provides candidate associations for 40% of the unidentified Fermi sources, showing them to be flat-spectrum radio quasars which are extraordinarily bright at millimeter (mm) wavelengths.

  3. Microwave ion source

    SciTech Connect

    Leung, Ka-Ngo; Reijonen, Jani; Thomae, Rainer W.

    2005-07-26

    A compact microwave ion source has a permanent magnet dipole field, a microwave launcher, and an extractor parallel to the source axis. The dipole field is in the form of a ring. The microwaves are launched from the middle of the dipole ring using a coaxial waveguide. Electrons are heated using ECR in the magnetic field. The ions are extracted from the side of the source from the middle of the dipole perpendicular to the source axis. The plasma density can be increased by boosting the microwave ion source by the addition of an RF antenna. Higher charge states can be achieved by increasing the microwave frequency. A xenon source with a magnetic pinch can be used to produce intense EUV radiation.

  4. Source and replica calculations

    SciTech Connect

    Whalen, P.P.

    1994-02-01

    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.

  5. Rf power sources

    SciTech Connect

    Allen, M.A.

    1988-05-01

    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.

  6. Dynamic radioactive particle source

    SciTech Connect

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

    2012-06-26

    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.

  7. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  8. Lithium ion sources

    NASA Astrophysics Data System (ADS)

    Roy, Prabir K.; Greenway, Wayne G.; Grote, Dave P.; Kwan, Joe W.; Lidia, Steven M.; Seidl, Peter A.; Waldron, William L.

    2014-01-01

    A 10.9 cm diameter lithium alumino-silicate ion source has been chosen as a source of ˜100mA lithium ion current for the Neutralized Drift Compression Experiment (NDCX-II) at LBNL. Research and development was carried out on lithium alumino-silicate ion sources prior to NDCX-II source fabrication. Space-charge-limited emission with the current density exceeding 1 mA/cm2 was measured with 0.64 cm diameter lithium alumino-silicate ion sources at 1275 °C. The beam current density is less for the first 10.9 cm diameter NDCX-II source, and it may be due to an issue of surface coverage. The lifetime of a thin coated (on a tungsten substrate) source is varied, roughly 40-50 h, when pulsed at 0.05 Hz and with pulse length of 6μs each, i.e., a duty factor of 3×10-7, at an operating temperature of 1250-1275 °C. The 10.9 cm diameter source lifetime is likely the same as of a 0.64 cm source, but the lifetime of a source with a 2 mm diameter (without a tungsten substrate) is 10-15 h with a duty factor of 1 (DC extraction). The lifetime variation is dependent on the amount of deposition of β-eucryptite mass, and the surface temperature. The amount of mass deposition does not significantly alter the current density. More ion source work is needed to improve the large source performance.

  9. Pulsed spallation neutron sources

    SciTech Connect

    Carpenter, J.M.

    1996-05-01

    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.

  10. Source identification with GLAST

    SciTech Connect

    Lonjou, Vincent; Knoedlseder, Juergen

    2007-07-12

    With more than 50% of unidentified sources, the third EGRET catalogue reflects the complexity of source identification in the GeV domain. In that context, we developed a dedicated GLAST ScienceTool dubbed gtsrcid for the general purpose of source identification. gtsrcid has been designed in a very flexible way and allows cross correlation with any counterpart catalogue using user-definable figures-of-merit. Our source identification strategy, the results for DC2 as well as possible improvements of our identification procedures are presented.

  11. Improved ion source

    DOEpatents

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

    1982-05-04

    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,

  12. Workshop on detectors for third-generation synchrotron sources: Proceedings

    SciTech Connect

    1994-12-01

    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.

  13. Controlled-source magnetotellurics: source effects

    SciTech Connect

    Smith, T.; Lee, K.H.

    1999-04-01

    In this paper we evaluate the CSMT impedance in the wavenumber domain, and compare the result with the full EM impedance obtained from the exact solution over the layered earth. Preliminary results show that we can find a pair of wavenumbers that reproduces the full EM impedance over the frequency range affected by source effects. This observation suggests that it is now possible to obtain the electrical resistivity using the low-frequency EM impedance data that can be represented by a pair of wavenumbers, thereby greatly simplifying the computational requirements. The process will involve a non-linear inversion of near-source impedance data for a pair of wavenumbers and a layered-earth resistivity structure.

  14. Energy Sources and Development.

    ERIC Educational Resources Information Center

    Crank, Ron

    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…

  15. Radiation Source Replacement Workshop

    SciTech Connect

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

    2010-12-01

    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.

  16. Creating Open Source Conversation

    ERIC Educational Resources Information Center

    Sheehan, Kate

    2009-01-01

    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…

  17. Energy Sources and Development.

    ERIC Educational Resources Information Center

    Crank, Ron

    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

  18. Marine petroleum source rocks

    SciTech Connect

    Brooks, J.; Fleet, A.J.

    1987-01-01

    This book contains over 20 papers. Some of the titles are: The role of hydrocarbon source rocks in petroleum exploration; The Genesis and palynofacies characteristics of marine petroleum source rocks; The use of lipids as facies indicators; Palaeo-upwelling and the distribution of organic-rich rocks; and Hydrothermal petroleum from diatomites in the Gulf of California.

  19. Radioisotopic heat source

    DOEpatents

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

    1975-09-30

    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)

  20. New Source Performance Standards

    ERIC Educational Resources Information Center

    Jenkins, Richard E.; McCutchen, Gary D.

    1972-01-01

    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 sulfuric

  1. Sources of Instructional Leadership.

    ERIC Educational Resources Information Center

    Selim, Philip D.

    This study assessed patterns of instructional leadership sources. The instrument, Sources of Instructional Leadership (SOIL), was based on instructional leadership and effective schools literature. It dealt with the management of instructional resources, and related to one of six leadership functions: organizing, coordinating, developing,…

  2. Creating Open Source Conversation

    ERIC Educational Resources Information Center

    Sheehan, Kate

    2009-01-01

    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

  3. 1972 Microfilm Source Book.

    ERIC Educational Resources Information Center

    1972

    The 1972 Microfilm Source Book has been designed to give sources of supply for important services and equipment related to microfilm. Events in the microfilm industry during 1971 are reviewed first, and a calendar is provided of major meetings and conferences held during 1972. The next section contains an index to products which lists them…

  4. New Source Performance Standards

    ERIC Educational Resources Information Center

    Jenkins, Richard E.; McCutchen, Gary D.

    1972-01-01

    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 sulfuric…

  5. Tapping Sources of Information.

    ERIC Educational Resources Information Center

    Rash, David W.

    1988-01-01

    Resources are described for helping parents inform themselves about their disabled child's medical problems. Included are the use of library tools (card catalogs, cross references, periodicals, and indexes), use of library services (interlibrary loans and online searching), and other sources of information such as government sources, associations,…

  6. Open Source Vision

    ERIC Educational Resources Information Center

    Villano, Matt

    2006-01-01

    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.

  7. PORTABLE SOURCE OF RADIOACTIVITY

    DOEpatents

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

    1959-06-16

    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.)

  8. Sources of inspiration

    PubMed Central

    McSweeney, Sean; Fromme, Petra

    2015-01-01

    Synchrotrons have long been the preferred X-ray sources for crystallography, but competition has arrived with the advent of X-ray free-electron lasers. A synchrotron expert and an advocate of free-electron lasers discuss the prospects of the respective source types for applications in structural biology. PMID:24476881

  9. On source radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    The power output from given sources is usually ascertained via an energy flux integral over the normal directions to a remote (far field) surface; an alternative procedure, which utilizes an integral that specifies the direct rate of working by the source on the resultant field, is described and illustrated for both point and continuous source distribution. A comparison between the respective procedures is made in the analysis of sound radiated from a periodic dipole source whose axis performs a periodic plane angular movement about a fixed direction. Thus, adopting a conventional approach, Sretenskii (1956) characterizes the rotating dipole in terms of an infinite number of stationary ones along a pari of orthogonal directions in the plane, and through the far field representation of the latter, arrives at a series development for the instantaneous radiated power, whereas the local manner of power calculation dispenses with the equivalent infinite aggregate of sources and yields a compact analytical result.

  10. Pulsed ion beam source

    DOEpatents

    Greenly, John B.

    1997-01-01

    An improved pulsed ion beam source 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.

  11. The Spitzer Source List

    NASA Astrophysics Data System (ADS)

    Teplitz, Harry I.; Capak, P.; Brooke, T.; Khan, I.; Laher, R.

    2010-01-01

    The Spitzer Science Center will produce a source list (SL) of photometry for a large subset of imaging data in the Spitzer Heritage Archive (SHA). The list will enable a large range of science projects. The primary requirement on the SL is very high reliability, with areal coverage, completeness and limiting depth being secondary considerations. The SHA at the NASA Infrared Science Archive (IRSA) will serve the SL as an enhanced data product. The SL will include data from the four channels of IRAC (3-8 microns) and the 24 micron channel of MIPS. The Source List will include image products (mosaics) and photometric data for Spitzer observations of about 1500 square degrees and include around 30 million sources. We describe the plans and timeline for development of the Spitzer Source List. We demonstrate the verification of the Source List pipeline using Spitzer Legacy catalogs at "truth tables". Finally, we discuss the range of use cases which will be supported.

  12. The Spitzer Source List

    NASA Astrophysics Data System (ADS)

    Teplitz, H. I.; Capak, P.; Brooke, T.; Shenoy, S.; Brinkworth, C.; Desai, V.; Khan, I.; Laher, R.

    2010-12-01

    The Spitzer Science Center will produce a source list (SL) of photometry for a large subset of imaging data in the Spitzer Heritage Archive (SHA). The list will enable a large range of science projects. The primary requirement on the SL is very high reliability, with areal coverage, completeness and limiting depth being secondary considerations. The SHA at the NASA Infrared Science Archive (IRSA) will serve the SL as an enhanced data product. The SL will include data from the four channels of IRAC (3-8 microns) and the 24 micron channel of MIPS. The Source List will include image products (mosaics) and photometric data for Spitzer observations of about 1500 square degrees and include around 30 million sources. We describe the plans and timeline for development of the Spitzer Source List. We demonstrate the verification of the Source List pipeline using Spitzer Legacy catalogs at truth tables. Finally, we discuss the range of use cases which will be supported.

  13. Radio source evolution

    NASA Astrophysics Data System (ADS)

    Perucho, M.

    2016-02-01

    Baldwin (1982) wrote that {``the distribution of sources in the radio luminosity, P, overall physical size, D, diagram''} could be considered as {``the radio astronomer's H-R diagram''}. However, unlike the case of stars, not only the intrinsic properties of the jets, but also those of the host galaxy and the intergalactic medium are relevant to explain the evolutionary tracks of radio radio sources. In this contribution I review the current status of our understanding of the evolution of radio sources from a theoretical and numerical perspective, using the P-D diagram as a framework. An excess of compact (linear size {≤ 10} kpc) sources could be explained by low-power jets being decelerated within the host galaxy, as shown by recent numerical simulations. Finally, I discuss the possible tracks that radio sources may follow within this diagram, and the physical processes that can explain the different tracks.

  14. Industrial ion source technology

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.

    1976-01-01

    A 30 cm electron bombardment ion source was designed and fabricated for micromachining and sputtering applications. This source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. An average ion current density of 1 ma/sq cm with 500 eV argon ions was selected as a design operating condition. The ion beam at this operating condition was uniform and well collimated, with an average variation of plus or minus 5 percent over the center 20 cm of the beam at distances up to 30 cm from the ion source. A variety of sputtering applications were undertaken with a small 10 cm ion source to better understand the ion source requirements in these applications. The results of these experimental studies are also included.

  15. Neutron sources and applications

    SciTech Connect

    Price, D.L.; Rush, J.J.

    1994-01-01

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

  16. Photonic crystal light source

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Bur, James A.

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  17. Piezotube borehole seismic source

    DOEpatents

    Daley, Tom M; Solbau, Ray D; Majer, Ernest L

    2014-05-06

    A piezoelectric borehole source capable of permanent or semipermanent insertion into a well for uninterrupted well operations is described. The source itself comprises a series of piezoelectric rings mounted to an insulative mandrel internally sized to fit over a section of well tubing, the rings encased in a protective housing and electrically connected to a power source. Providing an AC voltage to the rings will cause expansion and contraction sufficient to create a sonic pulse. The piezoelectric borehole source fits into a standard well, and allows for uninterrupted pass-through of production tubing, and other tubing and electrical cables. Testing using the source may be done at any time, even concurrent with well operations, during standard production.

  18. Nuclear electric power sources

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1978-01-01

    Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

  19. Microfabricated diffusion source

    DOEpatents

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    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.

  20. CALUTRON ION SOURCE

    DOEpatents

    Lofgren, E.J.

    1959-02-17

    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.

  1. Biographical Sources for Astronomers

    NASA Astrophysics Data System (ADS)

    Dick, Wolfgang R.

    2006-12-01

    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.

  2. Tunable terahertz radiation source

    DOEpatents

    Boulaevskii, Lev; Feldmann, David M; Jia, Quanxi; Koshelev, Alexei; Moody, Nathan A

    2014-01-21

    Terahertz radiation source and method of producing terahertz radiation, said source comprising a junction stack, said junction stack comprising a crystalline material comprising a plurality of self-synchronized intrinsic Josephson junctions; an electrically conductive material in contact with two opposing sides of said crystalline material; and a substrate layer disposed upon at least a portion of both the crystalline material and the electrically-conductive material, wherein the crystalline material has a c-axis which is parallel to the substrate layer, and wherein the source emits at least 1 mW of power.

  3. Multiscale blind source separation

    NASA Astrophysics Data System (ADS)

    Kisilev, Pavel; Zibulevsky, Michael; Zeevi, Yehoshua Y.; Pearlmutter, Barak A.

    2001-03-01

    The concern of the blind source separation problem is to extract the underlying source signals from a set of their linear mixtures, where the mixing matrix is unknown. It was discovered recently, that use of sparsity of source representation in some signal dictionary dramatically improves the quality of separation. In this work we use the property of multiscale transforms, such as wavelet or wavelet packets, to decompose signals into sets of local features with various degrees of sparsity. We use this intrinsic property for selecting the best (most sparse) subsets of features for further separation. Experiments with simulated signals, musical sounds and images demonstrate significant improvement of separation quality.

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

    PubMed

    Sun, R K

    1990-12-01

    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

  5. Air pollution source identification

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.

