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Sample records for surface-plasma negative-hydrogen-ion source

  1. Negative hydrogen ion sources for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Moehs, D.P.; /Fermilab; Peters, J.; /DESY; Sherman, J.; /Los Alamos

    2005-08-01

    A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

  2. An overview of negative hydrogen ion sources for accelerators

    Science.gov (United States)

    Faircloth, Dan; Lawrie, Scott

    2018-02-01

    An overview of high current (>1 mA) negative hydrogen ion (H-) sources that are currently used on particle accelerators. The current understanding of how H- ions are produced is summarised. Issues relating to caesium usage are explored. The different ways of expressing emittance and beam currents are clarified. Source technology naming conventions are defined and generalised descriptions of each source technology are provided. Examples of currently operating sources are outlined, with their current status and future outlook given. A comparative table is provided.

  3. Size scaling of negative hydrogen ion sources for fusion

    Science.gov (United States)

    Fantz, U.; Franzen, P.; Kraus, W.; Schiesko, L.; Wimmer, C.; Wünderlich, D.

    2015-04-01

    The RF-driven negative hydrogen ion source (H-, D-) for the international fusion experiment ITER has a width of 0.9 m and a height of 1.9 m and is based on a ⅛ scale prototype source being in operation at the IPP test facilities BATMAN and MANITU for many years. Among the challenges to meet the required parameters in a caesiated source at a source pressure of 0.3 Pa or less is the challenge in size scaling of a factor of eight. As an intermediate step a ½ scale ITER source went into operation at the IPP test facility ELISE with the first plasma in February 2013. The experience and results gained so far at ELISE allowed a size scaling study from the prototype source towards the ITER relevant size at ELISE, in which operational issues, physical aspects and the source performance is addressed, highlighting differences as well as similarities. The most ITER relevant results are: low pressure operation down to 0.2 Pa is possible without problems; the magnetic filter field created by a current in the plasma grid is sufficient to reduce the electron temperature below the target value of 1 eV and to reduce together with the bias applied between the differently shaped bias plate and the plasma grid the amount of co-extracted electrons. An asymmetry of the co-extracted electron currents in the two grid segments is measured, varying strongly with filter field and bias. Contrary to the prototype source, a dedicated plasma drift in vertical direction is not observed. As in the prototype source, the performance in deuterium is limited by the amount of co-extracted electrons in short as well as in long pulse operation. Caesium conditioning is much harder in deuterium than in hydrogen for which fast and reproducible conditioning is achieved. First estimates reveal a caesium consumption comparable to the one in the prototype source despite the large size.

  4. Size scaling of negative hydrogen ion sources for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Fantz, U., E-mail: ursel.fantz@ipp.mpg.de; Franzen, P.; Kraus, W.; Schiesko, L.; Wimmer, C.; Wünderlich, D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-04-08

    The RF-driven negative hydrogen ion source (H{sup −}, D{sup −}) for the international fusion experiment ITER has a width of 0.9 m and a height of 1.9 m and is based on a ⅛ scale prototype source being in operation at the IPP test facilities BATMAN and MANITU for many years. Among the challenges to meet the required parameters in a caesiated source at a source pressure of 0.3 Pa or less is the challenge in size scaling of a factor of eight. As an intermediate step a ½ scale ITER source went into operation at the IPP test facility ELISE with the first plasma in February 2013. The experience and results gained so far at ELISE allowed a size scaling study from the prototype source towards the ITER relevant size at ELISE, in which operational issues, physical aspects and the source performance is addressed, highlighting differences as well as similarities. The most ITER relevant results are: low pressure operation down to 0.2 Pa is possible without problems; the magnetic filter field created by a current in the plasma grid is sufficient to reduce the electron temperature below the target value of 1 eV and to reduce together with the bias applied between the differently shaped bias plate and the plasma grid the amount of co-extracted electrons. An asymmetry of the co-extracted electron currents in the two grid segments is measured, varying strongly with filter field and bias. Contrary to the prototype source, a dedicated plasma drift in vertical direction is not observed. As in the prototype source, the performance in deuterium is limited by the amount of co-extracted electrons in short as well as in long pulse operation. Caesium conditioning is much harder in deuterium than in hydrogen for which fast and reproducible conditioning is achieved. First estimates reveal a caesium consumption comparable to the one in the prototype source despite the large size.

  5. Negative hydrogen ion sources for neutral beam injectors

    International Nuclear Information System (INIS)

    Prelec, K.

    1977-01-01

    Negative ion sources offer an attractive alternative in the design of high energy neutral beam injectors. The requirements call for a single source unit capable of yielding H - or D - beam currents of up to 10 A, operating with pulses of 1 s duration or longer, with gas and power efficiencies comparable to or better than achievable with double electron capture systems. H - beam currents of up to 1 A have already been achieved in pulses of 10 ms; gas and power efficiencies were, however, lower than required. In order to increase the H - yield, extend the pulse length and improve gas and power efficiencies fundamental processes in the source plasma and on cesium covered electrode surfaces have to be analyzed; these processes will be briefly reviewed and scaling rules established. Based on these considerations as well as on results obtained with 1 A source models a larger model was designed and constructed, having a 7.5 cm long cathode with forced cooling. Results of initial tests will be presented and possible scaling up to 10 A units discussed

  6. Development of polarized negative hydrogen ion source with resonant charge-exchange plasma ionizer

    Science.gov (United States)

    Belov, A. S.; Esin, S. K.; Netchaeva, L. P.; Turbabin, A. V.; Vasil'Ev, G. A.

    2001-06-01

    Polarized negative hydrogen ion beam with peak current of 2.5 mA has been obtained from an atomic beam-type polarized ion source of Institute for Nuclear Research, Moscow. The intensity improvement has been achieved due to increase of efficiency of conversion of polarized hydrogen atoms into polarized negative ions. New converter for production of deuterium plasma with high density of unpolarized negative ions is described. Limitations of the method and possible improvements are discussed. .

  7. Characteristics and dynamics of the boundary layer in RF-driven sources for negative hydrogen ions

    International Nuclear Information System (INIS)

    Wimmer, Christian

    2014-01-01

    The design of the neutral beam injection system of the upcoming ITER fusion device is based on the IPP (Max-Planck-Institut fuer Plasmaphysik, Garching) prototype source for negative hydrogen ions. The latter consists of a driver, in which hydrogen (or deuterium) molecules are dissociated in a large degree in a hydrogen plasma; the plasma expands then towards the plasma grid, on which negative hydrogen ions are formed by conversion of atoms or positive ions by the surface process and are extracted in the following accompanied by the co-extraction of electrons via a three grid system. Electrons are removed out of the extracted beam prior full acceleration using deflection magnets, bending them onto the second grid. The thermal load limits the tolerable amount of co-extracted electrons. A magnetic filter field in the expansion chamber reduces the electron temperature and density, on the one hand in order to minimize the destruction process of negative hydrogen ions by electron collisions and on the other hand in order to reduce the co-extracted electron current density. Caesium is evaporated into the source for an effective production of negative hydrogen ions, lowering the work function of the plasma grid. Due to the high chemical reactivity of caesium, the high vacuum condition in the source and the plasma-wall interaction, complex redistribution processes of Cs take place in the ion source. The boundary layer is the plasma volume between the magnetic filter field and the plasma grid, in which the most important physics of the negative ion source takes place: the production of negative hydrogen ions at the plasma grid, their transport through the plasma and the following extraction. A deeper understanding of the plasma and Cs dynamics in the boundary layer is desirable in order to achieve a stable long-pulse operation as well as to identify possible future improvements. For this reason, the boundary layer of the prototype source has been characterized in this work

  8. Enhancement of negative hydrogen ion production in an electron cyclotron resonance source

    International Nuclear Information System (INIS)

    Dugar-Zhabon, V D; Murillo, M T; Karyaka, V I

    2013-01-01

    In this paper, we present a method for improving the negative hydrogen ion yield in the electron cyclotron resonance source with driven plasma rings where the negative ion production is realized in two stages. First, the hydrogen and deuterium molecules are excited in collisions with plasma electrons to high-laying Rydberg and high vibration levels in the plasma volume. The second stage leads to negative ion production through the process of repulsive attachment of low-energy electrons by the excited molecules. The low-energy electrons originate due to a bombardment of the plasma electrode surface by ions of a driven ring and the thermoelectrons produced by a rare earth ceramic electrode, which is appropriately installed in the source chamber. The experimental and calculation data on the negative hydrogen ion generation rate demonstrate that very low-energy thermoelectrons significantly enhance the negative-ion generation rate that occurs in the layer adjacent to the plasma electrode surface. It is found that heating of the tungsten filaments placed in the source chamber improves the discharge stability and extends the pressure operation range. (paper)

  9. Plasma characteristics of a large RF-driven negative hydrogen ion source

    International Nuclear Information System (INIS)

    Takanashi, Toshihiko; Takeiri, Yasuhiko; Kaneko, Osamu; Oka, Yoshihide; Tsumori, Katsuyoshi; Kuroda, Tsutomu

    1996-01-01

    A large rf-driven negative hydrogen ion source has been developed for a neutral beam injection (NBI) system in future experimental fusion devices. Dimensions of the rf plasma generator are 30 x 30 x 20 cm 3 . An induction coil antenna is fully immersed into the plasma generator. The rf-driven plasma with an electron density of 1.5 x 10 12 cm -3 was generated at 28 kW rf power at a frequency of 2 MHz. The electron temperature in the extraction region decreases as the line-integrated magnetic filter field strength increases. An electron temperature in the extraction region of 1 eV, which is suitable for generating negative ions, was obtained at a line-integrated filter field strength of 1030 G cm. Negative hydrogen ions are extracted from a single aperture of 13 mm in diameter in a pure-volume operation. An extracted negative ion current of 5.5 mA was obtained at 13.1 mTorr gas pressure and 15 kW rf power. This negative ion current corresponds to a power efficiency of 5.0 (mA/cm 2 )/(W/cm 3 ), which is superior to that in filament-arc negative ion sources. (author)

  10. Comparison of different antenna designs in the spallation neutron source negative hydrogen ion source

    Science.gov (United States)

    Veitzer, Seth A.; Kundrapu, Madhusudhan; Stoltz, Peter H.; Beckwith, Kristian R. C.

    2017-08-01

    Internal antenna negative hydrogen ion sources can fail when plasma heating causes ablation of the insulating coating due to small structural defects such as cracks. During this process, plasma ions impacting the surfaces of rf antennas causes heating of the coating, which can melt or ablate, thus exposing conducting surfaces to the plasma. Reducing antenna failures that reduce the operating capabilities of the Spallation Neutron Source (SNS) accelerator has been one of the top priorities of the SNS H-Source Program at ORNL. We have been utilizing numerical modeling of internal antenna negative hydrogen ion sources in order help optimize antenna designs in order to reduce antenna failures. We have implemented a number of fluid models with electromagnetics using the simulation tool USim and applied them to modeling the SNS internal antenna negative ion source. We report here on results comparing two different antenna designs. The baseline design, as is currently in use in the SNS source, and a wide-leg design, that has been tested, and may replace the baseline design if it can reduce antenna failures while still maintaining source performance. The wide-leg antenna is designed to move the antenna supports out of the high-density plasma regions, in order to decrease the possible negative effects of ion bombardment. We model the plasma evolution using a single-fluid MHD model with an imposed magnetic field due to the rf antenna current and the confining multi-cusp field for both the baseline and wide-leg antenna configurations. We find that the maximum plasma velocity near the antenna surfaces is reduced by nearly 50% in the wide-leg configuration, and that overall the bulk plasma velocity is reduced for this configuration. In addition, although we measure a small increase in the maximum plasma flux on the antenna surface for the wide-leg design, we see a broad-based reduction of plasma flux on the antenna in the regions where the antenna is mostly exposed to the

  11. 3D self-consistent modeling of a matrix source of negative hydrogen ions.