    1975-01-01

    Techniques for air pollution source identification are reviewed, and some results obtained with them are evaluated. Described techniques include remote sensing from satellites and aircraft, on-site monitoring, and the use of injected tracers and pollutants themselves as tracers. The use of a large number of trace elements in ambient airborne particulate matter as a practical means of identifying sources is discussed in detail. Sampling and analysis techniques are described, and it is shown that elemental constituents can be related to specific source types such as those found in the earth's crust and those associated with specific industries. Source identification sytems are noted which utilize charged particle X-ray fluorescence analysis of original field data.

  6. 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 ...

  7. National Synchrotron Light Source

    ScienceCinema

    None

    2010-01-08

    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

  8. Permutation codes for sources.

    NASA Technical Reports Server (NTRS)

    Berger, T.; Jelinek, F.; Wolf, J. K.

    1972-01-01

    Source encoding techniques based on permutation codes are investigated. For a broad class of distortion measures it is shown that optimum encoding of a source permutation code is easy to instrument even for very long block lengths. Also, the nonparametric nature of permutation encoding is well suited to situations involving unknown source statistics. For the squared-error distortion measure a procedure for generating good permutation codes of a given rate and block length is described. The performance of such codes for a memoryless Gaussian source is compared both with the rate-distortion function bound and with the performance of various quantization schemes. The comparison reveals that permutation codes are asymptotically ideal for small rates and perform as well as the best entropy-coded quantizers presently known for intermediate rates. They can be made to compare favorably at high rates, too, provided the coding delay associated with extremely long block lengths is tolerable.

  9. Alternative fuel information sources

    SciTech Connect

    Not Available

    1994-06-01

    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.

  10. 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 ...

  11. National Synchrotron Light Source

    SciTech Connect

    2009-03-10

    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

  12. Topology, Holes and Sources

    NASA Astrophysics Data System (ADS)

    Afriat, Alexander

    2013-03-01

    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."

  13. Air pollution source identification

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.

    1975-01-01

    The techniques available for source identification are reviewed: remote sensing, injected tracers, and pollutants themselves as tracers. The use of the large number of trace elements in the ambient airborne particulate matter as a practical means of identifying sources is discussed. Trace constituents are determined by sensitive, inexpensive, nondestructive, multielement analytical methods such as instrumental neutron activation and charged particle X-ray fluorescence. The application to a large data set of pairwise correlation, the more advanced pattern recognition-cluster analysis approach with and without training sets, enrichment factors, and pollutant concentration rose displays for each element is described. It is shown that elemental constituents are related to specific source types: earth crustal, automotive, metallurgical, and more specific industries. A field-ready source identification system based on time and wind direction resolved sampling is described.

  14. National Synchrotron Light Source

    ScienceCinema

    BNL

    2009-09-01

    A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. 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, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

  15. Magnetron sputtering source

    DOEpatents

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

    1994-08-02

    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.

  16. Magnetron sputtering source

    DOEpatents

    Makowiecki, Daniel M.; McKernan, Mark A.; Grabner, R. Fred; Ramsey, Philip B.

    1994-01-01

    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.

  17. Source Inspection Scheduling Calendar

    NASA Technical Reports Server (NTRS)

    Hollis, Brayden

    2011-01-01

    Quality is an essential component for creating flight hardware travelling through space since the hardware is extremely expensive and cannot be reworked or repaired once launched. An important step in this process is ensuring the quality of hardware procured from Jet Propulsion Laboratory's (JPL) suppliers. An important element of determining supplier quality is source inspection. Source inspections are performed at suppliers' facilities by JPL employeesto ensure that hardware characteristics are acceptable before being covered up and/or delivered to JPL.

  18. Hubble Source Catalog

    NASA Astrophysics Data System (ADS)

    Lubow, S.; Budavári, T.

    2013-10-01

    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.

  19. Diversification of energy sources

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The concept of energy source diversification was introduced as a substitution conservation action. The current status and philosophy behind a diversification program is presented in the context of a national energy policy. Advantages, disadvantages (constraints), and methods of implementation for diversification are discussed. The energy source systems for diversification are listed and an example impact assessment is outlined which deals with the water requirements of the specific energy systems.

  20. Field emission electron source

    DOEpatents

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  1. Heavy ion fusion sources

    SciTech Connect

    Grote, D.P.; Kwan, J.; Westenskow, G.

    2003-02-01

    In Heavy-Fusion and in other applications, there is a need for high brightness sources with both high current and low emittance. The traditional design with a single monolithic source, while very successful, has significant constraints on it when going to higher currents. With the Child-Langmuir current-density limit, geometric aberration limits, and voltage breakdown limits, the area of the source becomes a high power of the current, A {approx} I{sup 8/3}. We are examining a multi-beamlet source, avoiding the constraints by having many beamlets each with low current and small area. The beamlets are created and initially accelerated separately and then merged to form a single beam. This design offers a number of potential advantages over a monolithic source, such as a smaller transverse footprint, more control over the shaping and aiming of the beam, and more flexibility in the choice of ion sources. A potential drawback, however, is the emittance that results from the merging of the beamlets. We have designed injectors using simulation that have acceptably low emittance and are beginning to examine them experimentally.

  2. Light Sources 2007

    NASA Astrophysics Data System (ADS)

    Liu, M. Q.; Devonshire, R.

    2007-04-01

    This volume contains the proceedings of the 11th International Symposium on the Science and Technology of Light Sources (LS:11) held in Fudan University, Shanghai, China in the period May 20th to 24th, 2007. In the 32 years since the first symposium was held in Loughborough, UK, the LS series has established itself as the major international event which brings together on a regular basis the world's leading scientists and engineers involved in the research and development of light source technologies. The participants come from the R&D laboratories of the world’s leading light source manufacturing companies and from research groups in universities, government laboratories and research institutes. The highly multi-disciplinary nature of the field results in a unique mix of physicists, chemists, chemical physicists, materials scientists and electrical, electronic and mechanical engineers attending the symposia. The more than 250 papers in these LS:11 proceedings provide an excellent overview of the current status of light source science and technology. The energy efficiency and light emission characteristics of existing technologies continue to be improved, solid state technologies are advancing rapidly and innovation flourishes generally. Audience Professional scientists and engineers involved in light source related R&D. Postgraduate-level students in the physical sciences, applied mathematics, materials science, and electrical and electronic engineering. The contents will also be of interest to anyone with a background in science and engineering wishing to gain an overview of current activity in this important global industry and research field.

  3. Pulsed ion beam source

    DOEpatents

    Greenly, J.B.

    1997-08-12

    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.

  4. Terahertz Schottky Multiplier Sources

    NASA Technical Reports Server (NTRS)

    Schlecht, Erich T.

    2007-01-01

    This viewgraph presentation reviews the multiplier source technologies and the status/Performance of THz multiplier sources. An example of a THz application is imaging radar. The presentation reviews areas of requirements for THz sources: (1) Figures of merit, (i.e., Frequency Terahertz for high resolution Bandwidth of at least 15 GHz for high range resolution Efficiency (i.e., minimize power supply requirements) (2) Output power: (i.e., Milliwatts below 800 GHz, 10s of microwatts above 1 THz, 1-2 microwatts near 2 THz (3) Mechanical--stability, compact, low mass (4) Environmental -- radiation, vibration, thermal. Several sources for 0.3 - 2 THz are reviewed: FIR lasers, quantum cascade lasers (QCL), backward-wave oscillator (BWO), and Multiplier sources. The current state of the art (SoA) is shown as Substrateless Technology. It also shows where the SoA is for devices beyond 1 THz. The presentation concludes by reviewing the options for future development, and 2 technology roadmaps

  5. Dual source heat pump

    DOEpatents

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    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.

  6. Sources of gravitational waves

    NASA Technical Reports Server (NTRS)

    Schutz, Bernard F.

    1989-01-01

    Sources of low frequency gravitational radiation are reviewed from an astrophysical point of view. Cosmological sources include the formation of massive black holes in galactic nuclei, the capture by such holes of neutron stars, the coalescence of orbiting pairs of giant black holes, and various means of producing a stochastic background of gravitational waves in the early universe. Sources local to our Galaxy include various kinds of close binaries and coalescing binaries. Gravitational wave astronomy can provide information that no other form of observing can supply; in particular, the positive identification of a cosmological background originating in the early universe would be an event as significant as was the detection of the cosmic microwave background.

  7. Interferometry for rotating sources

    NASA Astrophysics Data System (ADS)

    Velle, S.; Mehrabi Pari, S.; Csernai, L. P.

    2016-06-01

    The two particle interferometry method to determine the size of the emitting source after a heavy ion collision is extended. Following the extension of the method to spherical expansion dynamics, here we extend the method to rotating systems. It is shown that rotation of a cylindrically symmetric system leads to modifications, which can be perceived as spatial asymmetry by the "azimuthal HBT" method. We study an exact rotating and expanding solution of the fluid dynamical model of heavy ion reactions. We consider a source that is azimuthally symmetric in space around the axis of rotation, and discuss the features of the resulting two particle correlation function. This shows the azimuthal asymmetry arising from the rotation. We show that this asymmetry leads to results similar to those given by spatially asymmetric sources.

  8. Modulated infrared radiant source

    NASA Technical Reports Server (NTRS)

    Stewart, W. F.; Edwards, S. F.; Vann, D. S.; Mccormick, R. F.

    1981-01-01

    A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest.

  9. Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  10. Nutrition Information Sources

    PubMed Central

    Farrell, Lois

    1972-01-01

    Medical personnel and medical librarians may tend to think of nutrition in medical terms and to forget its interdisciplinary aspects. For this reason, it is desirable for medical librarians to become familiar with a variety of sources of information on the composition of foods, nutrient values, food additives, and food protection. Many of these are government publications from such agencies as the U.S. Department of Agriculture, the National Research Council, and the Food and Agriculture Organization. Less familiar sources include nutrition materials from state agricultural experiment stations and extension services and important data published in a wide range of scientific or agricultural journals, which may be located through Nutrition Abstracts and Reviews, Food Science and Technology Abstracts, and the Bibliography of Agriculture. Sources of current information on nutrition research in progress include the Department of Agriculture's Current Research Information System (CRIS) and selective listings from the Smith-sonian Information Exchange. PMID:4563540

  11. Nutrition information sources.

    PubMed

    Farrell, L

    1972-10-01

    Medical personnel and medical librarians may tend to think of nutrition in medical terms and to forget its interdisciplinary aspects. For this reason, it is desirable for medical librarians to become familiar with a variety of sources of information on the composition of foods, nutrient values, food additives, and food protection. Many of these are government publications from such agencies as the U.S. Department of Agriculture, the National Research Council, and the Food and Agriculture Organization. Less familiar sources include nutrition materials from state agricultural experiment stations and extension services and important data published in a wide range of scientific or agricultural journals, which may be located through Nutrition Abstracts and Reviews, Food Science and Technology Abstracts, and the Bibliography of Agriculture. Sources of current information on nutrition research in progress include the Department of Agriculture's Current Research Information System (CRIS) and selective listings from the Smith-sonian Information Exchange. PMID:4563540

  12. MEMS Incandescent Light Source

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret; King, Kevin; Kim, Lynn; Hansler, Richard; Jones, Eric; George, Thomas

    2001-01-01

    A MEMS-based, low-power, incandescent light source is being developed. This light source is fabricated using three bonded chips. The bottom chip consists of a reflector on Silicon, the middle chip contains a Tungsten filament bonded to silicon and the top layer is a transparent window. A 25-micrometer-thick spiral filament is fabricated in Tungsten using lithography and wet-etching. A proof-of-concept device has been fabricated and tested in a vacuum chamber. Results indicate that the filament is electrically heated to approximately 2650 K. The power required to drive the proof-of-concept spiral filament to incandescence is 1.25 W. The emitted optical power is expected to be approximately 1.0 W with the spectral peak at 1.1 microns. The micromachining techniques used to fabricate this light source can be applied to other MEMS devices.

  13. COASTING ARC ION SOURCE

    DOEpatents

    Foster, J.S. Jr.

    1957-09-10

    An improved ion source is described and in particular a source in which the ions are efficiently removed. The plasma is generated in a tubular amode structure by the oscillation of electrons in an axial magnetic field, as in the Phillips Ion Gage. The novel aspect of the source is the expansion of the plasma as it leaves the anode structure, so as to reduce the ion density at the axis of the anode and present a uniform area of plasma to an extraction grid. The structure utilized in the present patent to expand the plasma comprises flange members of high permeability at the exitgrid end of the amode to diverge the magnetic field adjacent the exit.

  14. The Sources of Radio News.

    ERIC Educational Resources Information Center

    Whitney, D. Charles

    To examine the production of programing material in a radio newsroom, a study was undertaken of the sources presented to the newsroom, of sources within the sources, of sources actively sought by the news staff, of degrees of processing of news items, and of the sources comprising the news output. Information in each of these areas was collected…

  15. INEEL Source Water Assessment

    SciTech Connect

    Sehlke, Gerald

    2003-03-01

    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.

  16. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    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 1015-1021 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 1020 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.

  17. Femtosecond tunable light source

    NASA Astrophysics Data System (ADS)

    Miesak, Edward Jozef

    1999-09-01

    A practical source of continuously tunable coherent visible and infrared light would have an enormous impact on science, medicine and technology. While microwave and radio transmitters offer wide tunability at the ``turn of a knob,'' the best known source of coherent optical radiation, the laser, does not possess the same versatility. Dye lasers provide some degree of tunability, but many dyes are needed to cover even the visible region. Ti:sapphire lasers are tunable only over the red to near infra-red portion of the spectrum (about 65 0 nm to about 1.1μm). This presentation documents the development of a unique pulsed light source tunable across the visible and near infrared portion of the spectrum, a femtosecond optical parametric amplifier (OPA). Much work was expended in developing the system itself. But a great deal of work was also done in developing the support equipment (hardware and software) necessary to build as well as maintain and operate an OPA. Once completed, the system characteristics were measured and documented. Initially it possessed ``personality'' which had to be understood and removed as much as possible. In addition, the pump source for this OPA, a regenerative amplifier, is unique in that it uses Cr3+:LiSGaF as the gain medium. This regen was also characterized and compared to other more standard regenerative amplifiers. System verification was done by performing a standard experiment (Z-scan) on well known samples, several of which are well characterized at specific wavelengths (1.06 μm, 0.523 μm) in the nanosecond and picosecond regimes. The results were compared against previously published results. The OPA was also compared against another very similar system which became commercially available during the time of this research. The results were helpful in analyzing the light source(s) and data acquisition systems for areas that could be improved.

  18. FABRICATION OF NEUTRON SOURCES

    DOEpatents

    Birden, J.H.

    1959-04-21

    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.

  19. Ultrashort Pulsed Neutron Source

    NASA Astrophysics Data System (ADS)

    Pomerantz, I.; McCary, E.; Meadows, A. R.; Arefiev, A.; Bernstein, A. C.; Chester, C.; Cortez, J.; Donovan, M. E.; Dyer, G.; Gaul, E. W.; Hamilton, D.; Kuk, D.; Lestrade, A. C.; Wang, C.; Ditmire, T.; Hegelich, B. M.

    2014-10-01

    We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50 ps ) and high peak flux (>1018 n /cm2/s ), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3 μ m ) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory.

  20. Trends in source gases

    NASA Technical Reports Server (NTRS)

    Ehhalt, D. H.; Fraser, P. J.; Albritton, D.; Cicerone, R. J.; Khalil, M. A. K.; Legrand, M.; Makide, Y.; Rowland, F. S.; Steele, L. P.; Zander, R.

    1989-01-01

    Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form.

  1. Nanoplasmonics enhanced terahertz sources.

    PubMed

    Jooshesh, Afshin; Smith, Levi; Masnadi-Shirazi, Mostafa; Bahrami-Yekta, Vahid; Tiedje, Thomas; Darcie, Thomas E; Gordon, Reuven

    2014-11-17

    Arrayed hexagonal metal nanostructures are used to maximize the local current density while providing effective thermal management at the nanoscale, thereby allowing for increased emission from photoconductive terahertz (THz) sources. The THz emission field amplitude was increased by 60% above that of a commercial THz photoconductive antenna, even though the hexagonal nanostructured device had 75% of the bias voltage. The arrayed hexagonal outperforms our previously investigated strip array nanoplasmonic structure by providing stronger localization of the current density near the metal surface with an operating bandwidth of 2.6 THz. This approach is promising to achieve efficient THz sources. PMID:25402040

  2. OLED area illumination source

    DOEpatents

    Foust, Donald Franklin; Duggal, Anil Raj; Shiang, Joseph John; Nealon, William Francis; Bortscheller, Jacob Charles

    2008-03-25

    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.

  3. ATLAS OF SOURCE EMISSION PARTICLES

    EPA Science Inventory

    An atlas of various source emission particles characterized by electron optical techniques has been compiled for use by air pollution investigators. The particles studied were emitted by mobile, stationary, and natural sources. Sources included automobiles, manufacturing operatio...

  4. Oceanography Information Sources 70.

    ERIC Educational Resources Information Center

    Vetter, Richard C.

    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…

  5. Miniature Radioisotope Power Source

    NASA Technical Reports Server (NTRS)

    Chmielewski, Artur B.

    1995-01-01

    Proposed miniature power source generates electricity for years from heat developed in small radioisotope unit without addition of fuel or dependence on sunlight. Called powerstick, is relatively inexpensive, lightweight, and rugged. Supplies power to small vehicles or scientific instruments in remote locations on Earth or in outer space. Envisioned uses include Mars miniature rovers and monitoring equipment for toxic or nuclear storage sites.

  6. SOURCE ASSESSMENT: CRUSHED STONE

    EPA Science Inventory

    This report describes a study of air emissions from crushed stone production. The potential environmental effect of the source is evaluated. Crushed stone production in 1972 was 1.07 x 10 to the 8th power metric tons (1.18 x 10 to the 8th power tons), 68% of which was traprock. C...

  7. 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...

  8. Craft Information Sources.

    ERIC Educational Resources Information Center

    Hujsak, Mary Dodge

    1994-01-01

    Provides a brief history of the craft movement and the American Craft Council. Information available from the American Craft Information Center is described, including bibliographic sources, reference tools, periodicals and indices, exhibition catalogs, craft registry and database, clipping file, education, business, funding, and appraising

  9. Industrial ion source technology

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.

    1979-01-01

    In reactive ion etching of Si, varying amounts of O2 were added to the CF4 background. The experimental results indicated an etch rate less than that for Ar up to an O2 partial pressure of about .00006 Torr. Above this O2 pressure, the etch rate with CF4 exceeded that with Ar alone. For comparison the random arrival rate of O2 was approximately equal to the ion arrival rate at a partial pressure of about .00002 Torr. There were also ion source and ion pressure gauge maintenance problems as a result of the use of CF4. Large scale (4 sq cm) texturing of Si was accomplished using both Cu and stainless steel seed. The most effective seeding method for this texturing was to surround the sample with large inclined planes. Designing, fabricating, and testing a 200 sq cm rectangular beam ion source was emphasized. The design current density was 6 mA/sq cm with 500 eV argon ions, although power supply limitations permitted operation to only 2 mA/sq cm. The use of multiple rectangular beam ion sources for continuous processing of wider areas than would be possible with a single source was also studied. In all cases investigated, the most uniform coverage was obtained with 0 to 2 cm beam overlay. The maximum departure from uniform processing at optimum beam overlap was found to be +15%.

  10. Sources of Assistance.

    ERIC Educational Resources Information Center

    Wood, Douglas

    This module is one of a set of seven prepared in conjunction with the Title I "Project to Train Volunteer Leaders to Conduct Consumer Education Courses." It is designed to be a basic text for use in making a one-hour presentation on sources of consumer assistance. Topics include consumers' alternatives for self-help, functions of the Virginia…

  11. Evaluating Internet Sources.

    ERIC Educational Resources Information Center

    Santa Vicca, Edmund F.; And Others

    1994-01-01

    Three articles on evaluation cover the use of the Internet as a reference resource and raise network policy issues: "The Internet as a Reference and Research Tool" (Edmund F. Santa Vicca); "NREN Update, 1993: Washington Policy" (Carolyn S. Elliot); and "Evaluating Physical Science Reference Sources on the Internet" (Susan S. Starr). (Contains 36…

  12. Does Source Reduction Work?

    ERIC Educational Resources Information Center

    Allaway, David

    1992-01-01

    Suggests that quantification is essential to establish the cost-effectiveness of source reduction (SR). Presents case studies of monitoring methods for seven different kinds of SR efforts: (1) packaging changes, (2) SR businesses, (3) waste exchanges, (4) individual nonresidential efforts, (5) variable garbage rates, (6) yard waste reduction, and…

  13. BNL Sources Development Laboratory

    SciTech Connect

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

    1997-01-01

    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.

  14. CHARACTERIZATION AND SOURCE APPORTIONMENT

    EPA Science Inventory

    The results from this core's studies will be essential to interpret the results of the other cores. These measurements will permit development of a delivery system to provide exposures of specific radical species on model particles for toxicological studies. Source apportion...

  15. Tandem Terminal Ion Source

    SciTech Connect

    2000-10-23

    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.

  16. Evaluating Open Source Portals

    ERIC Educational Resources Information Center

    Goh, Dion; Luyt, Brendan; Chua, Alton; Yee, See-Yong; Poh, Kia-Ngoh; Ng, How-Yeu

    2008-01-01

    Portals have become indispensable for organizations of all types trying to establish themselves on the Web. Unfortunately, there have only been a few evaluative studies of portal software and even fewer of open source portal software. This study aims to add to the available literature in this important area by proposing and testing a checklist for…

  17. Selective ion source

    DOEpatents

    Leung, K.N.

    1996-05-14

    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.

  18. Poetry: Sources for Criticism.

    ERIC Educational Resources Information Center

    Van Noate, Judith, Comp.

    This handout is a guide to library resources in the J. Murrey Atkins Library at the University of North Carolina-Charlotte for the criticism of poetry. The guide enables the reader to find sources of criticism on poetry, including critical articles and essays about single poems, or writings on the work of a single author. The guide's sections…

  19. Open Source in Education

    ERIC Educational Resources Information Center

    Lakhan, Shaheen E.; Jhunjhunwala, Kavita

    2008-01-01

    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

  20. Refugees: Information Sources.

    ERIC Educational Resources Information Center

    Larson, Carole

    This guide to information sources on refugees covers indexes, abstracts, bibliographies, periodicals, and resource and research centers. The guide begins with a discussion of recent developments in the bibliographic control of the literature on refugees, and particularly the work of the International Refugee Integration Resource Center. It then…

  1. Detecting Illicit Radioactive Sources

    SciTech Connect

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  2. Open-Source Colorimeter

    PubMed Central

    Anzalone, Gerald C.; Glover, Alexandra G.; Pearce, Joshua M.

    2013-01-01

    The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories. PMID:23604032

  3. Custom uniform source system

    NASA Technical Reports Server (NTRS)

    Balcom, John L.

    1994-01-01

    The purpose and scope of this final report is to provide information on the Custom Uniform Source System (CSTM-USS-4000). The report includes documentation and summaries of the results for the work performed under the contract. The Annex contain laboratory test findings, photographs, and drawings of the sphere system.

  4. Evaluating Open Source Portals

    ERIC Educational Resources Information Center

    Goh, Dion; Luyt, Brendan; Chua, Alton; Yee, See-Yong; Poh, Kia-Ngoh; Ng, How-Yeu

    2008-01-01

    Portals have become indispensable for organizations of all types trying to establish themselves on the Web. Unfortunately, there have only been a few evaluative studies of portal software and even fewer of open source portal software. This study aims to add to the available literature in this important area by proposing and testing a checklist for

  5. Selective ion source

    DOEpatents

    Leung, Ka-Ngo

    1996-01-01

    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. Open Source in Education

    ERIC Educational Resources Information Center

    Lakhan, Shaheen E.; Jhunjhunwala, Kavita

    2008-01-01

    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…

  7. Fourth generation light sources

    SciTech Connect

    Winick, H.

    1997-05-01

    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.

  8. Square Source Type Diagram

    NASA Astrophysics Data System (ADS)

    Aso, N.; Ohta, K.; Ide, S.

    2014-12-01

    Deformation in a small volume of earth interior is expressed by a symmetric moment tensor located on a point source. The tensor contains information of characteristic directions, source amplitude, and source types such as isotropic, double-couple, or compensated-linear-vector-dipole (CLVD). Although we often assume a double couple as the source type of an earthquake, significant non-double-couple component including isotropic component is often reported for induced earthquakes and volcanic earthquakes. For discussions on source types including double-couple and non-double-couple components, it is helpful to display them using some visual diagrams. Since the information of source type has two degrees of freedom, it can be displayed onto a two-dimensional flat plane. Although the diagram developed by Hudson et al. [1989] is popular, the trace corresponding to the mechanism combined by two mechanisms is not always a smooth line. To overcome this problem, Chapman and Leaney [2012] developed a new diagram. This diagram has an advantage that a straight line passing through the center corresponds to the mechanism obtained by a combination of an arbitrary mechanism and a double-couple [Tape and Tape, 2012], but this diagram has some difficulties in use. First, it is slightly difficult to produce the diagram because of its curved shape. Second, it is also difficult to read out the ratios among isotropic, double-couple, and CLVD components, which we want to obtain from the estimated moment tensors, because they do not appear directly on the horizontal or vertical axes. In the present study, we developed another new square diagram that overcomes the difficulties of previous diagrams. This diagram is an orthogonal system of isotropic and deviatoric axes, so it is easy to get the ratios among isotropic, double-couple, and CLVD components. Our diagram has another advantage that the probability density is obtained simply from the area within the diagram if the probability density function of moment tensor's eigenvalues P(λ1, λ2, λ3) depends only on the scalar moment [(λ12+λ22+λ32)/2]0.5. Even if this is not the real case, the easiness of calculating the areal density is useful when we compare the results of analyzing real data with that of analyzing background noise.

  9. Future Synchrotron Radiation Sources

    SciTech Connect

    Winick, Herman

    2003-07-09

    Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose; the others, with energy up to 5 giga-electron volts (GeV), were used parasitically during the operation of the ring for high energy physics research. In addition, at that time synchrotron radiation from nine cyclic electron synchrotrons, with energy up to 5 GeV, was also used parasitically. At present no cyclic synchrotrons are used, while about 50 electron storage rings are in operation around the world as fully dedicated light sources for basic and applied research in a wide variety of fields. Among these fields are structural molecular biology, molecular environmental science, materials, analytic chemistry, microfabrication, archaeometry and medical diagnostics. These rings span electron energies from a few hundred MeV to 8 GeV. Several facilities serve 2000 or more users on 30-60 simultaneously operational experimental stations. The largest rings are more than 1 km in circumference, cost about US$1B to build and have annual budgets of about US$100M. This growth is due to the remarkable properties of synchrotron radiation, including its high intensity, brightness and stability; wide spectral range extending from the infra-red to hard x-rays; variable polarization; pulsed time structure; and high vacuum environment. The ever-expanding user community and the increasing number of applications are fueling a continued growth in the number of facilities around the world. In the past few years new types of light sources have been proposed based on linear accelerators. Linac-based sources now being pursued include the free-electron laser (FEL) and energy recovery linac (ERL). In some respects (e.g., coherence, peak brightness, sub-picosecond pulse duration) these sources will far exceed the performance of storage-ring-based sources. As a consequence, they will open entirely new experimental opportunities. In particular, scientific interest is growing in the short pulse lengths that linacs can provide, making it possible to study chemical reactions and biological processes on the femtosecond time scale. The high peak brightness and peak power of the FEL also makes it possible to create and probe novel states of matter such as warm dense matter. It may also make it possible to determine the structure of proteins using single molecules as targets rather than crystal arrays. Depending on the linac energy, these sources can reach photon energies of 10 keV or higher. The reasons that linacs can deliver higher performance than rings, particularly high peak brightness and short pulse length, are given below. Short pulses can also be obtained in other ways. At the Advanced Light Source at LBNL a femtosecond laser has been used to slice out part of the longer electron bunch to provide short pulses of x-rays. Such a facility could operate at high repetition rate with natural synchronization with the laser, facilitating pump-probe experiments. Also, a project called the Sub-Picosecond Photon Source (SPPS) is in construction at SLAC using a magnetic compressor in the linac to produce an 80 femtosecond electron beam which, when passed through an undulator at the end of the linac, will generate 80 femtosecond x-ray pulses. The figure shows how these sources compare in peak brightness and pulse length with conventional storage ring beams, ERLs and FELs. We can thus discern some broad trends for new sources. One is making more synchrotron radiation available, including regions in which there are no present facilities. Another is the focus on high performance intermediate energy facilities. A third is the use of linac-based sources to achieve shorter pulses and higher brightness and peak power than storage rings can provide.