    Science.gov (United States)

    Tarnev, Kh; Demerdjiev, A; Shivarova, A; Lishev, St

    2016-02-01

    The paper is in the scope of studies on the rf driving of a matrix source of negative hydrogen ions: a matrix of small radius discharges with planar-coil inductive driving and single aperture extraction from each discharge. The results from a three-dimensional model, in which plasma description is coupled to electrodynamics, confirm former conclusion that a single coil driving of the whole matrix by a zigzag coil with an omega-shaped conductor on the bottom of each discharge tube ensures efficient rf power deposition to the plasma. The latter is due to similarities with the rf driving of a single discharge by a single planar coil, shown by the obtained induced current and spatial distribution of the plasma parameters. Distinctions associated with the coil configuration as a single coil for the whole matrix are also discussed.

  12. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Young, E-mail: beacoolguy@snu.ac.kr; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2016-02-15

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H{sup −} ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H{sup −} ion generation in volume-produced negative hydrogen ion sources.

  13. Hydrogen atom temperature measured with wavelength-modulated laser absorption spectroscopy in large scale filament arc negative hydrogen ion source

    International Nuclear Information System (INIS)

    Nakano, H.; Goto, M.; Tsumori, K.; Kisaki, M.; Ikeda, K.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Nishiyama, S.; Sasaki, K.

    2015-01-01

    The velocity distribution function of hydrogen atoms is one of the useful parameters to understand particle dynamics from negative hydrogen production to extraction in a negative hydrogen ion source. Hydrogen atom temperature is one of the indicators of the velocity distribution function. To find a feasibility of hydrogen atom temperature measurement in large scale filament arc negative hydrogen ion source for fusion, a model calculation of wavelength-modulated laser absorption spectroscopy of the hydrogen Balmer alpha line was performed. By utilizing a wide range tunable diode laser, we successfully obtained the hydrogen atom temperature of ∼3000 K in the vicinity of the plasma grid electrode. The hydrogen atom temperature increases as well as the arc power, and becomes constant after decreasing with the filling of hydrogen gas pressure

  14. Surface generation of negative hydrogen ion beams

    International Nuclear Information System (INIS)

    Bommel, P.J.M. van.

    1984-01-01

    This thesis describes investigations on negative hydrogen ion sources at the ampere level. Formation of H - ions occurs when positive hydrogen ions capture two electrons at metal surfaces. The negative ionization probability of hydrogen at metal surfaces increases strongly with decreasing work function of the surface. The converters used in this study are covered with cesium. Usually there are 'surface plasma sources' in which the hydrogen source plasma interacts with a converter. In this thesis the author concentrates upon investigating a new concept that has converters outside the plasma. In this approach a positive hydrogen ion beam is extracted from the plasma and is subsequently reflected from a low work function converter surface. (Auth.)

  15. Performance of multi-aperture grid extraction systems for an ITER-relevant RF-driven negative hydrogen ion source

    Science.gov (United States)

    Franzen, P.; Gutser, R.; Fantz, U.; Kraus, W.; Falter, H.; Fröschle, M.; Heinemann, B.; McNeely, P.; Nocentini, R.; Riedl, R.; Stäbler, A.; Wünderlich, D.

    2011-07-01

    The ITER neutral beam system requires a negative hydrogen ion beam of 48 A with an energy of 0.87 MeV, and a negative deuterium beam of 40 A with an energy of 1 MeV. The beam is extracted from a large ion source of dimension 1.9 × 0.9 m2 by an acceleration system consisting of seven grids with 1280 apertures each. Currently, apertures with a diameter of 14 mm in the first grid are foreseen. In 2007, the IPP RF source was chosen as the ITER reference source due to its reduced maintenance compared with arc-driven sources and the successful development at the BATMAN test facility of being equipped with the small IPP prototype RF source ( {\\sim}\\frac{1}{8} of the area of the ITER NBI source). These results, however, were obtained with an extraction system with 8 mm diameter apertures. This paper reports on the comparison of the source performance at BATMAN of an ITER-relevant extraction system equipped with chamfered apertures with a 14 mm diameter and 8 mm diameter aperture extraction system. The most important result is that there is almost no difference in the achieved current density—being consistent with ion trajectory calculations—and the amount of co-extracted electrons. Furthermore, some aspects of the beam optics of both extraction systems are discussed.

  16. A CW radiofrequency ion source for production of negative hydrogen ion beams for cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Kalvas, T.; Tarvainen, O.; Komppula, J.; Koivisto, H.; Tuunanen, J. [University of Jyväskylä, Department of Physics (Finland); Potkins, D.; Stewart, T.; Dehnel, M. P. [D-Pace, Inc., Nelson, B.C. Canada (Canada)

    2015-04-08

    A CW 13.56 MHz radiofrequency-driven ion source RADIS for production of H{sup −} and D{sup −} beams is under development for replacing the filament-driven ion source of the MCC30/15 cyclotron. The RF ion source has a 16-pole multicusp plasma chamber, an electromagnet-based magnetic filter and an external planar spiral RF antenna behind an AlN window. The extraction is a 5-electrode system with an adjustable puller electrode voltage for optimizing the beam formation, a water-cooled electron dump electrode and an accelerating einzel lens. At 2650 W of RF power, the source produces 1 mA of H{sup −} (2.6 mA/cm{sup 2}), which is the intensity needed at injection for production of 200 µA H{sup +} with the filament-driven ion source. A simple pepperpot device has been developed for characterizing the beam emittance. Plans for improving the power efficiency with the use of a new permanent magnet front plate is discussed.

  17. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    International Nuclear Information System (INIS)

    Bandyopadhyay, M.

    2004-01-01

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  18. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, M.

    2004-08-24

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  19. Development of a 20 mA negative hydrogen ion source for cyclotrons

    Science.gov (United States)

    Etoh, H.; Onai, M.; Arakawa, Y.; Aoki, Y.; Mitsubori, H.; Sakuraba, J.; Kato, T.; Mitsumoto, T.; Yajima, S.; Hatayama, A.; Okumura, Y.

    2017-08-01

    A cesiated DC negative ion source has been developed for proton cyclotrons in medical applications. A continuous H- beam of 23 mA was stably extracted at an arc power of 3 kW. The beam current gradually decreases with a constant arc power and without additional Cs injection and the decay rate was about 0.03 mA (0.14%) per hour. A feed-back control system that automatically adjusts the arc power to stabilize the beam current is able to keep the beam current constant at ±0.04 mA (±0.2%).

  20. Progress of the ''batman'' RF source for negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Frank, P.; Heinemann, B.; Kraus, W.; Probst, F.; Speth, E.; Vollmer, O. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Bucalossi, J.; Trainham, R. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1998-07-01

    The aim of a collaboration between CEA Cadarache and IPP Garching is to investigate the ability of an rf source to produce negative-ion current densities compatible with ITER NBI requirements (20 mA/cm{sup 2} D-). A standard PlNI-size rf source developed for ASDEX-Upgrade and a three-grid extraction system form the basis of BATMAN (Bavarian Test Machine for Negative Ions). In the case of a pure hydrogen plasma a current density of 5.5 mA/cm{sup 2} at elevated pressure (2.4 Pa) can be reached. Adding small amounts of argon (< 15 %) the current density increases up to a maximum of 8.5 mA/cm{sup 2}. In the low pressure range (0.7 Pa) the negative ion yield is strongly reduced, but with an admixture of argon and a cesium injection the current density is higher approx. by a factor 8 (4 mA/cm{sup 2}) compared to the pure hydrogen discharge. The negative ion yield shows a saturation with increasing rf power. (author)

  1. Development of a novel radio-frequency negative hydrogen ion source in conically converging configuration.

    Science.gov (United States)

    Jung, B K; Dang, J J; An, Y H; Chung, K J; Hwang, Y S

    2014-02-01

    Volume-produced negative ion source still requires enhancement of current density with lower input RF (radio-frequency) power in lower operating pressure for various applications. To confirm recent observation of efficient negative ion production with a short cylindrical chamber with smaller effective plasma size, the RF-driven transformer-coupled plasma H(-) ion source at Seoul National University is modified by adopting a newly designed quartz RF window to reduce the chamber length. Experiments with the reduced chamber length show a few times enhancement of H(-) ion beam current compared to that extracted from the previous chamber design, which is consistent with the measured H(-) ion population. Nevertheless, decrease in H(-) ion beam current observed in low pressure regime below ∼5 mTorr owing to insufficient filtering of high energy electrons in the extraction region needs to be resolved to address the usefulness of electron temperature control by the change of geometrical configuration of the discharge chamber. A new discharge chamber with conically converging configuration has been developed, in which the chamber diameter decreases as approaching to the extraction region away from the planar RF antenna such that stronger filter magnetic field can be utilized to prohibit high energy electrons from transporting to the extraction region. First experimental results for the H(-) ion beam extraction with this configuration show that higher magnetic filter field makes peak negative beam currents happen in lower operating pressure. However, overall decrease in H(-) ion beam current due to the change of chamber geometry still requires further study of geometrical effect on particle transport and optimization of magnetic field in this novel configuration.

  2. Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

    Energy Technology Data Exchange (ETDEWEB)

    Gutser, Raphael

    2010-07-21

    The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

  3. Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

    International Nuclear Information System (INIS)

    Gutser, Raphael

    2010-01-01

    The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

  4. Improved beam extraction for a negative hydrogen ion source for the LHC injector chain upgrade, Linac4

    CERN Document Server

    Midttun, Øystein; Scrivens, Richard

    In the scope of an upgrade of the injector chain of CERN’s accelerator complex, a new linear accelerator, Linac4, is under construction. This accelerator will replace the existing 50 MeV proton linac, Linac2. By increasing the beam energy to 160 MeV, Linac4 makes it possible to double the brightness in the PSB, and ultimately increase the luminosity in the LHC. Linac4 will accelerate beams of negative hydrogen (H-) to be injected into the PSB by multi-turn, charge exchange injection. The ion source was initially based on the non-caesiated RF-volume source from DESY. However, the beam extraction from this source could not handle the 45 keV beam energy required by the RFQ. A new beam extraction system has therefore been designed, via IBSimu simulations [1], to extract and transport the H- ion beam respecting the Linac4 requirements. Key features of the extraction system is a tuneable puller voltage to adapt the extraction field to the ion and electron beam currents, and a magnetized Einzel lens to dump the co...

  5. Doppler shift measurement of Balmer-alpha line spectrum emission from a plasma in a negative hydrogen ion source

    International Nuclear Information System (INIS)

    Wada, M.; Doi, K.; Kisaki, M.; Nakano, H.; Tsumori, K.; Nishiura, M.