  10. The Advanced Photon Source

    SciTech Connect

    Galayda, John N.

    1996-01-01

    The Advanced Photon Source (APS) is a 7-GeV third-generation synchrotron radiation storage ring and full-energy positron injector. Construction project funding began in 1989, and ground breaking took place on 5 May 1990. Construction of all accelerator facilities was completed in January 1995 and storage ring commissioning is underway. First observation of x-rays from a bending magnet source took place on 26 March 1995. Nearly all performance specifications of the injector have been reached, and first observations indicate that the reliability, dynamic aperture, emittance, and orbit stability in the storage ring are satisfactory. Observation of radiation from the first of 20 insertion device beamlines is scheduled for October 1995. Start of regular operations is expected to take place well before the APS Project target date of December 1996.

  11. Advanced Light Source

    SciTech Connect

    Sah, R.C.

    1983-03-01

    The Advanced Light Source (ALS) is a new synchrotron radiation source which has been proposed by Lawrence Berkeley Laboratory. The ALS will be a key component in a major new research facility, the National Center for Advanced Materials. The ALS will consist of an electron linear accelerator, a booster synchrotron, a 1.3-GeV electron storage ring, and a number of photon beam lines. Most or all photon beam lines will originate from wiggler and undulator magnets placed in the 12 long straight sections of the ALS. A very low electron beam emittance will provide photon beams of unsurpassed spectral brilliance from specially-designed undulators, and a high radiofrequency will produce very short pulse lengths.

  12. Ion source apparatus

    SciTech Connect

    Sugawara, T.; Ito, Y.

    1985-03-19

    A gas is introduced into a discharge chamber of an ion source apparatus, and a gas discharge is performed between a thermionic cathode and an anode. Ions are extracted from the plasma formed in this gas discharge by a grid electrode. The thermionic cathode has a hollow cylindrical shape. A cathode chamber is defined by the thermionic cathode and a cylindrical partition wall supporting it. A columnar auxiliary electrode is coaxially inserted in the thermionic cathode. An A.C. voltage from a power source unit is supplied between the thermionic cathode and the auxiliary electrode such that effective power for keeping the thermionic cathode at a positive potential with respect to the auxiliary electrode is higher than that for keeping the auxiliary electrode at a positive potential with respect to the thermionic cathode.

  13. Moving source profiling (MSP)

    SciTech Connect

    Brauner, W.; Durschner, H.; Koopmann, B.; Marschall, R.; Peters, K.

    1988-01-01

    Moving source profiling is a modification of walk-away vertical seismic profiling in which the source is moved along a line across a well while the signal is recorded in the well at a certain depth. The method was designed to better predict the target horizon below the drill bit and away from the well location. The method has several advantages in areas of complicated overburden. In overthrust regions, the receiver is placed below much of the complicated structure to minimize distortion of the reflected signal. The final seismic image is a depth presentation of the subsurface structure and stratigraphy based on wavefront calculations. This depth estimation is obtained without extensive processing of the recorded data. The final result is available within a few days and can help interpreters to decide if and where to sidetrack the well. The method is demonstrated using an example from the overthrust zone of the Lower Saxonian Basin and the Pompeckj's well in Northern Germany.

  14. Terahertz sources and detectors

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

    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.

  15. Filtered cathodic arc source

    DOEpatents

    Falabella, S.; Sanders, D.M.

    1994-01-18

    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 is described. 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[degree] 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. 3 figures.

  16. Voltage controlled current source

    DOEpatents

    Casne, Gregory M.

    1992-01-01

    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.

  17. Mars Spark Source Prototype

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  18. Understanding Slat Noise Sources

    NASA Technical Reports Server (NTRS)

    Khorrami, Medhi R.

    2003-01-01

    Model-scale aeroacoustic tests of large civil transports point to the leading-edge slat as a dominant high-lift noise source in the low- to mid-frequencies during aircraft approach and landing. Using generic multi-element high-lift models, complementary experimental and numerical tests were carefully planned and executed at NASA in order to isolate slat noise sources and the underlying noise generation mechanisms. In this paper, a brief overview of the supporting computational effort undertaken at NASA Langley Research Center, is provided. Both tonal and broadband aspects of slat noise are discussed. Recent gains in predicting a slat s far-field acoustic noise, current shortcomings of numerical simulations, and other remaining open issues, are presented. Finally, an example of the ever-expanding role of computational simulations in noise reduction studies also is given.

  19. Evaluated teletherapy source library

    DOEpatents

    Cox, Lawrence J.; Schach Von Wittenau, Alexis E.

    2000-01-01

    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.

  20. Calibrated vapor generator source

    DOEpatents

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  1. Calibrated vapor generator source

    DOEpatents

    Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

    1995-01-01

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  2. Alternative energy sources

    NASA Astrophysics Data System (ADS)

    Todd, R. W.

    1982-04-01

    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.

  3. Filtered cathodic arc source

    DOEpatents

    Falabella, Steven (Livermore, CA); Sanders, David M. (Livermore, CA)

    1994-01-01

    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.degree. 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.

  4. FABRICATION OF NEUTRON SOURCES

    DOEpatents

    Birden, J.H.

    1959-01-20

    A method is presented for preparing a more efficient neutron source comprising inserting in a container a quantity of Po-210, inserting B powder coated with either Ag, Pt, or Ni. The container is sealed and then slowly heated to about 450 C to volatilize the Po and effect combination of the coated powder with the Po. The neutron flux emitted by the unit is moritored and the heating step is terminated when the flux reaches a maximum or selected level.

  5. Alternatives to source reduction

    SciTech Connect

    Carstens, R.

    1990-11-01

    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.

  6. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; Van Sant, J.H.

    1992-01-21

    This patent describes an isotopic heat source. It comprises; at least one isotopic fuel stack, comprising alternating layers of: thulium oxide; and a low atomic weight diluent for thulium oxide; a heat block defining holes into which the fuel stacks can be placed; at least one heat pipe for heat removal, with the heat pipe being positioned in the heat block in thermal connection with the fuel stack; and a structural container surrounding the heat block.

  7. High current ion source

    DOEpatents

    Brown, Ian G.; MacGill, Robert A.; Galvin, James E.

    1990-01-01

    An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

  8. Extended HXR Sources - Albedo Patches or Coronal Sources

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.

    2011-01-01

    Extended HXR sources in the presence of compact footpoints have been reported based on visibility amplitudes from different detectors. Attempts have been made to determine the location and extent of these sources through direct imaging. Results of this work will be described for simulated sources and for specific flares at different solar longitudes, with a discussion of the possible nature of the extended sources as either albedo patches or coronal sources or a combination of the two.

  9. Overdistribution in source memory.

    PubMed

    Brainerd, C J; Reyna, V F; Holliday, R E; Nakamura, K

    2012-03-01

    Semantic false memories are confounded with a second type of error, overdistribution, in which items are attributed to contradictory episodic states. Overdistribution errors have proved to be more common than false memories when the 2 are disentangled. We investigated whether overdistribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly overdistribution errors, but unlike semantic false memory, overdistribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of overdistribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that (a) overdistribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions. PMID:21942494

  10. VCSEL Swept Light Sources

    NASA Astrophysics Data System (ADS)

    Jayaraman, Vijaysekhar; Jiang, James; Potsaid, Benjamin; Robertson, Martin; Heim, Peter J. S.; Burgner, Christopher; John, Demis; Cole, Garrett D.; Grulkowski, Ireneusz; Fujimoto, James G.; Davis, Anjul M.; Cable, Alex E.

    Wavelength-swept light sources are widely recognized as a critical enabling technology for swept source optical coherence tomography (SS-OCT). In recent years, amplified micro-electromechanical systems tunable vertical cavity surface-emitting lasers (MEMS-VCSELs) have emerged as a high performance swept source, providing a unique combination of of wide tuning range, high maximum sweep rate, variable sweep rate, long dynamic coherence length enabled by dynamic mode-hop-free single mode operation, high optical power, and excellent imaging quality. Other important parameters provided by these devices include operation in a stable polarization state, low output power ripple, and linearized wavelength sweeping. This work describes MEMS-VCSEL device design, fabrication, and performance for devices in the 1050nm band relevant to ophthalmic imaging, and the 1310nm band relevant to vascular, skin, and anatomic imaging. Tuning ranges achieved include 100 nm at 1050nm and 150nm at 1310, with the latter result representing the widest tuning range of any MEMS-VCSEL at any wavelength. Both 1050 and 1310nm devices have enabled record imaging speed, record imaging range, and enhanced SS-OCT imaging.

  11. Chemical plume source localization.

    PubMed

    Pang, Shuo; Farrell, Jay A

    2006-10-01

    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 vehicle is capable of detecting above-threshold chemical concentration and sensing the fluid flow velocity at the vehicle location. This paper reviews instances of biological plume tracing and reviews previous strategies for a vehicle-based plume tracing. The main contribution is a new source-likelihood mapping approach based on Bayesian inference methods. Using this Bayesian methodology, the source-likelihood map is propagated through time and updated in response to both detection and nondetection events. Examples are included that use data from in-water testing to compare the mapping approach derived herein with the map derived using a previously existing technique. PMID:17036813

  12. Seismic source parameters

    SciTech Connect

    Johnson, L.R.

    1994-06-01

    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.

  13. Coded source neutron imaging

    SciTech Connect

    Bingham, Philip R; Santos-Villalobos, Hector J

    2011-01-01

    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.

  14. Open-Source GIS

    SciTech Connect

    Vatsavai, Raju; Burk, Thomas E; Lime, Steve

    2012-01-01

    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.

  15. Capillary discharge source

    DOEpatents

    Bender, III, Howard Albert

    2003-11-25

    Debris generation from an EUV electric discharge plasma source device can be significantly reduced or essentially eliminated by encasing the electrodes with dielectric or electrically insulating material so that the electrodes are shielded from the plasma, and additionally by providing a path for the radiation to exit wherein the electrodes are not exposed to the area where the radiation is collected. The device includes: (a) a body, which is made of an electrically insulating material, that defines a capillary bore that has a proximal end and a distal end and that defines at least one radiation exit; (b) a first electrode that defines a first channel that has a first inlet end that is connected to a source of gas and a first outlet end that is in communication with the capillary bore, wherein the first electrode is positioned at the distal end of the capillary bore; (c) a second electrode that defines a second channel that has a second inlet end that is in communication with the capillary bore and an outlet end, wherein the second electrode is positioned at the proximal end of the capillary bore; and (d) a source of electric potential that is connected across the first and second electrodes, wherein radiation generated within the capillary bore is emitted through the at least one radiation exit and wherein the first electrode and second electrode are shielded from the emitted radiation.

  16. Inverted magnetron ion source

    SciTech Connect

    Singh, B.; Boyarsky, D.

    1985-09-17

    The present invention provides, in a preferred embodiment, a cylindrical stainless steel cathode with end pieces thereon to form a cathode chamber within. In addition, in a preferred embodiment, there is a stainless steel rod which passes axially through the cathode chamber and which is electrically insulated therefrom at the end pieces. The stainless steel cathode has first and second apertures formed therein with the first to be connected to a source of ionizable gas and the second to act as the opening through which there passes a stream of ions to an ion beam target. A magnetic flux source is coupled to the cathode chamber to pass magnetic flux therethrough and a voltage source is connected between the anode and the cathode to provide an electrostatic field therebetween whereby when ionizable gas is fed into the cathode chamber, it is ionized and a stream of ions emanates from the second aperture. In a preferred embodiment there is further provided an electrostatic ion focusing means to focus the ion stream emanating from the second aperture.

  17. Plasmatic ion source

    NASA Astrophysics Data System (ADS)

    Semenov, A. P.

    1986-02-01

    A plasmatic ion source was built in which the hollow cathode above the two discharge chamber cathodes is readily replaced upon depletion after 250 to 300 h. The emission outlet hole is restored to original size by replacement of the cathode insert, while gas is continuously admitted by means of a spring mechanism. The source operates in the Penning discharge mode, with argon as the working gas. The hollow cathode is 36 mm long and has an inside diameter of 4 mm. The other two cathodes serve as pole shoes of a toroidal ferrite magnet which produces a longitudinal magnet field of 0.1 T induction in the discharge chamber. All three cathodes are made of magnetic steel and are insulated from cylindrical copper anode by teflon spacers. Heat is dissipated by oil, which carries it away to a water cooled housing compartment. The source generates an ion emission current of 20 mA with a discharge current of 200 mA at a pull voltage of 20kV.

  18. Improved negative ion source

    DOEpatents

    Delmore, J.E.

    1984-05-01

    A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

  19. Negative ion source

    DOEpatents

    Delmore, James E.

    1987-01-01

    A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

  20. A useful infrared source.

    PubMed

    Carlon, H R

    1966-08-01

    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

  1. 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...

  2. Online Sources of Competitive Intelligence.

    ERIC Educational Resources Information Center

    Wagers, Robert

    1986-01-01

    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…

  3. Source Monitoring in Alzheimer's Disease

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

  4. Chandra Source Catalog: User Interface

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    The Chandra Source Catalog (CSC) is intended to be the definitive catalog of all X-ray sources detected by Chandra. For each source, the CSC provides positions and multi-band fluxes, as well as derived spatial, spectral, and temporal source properties. Full-field and source region data products are also available, including images, photon event lists, light curves, and spectra. The Chandra X-ray Center CSC website (http://cxc.harvard.edu/csc/) is the place to visit for high-level descriptions of each source property and data product included in the catalog, along with other useful information, such as step-by-step catalog tutorials, answers to FAQs, and a thorough summary of the catalog statistical characterization. Eight categories of detailed catalog documents may be accessed from the navigation bar on most of the 50+ CSC pages; these categories are: About the Catalog, Creating the Catalog, Using the Catalog, Catalog Columns, Column Descriptions, Documents, Conferences, and Useful Links. There are also prominent links to CSCview, the CSC data access GUI, and related help documentation, as well as a tutorial for using the new CSC/Google Earth interface. Catalog source properties are presented in seven scientific categories, within two table views: the Master Source and Source Observations tables. Each X-ray source has one ``master source'' entry and one or more ``source observation'' entries, the details of which are documented on the CSC ``Catalog Columns'' pages. The master source properties represent the best estimates of the properties of a source; these are extensively described on the following pages of the website: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The eight tutorials (``threads'') available on the website serve as a collective guide for accessing, understanding, and manipulating the source properties and data products provided by the catalog.

  5. Cryogenic blackbody radiation calibration source

    NASA Technical Reports Server (NTRS)

    Burkett, Cecil G., Jr.; Daryabeigi, Kamran

    1992-01-01

    A cryogenic blackbody radiation source for providing target temperatures between room temperature and -100 C was designed, fabricated, and tested. This blackbody radiation source is intended for calibration of radiometric infrared imaging systems down to -100 C. The construction and operating principles of this apparatus are described. The long term and short term stability of the radiant source have been investigated. The emittance of the source and the source radiant uniformity have been addressed.

  6. SYNCHROTRON RADIATION SOURCES

    SciTech Connect

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

    1998-07-01

    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.

  7. Chernobyl source term estimation

    SciTech Connect

    Gudiksen, P.H.; Harvey, T.F.; Lange, R.

    1990-09-01

    The Chernobyl source term available for long-range transport was estimated by integration of radiological measurements with atmospheric dispersion modeling and by reactor core radionuclide inventory estimation in conjunction with WASH-1400 release fractions associated with specific chemical groups. The model simulations revealed that the radioactive cloud became segmented during the first day, with the lower section heading toward Scandinavia and the upper part heading in a southeasterly direction with subsequent transport across Asia to Japan, the North Pacific, and the west coast of North America. By optimizing the agreement between the observed cloud arrival times and duration of peak concentrations measured over Europe, Japan, Kuwait, and the US with the model predicted concentrations, it was possible to derive source term estimates for those radionuclides measured in airborne radioactivity. This was extended to radionuclides that were largely unmeasured in the environment by performing a reactor core radionuclide inventory analysis to obtain release fractions for the various chemical transport groups. These analyses indicated that essentially all of the noble gases, 60% of the radioiodines, 40% of the radiocesium, 10% of the tellurium and about 1% or less of the more refractory elements were released. These estimates are in excellent agreement with those obtained on the basis of worldwide deposition measurements. The Chernobyl source term was several orders of magnitude greater than those associated with the Windscale and TMI reactor accidents. However, the {sup 137}Cs from the Chernobyl event is about 6% of that released by the US and USSR atmospheric nuclear weapon tests, while the {sup 131}I and {sup 90}Sr released by the Chernobyl accident was only about 0.1% of that released by the weapon tests. 13 refs., 2 figs., 7 tabs.

  8. Integrated Power Source Grant

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed panel applications, these radiators maintain the battery cells in an appropriate operational temperature range.

  9. Compact ion accelerator source

    DOEpatents

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

    2014-04-29

    An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

  10. The European Spallation Source

    NASA Astrophysics Data System (ADS)

    Lindroos, M.; Bousson, S.; Calaga, R.; Danared, H.; Devanz, G.; Duperrier, R.; Eguia, J.; Eshraqi, M.; Gammino, S.; Hahn, H.; Jansson, A.; Oyon, C.; Pape-Møller, S.; Peggs, S.; Ponton, A.; Rathsman, K.; Ruber, R.; Satogata, T.; Trahern, G.

    2011-12-01

    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.

  11. Leptospirosis from water sources

    PubMed Central

    Wynwood, Sarah Jane; Graham, Glenn Charles; Weier, Steven Lance; Collet, Trudi Anne; McKay, David Brian; Craig, Scott Benjamin

    2014-01-01

    Leptospirosis outbreaks have been associated with many common water events including water consumption, water sports, environmental disasters, and occupational exposure. The ability of leptospires to survive in moist environments makes them a high-risk agent for infection following contact with any contaminated water source. Water treatment processes reduce the likelihood of leptospirosis or other microbial agents causing infection provided that they do not malfunction and the distribution networks are maintained. Notably, there are many differences in water treatment systems around the world, particularly between developing and developed countries. Detection of leptospirosis in water samples is uncommonly performed by molecular methods. PMID:25348115

  12. Ion beam source

    SciTech Connect

    Futamoto, M.; Kawabe, U.; Yuito, I.

    1984-08-21

    An ion beam source characterized in that a needle-like tip is comprised of a carbide, a nitride, or a diboride of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, and Ta, a hexaboride of at least one element of rare earth metal elements of atomic numbers 57-70, or carbon. Stable ion beam emission of high brightness and long life can be obtained by using the needle-like tip of the said material.

  13. The European Spallation Source

    SciTech Connect

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

    2011-04-20

    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.

  14. Sources of tritium

    SciTech Connect

    Phillips, J.E.; Easterly, C.E.

    1980-12-01

    A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

  15. Regenerative energy sources

    NASA Astrophysics Data System (ADS)

    Meliss, M.

    1981-04-01

    The significance of the regenerative energy sources for West Germany is examined, taking into account heat pump installations, solar collectors, water power, wind energy converters, and biomass. It is estimated that between 250,000 and 400,000 heat pumps will be sold per year. Passive systems, low-temperature collector installations, and heat pumps are discussed. Attention is also given to high-temperature collector installations and solar cells, design data for a solar farming installation, the installation of a power station for utilizing wind energy, geothermal energy, wave energy conversion, the utilization of the temperature difference at different depths in sea water, questions of biomass conversion, and firewood.

  16. Focused pulsed neutron source

    SciTech Connect

    Friedman, M.; Drobot, A.; Wyeth, N.C.

    1995-09-08

    A non-reactor neutron source is disclosed that allows for a pulse intense current of ions to generate neutrons that are epithermal neutrons and provide low-energy neutron energy particularly suited for Boron Neutron Capture Therapy (BNCT) treatment. The present invention provides for a neutron fluence on a tumor which can be more than 10{sup 12} neutrons/cm{sup 2} and is generated into a time scale of less than 1 second. The radiation dose provided by the present invention is focused yet uniformly distributed so as to attack cancerous tissues and reduce collateral damage to healthy tissues.

  17. Variable leak gas source

    DOEpatents

    Henderson, Timothy M.; Wuttke, Gilbert H.

    1977-01-01

    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.

  18. Evaluation of Electroencephalography Source Localization Algorithms with Multiple Cortical Sources

    PubMed Central

    Bradley, Allison; Yao, Jun; Dewald, Jules; Richter, Claus-Peter

    2016-01-01

    Background Source localization algorithms often show multiple active cortical areas as the source of electroencephalography (EEG). Yet, there is little data quantifying the accuracy of these results. In this paper, the performance of current source density source localization algorithms for the detection of multiple cortical sources of EEG data has been characterized. Methods EEG data were generated by simulating multiple cortical sources (2–4) with the same strength or two sources with relative strength ratios of 1:1 to 4:1, and adding noise. These data were used to reconstruct the cortical sources using current source density (CSD) algorithms: sLORETA, MNLS, and LORETA using a p-norm with p equal to 1, 1.5 and 2. Precision (percentage of the reconstructed activity corresponding to simulated activity) and Recall (percentage of the simulated sources reconstructed) of each of the CSD algorithms were calculated. Results While sLORETA has the best performance when only one source is present, when two or more sources are present LORETA with p equal to 1.5 performs better. When the relative strength of one of the sources is decreased, all algorithms have more difficulty reconstructing that source. However, LORETA 1.5 continues to outperform other algorithms. If only the strongest source is of interest sLORETA is recommended, while LORETA with p equal to 1.5 is recommended if two or more of the cortical sources are of interest. These results provide guidance for choosing a CSD algorithm to locate multiple cortical sources of EEG and for interpreting the results of these algorithms. PMID:26809000

  19. Bepcii Positron Source

    NASA Astrophysics Data System (ADS)

    Pei, Guoxi; Sun, Yaolin; Liu, Jintong; Chi, Yunlong; Liu, Yuncheng; Liu, Nianzong

    2013-10-01

    BEPCII- an upgrade project of the Beijing Electron Positron Collider (BEPC) is a factory type of e+e- collider. The fundamental requirements for its injector 1inac are the beam energy of 1.89GeV for on-energy injection and a 40mA positron beam current at the linac end with a low beam emittance of 1.6μm and a low energy spread of ±0.5% so as to guarantee a higher injection rate (≥50mA/min) to the storage ring. Since the positron flux is proportional to the primary electron beam power on the target, we will increase the electron gun current from 4A to 10A by using a new electmn gun system and increase the primary electron energy from 120MeV to 240MeV. The positron souree itself is an extremely important system for producing more positrons, including a positron converter target chamber, a 12kA flux modulator, the 7-m focusing module with DC power supplies and the support. The new positron production linac from the electron gun to the positron source has been installed into the tunnel. In what follows, we will emphasize the positron source design, manufacture and tests.

  20. [Microbial sources of pigments].

    PubMed

    Cañizares-Villanueva, R O; Ríos-Leal, E; Olvera Ramírez, R; Ponce Noyola, T; Márquez Rocha, F

    1998-01-01

    Pigments from natural sources has been obtained since long time ago, and their interest has increased due to the toxicity problems caused by those of synthetic origin. In this way the pigments from microbial sources are a good alternative. Some of more important natural pigments, are the carotenoids, flavonoids (anthocyanins) and some tetrapirroles (chloropyls, phycobilliproteins). Another group less important are the betalains and quinones. The carotenoids are molecules formed by isoprenoids units and the most important used as colorant are the alpha and beta carotene which are precursors of vitamin A, and some xantophylls as astaxanthin. The pigment more used in the industry is the beta-carotene which is obtained from some microalgae and cyanobacteria. The astaxanthin another important carotenoid is a red pigment of great commercial value, and it is used in the pharmaceutical feed and acuaculture industries. This pigments is mainly obtained from Phaffia rhodozyma and Haematococcus pluvialis and other organisms. The phycobilliproteins obtained from cyanobacteria and some group of algae, have recently been increased on the food industries. In the last years it has been used as fluorescent marker in biochemical assays. Our research group have carried out studies about the factors that improve the production of these pigments obtained from different microbial species as well as the methods for their extraction and application. PMID:10932737

  1. NUBEAM Sources in FACETS

    NASA Astrophysics Data System (ADS)

    Pletzer, A.; McCune, D.; Indireshkumar, K.; Morris, A.; Pankin, A.; Cary, J. R.

    2009-05-01

    The SciDAC project for the development of a Framework Application for Core Edge Transport Simulation (FACETS) aims at producing tokamak core-to-wall transport simulations on massively parallel architectures. Here, we report on the progress of integrating the new parallel, PlasmaState based, Monte-Carlo NUBEAM module into the FACETS framework to provide neutral beam and fusion source terms in the plasma core diffusion equations. NUBEAM has recently been improved to facilitate invocation from third party software (e.g. SWIM). This was achieved by consolidating 100s of input variables into separate structures according to machine specificity, shot specificity, or time-slice specificity. Thanks to a combination of auto-generated code and a newly developed methodology for exposing Fortran90 derived types to C, all derived type members of NUBEAM structures have become in-memory accessible to FACETS's C++ infrastructure. NUBEAM, which is the first volumetric-coupling component in FACETS, has been wrapped with methods complying to the FACETS standard interface definition for easy interchangeability of modules at run time. Examples of neutral beam computations instrumented with TAU/Paratools on leadership class machines will be presented, as well as first coupled core-source FACETS simulations.

  2. Nuclear sources in galaxies

    NASA Astrophysics Data System (ADS)

    Elvis, M.

    In the local Universe most massive black holes at the centers of galaxies are not luminous quasars. Is this because (1) they are starved of gas, (2) they accrete without emitting radiation, (3) they refuse to eat, ejecting the incoming material, or (4) they are storing up matter in an accretion disk to feast later?With Chandra ACIS we have imaged a pilot sample of 6 nearby (D 30 Mpc) elliptical galaxies chosen to be especially quiescent based on the careful optical spectroscopy of Ho, measured black hole masses (Mbh > 10(7)Msol), and with existing X-ray upper limits (Lx 10(40)erg/s) implying far sub-Eddington accretion. In these galaxies we can measure, or limit, the diffuse hot interstellar medium, and so constrain the Bondi accretion rate.Faint X-ray emission is detected at or around the nucleus in each galaxy. The morphology of these weak X-ray sources is complex. The X-ray colors of the sources can be determined, and a moderate quality spectrum for one was obtained. We discuss these results against the possible explanations of black hole quiescence.On the other hand, a few percent of all galaxies shows evidence for nuclear activity and a brief review of the high energy emission from Active Galactic Nuclei is given.

  3. Inductive source induced polarization

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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.

  4. Modeling Magnetospheric Sources

    NASA Technical Reports Server (NTRS)

    Walker, Raymond J.; Ashour-Abdalla, Maha; Ogino, Tatsuki; Peroomian, Vahe; Richard, Robert L.

    2001-01-01

    We have used global magnetohydrodynamic, simulations of the interaction between the solar wind and magnetosphere together with single particle trajectory calculations to investigate the sources of plasma entering the magnetosphere. In all of our calculations solar wind plasma primarily enters the magnetosphere when the field line on which it is convecting reconnects. When the interplanetary magnetic field has a northward component the reconnection is in the polar cusp region. In the simulations plasma in the low latitude boundary layer (LLBL) can be on either open or closed field lines. Open field lines occur when the high latitude reconnection occurs in only one cusp. In the MHD calculations the ionosphere does not contribute significantly to the LLBL for northward IMF. The particle trajectory calculations show that ions preferentially enter in the cusp region where they can be accelerated by non-adiabatic motion across the high latitude electric field. For southward IMF in the MHD simulations the plasma in the middle and inner magnetosphere comes from the inner (ionospheric) boundary of the simulation. Solar wind plasma on open field lines is confined to high latitudes and exits the tailward boundary of the simulation without reaching the plasma sheet. The LLBL is populated by both ionospheric and solar wind plasma. When the particle trajectories are included solar wind ions can enter the middle magnetosphere. We have used both the MHD simulations and the particle calculations to estimate source rates for the magnetosphere which are consistent with those inferred from observations.

  5. Nitride quantum light sources

    NASA Astrophysics Data System (ADS)

    Zhu, T.; Oliver, R. A.

    2016-02-01

    Prototype nitride quantum light sources, particularly single-photon emitters, have been successfully demonstrated, despite the challenges inherent in this complex materials system. The large band offsets available between different nitride alloys have allowed device operation at easily accessible temperatures. A wide range of approaches has been explored: not only self-assembled quantum dot growth but also lithographic methods for site-controlled nanostructure formation. All these approaches face common challenges, particularly strong background signals which contaminate the single-photon stream and excessive spectral diffusion of the quantum dot emission wavelength. If these challenges can be successfully overcome, then ongoing rapid progress in the conventional III-V semiconductors provides a roadmap for future progress in the nitrides.