    2015-01-01

    Balmer-α light emission from the extraction region of the LHD one-third ion source has shown a characteristic Doppler broadening in the wavelength spectrum detected by a high resolution spectrometer. The spectrum resembles Gaussian distribution near the wavelength of the intensity peak, while it has an additional component of a broader foot. The measured broadening near the wavelength of the intensity peak corresponds to 0.6 eV hydrogen atom temperature. The spectrum exhibits a larger expansion in the blue wing which becomes smaller when the line of sight is tilted toward the driver region from the original observation axis parallel to the plasma grid. A surface collision simulation model predicts the possibility of hydrogen reflection at the plasma grid surface to form a broad Balmer-α light emission spectrum

  6. On the meniscus formation and the negative hydrogen ion extraction from ITER neutral beam injection relevant ion source

    Science.gov (United States)

    Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Fantz, U.; Franzen, P.; Minea, T.

    2014-10-01

    The development of a large area (Asource,ITER = 0.9 × 2 m2) hydrogen negative ion (NI) source constitutes a crucial step in construction of the neutral beam injectors of the international fusion reactor ITER. To understand the plasma behaviour in the boundary layer close to the extraction system the 3D PIC MCC code ONIX is exploited. Direct cross checked analysis of the simulation and experimental results from the ITER-relevant BATMAN source testbed with a smaller area (Asource,BATMAN ≈ 0.32 × 0.59 m2) has been conducted for a low perveance beam, but for a full set of plasma parameters available. ONIX has been partially benchmarked by comparison to the results obtained using the commercial particle tracing code for positive ion extraction KOBRA3D. Very good agreement has been found in terms of meniscus position and its shape for simulations of different plasma densities. The influence of the initial plasma composition on the final meniscus structure was then investigated for NIs. As expected from the Child-Langmuir law, the results show that not only does the extraction potential play a crucial role on the meniscus formation, but also the initial plasma density and its electronegativity. For the given parameters, the calculated meniscus locates a few mm downstream of the plasma grid aperture provoking a direct NI extraction. Most of the surface produced NIs do not reach the plasma bulk, but move directly towards the extraction grid guided by the extraction field. Even for artificially increased electronegativity of the bulk plasma the extracted NI current from this region is low. This observation indicates a high relevance of the direct NI extraction. These calculations show that the extracted NI current from the bulk region is low even if a complete ion-ion plasma is assumed, meaning that direct extraction from surface produced ions should be present in order to obtain sufficiently high extracted NI current density. The calculated extracted currents, both ions

  7. Study on space charge compensation in negative hydrogen ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, A. L.; Chen, J. E. [University of Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Peng, S. X., E-mail: sxpeng@pku.edu.cn; Ren, H. T.; Zhang, T.; Zhang, J. F.; Xu, Y.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

    2016-02-15

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H{sup +} beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H{sup −} beam from a 2.45 GHz microwave driven H{sup −} ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  8. Reconstruction of negative hydrogen ion beam properties from beamline diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Benjamin

    2014-09-25

    (BES). BES measures the beam divergence and beam power losses from heavy-particle collisions by evaluating the spectrum of the Balmer H{sub α} light of the beam. The light is emitted since beam particles are excited by collisions with the hydrogen background gas. For ITER, BES will be the main beam diagnostic tool for beam quality measurements. The main results are, that first of all, the evaluation of the beam divergence from a BES spectrum was improved with the parametrisation method. Furthermore it turned out that the evaluation of stripping losses and beam inhomogeneity in large negative hydrogen ion sources cannot be performed by backward calculations from a BES spectra, i.e. by the analysis of the spectra. This means forward modeling has to be done, which does also include the simulation of other beam diagnostic tools, like the power density profile measured by the calorimeter. Combining all beam diagnostic tools and reconstructing their outcome with a BBC-NI Advanced simulation, gives the possibility to determine the beam parameters by extracting them from the BBC-NI code protocols. This requires a lot of effort and is not well suited for a routine analysis. For ITER this means that solely a BES system for the determination of the beam parameters (i.e. stripping losses and beam inhomogeneity), as it is presently foreseen, is not sufficient. Several beam diagnostic tools, e.g. the calorimeter which can determine the power density profile of the beam, and a code like BBC-NI are necessary. Additionally for the application of BBC-NI Advanced, a beam optic code is needed, which is able to generate a realistic electric field map in the extraction system. Such an optic code is not available so far.

  9. A feature of negative hydrogen ion production in the Uramoto-type sheet plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jimbo, Kouichi [Kyoto Univ., Uji (Japan). Inst. of Atomic Energy

    1997-02-01

    It seems that negative hydrogen ions H{sup -} are formed directly from atomic hydrogens H. When the chamber was biased more negative against the anode potential at constant are power, forming a much deeper electrostatic well in the Uramoto-type sheet plasma negative ion source, more negative hydrogen ion currents were extracted. The chamber potential V{sub B} was biased down to -100V in the 150V discharge. The negative ion current J{sup -} was evaluated by the JAERI-probe measurement. J{sup -} increases linearly with the chamber current I{sub B}. The largest J{sup -} value was obtained at absolute value of |V{sub prob,f}|=15V and absolute value of |V{sub B}|=100V; the discharge was not operated for absolute value of |V{sub B}|>100V. We speculate the following collisional (three-body) electron attachment to H as a possible production process for H{sup -}; e+e+H{yields}e+H{sup -}. This process may explain the linear increase of J{sup -} with absolute value of |V{sub prob,f}|. (S.Y.)

  10. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields ({proportional_to} 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H{sup -})=1.10{sup 17} 1/m{sup 3}, which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  11. Method of production of polarized negative hydrogen ions

    International Nuclear Information System (INIS)

    Belov, A.S.; Kuzik, V.E.; Yakushev, V.P.

    1990-01-01

    Result of experimental examination of the method of producing negative polarized hydrogen ions are presented. Beams of polarized hydrogen atoms and deuterium plasma are injected towards each other and meet in the region of recharging 1 in 1.3 kGs magnetic field, created by a solenoid. As follows from the measurements performed and the method analysis, a possibility of producing an intense H-vector - ion beam according to the given method is mainly dependent on plasma deuterium target parameters. It is possible to produce ∼500 μA current H-vector - ion beam by the method considered under ∼0.1 relative D - ion density in plasma, ∼1 eV electron temperature, ∼10 2 eV ion temperature (typical of surface - plasma sources) and 2 cm 2 transverse area of recharging volume. The method advantages as well include the absence in a source of targets of alkali metal vapours, the presence of which in other methods limits the time of continuous source operation and makes their operation difficult

  12. Mechanism of negative hydrogen ion emission from heated saline hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Hiroyuki; Serizawa, Naoshi; Takeda, Makiko; Hasegawa, Seiji [Ehime Univ., Matsuyama (Japan). Faculty of Science

    1997-02-01

    To find a clue to the mechanism of negative hydrogen ion emission from a heated sample ({approx}10 mg) of powdery saline hydride (LiH or CaH{sub 2}) deposited on a molybdenum ribbon ({approx}0.1 cm{sup 2}), both the ionic and electronic emission currents were measured as a function of sample temperature ({approx}700 - 800 K), thereby yielding {approx}10{sup -15} - 10{sup -12} A of H{sup -} after mass analysis and {approx}10{sup -7} - 10{sup -5} A of thermal electron. Thermophysical analysis of these data indicates that the desorption energy (E{sup -}) of H{sup -} and work function ({phi}) of the emitting sample surface are 5.1 {+-} 0.3 and 3.1 {+-} 0.2 eV for LiH, respectively, while E{sup -} is 7.7 {+-} 0.3 eV and {phi} is 5.0 {+-} 0.2 eV for CaH{sub 2}. Thermochemical analysis based on our simple model on the emissions indicates that the values of E{sup -} - {phi} are 2.35 and 2.31 eV for LiH and CaH{sub 2}, respectively, which are in fair agreement with the respective values (2.1 {+-} 0.3 and 2.6 {+-} 0.3 eV) determined experimentally. This agreement indicates that the emission of H{sup -} is reasonably explained by our model from the viewpoint of reaction energy. (author)

  13. A future, intense source of negative hydrogen ions

    Science.gov (United States)

    Siefken, Hugh; Stein, Charles

    1994-01-01

    By directly heating lithium hydride in a vacuum, up to 18 micro-A/sq cm of negative hydrogen has been obtained from the crystal lattice. The amount of ion current extracted and analyzed is closely related to the temperature of the sample and to the rate at which the temperature is changed. The ion current appears to be emission limited and saturates with extraction voltage. For a fixed extraction voltage, the ion current could be maximized by placing a grid between the sample surface and the extraction electrode. Electrons accompanying the negative ions were removed by a magnetic trap. A Wein velocity filter was designed and built to provide definitive mass analysis of the extracted ion species. This technique when applied to other alkali hydrides may produce even higher intensity beams possessing low values of emittance.

  14. Investigations on Cs-free alternative materials for negative hydrogen ion formation

    International Nuclear Information System (INIS)

    Kurutz, Uwe

    2017-01-01

    Neutral beam injection (NBI) represents a main auxiliary heating and current drive system for thermonuclear fusion devices. For ITER, a total heating power of up to 33 MW will be delivered for up to one hour pulses at particle energies of up to 1 MeV by two NBI systems. The respective ion sources will therefore have to allow for the extraction and acceleration of negative hydrogen ions at a current density of 200 A/m 2 from a low pressure low temperature hydrogen plasma. Also for the succeeding demonstration reactor DEMO the application of NBI is currently discussed. Respective systems will, however, have to fulfil even higher demands, like higher powers (up to 135 MW), longer pulse lengths (2 h or even cw operation), and more restrictive constrains regarding the reliability and stability. Today efficient NBI negative hydrogen ion sources are based mainly on the conversion of positive hydrogen ions and/or hydrogen atoms at a grid surface coated with caesium. Cs is used for reducing the grid's work function which significantly enhances the particle conversion probability. However, the alkali metal is chemically very reactive and easily forms compounds with residual gas impurities. Furthermore, complex redistribution dynamics of the deposited Cs layer is given. This inherently links the application of Cs with a temporal and spatial non-stability of the negative ion yield, which contradicts the required reliability of a DEMO NBI system. Thus, for DEMO, Cs-free alternative materials for negative ion formation are investigated within this work at a flexible laboratory experiment. An ECR discharge is used which provides comparable parameters (pressure, densities, particle fluxes and -energies) to the NBI ion sources. Negative ion formation is measured above different material samples via laser photodetachment together with global plasma parameters using a Langmuir probe and optical emission spectroscopy. The plasma parameters are used for modelling the inherently

  15. An improved value for the electron affinity of the negative hydrogen ion

    International Nuclear Information System (INIS)

    Scherk, L.R.

    1979-01-01

    An expression is derived for the lifetime of a negative ion in a weak and static electric field. Using this expression, existing experimental data are analyzed to improve the empirical value of the electron affinity of the negative hydrogen ion by an order of magnitude. (author)

  16. Space Charge Compensation in the Linac4 Low Energy Beam Transport Line with Negative Hydrogen Ions

    CERN Document Server

    Valerio-Lizarraga, C; Leon-Monzon, I; Lettry, J; Midttun, O; Scrivens, R

    2014-01-01

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Tranport (LEBT) using the package IBSimu1, which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H- beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  17. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Valerio-Lizarraga, Cristhian A., E-mail: cristhian.alfonso.valerio.lizarraga@cern.ch [CERN, Geneva (Switzerland); Departamento de Investigación en Física, Universidad de Sonora, Hermosillo (Mexico); Lallement, Jean-Baptiste; Lettry, Jacques; Scrivens, Richard [CERN, Geneva (Switzerland); Leon-Monzon, Ildefonso [Facultad de Ciencias Fisico-Matematicas, Universidad Autónoma de Sinaloa, Culiacan (Mexico); Midttun, Øystein [CERN, Geneva (Switzerland); University of Oslo, Oslo (Norway)

    2014-02-15

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H{sup −} beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  18. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions

    International Nuclear Information System (INIS)

    Valerio-Lizarraga, Cristhian A.; Lallement, Jean-Baptiste; Lettry, Jacques; Scrivens, Richard; Leon-Monzon, Ildefonso; Midttun, Øystein

    2014-01-01

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H − beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree

  19. Negative ion surface plasma source development for plasma trap injectors in Novosibirsk

    International Nuclear Information System (INIS)

    Bel'chenko, Yu.I.; Dimov, G.I.; Dudnikov, V.G.; Kupriyanov, A.S.

    1989-01-01

    Work on high-current ion sources carried out at the Novosibirsk Institute of Nuclear Physics (INP) is presented. The INP investigations on ''pure plasma'' planotron and ''pure surface'' secondary emission systems of H - generation, which preceded the surface-plasma concept developed in Novosibirsk, are described. The physical basis of the surface-plasma method of negative-ion production is considered. The versions and operating characteristics of different surface-plasma sources including the multi-ampere (approx-gt 10A) source are discussed. Research on efficient large-area (∼10 2 cm 2 ) negative ion surface-plasma emitters is described. The INP long-pulse multiaperture surface- plasma generators, with a current of about 1A, are described. 38 refs., 17 figs

  20. Development of the negative ion source at the National Laboratory for High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Akira [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-02-01

    On formation of direct high frequency chopped negative hydrogen ion beam from surface forming type negative hydrogen ion source, incident acceleration due to proton synchrotron was tried for a forming experiment and its application. By overlapping a high frequency pulse onto a bias DC voltage of convertor electrode, control of formation of negative hydrogen ion with high speed RF pulse of 2 MHz could be realized. And, incidence into 12 GeV proton accelerator to catch RF particles with waiting bucket system due to booster synchrotron, was effective for control of longitudinal emittance in the booster synchrotron. As a result, controls of the beam width and shape emitted from the booster synchrotron were possible. On application of high speed chopped negative hydrogen ion beam to accelerator, improvement of beam capture efficiency to the accelerated RF bucket, control of longitudinal emittance of accelerated beam, beam measurement at incidence into the accelerator and so forth were conducted. In this paper, results of the high speed chopped beam formation experiment using surface plasma forming type negative ion source and application of high speed beam chopping method synchronized with high frequency pulse at the National Laboratory of High Energy Physics are described. (G.K.)

  1. Application of the nuclear liquid drop model to a negative hydrogen ion in the strong electric field of a laser

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M.Ya.; Kornyushin, Y. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)]. E-mail: yurik@vms.huji.ac.il

    2000-09-01

    The nuclear liquid drop model is applied to describe some basic properties of a negative hydrogen ion in the strong electric field of a laser. The equilibrium ionic size, energy and polarizability of the ion are calculated. Collective modes of the dipole oscillations are considered. A barrier which arises in a strong electric field is studied. The barrier vanishes at some large value of the electric field, which is defined as a critical value. The dependence of the critical field on frequency is studied. At frequencies {omega}{>=}({omega}{sub d}/2{sup 1/2}) ({omega}{sub d} is the frequency of the dipole oscillations of the electronic cloud relative to the nucleus) the barrier remains for any field. At high frequencies a 'stripping' mechanism for instability arises. At the resonant frequency a rather low amplitude of the electric field causes the 'stripping' instability. (author)

  2. Suppression of the e- coextracted from a Penning surface-plasma H- source

    International Nuclear Information System (INIS)

    Smith, H.V. Jr.; Allison, P.

    1992-01-01

    The ratio of electrons to negative ions extracted from Penning surface-plasma sources (SPS) such as the 8X source is low even before any steps are taken to suppress the electrons. For the 8X source the e - /H - ratio is typically four or five to one for H - operation and nine to one for D - operation. Because the coextracted e - present a power-loading problem to the 8X source extraction system, methods to dissipate and/or reduce the power in the e - beam must be developed before extracting a dc H - or D - beam. Thus, an experiment was run to see if a collar installed in the near extraction region of the 8X source suppresses the electrons extracted from that source

  3. Evaluation of beam divergence of a negative hydrogen ion beam using Doppler shift spectroscopy diagnostics

    Science.gov (United States)

    Deka, A. J.; Bharathi, P.; Pandya, K.; Bandyopadhyay, M.; Bhuyan, M.; Yadav, R. K.; Tyagi, H.; Gahlaut, A.; Chakraborty, A.

    2018-01-01

    The Doppler Shift Spectroscopy (DSS) diagnostic is in the conceptual stage to estimate beam divergence, stripping losses, and beam uniformity of the 100 keV hydrogen Diagnostics Neutral Beam of International Thermonuclear Experimental Reactor. This DSS diagnostic is used to measure the above-mentioned parameters with an error of less than 10%. To aid the design calculations and to establish a methodology for estimation of the beam divergence, DSS measurements were carried out on the existing prototype ion source RF Operated Beam Source in India for Negative ion Research. Emissions of the fast-excited neutrals that are generated from the extracted negative ions were collected in the target tank, and the line broadening of these emissions were used for estimating beam divergence. The observed broadening is a convolution of broadenings due to beam divergence, collection optics, voltage ripple, beam focusing, and instrumental broadening. Hence, for estimating the beam divergence from the observed line broadening, a systematic line profile analysis was performed. To minimize the error in the divergence measurements, a study on error propagation in the beam divergence measurements was carried out and the error was estimated. The measurements of beam divergence were done at a constant RF power of 50 kW and a source pressure of 0.6 Pa by varying the extraction voltage from 4 kV to10 kV and the acceleration voltage from 10 kV to 15 kV. These measurements were then compared with the calorimetric divergence, and the results seemed to agree within 10%. A minimum beam divergence of ˜3° was obtained when the source was operated at an extraction voltage of ˜5 kV and at a ˜10 kV acceleration voltage, i.e., at a total applied voltage of 15 kV. This is in agreement with the values reported in experiments carried out on similar sources elsewhere.

  4. Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

    Energy Technology Data Exchange (ETDEWEB)

    Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T. [National Inst. for Fusion Science, Nagoya (Japan); Guharay, S.K.

    1997-02-01

    A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H{sup -}) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

  5. Study of negative hydrogen ion beam optics using the 3D3V PIC model

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K., E-mail: kmiyamot@naruto-u.ac.jp [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima, 772-8502 (Japan); Nishioka, S.; Goto, I.; Hatayama, A. [Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522 (Japan); Hanada, M.; Kojima, A. [Japan Atomic Energy Agency, 801-1,Mukoyama, Naka, 319-0913 (Japan)

    2015-04-08

    The mechanism of negative ion extraction under real conditions with the complex magnetic field is studied by using the 3D PIC simulation code. The extraction region of the negative ion source for the negative ion based neutral beam injection system in fusion reactors is modelled. It is shown that the E x B drift of electrons is caused by the magnetic filter and the electron suppression magnetic field, and the resultant asymmetry of the plasma meniscus. Furthermore, it is indicated that that the asymmetry of the plasma meniscus results in the asymmetry of negative ion beam profile including the beam halo. It could be demonstrated theoretically that the E x B drift is not significantly weakened by the elastic collisions of the electrons with neutral particles.

  6. Experimental investigation of the formation of negative hydrogen ions in collisions between positive ions and atomic or molecular targets

    International Nuclear Information System (INIS)

    Lattouf, Elie

    2013-01-01

    The formation of the negative hydrogen ion (H - ) in collisions between a positive ion and a neutral atomic or molecular target is studied experimentally at impact energies of a few keV. The doubly-differential cross sections for H - formation are measured as a function of the kinetic energy and emission angle for the collision systems OH + + Ar and O + + H 2 O at 412 eV/a.m.u. These H - ions can be emitted at high energies (keV) in hard quasi-elastic two-body collisions involving a large momentum transfer to the H center. However, H - anions are preferentially emitted at low energy (eV) due to soft many-body (≥ 2) collisions resulting in a low momentum transfer. The formation of H - ions by electron capture follows excitation or ionization of the molecule. The molecular fragmentation dynamics is modeled to simulate the emission of H - ions. The overall good agreement between the simulation and the experiment leads to the understanding of most of the experimental observations. (author) [fr

  7. Electron suppression in the H- beam from a Penning surface-plasma source

    International Nuclear Information System (INIS)

    Smith, H.V. Jr.; Allison, P.

    1993-01-01

    The ratio of electrons to negative ions extracted from Penning surface-plasma sources such as the 8X source is low even before any further steps are taken to suppress the electrons. For the 8X source the e - /H - ratio is typically four or five to one for H - operation and nine to one for D - operation. Because the coextracted e - present a power-loading problem to the 8X-source extraction system, methods to dissipate and/or reduce the power in the e - beam must be developed before extracting a dc H - or D - beam. Thus, we systematically varied the geometry of a cylindrical collar installed in the near-extraction region of the 8X source. The observed dependence of the extracted e - and H - currents on the collar radii and lengths suggests that a conical collar would provide superior electron suppression. The conical collar that we tested lowered the e - /H - ratio to 0.9/1 without reducing the extracted H - current

  8. Evaluation of a simple method for chopping Penning surface-plasma source H- beams

    International Nuclear Information System (INIS)

    Smith, H.V. Jr.; Allison, P.; Schneider, J.D.; Stelzer, J.E.; Stevens, R.R. Jr.

    1995-01-01

    Accumulator rings proposed for use in high-intensity spallation-neutron sources require a chopped beam with ∼100-ns-wide particle-free gaps at 1--2 MHz rates, with fall and rise times ≤20 ns. Chopping the beam directly in the ion source may be an attractive way to provide the desired beam structure. Previous measurements showed that placing a grounded collar in the drift region just before the emission aperture lowers the e - /H - ratio in the Penning surface-plasma source H - beam. We electrically isolated the collar and biased it to modulate the extracted H - current. Positive collar bias decreases the H - beam by up to 90%. The fastest H - current fall and rise times achieved to date are 400 ns and 2 μs, respectively. The current fall time is close to the 300-ns pulser rise time. The current rise time is considerably longer than the 500-ns pulser fall time. Negative collar bias lowers the H - beam by up to 50%. Simulations indicate that the beam time structure will be preserved in transport from the ion source to the radio-frequency quadrupole entrance

  9. Measurements of the cesium flow from a surface-plasma H- ion source

    International Nuclear Information System (INIS)

    Smith, H.V.; Allison, P.W.