  6. PULSED ION SOURCE

    DOEpatents

    Anderson, C.E.; Ehlers, K.W.

    1958-06-17

    An ion source is described for producing very short high density pulses of ions without bcam scattering. The ions are created by an oscillating electron discharge within a magnetic field. After the ions are drawn from the ionization chamber by an accelerating electrode the ion beam is under the influence of the magnetic field for separation of the ions according to mass and, at the same time, passes between two neutralizing plntes maintained nt equal negative potentials. As the plates are formed of a material having a high ratio of secondary electrons to impinging ions, the ion bombardment of the plntes emits electrons which neutralize the frirge space-charge of the beam and tend to prevent widening of the beam cross section due to the mutual repulsion of the ions.

  7. Multiple source heat pump

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    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.

  8. Thulium-170 heat source

    DOEpatents

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  9. Sources of radioactive ions

    SciTech Connect

    Alonso, J.R.

    1985-05-01

    Beams of unstable nuclei can be formed by direct injection of the radioactive atoms into an ion source, or by using the momentum of the primary production beam as the basis for the secondary beam. The effectiveness of this latter mechanism in secondary beam formation, i.e., the quality of the emerging beam (emittance, intensity, energy spread), depends critically on the nuclear reaction kinematics, and on the magnitude of the incident beam energy. When this beam energy significantly exceeds the energies typical of the nuclear reaction process, many of the qualities of the incident beam can be passed on to the secondary beam. Factors affecting secondary beam quality are discussed, along with techniques for isolating and purifying a specific secondary product. The ongoing radioactive beam program at the Bevalac is used as an example, with applications, present performance and plans for improvements.

  10. Arsenic pollution sources.

    PubMed

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

    2008-01-01

    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

  11. Infrared source test

    SciTech Connect

    Ott, L.

    1994-11-15

    The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

  12. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

    1990-09-06

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  13. High brightness electron sources

    SciTech Connect

    Sheffield, R.L.

    1995-07-01

    High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10{sup {minus}8} torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given.

  14. Extragalactic radio sources

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1984-01-01

    The standard model for extragalactic variable radio sources comprises an isotropically expanding plasmoid with frozen magnetic flux and an electron distribution which evolves adiabatically. This model leads to the following relaton between the peak luminosity L (sub nu, m) and the relevant frequency nu(sub m) which are functions of time: L(sub nu,m) is proportional to nu(sub m)(n) where N = (7n + 5)/(4n + 5). In this expression, n is the spectral index in the optically thin part of the spectrum, where L (sub nu) is proportional to nu (-n). For n in the range 0.5 to 1.5, the standard model yields N in the range 1.2 to 1.4. By contrast, analysis of observational data yields estimates of N in a small range about the mean value 0.4, in clear contradiction with the standard model.

  15. The velocity source concept

    NASA Astrophysics Data System (ADS)

    van Suchtelen, J.; Nijdam, A. J.; van Veenendaal, E.

    1999-03-01

    Traditional kinematic wave theory neglects considerations involving free energy of a surface and nucleation at the boundary of a surface. As a consequence, strictly speaking this theory is only applicable to freely floating perfect crystals, and when applied to more complex situations the conclusions may be false. In this paper we argue that boundary conditions, to be taken into account at interface junctions, affect the shape of the crystal. The effect is either microscopic or macroscopic. In the first case, we have a "kinetic meniscus", a curved transition of the size of the critical radius. In the second case, the growth rate is affected macroscopically and we may consider the boundary as a "velocity source" for the affected interface. These concepts are essential elements in a version of kinematic wave theory that is applicable to all physically relevant situations.

  16. Large area plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor); Patterson, Michael (Inventor)

    2008-01-01

    An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.

  17. Fortran 90 Source Module

    Energy Science and Technology Software Center (ESTSC)

    1998-01-13

    A major advance contained in the new Fortran 90 language standard is the ability to define new data types and the operators associated with them. Writing computer code to implement computations with real and complex three domensional vectors and dyadics is greatly simplified if the equations can be implemented directly, without the need to code the vector arithmetic explicitly. The Fortran 90 module VECTORS contains source code which defines new data types for real andmore » complex 3-dimensional vectors and dyadics, along with the common operations needed to work with these objects. Routines to allow convenient initalization and output of the new types are also included. in keeping with the philosophy of data abstraction, the details of the implementation of the data types are maintained private, and the functions and operators are made generic to simplify the combining of real, complex, single and double precision vectors and dyadics.« less

  18. Perovskite photonic sources

    NASA Astrophysics Data System (ADS)

    Sutherland, Brandon R.; Sargent, Edward H.

    2016-05-01

    The field of solution-processed semiconductors has made great strides; however, it has yet to enable electrically driven lasers. To achieve this goal, improved materials are required that combine efficient (>50% quantum yield) radiative recombination under high injection, large and balanced charge-carrier mobilities in excess of 10 cm2 V-1 s-1, free-carrier densities greater than 1017 cm-3 and gain coefficients exceeding 104 cm-1. Solid-state perovskites are -- in addition to galvanizing the field of solar electricity -- showing great promise in photonic sources, and may be the answer to realizing solution-cast laser diodes. Here, we discuss the properties of perovskites that benefit light emission, review recent progress in perovskite electroluminescent diodes and optically pumped lasers, and examine the remaining challenges in achieving continuous-wave and electrically driven lasing.

  19. AGRICULTURAL NONPOINT SOURCE POLLUTION (AGNPS)

    EPA Science Inventory

    Developed by the USDA Agricultural Research Service, Agricultural Nonpoint Source Pollution (AGNPS) model addresses concerns related to the potential impacts of point and nonpoint source pollution on surface and groundwater quality (Young et al., 1989). It was designed to quantit...

  20. How Is Open Source Special?

    ERIC Educational Resources Information Center

    Kapor, Mitchell

    2005-01-01

    Open source software projects involve the production of goods, but in software projects, the "goods" consist of information. The open source model is an alternative to the conventional centralized, command-and-control way in which things are usually made. In contrast, open source projects are genuinely decentralized and transparent. Transparent…

  1. Atlas of source emission particles

    SciTech Connect

    Miller, J.L.

    1983-06-01

    An atlas of various source emission particles characterized by electron optical techniques has been compiled for use by air pollution investigators. The particles studied were emitted by mobile, stationary, and natural sources. Sources included automobiles, manufacturing operations, power plants, smelters, mining and quarring. Filter media and sample preparation methodology as well as morphological and chemical data are presented.

  2. Authorship Attribution of Source Code

    ERIC Educational Resources Information Center

    Tennyson, Matthew F.

    2013-01-01

    Authorship attribution of source code is the task of deciding who wrote a program, given its source code. Applications include software forensics, plagiarism detection, and determining software ownership. A number of methods for the authorship attribution of source code have been presented in the past. A review of those existing methods is…

  3. How Is Open Source Special?

    ERIC Educational Resources Information Center

    Kapor, Mitchell

    2005-01-01

    Open source software projects involve the production of goods, but in software projects, the "goods" consist of information. The open source model is an alternative to the conventional centralized, command-and-control way in which things are usually made. In contrast, open source projects are genuinely decentralized and transparent. Transparent

  4. Source memory in the rat.

    PubMed

    Crystal, Jonathon D; Alford, Wesley T; Zhou, Wenyi; Hohmann, Andrea G

    2013-03-01

    Source memory is a representation of the origin (source) of information. When source information is bound together, it makes a memory episodic, allowing us to differentiate one event from another. Here, we asked whether rats remember the source of encoded information. Rats foraged for distinctive flavors of food that replenished (or failed to replenish) at its recently encountered location according to a source-information rule. To predict replenishment, rats needed to remember where they had encountered a preferred food type (chocolate) with self-generated (walking along a runway encountering chocolate) or experimenter-generated (placement of the rat at the chocolate site by an experimenter) cues. Three lines of evidence implicate the presence of source memory. First, rats selectively adjusted revisits to the chocolate location based on source information, under conditions in which familiarity of events could not produce successful performance. Second, source memory was dissociated from location memory by different decay rates. Third, temporary inactivation of the CA3 region of the hippocampus with lidocaine selectively eliminated source memory, suggesting that source memory is dependent upon an intact hippocampus. Development of an animal model of source memory may be valuable to probe the biological underpinnings of memory disorders marked by impairments in source memory. PMID:23394830

  5. Source-space ICA for MEG source imaging

    NASA Astrophysics Data System (ADS)

    Jonmohamadi, Yaqub; Jones, Richard D.

    2016-02-01

    Objective. One of the most widely used approaches in electroencephalography/magnetoencephalography (MEG) source imaging is application of an inverse technique (such as dipole modelling or sLORETA) on the component extracted by independent component analysis (ICA) (sensor-space ICA + inverse technique). The advantage of this approach over an inverse technique alone is that it can identify and localize multiple concurrent sources. Among inverse techniques, the minimum-variance beamformers offer a high spatial resolution. However, in order to have both high spatial resolution of beamformer and be able to take on multiple concurrent sources, sensor-space ICA + beamformer is not an ideal combination. Approach. We propose source-space ICA for MEG as a powerful alternative approach which can provide the high spatial resolution of the beamformer and handle multiple concurrent sources. The concept of source-space ICA for MEG is to apply the beamformer first and then singular value decomposition + ICA. In this paper we have compared source-space ICA with sensor-space ICA both in simulation and real MEG. The simulations included two challenging scenarios of correlated/concurrent cluster sources. Main Results. Source-space ICA provided superior performance in spatial reconstruction of source maps, even though both techniques performed equally from a temporal perspective. Real MEG from two healthy subjects with visual stimuli were also used to compare performance of sensor-space ICA and source-space ICA. We have also proposed a new variant of minimum-variance beamformer called weight-normalized linearly-constrained minimum-variance with orthonormal lead-field. Significance. As sensor-space ICA-based source reconstruction is popular in EEG and MEG imaging, and given that source-space ICA has superior spatial performance, it is expected that source-space ICA will supersede its predecessor in many applications.

  6. Chandra Source Catalog: User Interfaces

    NASA Astrophysics Data System (ADS)

    Bonaventura, Nina; Evans, I. N.; Harbo, P. N.; Rots, A. H.; Tibbetts, M. S.; Van Stone, D. W.; Zografou, P.; Anderson, C. S.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Glotfelty, K. J.; Grier, J. D.; Hain, R.; Hall, D. M.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Primini, F. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Winkelman, S. L.

    2010-02-01

    The CSCview data mining interface is available for browsing the Chandra Source Catalog (CSC) and downloading tables of quality-assured source properties and data products. Once the desired source properties and search criteria are entered into the CSCview query form, the resulting source matches are returned in a table along with the values of the requested source properties for each source. (The catalog can be searched on any source property, not just position.) At this point, the table of search results may be saved to a text file, and the available data products for each source may be downloaded. CSCview save files are output in RDB-like and VOTable format. The available CSC data products include event files, spectra, lightcurves, and images, all of which are processed with the CIAO software. CSC data may also be accessed non-interactively with Unix command-line tools such as cURL and Wget, using ADQL 2.0 query syntax. In fact, CSCview features a separate ADQL query form for those who wish to specify this type of query within the GUI. Several interfaces are available for learning if a source is included in the catalog (in addition to CSCview): 1) the CSC interface to Sky in Google Earth shows the footprint of each Chandra observation on the sky, along with the CSC footprint for comparison (CSC source properties are also accessible when a source within a Chandra field-of-view is clicked); 2) the CSC Limiting Sensitivity online tool indicates if a source at an input celestial location was too faint for detection; 3) an IVOA Simple Cone Search interface locates all CSC sources within a specified radius of an R.A. and Dec.; and 4) the CSC-SDSS cross-match service returns the list of sources common to the CSC and SDSS, either all such sources or a subset based on search criteria.

  7. Ion dynamics in helicon sources.

    SciTech Connect

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

    2002-01-01

    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.

  8. The heliospheric energy source

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1986-01-01

    The solar wind and the heliosphere exist as a consequence of the heat input to the corona, particularly the coronal holes. The necessary energy input to coronal holes has been estimated to be 10 to the 6th erg/sq cm sec, requiring Alfven waves with rms fluid velocities of 100 km/sec. Observational upper limits on coronal fluid velocities are of the order of 25 km/sec, which may not apply to the transparent coronal hole. Alternatively it has been suggested that coronal holes may be heated by agitation from neighboring active regions, suggesting that the vigor of a coronal hole depends upon its location. The Ulysses Mission will provide a direct comparison of the strength of the high speed wind from coronal holes at low latitude and coronal holes at high latitude, from which the nature of the presently unknown energy sources of the coronal holes and the resulting structure of the heliosphere may be better judged. The question is fundamental to the dynamics of the windspheres of all stars.

  9. Industrial ion source technology

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.

    1978-01-01

    An analytical model was developed to describe the development of a coned surface texture with ion bombardment and simultaneous deposition of an impurity. A mathematical model of sputter deposition rate from a beveled target was developed in conjuction with the texturing models to provide an important input to that model. The establishment of a general procedure that will allow the treatment of manay different sputtering configurations is outlined. Calculation of cross sections for energetic binary collisions was extened to Ar, Kr.. and Xe with total cross sections for viscosity and diffusion calculated for the interaction energy range from leV to 1000eV. Physical sputtering and reactive ion etching experiments provided experimental data on the operating limits of a broad beam ion source using CF4 as a working gas to produce reactive species in a sputtering beam. Magnetic clustering effects are observed when Al is seeded with Fe and sputtered with Ar(?) ions. Silicon was textured at a micron scale by using a substrate temperature of 600 C.

  10. Eradicating rabies at source.

    PubMed

    Pastoret, P-P; Van Gucht, S; Brochier, B

    2014-08-01

    Along with zoonotic influenza and antimicrobial resistance, rabies has been identified as a key One Health issue by the World Organisation for Animal Health (OIE), World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO). It provides an excellent example of a disease that has an impact on public, animal and environmental health, and therefore benefits from a One Health approach to management. Regrettably, this zoonotic disease is still neglected despite the fact that, annually, it kills as many as 70,000 people worldwide (chiefly children in Asia and Africa), millions of dogs suffer and die, and the disease threatens some populations of endangered wildlife. This is particularly unfortunate, given that effective means of prevention exist. As Her Royal Highness Princess Haya of Jordan pointed out in a video to mark World Rabies Day on 28 September 2013, rabies is a serious world public health problem that is all too often underestimated and even neglected. Yet we know it can be eliminated. By combatting rabies at its source in animals and vaccinating 70% of dogs, we can eradicate it. PMID:25707180

  11. 4X source

    SciTech Connect

    Smith, H.V. Jr.; Allison, P.; Sherman, J.D.