    1979-01-01

    A surface ionization gauge (SIG) was constructed and used to measure the Cs 0 flow rate through the emission slit of a surface-plasma source (SPS) of H - ions with Penning geometry. The equivalent cesium density in the SPS discharge is deduced from these flow measurements. For dc operation the optimum H - current occurs at an equivalent cesium density of approx. 7 x 10 12 cm -3 (corresponding to an average cesium consumption rate of 0.5 mg/h). For pulsed operation the optimum H - current occurs at an equivalent cesium density of approx. 2 x 10 13 cm -3 (1-mg/h average cesium consumption rate). Cesium trapping by the SPS discharge was observed for both dc and pulsed operation. A cesium energy of approx. 0.1 eV is deduced from the observed time of flight to the SIG. In addition to providing information on the physics of the source, the SIG is a useful diagnostic tool for source startup and operation

  10. 3D numerical simulations of negative hydrogen ion extraction using realistic plasma parameters, geometry of the extraction aperture and full 3D magnetic field map

    Science.gov (United States)

    Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Franzen, P.; Fantz, U.; Minea, T.

    2014-02-01

    Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.

  11. RF H-minus ion source development in China spallation neutron source

    Science.gov (United States)

    Chen, W.; Ouyang, H.; Xiao, Y.; Liu, S.; Lü, Y.; Cao, X.; Huang, T.; Xue, K.

    2017-08-01

    China Spallation Neutron Source (CSNS) phase-I project currently uses a Penning surface plasma H- ion source, which has a life time of several weeks with occasional sparks between high voltage electrodes. To extend the life time of the ion source and prepare for the CSNS phase-II, we are trying to develop a RF negative hydrogen ion source with external antenna. The configuration of the source is similar to the DESY external antenna ion source and SNS ion source. However several changes are made to improve the stability and the life time. Firstly, Si3N4 ceramic with high thermal shock resistance, and high thermal conductivity is used for plasma chamber, which can endure an average power of 2000W. Secondly, the water-cooled antenna is brazed on the chamber to improve the energy efficiency. Thirdly, cesium is injected directly to the plasma chamber if necessary, to simplify the design of the converter and the extraction. Area of stainless steel exposed to plasma is minimized to reduce the sputtering and degassing. Instead Mo, Ta, and Pt coated materials are used to face the plasma, which makes the self-cleaning of the source possible.

  12. Some developments in polarized ion sources

    International Nuclear Information System (INIS)

    Witteveen, G.J.

    1979-01-01

    Investigations concerning an atomic beam source are presented and a new polarized ion source of a more universal type is introduced. Polarized and unpolarized beams of positively or negatively charged ions can be produced with this new version and the theoretical limits are a polarized negative hydrogen ion beam with an intensity of about 1 mH and a polarized proton beam with an intensity of 10 mH. (C.F.)

  13. Production of negative hydrogen ions from accelerated cluster ions

    International Nuclear Information System (INIS)

    Becker, E.W.; Falter, H.D.; Hagena, O.F.; Henkes, W.; Klingelhoefer, R.; Moser, H.O.; Obert, W.; Poth, I.

    1976-11-01

    Cluster ion acceleration is a method particularly well suited to produce neutral beams of high particle current density at energies of the order of 1 keV/atom. Since this is the energy required for converting hydrogen atoms or molecules into negative ions in a cesium vapour cell, it is proposed to use cluster ions for the production of negative ion beams of high current density. The system is envisaged as a tandem accelerator with a terminal voltage of 1 MV. (orig.) [de

  14. Production of ultra cold protons and negative hydrogen ions

    International Nuclear Information System (INIS)

    Kenefick, R.A.

    1992-01-01

    Resistive cooling of He + ions has been studied in a 4 K Penning trap optimized for ω + cooling. A Nb/Ti superconducting inductor gives a Q of 1800 resulting in energy cooling time constants as low as 1.8 seconds and the cooling has been followed from 60,000 K to 300 K. In a separate study in a room-temperature trap, the possible conversion of H + to H - at a cesiated trap electrode and subsequent capture of the H - by fast reversal of the trap electrode polarity was not yet proved to be a workable mechanism. Features of the apparatus and technique are briefly described and the details are continued in three publications attached as appendices

  15. The development of the radio frequency driven negative ion source for neutral beam injectors (invited).

    Science.gov (United States)

    Kraus, W; Fantz, U; Franzen, P; Fröschle, M; Heinemann, B; Riedl, R; Wünderlich, D

    2012-02-01

    Large and powerful negative hydrogen ion sources are required for the neutral beam injection (NBI) systems of future fusion devices. Simplicity and maintenance-free operation favors RF sources, which are developed intensively at the Max-Planck-Institut für Plasmaphysik (IPP) since many years. The negative hydrogen ions are generated by caesium-enhanced surface conversion of atoms and positive ions on the plasma grid surface. With a small scale prototype the required high ion current density and the low fraction of co-extracted electrons at low pressure as well as stable pulses up to 1 h could be demonstrated. The modular design allows extension to large source dimensions. This has led to the decision to choose RF sources for the NBI of the international fusion reactor, ITER. As an intermediate step towards the full size ITER source at IPP, the development will be continued with a half-size source on the new ELISE testbed. This will enable to gain experience for the first time with negative hydrogen ion beams from RF sources of these dimensions.

  16. The development of the radio frequency driven negative ion source for neutral beam injectors (invited)a)

    Science.gov (United States)

    Kraus, W.; Fantz, U.; Franzen, P.; Fröschle, M.; Heinemann, B.; Riedl, R.; Wünderlich, D.

    2012-02-01

    Large and powerful negative hydrogen ion sources are required for the neutral beam injection (NBI) systems of future fusion devices. Simplicity and maintenance-free operation favors RF sources, which are developed intensively at the Max-Planck-Institut für Plasmaphysik (IPP) since many years. The negative hydrogen ions are generated by caesium-enhanced surface conversion of atoms and positive ions on the plasma grid surface. With a small scale prototype the required high ion current density and the low fraction of co-extracted electrons at low pressure as well as stable pulses up to 1 h could be demonstrated. The modular design allows extension to large source dimensions. This has led to the decision to choose RF sources for the NBI of the international fusion reactor, ITER. As an intermediate step towards the full size ITER source at IPP, the development will be continued with a half-size source on the new ELISE testbed. This will enable to gain experience for the first time with negative hydrogen ion beams from RF sources of these dimensions.

  17. Volume production of negative ions in the reflex-type ion source

    Energy Technology Data Exchange (ETDEWEB)

    Jimbo, K.

    1982-06-01

    The production of negative hydrogen ions is investigated in the reflex-type negative ion source. The extracted negative hydrogen currents of 9.7 mA (100 mA/cm/sup 2/) for H/sup -/ and of 4.1 mA(42 mA/cm/sup 2/) for D/sup -/ are obtained continuously. The impurity is less than 1%. An isotope effect of negative ion production is observed.

  18. Proton and Ion Sources for High Intensity Accelerators

    CERN Multimedia

    Scrivens, R

    2004-01-01

    Future high intensity ion accelerators, including the Spallation Neutron Source (SNS), the European Spallation Source (ESS), the Superconducting Proton Linac (SPL) etc, will require high current and high duty factor sources for protons and negative hydrogen ions. In order to achieve these goals, a comparison of the Electron Cyclotron Resonance, radio-frequency and Penning ion sources, among others, will be made. For each of these source types, the present operational sources will be compared to the state-of-the-art research devices with special attention given to reliability and availability. Finally, the future research and development aims will be discussed.

  19. Development of a compact powdery sample negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Motoi [Doshisha Univ., Tanabe, Kyoto (Japan). Faculty of Engineering; Sasao, Mamiko; Kawano, Hiroyuki

    1997-02-01

    A gas-feed-free compact negative ion source can be realized by utilizing the process of electron stimulated desorption from powdery sample. A negative ion source of this type is designed to be attached to a standard 1.33 inch copper-gasket-flange. The ion source is operated stable with LiH powder for more than 10 hours with the mass-separated negative hydrogen ion current of 1 nA. The source causes minute gas emission, and particularly suitable for ion beam applications in which a good vacuum is required. The present status of the compact ion source development is briefly described. (author)

  20. Oxygen ion source and RFQ for Linac 1

    CERN Multimedia

    Photographic Service

    1986-01-01

    As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions. In 1984, its Cockcroft-Walton preinjector was replaced by an RFQ. In the foreground at the right is the oxygen ion source. A 90 deg bending magnet selects O6+ ions which are preaccelerated in an RFQ and enter Linac 1, at the far left. In the background is the proton and negative hydrogen ion source, followed by the 520 keV RFQ-1 and a bending magnet towards the entrance of Linac 1.

  1. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 61; Issue 3. Surface plasma waves over bismuth–vacuum interface. Ashim P Jain J Parashar. Brief Report Volume 61 Issue ... Author Affiliations. Ashim P Jain1 J Parashar1. Department of Applied Physics, Samrat Ashok Technological Institute, Vidisha 464 001, India ...

  2. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    electron laser, a fast emerging device of high power coherent radiation. In §2 we derive the dispersion relation for surface plasma waves using a fluid theory. In §3 we study the SPW excitation by an electron beam. A discussion of results is given in §4. 2. SPW propagation. Consider a bismuth (Bi)–free space interface (x = 0) ...

  3. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    Abstract. A microwave propagating along vacuum–dielectric–plasma interface excites surface plasma wave (SPW). A periodic slow-wave structure placed over dielectric slows down the SPW. The phase velocity of slow SPW is sensitive to height, periodicity, number of periods, thickness and the separation between ...

  4. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    A surface plasma wave (SPW) over bismuth–vacuum interface has a signature of mass anisotropy of free electrons. For SPW propagation along the trigonal axis there is no birefringence. The frequency cutoff of SPW cutoff= p / 2 ( L + ) lies in the far infrared region and can be accessed using free electron laser.

  5. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    A surface plasma wave (SPW) over bismuth–vacuum interface has a signature of mass anisotropy of free electrons. For SPW propagation along the trigonal axis there is no birefringence. The frequency cutoff of SPW ωcutoff = ωp/. Ô. 2(εL +ε) lies in the far infrared region and can be accessed using free electron laser.

  6. Relativistic Electron Acceleration by Surface Plasma Waves in the High Intensity Regime

    Science.gov (United States)

    Zhu, Xiaoming; Cerchez, Mirela; Swantusch, Marco; Aurand, Bastian; Prasad, Rajendra; Andreev, Alexander; Willi, Oswald

    2017-10-01

    High field plasmonics is one of the new research fields which has synergetically benefited from the advances in laser technology. The availability of radiation fields of intensities exceeding 1018 W/cm2 brought plasmonics into a new regime where relativistic and nonlinear effects start to dominate the dynamics of the surface plasma waves (SPWs). Moreover, surface plasma waves are a very efficient route to transfer the laser energy to the secondary sources including laser driven particle and radiation beams and to control and optimize the physical properties of these sources. We present here experimental evidence of a novel regime of the SPWs excitation by ultra-high intensity laser field (I>1020 W/cm2) on grating targets and its effect on high energy surface electron acceleration. The peak of the electron emission was detected at a laser incidence angle of 45°. The results indicate new conditions for resonant excitation of SPWs since in the limit of the linear regime (moderate intensities of 1019 W/cm2 and step preplasma profile), the resonance angle is predicted at 30°. 2D PIC simulations and a novel analytical model confirm the experimental data and reveal that, at laser intensities above 1020W/cm2, nonlinearities induced by the preplasma condition and relativistic effects change the SPWs resonance.

  7. Development of H- sources at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Prelec, K.

    1977-01-01

    Negative hydrogen ion sources have been developed at Brookhaven National Laboratory for several years, with the initial goal to design a source for accelerator applications and later on to design a large unit for applications in neutral beam injectors of magnetic fusion devices. Three types of sources were investigated, a hollow discharge duoplasmatron yielding H - currents up to 60 mA, a Penning source yielding H - currents up to 440 mA, and a magnetron source yielding H - currents up to 1 A. All sources operate with a mixture of hydrogen gas and cesium vapors, and H - ions are most likely produced on cesium covered electrode surfaces. A larger model of a Penning/magnetron source was constructed and will be tested soon; it incorporates among other new features a system for the cooling of the cathode

  8. Transport of negative hydrogen and deuterium ions in RF-driven ion sources

    International Nuclear Information System (INIS)

    Gutser, R; Wuenderlich, D; Fantz, U

    2010-01-01

    Negative hydrogen ion sources are major components of neutral beam injection systems for plasma heating in future large-scale fusion experiments such as ITER. In order to fulfill the requirements of the ITER neutral beam injection, a high-performance, large-area RF-driven ion source for negative ions is being developed at the MPI fuer Plasmaphysik. Negative hydrogen ions are mainly generated on a converter surface by impinging neutral particles and positive ions under the influence of magnetic fields and the plasma sheath potential. The 3D transport code TrajAn has been applied in order to obtain the total and spatially resolved extraction probabilities for H - and D - ions under identical plasma parameters and the realistic magnetic field topology of the ion source. A comparison of the isotopes shows a lower total extraction probability in the case of deuterium ions, caused by a different transport effect. The transport calculation shows that distortions of the spatial distributions of ion birth and extraction by the magnetic electron suppression field are present for both negative hydrogen and deuterium ions.

  9. High intensity surface plasma waves, theory and PIC simulations

    Science.gov (United States)

    Raynaud, M.; Héron, A.; Adam, J.-C.

    2018-01-01

    With the development of intense (>1019 W cm‑2) short pulses (≤25 fs) laser with very high contrast, surface plasma wave (SPW) can be explored in the relativistic regime. As the SPW propagates with a phase velocity close to the speed of light it may results in a strong acceleration of electron bunches along the surface permitting them to reach relativistic energies. This may be important e.g. for applications in the field of plasma-based accelerators. We investigate in this work the excitation of SPWs on grating preformed over-dense plasmas for laser intensities ranging from 1019 up to 1021 W cm‑2. We discuss the nature of the interaction with respect to the solid case in which surface plasmon can be resonantly excited with weak laser intensity. In particular, we show the importance of the pulse duration and focalization of the laser beam on the amplitude of the SPW.

  10. Improved ion acceleration via laser surface plasma waves excitation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Héron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2013-05-15

    The possibility of enhancing the emission of the ions accelerated in the interaction of a high intensity ultra-short (<100 fs) laser pulse with a thin target (<10λ{sub 0}), via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed for laser intensities ranging from 10{sup 19} to 10{sup 20} Wcm{sup −2}μm{sup 2}. The surface wave is resonantly excited by the laser via the coupling with a modulation at the target surface. In the cases where the surface wave is excited, we find an enhancement of the maximum ion energy of a factor ∼2 compared to the cases where the target surface is flat.

  11. Physical principles of the surface plasma method for producing beams of negative ions

    International Nuclear Information System (INIS)

    Bel'chenko, Yu.I.; Dimov, G.I.; Dudnikov, V.G.

    1977-01-01

    The processes which are important for the production of intense beams of negative ions from surface plasma sources (SPS) are examined. The formation of negative ions when atomic particles interact with a surface is analyzed on the basis of both experimental results obtained when a surface was bombarded with beams and recently developed theoretical considerations of reflection, scattering, and electron exchange. The characteristic features of these processes in SPS, when a surface is bombarded with intense fluxes of plasma particles, are revealed in special experiments. The characteristics of generation and acceleration of the bombarding particles in a gas discharge SPS plasma, the characteristics of transportation of negative ions through the plasma toward the beam forming system, the role of cesium in SPS, and the characteristics of formation of the intense negative ion beams as well as the removal of parasite electrons from the beam

  12. Simple scalings for various regimes of electron acceleration in surface plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Riconda, C.; Vialis, T. [LULI, Sorbonne Université, Université Pierre et Marie Curie, Ecole Polytechnique, CNRS UMR 7605, CEA, Paris 75005 (France); Raynaud, M. [Laboratoire des Solides Irradiés, CNRS UMR 7642, CEA-DSM-IRAMIS, Ecole Polytechnique, Université Paris-Saclay, 91128 Palaiseau (France); Grech, M. [LULI, CNRS UMR 7605, Université Pierre et Marie Curie, Ecole Polytechnique, CEA, 91128 Palaiseau (France)

    2015-07-15

    Different electron acceleration regimes in the evanescent field of a surface plasma wave are studied by considering the interaction of a test electron with the high-frequency electromagnetic field of a surface wave. The non-relativistic and relativistic limits are investigated. Simple scalings are found demonstrating the possibility to achieve an efficient conversion of the surface wave field energy into electron kinetic energy. This mechanism of electron acceleration can provide a high-frequency pulsed source of relativistic electrons with a well defined energy. In the relativistic limit, the most energetic electrons are obtained in the so-called electromagnetic regime for surface waves. In this regime, the particles are accelerated to velocities larger than the wave phase velocity, mainly in the direction parallel to the plasma-vacuum interface.

  13. High-intensity ion sources for accelerators with emphasis on H- beam formation and transport (invited)

    International Nuclear Information System (INIS)

    Keller, R.

    2010-01-01

    This paper lays out the fundamental working principles of a variety of high-current ion sources for accelerators in a tutorial manner, and gives examples of specific source types such as dc discharge-driven and rf-driven multicusp sources, Penning-type, and electron cyclotron resonance-based sources while discussing those principles, pointing out general performance limits as well as the performance parameters of specific sources. Laser-based, two-chamber, and surface-ionization sources are briefly mentioned. Main aspects of this review are particle feed, ionization mechanism, beam formation, and beam transport. Issues seen with beam formation and low-energy transport of negative hydrogen-ion beams are treated in detail.

  14. Intense negative heavy ion sources

    Science.gov (United States)

    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.

  15. A magnetized Einzel lens electron dump for the Linac4 H− ion source

    CERN Document Server

    Midttun, O; Kronberger, M; Lettry, J; Pereira, H; Scrivens, R

    2013-01-01

    Linac4 is a 160 MeV linear accelerator which will inject negative hydrogen ions (H−) into CERN’s Proton Synchrotron Booster, a required upgrade to improve the beam brightness in the LHC injector chain. A volume production RF ion source, based on the design of the DESY RF source was implemented, but showed considerable electron dump ablation during operation at 45 keV beam energy. To reduce the electron beam power density in the dump, a magnetized Einzel lens is designed that reduces the beam energy to 10 keV before permanentmagnets dump the electrons on a tungsten surface. Presented in this paper are simulations of the design using IBSimu, the tunable range of parameters depending on the extracted H− and electron current, as well as details of the implementation, the choice of pulsed power converters and the electrode alignment system. In addition, simulations of proton extraction from this source will be shown.

  16. Dependence of the source performance on plasma parameters at the BATMAN test facility

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, C.; Fantz, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-04-08

    The investigation of the dependence of the source performance (high j{sub H{sup −}}, low j{sub e}) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H{sup −}, its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H{sup −} density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa)

  17. Dependence of the source performance on plasma parameters at the BATMAN test facility

    Science.gov (United States)

    Wimmer, C.; Fantz, U.

    2015-04-01

    The investigation of the dependence of the source performance (high jH-, low je) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H-, its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H- density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa).

  18. Laser diagnostics of H- formation in a magnetic multicusp ion source

    International Nuclear Information System (INIS)

    Young, A.T.; Chen, P.; Kunkel, W.B.; Leung, K.N.; Li, C.Y.; Stutzin, G.C.

    1991-05-01

    The populations of ground electronic state atomic hydrogen and ground electronic state, vibrationally-rotationally excited hydrogen molecules in a negative hydrogen ion source discharge have been measured using vacuum ultraviolet (VUV) laser absorption spectroscopy. Vibrational states up to v=8 and rotational levels as high as J=15 have been measured. The measurements have been made under a range of discharge conditions. The complete vibrational population distribution for v=1-8, J=1 has been obtained. The vibrational distribution appears to be thermalized and does not exhibit a ''plateau'' at the higher vibrational levels, in contrast to most models of this system. In contrast, the high rotational states are populated suprathermally. These determinations indicate that rotationally excited molecules may play an important role in the production of H minus in these sources. 5 refs., 5 figs

  19. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    elements in metal waveguides increase the number of their natural modes and give rise to new effects accompanying wave propagation, e.g. excitation of SPW in these waveguides. Such large area surface wave plasma sources have been reported using a microwave launcher of large aperture formed on a waveguide, ...

  20. Surface plasma wave assisted second harmonic generation of laser over a metal film

    International Nuclear Information System (INIS)

    Chauhan, Santosh; Parashar, J.

    2015-01-01

    Second harmonic generation of laser mode converted surface plasma wave (SPW) over a corrugated metal film is studied. The laser, impinged on the metal film, under attenuated total reflection configuration, excites SPW over the metal–vacuum interface. The excited SPW extends over a much wider surface area than the laser spot cross-section. It exerts a second harmonic ponderomotive force on metal electrons, imparting them velocity that beats with the surface ripple to produce a nonlinear current, driving resonant second harmonic surface plasma wave

  1. Surface Plasma Arc by Radio-Frequency Control Study (SPARCS)

    International Nuclear Information System (INIS)

    Ruzic, David N.

    2013-01-01

    This paper is to summarize the work carried out between April 2012 and April 2013 for development of an experimental device to simulate interactions of o-normal detrimental events in a tokamak and ICRF antenna. The work was mainly focused on development of a pulsed plasma source using theta pinch and coaxial plasma gun. This device, once completed, will have a possible application as a test stand for high voltage breakdown of an ICRF antenna in extreme events in a tokamak such as edge-localized modes or disruption. Currently, DEVeX does not produce plasma with high temperature enough to requirement for an ELM simulator. However, theta pinch is a good way to produce high temperature ions. The unique characteristic of plasma heating by a theta pinch is advantageous for an ELM simulator due to its effective ion heating. The objective of the proposed work, therefore, is to build a test facility using the existing theta pinch facility in addition to a coaxial plasma gun. It is expected to produce a similar pulsed-plasma heat load to the extreme events in tokamaks and to be applied for studying interactions of hot plasma and ICRF antennas

  2. Performance evaluation of a permanent ring magnet based helicon plasma source for negative ion source research

    Science.gov (United States)

    Pandey, Arun; Bandyopadhyay, M.; Sudhir, Dass; Chakraborty, A.