    1985-01-01

    Our Penning surface-plasma source (SPS) discharge chamber was enlarged 4X in two dimensions. To date, three pulsed discharge modes have been studied: two with noisy arc (greater than or equal to 20% H/sup -/ current fluctuations) and one with quiescent arc (less than or equal to 1% H/sup -/ current fluctuations). Lower arc magnetic field and higher H/sub 2/ gas flow allow switching from the noisy to the quiescent mode. The noisy modes yield up to 120 mA of 29-keV H/sup -/ beam; for 110 mA at 29 keV, the two-dimensional normalized rms emittance is 0.017 x 0.018 ..pi...cm.mrad. The quiescent mode yields 75 mA of 29-keV H/sup -/beam; for 67 mA at 24 keV, the emittance is 0.011 x 0.012 ..pi...cm.mrad.

  12. [The source of antioxidants].

    PubMed

    Guggenbühl, N

    2006-01-01

    Free radicals are thought to play an important part in the phenomenon of aging, especially as regards the eye. Antioxydants represent an interesting means of limiting the damage due to oxydation, as is shown by a number of studies. Food is an unexpected source of antioxydants, which exist in the form of thousands of different compounds. Colored fruits and vegetables are known to be rich in carotenoids, some of which such as lutein and zeaxanthin tend to accumulate at the level of the macula. But there are plenty of other foodstuffs that supply the antiradical armoury, as has been shown by analytical findings over a number of years. Legumes and whole cereals have a very high antioxydant potential. Other items, from tea to...chocolate, contribute to providing antioxydants through food. Although some specific antioxydants appear so far to be particularly interesting, the results gathered over a number of years in various fields show the advantages of combining several interacting antioxydants. A diet with a strong vegetal component, without being vegetarian, provides a very broad range of antioxydants and thus appears to be an important defense against oxidative stress. PMID:17552431

  13. Ion sources for microfabrication (invited)

    NASA Astrophysics Data System (ADS)

    Grotjohn, Timothy A.

    1994-04-01

    Several microfabrication processes benefit from the application of ion sources including the physical, reactive, and chemically assisted sputtering/etching of surfaces, the deposition/growth of materials, and the modification/cleaning/preparation of surfaces. This paper reviews the types, properties, and requirements of ion sources applied to microfabrication processes including etching, epitaxial growth, ion implantation, and nanostructure formation. Particular emphasis is given to the requirements of ion streams for low-damage semiconductor processing. The types of sources covered include broad-beam ion sources; ECR, helicon, helical resonator, and inductively coupled plasma/ion sources; ion implanters; compact MBE-ECR ion/free radical sources; and focused ion beam sources.

  14. Radiation sources working group summary

    SciTech Connect

    Fazio, M.V.

    1998-12-31

    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.

  15. Reull Vallis Source Region

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] (Released 1 July 2002) The jumbled, chaotic terrain in this THEMIS image may represent a source region for the Reull Vallis, one of the larger channel systems in the southern hemisphere of Mars. Such regions of chaos are thought to form by the catastrophic release of groundwater. If this was the case, then the water would have flowed down gradient to the south and may have contributed to the formation of the Reull Vallis. The top of the image shows two short segments of channels that are interrupted by the chaos, demonstrating that there was a channel system in place before the ground foundered to produce the chaos. One of the more intriguing features seen among the jumbled blocks are narrow ledges that vaguely resemble bath tub rings in the way they conform to the topography. Two good examples are seen running roughly left-right across the image about a fourth of the way down. At first they appear to be layers protruding from the cliff faces, but upon closer inspection a more ledge-like character is evident. Note how they appear different between the south-facing and north facing cliffs. The occurrence of one of these features on the south-facing interior rim of the largest crater in the image but nowhere else around the rim argues against the idea that the ledges are due to a layer of rock cropping out throughout the landscape. Instead, they appear more like the edges of a layer of sediment that drapes the topography. It is possible that the sediment is mixed with ice and is best preserved in the shadowed portions of the terrain. There is no easy explanation for these unusual features. They represent one more Martian enigma.

  16. Sources of Terrestrial Volatiles

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.; Dones, L.

    1998-01-01

    Atmospheres are found enveloping those planets and satellites best able to hold them. The obvious conclusion is that volatile escape must have played nearly as great a role as volatile supply. A consequence of this view is that volatile supplies were probably much greater than the atmospheres that remain. The likeliest candidates are sources associated with the main events of planetary accretion itself such as volatile-rich planetesimals, or direct gravitational capture of nebular gases. Late asteroidal or cometary volatile-rich veneers are attractive, but they present quantitative difficulties. Comets in particular are inadequate, because the associated mass of stray comets that would have been scattered to the Oort Cloud or beyond is excessive. This difficulty applies to Uranus-Neptune planetesimals as well as to a putative massive early Kuiper Belt. Another potential problem with comets is that the D/H ratio in the three comets for which this has been measured is about twice that of Earth's oceans. Objects falling from a much augmented ancient asteroid belt remain a viable option, but timing is an issue: Can the depopulation of the asteroid belt be delayed long enough that it makes sense to talk of asteroids as a late veneer? Early accretion of asteroids as objects scattered into the maw of infant Earth makes more sense. Another appealing candidate population of volatile-rich objects for the inner solar system would be scattered planetesimals associated with the accretion of Jupiter, for two reasons: (1) Before there was Jupiter, there was no object in the solar system capable of expelling comets efficiently, and (2) the cross section of the inner solar system to stray objects was Greater when there were m many planetesimals.

  17. Portable source identification device

    NASA Astrophysics Data System (ADS)

    Andersen, Eric S.; Samuel, Todd J.; Gervais, Kevin L.

    2005-05-01

    U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation"s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. As the deployment of radiation detection systems proceeds, there is a need to adapt the baseline radiation portal monitor (RPM) system technology to operations at these diverse ports of entry. When screening produces an alarm in the primary inspection RPM, the alarming vehicle is removed from the flow of commerce and the alarm is typically confirmed in a secondary inspection RPM. The portable source identification device (PSID) is a radiation sensor panel (RSP), based on thallium-doped sodium iodide (NaI(Tl)) scintillation detector and gamma spectroscopic analysis hardware and software, mounted on a scissor lift on a small truck. The lift supports a box containing a commercial off-the-shelf (COTS) sodium iodide detector that provides real-time isotopic identification, including neutron detectors to interdict Weapons of Mass Destruction (WMD) and radiation dispersion devices (RDD). The scissor lift will lower the detectors to within a foot off the ground and raise them to approximately 24 feet (7.3 m) in the air, allowing a wide vertical scanning range.

  18. Portable Source Identification Device

    SciTech Connect

    Andersen, Eric S.; Samuel, Todd J.; Gervais, Kevin L.

    2005-08-01

    U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation’s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. As the deployment of radiation detection systems proceeds, there is a need to adapt the baseline radiation portal monitor (RPM) system technology to operations at these diverse ports of entry. When screening produces an alarm in the primary inspection RPM, the alarming vehicle is removed from the flow of commerce and the alarm is typically confirmed in a secondary inspection RPM. The portable source identification device (PSID) is a radiation sensor panel (RSP), based on thallium-doped sodium iodide (NaI(Tl)) scintillation detector and gamma spectroscopic analysis hardware and software, mounted on a scissor lift on a small truck. The lift supports a box containing a commercial off-the-shelf (COTS) sodium iodide detector that provides real-time isotopic identification, including neutron detectors to interdict Weapons of Mass Destruction (WMD) and radiation dispersion devices (RDD). The scissor lift will lower the detectors to within a foot off the ground and raise them to approximately 24 feet in the air, allowing a wide vertical scanning range.

  19. Design calculations for the ANS (Advanced Neutron Source) cold source

    SciTech Connect

    Lillie, R.A.; Alsmiller, R.G. Jr.

    1988-01-01

    The calculation procedure, based on discrete ordinates transport methods, that is being used to carry out design calculations for the Advanced Neutron Source cold source is described. Calculated results on the gain in cold neutron flux produced by a liquid deuterium cold source are compared with experimental data and with calculated data previously obtained by P. Ageron et al., at the Institute Max von Laue-Paul Langevin in Grenoble, France. Calculated results are also presented that indicated how the flux of cold neutrons vary with cold source parameters. 23 refs., 5 figs., 3 tabs.

  20. Retrospective source attribution for source-oriented sampling

    NASA Astrophysics Data System (ADS)

    Bein, K. J.; Zhao, Y.; Wexler, A. S.

    2015-10-01

    Previous work successfully implemented a novel system that uses a single particle mass spectrometer to conditionally sample size-segregated, source-oriented particles from the ambient atmosphere in real-time. The underlying hypothesis is that the composition of individual particles is a metric of particle source and thus sampling particles based on composition should be synonymous with sampling based on source. System operation relies on real-time pattern recognition to control the actuation of different ChemVol samplers, where each ChemVol is associated with a unique composition signature. In the current work, a synthesis of data collected during these studies is used in retrospect to reconcile the actual source combinations contributing to the particles collected by each ChemVol. Source attribution is based on correlations between ChemVol sampling periods and coincident wind direction and temporal emissions patterns, coupled to knowledge of single particle composition and surrounding sources. Residential and commercial cooking, vehicular emissions, residential heating and highly processed regional background PM were identified as the major sources. Results show that real-time patterns in single particle mixing state correctly identified specific sources and that these sources were successfully separated into different ChemVols for both summer and winter seasons.

  1. Nonradiating sources and quantum communications

    NASA Astrophysics Data System (ADS)

    Marengo, Edwin A.; Ziolkowski, Richard W.

    1999-10-01

    In the classical theory of electromagnetic radiation, there are certain localized charge-current distributions which do not radiate. Such sources, referred to as nonradiating (NR) sources, generate fields that are themselves confined within the region of localization of the source (A.J. Devaney and E. Wolf, Phys. Rev. D, Vol. 8, p. 1044-47, 1973). The question arises whether NR sources have or not a counterpart in the quantum theory. This fundamental question has never been addressed, despite its possible connection to the Aharonov-Bohm effect and the very limits of measurability of sources and fields. This talk presents some aspects of our work on classical and quantum NR sources, with applications to quantum communications. Of particular interest to quantum communication technologies is the possibility of generating fields that are confined, classically, within a transmitting source's region of support, but that are not so quantum-mechanically. A new description of classical NR sources as nonreceptors is given which is based on the Lorentz reciprocity principle. The classical definition of a NR source as a source whose field is confined within its support is meaningless in the quantum regime since quantized fields cannot be such localized in view of the uncertainty principle. Nevertheless, an analogy between classical and quantum NR sources can be drawn if one defines the quantum counterparts carefully. This is done in this talk from an information-transmistion (rather than field-localization) point of view. Quantum-electrodynamically, the issue is whether a given localized, time-dependent NR source that is turned at an initial transient time t=0, which possesses no external classical observability whatsoever, can or not modify an initial external vacuum state in a measurable way. By using this approach, a comparison of the classical and quantum manifestations of a NR source is given. A one-dimensional example is presented which illustrates the applicability of these concepts to plane wave or transmission line systems.

  2. Disintegrins from Hematophagous Sources

    PubMed Central

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

    2012-01-01

    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

  3. A source of innovation.

    PubMed

    Gillespie, D G

    1992-12-01

    In 1992, the USAID Population Assistance Program turned 25 years old. The program is noteworthy for being the largest of all national government programs with a current annual budget of $300 million, having wide support from the US congress and public, developing a wide variety of experts in many areas of family planning (FP), and developing and relying upon a strong infrastructure of private sector agencies. The agency has been instrumental in injecting competition into government service, using market methods, providing for choice among service providers, and investing and not just spending money. The important lessons learned over the years are identified. 1) Products, services, and information can be generated through the private sector, which was supported by USAID. The International Planned Parenthood Federation was one of the 1st to receive grants. 2) The commitment of the private sector to FP is shown in its achievement of goals, not on rules and budgets. The willingness of staff to work for low pay levels exemplifies the depth of commitment. 3) The private sector sometimes can be and often has been a source of innovation and experiment. Examples of this creativity are evident in the development of Norplant by the Population Council and RAPID computerized illustration of the impact of future population growth by the Futures Group. 4) Healthy competition and expansion of government resources can be generated through the contribution of expertise and specialization in the private sector. Grants have been distributed to private groups for delivery of FP services, management skills, training, survey research, operations research, contraceptive development an clinical testing, communication, and evaluation. 5) Use of the private sector, particularly the commercial sector, in providing services has meant a shared cost for services and less cost for taxpayers. 6) USAID has funded projects for FP services through place of employment or union, which has proven to be cost effective. The basic objective of the USAID program is to provide assurances that informed decisions and FP choices to satisfy personal needs are possible for all individuals and families in the developing world. Government policies and the efforts of private agencies to inform, service, and supply largely determine the success in FP adoption. With fewer government resources, the role of the private sector becomes very important. PMID:12317827

  4. Constricted glow discharge plasma source

    DOEpatents

    Anders, Andre; Anders, Simone; Dickinson, Michael; Rubin, Michael; Newman, Nathan

    2000-01-01

    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.

  5. Advanced Neutron Source (ANS) Project

    NASA Astrophysics Data System (ADS)

    Campbell, J. H.

    1992-01-01

    This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I & C Research and Development; Design; and Safety.

  6. Curium-248 standard neutron source

    PubMed

    Radchenko; Ryabinin; Andreytchuk; Gavrilov; Karelin

    2000-10-01

    A new standard neutron source based on curium-248 has been developed, prepared, and certified. The curium-248 isotope is more long-lived than californium-252. The active core of this source is a pellet made of an alloy of platinum with curium. The measured full neutron yield for this source is 2.30 x 10(4) s(-1) with 4% error at 0.95 confidence. PMID:11003529

  7. Source-circuit design overview

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1983-01-01

    The source circuit is the fundamental electrical building block of a large central-station array; it consists of a series-parallel network of solar cells that develops full system voltage. The array field is generally made up of a large number of parallel source circuits. Source-circuit electrical configuration is driven by a number of design considerations, which must be considered simultaneously. Array fault tolerance and hot spot heating endurance are examined in detail.