    2017-10-01

    Helicon wave heated plasmas are much more efficient in terms of ionization per unit power consumed. A permanent magnet based compact helicon wave heated plasma source is developed in the Institute for Plasma Research, after carefully optimizing the geometry, the frequency of the RF power, and the magnetic field conditions. The HELicon Experiment for Negative ion-I source is the single driver helicon plasma source that is being studied for the development of a large sized, multi-driver negative hydrogen ion source. In this paper, the details about the single driver machine and the results from the characterization of the device are presented. A parametric study at different pressures and magnetic field values using a 13.56 MHz RF source has been carried out in argon plasma, as an initial step towards source characterization. A theoretical model is also presented for the particle and power balance in the plasma. The ambipolar diffusion process taking place in a magnetized helicon plasma is also discussed.

  3. Operation Status of the J-PARC Ion Source

    Science.gov (United States)

    Oguri, Hidetomo; Ohkoshi, Kiyonori; Ikegami, Kiyoshi; Yamazaki, Saishun; Takagi, Akira; Koizumi, Isao; Ueno, Akira

    A cesium-free negative hydrogen ion source driven with a LaB6 filament is being operated for J-PARC. The ion source has been providing a beam for approximately eight years without any serious troubles. The ion source consists of a cylindrical plasma chamber, a beam extractor and a large vacuum chamber with 2 turbo molecular pumps of 1500 l/s for differential pumping. The source plasma is produced by an arc discharge and confined by a multi-cusp magnetic field produced by permanent magnets surrounding the chamber wall. The 50 keV negative hydrogen beam is extracted by applying about -50 kV to the beam extractor. The basic structure of the ion source has not been changed since the operation was started. The ion source has been operated in two different modes such as low current mode of 20 mA and high current mode of 32 mA. Continuous operation for about 1,000 h and about 500 h was achieved in low and high current mode, respectively. After the operation, we replace the filament by a brand-new one to prevent the filament from failing during the operation. The required time for the replacement including the filament degassing process, the vacuuming and the conditioning operation is about 15 h.

  4. Operation status of the J-PARC ion source

    International Nuclear Information System (INIS)

    Oguri, Hidetomo; Ohkoshi, Kiyonori; Yamazaki, Saishun; Koizumi, Isao; Ueno, Akira; Ikegami, Kiyoshi; Takagi, Akira

    2015-01-01

    A cesium-free negative hydrogen ion source driven with a LaB 6 filament is being operated for J-PARC. The ion source has been providing a beam for approximately eight years without any serious troubles. The ion source consists of a cylindrical plasma chamber, a beam extractor and a large vacuum chamber with 2 turbo molecular pumps of 1500 l/s for differential pumping. The source plasma is produced by an arc discharge and confined by a multi-cusp magnetic field produced by permanent magnets surrounding the chamber wall. The 50 keV negative hydrogen beam is extracted by applying about -50 kV to the beam extractor. The basic structure of the ion source has not been changed since the operation was started. The ion source has been operated in two different modes such as low current mode of 20 mA and high current mode of 32 mA. Continuous operation for about 1,000 h and about 500 h was achieved in low and high current mode, respectively. After the operation, we replace the filament by a brand-new one to prevent the filament from failing during the operation. The required time for the replacement including the filament degassing process, the vacuuming and the conditioning operation is about 15 h. (author)

  5. Comparative study of NO removal in surface-plasma and volume-plasma reactors based on pulsed corona discharges.

    Science.gov (United States)

    Malik, Muhammad Arif; Kolb, Juergen F; Sun, Yaohong; Schoenbach, Karl H

    2011-12-15

    Nitric oxide (NO) conversion has been studied for two different types of atmospheric-pressure pulsed-corona discharges, one generates a surface-plasma and the other provides a volume-plasma. For both types of discharges the energy cost for NO removal increases with decreasing oxygen concentration and initial concentration of NO. However, the energy cost for volume plasmas for 50% NO removal, EC(50), from air was found to be 120 eV/molecule, whereas for the surface plasma, it was only 70 eV/molecule. A smaller difference in energy cost, but a higher efficiency for removal of NO was obtained in a pure nitrogen atmosphere, where NO formation is restricted due to the lack of oxygen. For the volume plasma, EC(50) in this case was measured at 50 eV/molecule, and for the surface plasma it was 40 eV/molecule. Besides the higher NO removal efficiency of surface plasmas compared to volume plasmas, the energy efficiency of surface-plasmas was found to be almost independent of the amount of electrical energy deposited in the discharge, whereas the efficiency for volume plasmas decreases considerably with increasing energy. This indicates the possibility of operating surface plasma discharges at high energy densities and in more compact reactors than conventional volume discharges. Published by Elsevier B.V.

  6. High brilliance multicusp ion source for hydrogen microscopy at SNAKE

    Energy Technology Data Exchange (ETDEWEB)

    Moser, M., E-mail: marcus.moser@unibw.de [Universitaet der Bundeswehr Muenchen, Institut fuer Angewandte Physik und Messtechnik, LRT2, Department fuer Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Reichart, P. [Universitaet der Bundeswehr Muenchen, Institut fuer Angewandte Physik und Messtechnik, LRT2, Department fuer Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Carli, W. [Maier-Leibniz-Laboraturium der LMU und TU Muenchen, 85478 Garching (Germany); Greubel, C.; Peeper, K. [Universitaet der Bundeswehr Muenchen, Institut fuer Angewandte Physik und Messtechnik, LRT2, Department fuer Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany); Hartung, P. [Maier-Leibniz-Laboraturium der LMU und TU Muenchen, 85478 Garching (Germany); Dollinger, G. [Universitaet der Bundeswehr Muenchen, Institut fuer Angewandte Physik und Messtechnik, LRT2, Department fuer Luft- und Raumfahrttechnik, 85577 Neubiberg (Germany)

    2012-02-15

    In order to improve the lateral resolution of the 3D hydrogen microscopy by proton-proton scattering at the Munich microprobe SNAKE, we have installed a new multicusp ion source for negative hydrogen ions manufactured by HVEE at the Munich 14 MV tandem accelerator that boosts the proton beam brilliance with the potential to reduce the beam diameter at the focal plane of SNAKE. We measured a beam brilliance B = 27 A m{sup -2} rad{sup -2} eV{sup -1} directly behind the ion source that is at the space charge limit for conventional ion sources. After preacceleration to in total 180 keV beam energy we measure a slightly reduced beam brilliance of B = 10 {mu}A mm{sup -2} mrad{sup -2} MeV{sup -1}. For injection into the tandem accelerator, the extracted H{sup -}-current of the multicusp source of 1 mA is reduced to about 10 {mu}A because of radiation safety regulations and heating problems at the object slits of SNAKE. Due to beam oscillations and influences of the terminal stripper of the tandem we measured a reduced beam brilliance of 0.8 {mu}A mm{sup -2} mrad{sup -2} MeV{sup -1} in front of SNAKE at 25 MeV but still being nearly 10 times larger than measured with any other ion source.

  7. Orienting Block Copolymer Thin Films via Entropy and Surface Plasma Treatment

    Science.gov (United States)

    Ho, Rong-Ming; Lu, Kai-Yuan; Lo, Ting-Ya; Dehghan, Ashkan; Shi, An-Chang; Prokopios, Georgopanos; Avgeropoulos, Apostolos

    Controlling the orientation of nanostructured thin films of block copolymers (BCPs) is essential for next generation lithography. In the thin-film state, how to achieve the perpendicular orientation of the nanostructured microdomains remains challenging due to the interfacial effects from the air and also the substrate, especially for the blocks with silicon containing segments which usually have different surface energies, favoring parallel microdomain orientation. Here, we show that entropic effect can be used to control the orientation of BCP thin films. Specifically, we used the architecture of star-block copolymers consisting of polystyrene (PS) and poly(dimethylsiloxane) (PDMS) blocks to regulate the entropic contribution to the self-assembled nanostructures. Moreover, we aim to achieve the formation of perpendicular orientation from the air surface via surface plasma treatment to neutralize the interfacial energy difference. By combining the architecture effect (entropy effect) on BCP self-assembly and the surface plasma treatment (enthalpy effect), well-defined perpendicular PDMS microdomains in the PS-b-PDMS thin film can be formed from the bottom of non-neutral substrate and the top of the thin film surface, giving great potential for lithographic applications.

  8. Efficient laser-overdense plasma coupling via surface plasma waves and steady magnetic field generation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Heron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Macchi, A. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (CNR/INO), Dipartimento di Fisica ' ' E. Fermi' ' , Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2011-10-15

    The efficiency of laser overdense plasma coupling via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed over a wide range of laser pulse intensity from 10{sup 15} to 10{sup 20} W cm{sup -2}{mu}m{sup 2} with electron density ranging from 25 to 100n{sub c} to describe the laser interaction with a grating target where a surface plasma wave excitation condition is fulfilled. The numerical studies confirm an efficient coupling with an enhancement of the laser absorption up to 75%. The simulations also show the presence of a localized, quasi-static magnetic field at the plasma surface. Two interaction regimes are identified for low (I{lambda}{sup 2} < 10{sup 17} W cm{sup -2}{mu}m{sup 2}) and high (I{lambda}{sup 2} > 10{sup 17} W cm{sup -2}{mu}m{sup 2}) laser pulse intensities. At ''relativistic'' laser intensity, steady magnetic fields as high as {approx}580 MG {mu}m/{lambda}{sub 0} at 7 x 10{sup 19} W cm{sup -2}{mu}m{sup 2} are obtained in the simulations.

  9. H- source developments

    International Nuclear Information System (INIS)

    Allison, P.W.

    1978-01-01

    The design and operation of a Penning discharge, cold cathode, surface plasma H - ion source are described. A high current density, about 2 A/cm 2 , is extracted from the source by putting about 20 keV across the 2 to 2 1 / 2 mm gap

  10. Pulsed negative hydrogen source for currents up to one ampere

    International Nuclear Information System (INIS)

    Prelec, K.; Sluyters, T.

    1975-01-01

    During the 2nd Symposium on Ion Sources and Formation of Ion Beams, the development of a Mk II pulsed double slit magnetron source for the production of negative hydrogen ions was discussed. The source was capable of yielding beam currents up to 125 milliamperes, corresponding to current densities of 1.25 A/cm 2 . In order to increase negative hydrogen beam intensities by an order of magnitude (this would be quite useful for initial high energy neutral injector systems on Tokamaks), a larger, Mk III magnetron has been constructed, with the number of slits increased up to six. The idea was to utilize in a more efficient way the plasma width. In addition, such a source geometry will be more adaptable for beam formation and acceleration than single slit structures. With three extraction slits, a negative hydrogen yield of 300 mA was obtained with current densities of 1.2 A/cm 2 ; preliminary results with six extraction slits showed beam currents in excess of half an ampere with averaged current densities in excess of 0.75 A/cm 2 . (U.S.)