  8. ION SOURCE UNIT FOR CALUTRON

    DOEpatents

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

    1959-04-14

    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.

  9. ACCELERATOR BASED CONTINUOUS NEUTRON SOURCE.

    SciTech Connect

    SHAPIRO,S.M.; RUGGIERO,A.G.; LUDEWIG,H.

    2003-03-25

    Until the last decade, most neutron experiments have been performed at steady-state, reactor-based sources. Recently, however, pulsed spallation sources have been shown to be very useful in a wide range of neutron studies. A major review of neutron sources in the US was conducted by a committee chaired by Nobel laureate Prof. W. Kohn: ''Neutron Sources for America's Future-BESAC Panel on Neutron Sources 1/93''. This distinguished panel concluded that steady state and pulsed sources are complementary and that the nation has need for both to maintain a balanced neutron research program. The report recommended that both a new reactor and a spallation source be built. This complementarity is recognized worldwide. The conclusion of this report is that a new continuous neutron source is needed for the second decade of the 20 year plan to replace aging US research reactors and close the US neutron gap. it is based on spallation production of neutrons using a high power continuous superconducting linac to generate protons impinging on a heavy metal target. There do not appear to be any major technical challenges to the building of such a facility since a continuous spallation source has been operating in Switzerland for several years.

  10. Neutron imaging of radioactive sources

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

    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.

  11. AKARI infrared bright source catalogues

    NASA Astrophysics Data System (ADS)

    Oyabu, S.; Yamamura, I.; Alfageme, C.; Barthel, P.; Cassatella, A.; Cohen, M.; Cox, N.; Figueredo, E.; Fujiwara, H.; Ikeda, N.; Ishihara, D.; Jeong, W.-S.; Kataza, H.; Kester, Do; Lee, H. M.; Makiuti, S.; Mueller, T. G.; Nakagawa, T.; Takita, S.; Oh, S. H.; Oliver, S.; Pearson, C.; Rahman, N.; Rowan-Robinson, M.; Salama, A.; Savage, R.; Serjeant, S.; White, G. J.; Yamauchi, C.

    2010-07-01

    Bright source catalogues based on the new mid- and far-infrared all-sky survey by the infrared astronomical satellite AKARI were released into the public domain in March 2010. The mid-infrared catalogue contains more than 870 thousand sources observed at 9 and 18 ?m, and the far-infrared catalogue provides information of about 427 thousand sources at 65, 90, 140, and 160 ?m. The AKARI catalogues will take over the IRAS catalogues and will become one of the most important catalogues in astronomy. We present the characteristics of the AKARI infrared source catalogues as well as current activity for the future versions.

  12. SOURCE PARTITIONING USING STABLE ISOTOPES: COPING WITH TOO MANY SOURCES

    EPA Science Inventory

    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 st...

  13. Multiple source energy recovery system

    SciTech Connect

    Nussbaum, O. J.

    1985-10-15

    A multiple source energy recovery system incorporating a finned heat exchanger having a plurality of primary fluid circuits, at least some of which are connected to waste heat sources. A heated medium in a secondary fluid circuit is stored in a tank and then circulated to a second heat exchanger where the waste heat is recovered and utilized.

  14. 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...

  15. 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...

  16. METHANE EMISSIONS FROM INDUSTRIAL SOURCES

    EPA Science Inventory

    The chapter identifies and describes major industrial sources of methane (CH4) emissions. or each source type examined, it identifies CH4 release points and discusses in detail the factors affecting emissions. t also summarizes and discusses available global and country-specific ...

  17. Online Sources for Competitor Information.

    ERIC Educational Resources Information Center

    Weiss, Arthur

    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…

  18. School Principals' Sources of Knowledge

    ERIC Educational Resources Information Center

    Perkins, Arland Early

    2014-01-01

    The purpose of this study was to determine what sources of professional knowledge are available to principals in 1 rural East Tennessee school district. Qualitative research methods were applied to gain an understanding of what sources of knowledge are used by school principals in 1 rural East Tennessee school district and the barriers they face…

  19. The Linac Coherent Light Source

    PubMed Central

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-01-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed. PMID:25931055

  20. The Linac Coherent Light Source

    DOE PAGESBeta

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-05-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  1. Electrical Neuroimaging with Irrotational Sources

    PubMed Central

    Grave de Peralta Menendez, Rolando; Gonzalez Andino, Sara

    2015-01-01

    This paper discusses theoretical aspects of the modeling of the sources of the EEG (i.e., the bioelectromagnetic inverse problem or source localization problem). Using the Helmholtz decomposition (HD) of the current density vector (CDV) of the primary current into an irrotational (I) and a solenoidal (S) part we show that only the irrotational part can contribute to the EEG measurements. In particular we present for the first time the HD of a dipole and of a pure irrotational source. We show that, for both kinds of sources, I extends all over the space independently of whether the source is spatially concentrated (as the dipole) or not. However, the divergence remains confined to a region coinciding with the expected location of the sources, confirming that it is the divergence rather than the CDV that really defines the spatial extension of the generators, from where it follows that an irrotational source model (ELECTRA) is always physiologically meaningful as long as the divergence remains confined to the brain. Finally we show that the irrotational source model remains valid for the most general electrodynamics model of the EEG in inhomogeneous anisotropic dispersive media and thus far beyond the (quasi) static approximation. PMID:26113873

  2. The Linac Coherent Light Source

    SciTech Connect

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-04-21

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  3. Hollow electrode plasma excitation source

    DOEpatents

    Ballou, N.E.

    1992-04-14

    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.

  4. Hollow electrode plasma excitation source

    DOEpatents

    Ballou, Nathan E.

    1992-01-01

    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. Cretaceous source rocks in Pakistan

    SciTech Connect

    Kari, I.B. )

    1993-02-01

    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.

  6. FORTRAN Static Source Code Analyzer

    NASA Technical Reports Server (NTRS)

    Merwarth, P.

    1982-01-01

    FORTRAN Static Source Code Analyzer program (SAP) automatically gathers and reports statistics on occurrences of statements and structures within FORTRAN program. Provisions are made for weighting each statistic, providing user with overall figure of complexity. Statistics, as well as figures of complexity, are gathered on module-by-module basis. Overall summed statistics are accumulated for complete input source file.

  7. 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...

  8. Regional source rock mapping using a source potential rating index

    SciTech Connect

    Dembicki, H.; Pirkle, F.L.

    1985-04-01

    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.

  9. Effects of source depth on near-source seismograms

    NASA Astrophysics Data System (ADS)

    Flynn, Elizabeth C.; Stump, Brian W.

    1988-05-01

    Source depth effects are examined for five 115-kg trinitrotoluene (TNT) explosions buried at depths ranging from the optimum cratering depth of 1.8 m to the fully contained depth of 11.5 m. Data were recovered at near source ranges from 17 to 228 m. The waveforms are dominated by P and SV-Rayleigh energy. Depth effects are evident in the increase of P to SV-Rayleigh amplitude ratios and in the twofold increase of high-frequency energy for the deeper sources. Theoretical propagation depth effects are modeled by Green's functions calculated for a velocity gradient which approximates the velocity structure of the experimental site. The effects of depth on the explosion source function are predicted using the scaling laws of Mueller and Murphy (1971). These models did not reproduce the observed twofold increase of high-frequency energy. The discrepancy between the model and observations is attributed to increased coupling of high frequency P wave energy for fully contained sources. Energy calculations confirm that the shallowest event coupled 40% and the fully contained event 80% of the total seismic energy into the P wave. Source coupling efficiencies ranged from 0.7˜1.0% for the near surface source to 1.5˜2.9% for the fully contained explosion.

  10. Slotted antenna waveguide plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor)

    2007-01-01

    A high density plasma generated by microwave injection using a windowless electrodeless rectangular slotted antenna waveguide plasma source has been demonstrated. Plasma probe measurements indicate that the source could be applicable for low power ion thruster applications, ion implantation, and related applications. This slotted antenna plasma source invention operates on the principle of electron cyclotron resonance (ECR). It employs no window and it is completely electrodeless and therefore its operation lifetime is long, being limited only by either the microwave generator itself or charged particle extraction grids if used. The high density plasma source can also be used to extract an electron beam that can be used as a plasma cathode neutralizer for ion source beam neutralization applications.

  11. Housing for a radioactive source

    SciTech Connect

    Domnanovich, J. R.; Erwin, W. D.

    1985-04-23

    The radioactive structure comprises a radioactive source surrounded by a housing. The housing contains a first and second shielding body and a connecting device. The first shielding body has a protrusion which contains a first recess for receiving the radioactive source. The second shielding body has a second recess in one face end which accommodates the protrusion and a conical aperture communicating with the second recess in another face end. The connecting device connects the first shielding body to the second shielding body. When the radioactive source is inserted into the first recess and when the protrusion is located in the second recess, the radioactive source emits radiation primarily through the conical aperture into the environment. The source preferably contains americium which emits gamma radiation. The structure may be used as a motion correction sensor or as a marker in a nuclear diagnostic imaging.

  12. Sealed source peer review plan

    SciTech Connect

    Feldman, Alexander; Leonard, Lee; Burns, Ron

    2009-01-01

    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.

  13. Sources of Stem Cells for Transplant

    MedlinePlus

    ... Topic Donor matching for allogeneic transplant Sources of stem cells for transplant There are 3 possible sources of ... cord blood transplants are being actively studied. Which stem cell source is best? All 3 sources of stem ...

  14. Source and Propagation Characteristics of Explosive and Other Seismic Sources

    SciTech Connect

    Ni, X; Chan, W; Wagner, R; Walter, W R; Matzel, E M

    2005-07-14

    Understanding of the source and propagation characteristics of seismic events of different types including earthquakes, explosions and mining-induced events is essential for successful discrimination of nuclear explosions. We are compiling a data set of mining related seismic events in east Eurasia. Natural earthquake data in the same region are also collected for comparison study between mining related events and earthquakes. The ground-truth data set will provide a unique and valuable resource for monitoring research. We will utilize the data set to investigate the source and propagation characteristics of seismic sources of different types including mine blasts, tremors, collapses and earthquakes. We will use various seismological techniques including spectral analysis, and waveform modeling to conduct the investigation. The research will improve our understanding of the S-wave excitation and propagation characteristics of chemical explosions and other source types.

  15. Diversity employment and recruitment sources

    SciTech Connect

    Not Available

    1994-08-01

    Effective human resources management has been identified as one of four critical success factors in the Department of Energy Strategic Plan. The Plan states relative to this factor: ``The Department seeks greater alignment of resources with agency priorities and increased diversification of the workforce, including gender, ethnicity, age, and skills. This diversification will bring new thinking and perspectives that heretofore have not had a voice in departmental decision-making.`` This Guide has been developed as a key tool to assist Department of Energy management and administrative staff in achieving Goal 2 of this critical success factor, which is to ``Ensure a diverse and talented workforce.`` There are numerous sources from which to recruit minorities, women and persons with disabilities. Applying creativity and proactive effort, using traditional and non-traditional approaches, and reaching out to various professional, academic and social communities will increase the reservoir of qualified candidates from which to make selections. In addition, outreach initiatives will undoubtedly yield further benefits such as a richer cultural understanding and diversity awareness. The resource listings presented in this Guide are offered to encourage active participation in the diversity recruitment process. This Guide contains resource listings by state for organizations in the following categories: (1) African American Recruitment Sources; (2) Asian American/Pacific Islander Recruitment Sources; (3) Hispanic Recruitment Sources; (4) Native American/Alaskan Native Recruitment Sources; (5) Persons with Disabilities Recruitment Sources; and (6) Women Recruitment Sources.

  16. Intense negative heavy ion sources

    NASA Astrophysics Data System (ADS)

    Mori, Yoshiharu; Takagi, Akira; Ikegami, Kiyoshi; Ueno, Akira; Fukumoto, Sadayoshi

    1990-08-01

    Negative ion sources based on plasma-surface interactions (BLAKE ion source) have been developed at KEK for producing negative heavy ions. The first negative heavy ion source (BLAKE-II) was developed by modifying the ordinary negative hydrogen ion source with converter (BLAKE-I) placed into the plasma. It generates various species of negative heavy ions with intense beam currents. For example, a more than 10 mA Au- ion beam was obtained from the ion source. Recently, the large scaled negative heavy ion source (BLAKE-III) has been developed and in the preliminary test experiment, more than 100 mA Cu- ion beam has been stably obtained with a 10% duty factor in pulsed operation. The BLAKE-II ion source was attached to the BNL 15 MV and Tsukuba University TANDEM accelerators and large current negative heavy ion beams were successfully accelerated in pulsed mode operation. Also, it was found that the space charge effect should be carefully considered for such a large current acceleration in a tandem accelerator, especially at the injection beam line and low energy end. In order to examine the negative ion formation process fundamentally, negative ion production probability related on sputtered particle velocity was measured and the results showed exponential dependence of the production probability on particle velocity as Norskov and Lindquist's theory predicted.

  17. Major sources of benzene exposure.

    PubMed Central

    Wallace, L A

    1989-01-01

    Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population. These sources turn out to be quite different from what had previously been considered the important sources. The most important source of exposure for 50 million smokers is the mainstream smoke from their cigarettes, which accounts for about half of the total population burden of exposure to benzene. Another 20% of nationwide exposure is contributed by various personal activities, such as driving and using attached garages. (Emissions from consumer products, building materials, paints, and adhesives may also be important, although data are largely lacking.) The traditional sources of atmospheric emissions (auto exhaust and industrial emissions) account for only about 20% of total exposure. Environmental tobacco smoke is an important source, accounting for about 5% of total nationwide exposure. A number of sources sometimes considered important, such as petroleum refining operations, petrochemical manufacturing, oil storage tanks, urban-industrial areas, service stations, certain foods, groundwater contamination, and underground gasoline leaks, appear to be unimportant on a nationwide basis. PMID:2477239

  18. International Data on Radiological Sources

    SciTech Connect

    Martha Finck; Margaret Goldberg

    2010-07-01

    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.

  19. Source rock potential in Pakistan

    SciTech Connect

    Raza, H.A. )

    1991-03-01

    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.

  20. Spallation neutron source and other high intensity froton sources

    SciTech Connect

    Weiren Chou

    2003-02-06

    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.