  11. Overview of ion source characterization diagnostics in INTF

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, M., E-mail: mainak@iter-india.org; Sudhir, Dass; Bhuyan, M.; Tyagi, H.; Joshi, J.; Yadav, A.; Rotti, C.; Parmar, Deepak; Patel, H.; Pillai, S.; Chakraborty, A. [ITER-India, Institute for Plasma Research, A-29 GIDC, Sector-25, Gandhinagar, Gujarat 382016 (India); Soni, J. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382 428 (India)

    2016-02-15

    INdian Test Facility (INTF) is envisaged to characterize ITER diagnostic neutral beam system and to establish the functionality of its eight inductively coupled RF plasma driver based negative hydrogen ion source and its beamline components. The beam quality mainly depends on the ion source performance and therefore, its diagnostics plays an important role for its safe and optimized operation. A number of diagnostics are planned in INTF to characterize the ion source performance. Negative ions and its cesium contents in the source will be monitored by optical emission spectroscopy (OES) and cavity ring down spectroscopy. Plasma near the extraction region will be studied using standard electrostatic probes. The beam divergence and negative ion stripping losses are planned to be measured using Doppler shift spectroscopy. During initial phase of ion beam characterization, carbon fiber composite based infrared imaging diagnostics will be used. Safe operation of the beam will be ensured by using standard thermocouples and electrical voltage-current measurement sensors. A novel concept, based on plasma density dependent plasma impedance measurement using RF electrical impedance matching parameters to characterize the RF driver plasma, will be tested in INTF and will be validated with OES data. The paper will discuss about the overview of the complete INTF diagnostics including its present status of procurement, experimentation, interface with mechanical systems in INTF, and integration with INTF data acquisition and control systems.

  12. Two approaches for $H^{-}$ ion production with 245 GHz ion sources

    CERN Document Server

    Gobin, R; Bacal, M; Breton, J; Delferrière, O; Harrault, F; Ivanov, A A; Svarnas, P; Tuske, O

    2006-01-01

    Over the last few years, the accelerator community requested the development of improved negative hydrogen ion sources. For spallation sources, like SNS or ESS, pulsed high intensity H/sup negative ion beams of a few tens of milliamperes, with a duty cycle close to 10%, are required. New facilities like CERN also ask for high performance negative ion beams. Since CEA undertook an electron cyclotron resonance (ECR)-based ion source programme, a European network devoted to high performance negative ion source development has been created. In this group, several laboratories developing 2.45 GHz ECR sources follow different approaches to increase the extracted ion current. At Saclay, with a solenoidal magnetic structure based on coils, close to 3 mA H/sup negative ion beam is now extracted in pulsed mode (2 ms/100 ms). A metallic biased grid separates the plasma bulk from the H/sup negative ion production zone and significantly improves the H/sup negative extracted current. At Ecole Polytechnique, the source Came...

  13. A Langmuir probe system for high power RF-driven negative ion sources on high potential

    International Nuclear Information System (INIS)

    McNeely, P; Christ-Koch, S; Fantz, U; Dudin, S V

    2009-01-01

    A fully automated Langmuir probe system capable of operating simultaneously with beam extraction has been developed and commissioned for the negative hydrogen ion source testbeds at IPP Garching. It allows the measurement of temporal and spatial distributions of the plasma parameters within a single plasma pulse ( 10 18 m -3 ) and hot (T e > 10 eV) plasma with bi-Maxwellian electron energy distribution at low pressures. The plasma found near the plasma grid is very different being of low density (≤10 17 m -3 ) and very cold (T e < 2 eV). This plasma is also strongly influenced by the presence of caesium, the potential of the plasma grid, and if an ion beam is extracted from the source. Caesium strongly reduces the plasma potential of the source and enhances the negative ion density near the plasma grid. Extracting an ion beam is observed to reduce the electron density and increase the potential near the plasma grid. Applying a potential greater than the plasma potential to the plasma grid is found to significantly decrease the electron density near the plasma grid.

  14. Upgrade of the BATMAN test facility for H- source development

    Science.gov (United States)

    Heinemann, B.; Fröschle, M.; Falter, H.-D.; Fantz, U.; Franzen, P.; Kraus, W.; Nocentini, R.; Riedl, R.; Ruf, B.

    2015-04-01

    The development of a radio frequency (RF) driven source for negative hydrogen ions for the neutral beam heating devices of fusion experiments has been successfully carried out at IPP since 1996 on the test facility BATMAN. The required ITER parameters have been achieved with the prototype source consisting of a cylindrical driver on the back side of a racetrack like expansion chamber. The extraction system, called "Large Area Grid" (LAG) was derived from a positive ion accelerator from ASDEX Upgrade (AUG) using its aperture size (ø 8 mm) and pattern but replacing the first two electrodes and masking down the extraction area to 70 cm2. BATMAN is a well diagnosed and highly flexible test facility which will be kept operational in parallel to the half size ITER source test facility ELISE for further developments to improve the RF efficiency and the beam properties. It is therefore planned to upgrade BATMAN with a new ITER-like grid system (ILG) representing almost one ITER beamlet group, namely 5 × 14 apertures (ø 14 mm). Additionally to the standard three grid extraction system a repeller electrode upstream of the grounded grid can optionally be installed which is positively charged against it by 2 kV. This is designated to affect the onset of the space charge compensation downstream of the grounded grid and to reduce the backstreaming of positive ions from the drift space backwards into the ion source. For magnetic filter field studies a plasma grid current up to 3 kA will be available as well as permanent magnets embedded into a diagnostic flange or in an external magnet frame. Furthermore different source vessels and source configurations are under discussion for BATMAN, e.g. using the AUG type racetrack RF source as driver instead of the circular one or modifying the expansion chamber for a more flexible position of the external magnet frame.

  15. Surface plasma preionization produced on a specially patterned PCB and its application in a pulsed CO2 laser

    Science.gov (United States)

    Ghorbanzadeh, Atamalek; Pakmanesh, Nahid; Rastegari, Ali; Abdolghader, Pedram; Feizollah, Peyman; Siadati, Neda

    2016-04-01

    The performance of an atmospheric pressure pulsed carbon dioxide laser employing surface plasma preionization, produced on a specially patterned printed circuit board (PCB), is reported. The surface plasma is formed due to many tiny plasma channels produced in millimeter sized open circular gaps, made by lithography on one side of PCB. The preionizing plasma is mostly consisted of corona or glow stage and transition to spark one hardly occurs. This type of preionization allows a maximum of 220 J/l energy deposition into the main plasma, while up scaling is yet possible by more optimization of PCB and the pattern. The laser output energy of 1.2 J per pulse with overall efficiency of 7% has been obtained with gas mixture of He:CO2:N2=3:1:1. This type of surface plasma preionization is specifically appropriate for very large volumes and high pressures, where the conventional UV emitting preionizations like spark arrays or corona are not effective.

  16. Generation of H-, D- ions on composite surfaces with application to surface/plasma ion source systems

    International Nuclear Information System (INIS)

    Hiskes, J.R.; Karo, A.M.; Wimmer, E.; Freeman, A.J.; Chubb, S.R.

    1983-01-01

    We review some salient features of the experimental and theoretical data pertaining to hydrogen negative ion generation on minimum-work-function composite surfaces consisting of Cs/transition metal substrates. Cesium or hydrogen ion bombardment of a cesium-activated negatively-biased electrode exposed to a cesium-hydrogen discharge results in the release of hydrogen negative ions. These ions originate through desorbtion of hydrogen particles by incident cesium ions, desorbtion by incident hydrogen ions, and by backscattering of incident hydrogen. Each process is characterized by a specific energy and angular distribution. The calculation of ion formation in the crystal selvage region is discussed for different approximations to the surface potential. An ab initio, all-electron, local density functional model for the composite surface electronics is discussed

  17. Correlation of H- production and the work function of a surface in a hydrogen plasma

    International Nuclear Information System (INIS)

    Wada, M.

    1983-01-01

    Surface-plasma negative hydrogen ion sources are being developed as possible parts for future netural beam systems. In these ion sources, negative hydrogen ions (H - ) are produced at low work function metal surfaces immersed in hydrogen plasmas. To investigate the correlation between the work function and the H-production at the surface with a condition similar to the one in the actual plasma ion source, these two parameters were simultaneously measured in the hydrogen plasma environment. The photoelectron emission currents from Mo and Cu surfaces in a cesiated hydrogen discharge were measured in the photon energy range from 1.45 to 4.14 eV, to determine the work function based on Fowler's theory. A small magnetic line cusp plasma container was specially designed to minimize the plasma noise and to realize the efficient collection of incident light onto the target. The photelectron current was detected phase sensitively and could be measured with reasonable accuracy up to about 5 x 10 11 cm -3 of the plasma electron density. As Cs density was increased in the hydrogen discharge, the work function decreased until it reached a minimum value. This value of the lowest work function was approximately 1.4 eV for both Mo and Cu surfaces, and the detected total H - current was a maximum at this condition

  18. Studies on the nondestructive emittance measurement at a negative-hydrogen-ion beam; Untersuchungen zur zerstoerungsfreien Emittanzmessung an einem negativen Wasserstoffionenstrahl

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, C.

    2007-07-01

    In the present thesis the already known idea to apply photodetechment for the diagnosis at a H{sup -} beam has be newly interpretated and improved. Thereby a nondestructive emittance measurement method was developed, which is especially suited for future high-current accelerator projects. For emittance measurements thereby mechanical components can be totally abandoned, if at a small part of the H{sup -} ions the additional with only 0.754 eV weak bound electron is separated by photodetachment {Dirac_h}{omega}+H{sup -}{yields}H{sup 0}+e{sup -}. The neutralized H{sup -} ions can be magnetically or electrostatically separated from the electrons and the remaining H{sup -} ions. Especially the neutral particles are offered by their insensitivity against external electromagnetic fields for the determination of the phase-space distribution of the ion beam. Also the momentum transfer by photodetechment can be neglected at the neutralized ions. The detection of the divergence angle has been pursued by a scintillator with a CCD camera. For the calculation of the number of neutralized particles a simplified model under assumption of homogeneous density distributions was developed. The aim of the approximation was to make statements about the requirement on the laser system and the detector. Thereby especially the suitability of the measurement for high beam currents and beam parameters, as they are typically present behind a RFQ. Further aspects like the influence of the angle between laser and ion beams, relativistic ion beam, as well as the position and angular resolution have been also object of the discussion.

  19. Work function dependence and isotope effect in the production of negative hydrogen ions during sputtering of adsorbed hydrogen on Cs covered Mo(100) surfaces

    International Nuclear Information System (INIS)

    Yu, M.L.

    1977-01-01

    The enhancement of the H - yield, during sputtering of adsorbed hydrogen on a Mo(100) surface, by a Cs overlayer was investigated. An exponential dependence of the H - yield on the work function was observed for a wide range of Cs coverages. A simple electron tunneling model was proposed. A large reduction in the ion yield was also observed when D 2 replaced H 2 as the adsorbate

  20. Detection of swine-origin influenza A (H1N1) viruses using a paired surface plasma waves biosensor

    Science.gov (United States)

    Su, Li-Chen; Chang, Ying-Feng; Li, Ying-Chang; Hsieh, Jo-Ping; Lee, Cheng-Chung; Chou, Chien

    2010-08-01

    In order to enhance the sensitivity of conventional rapid test technique for the detection of swine-origin influenza A (H1N1) viruses (S-OIVs), we used a paired surface plasma waves biosensor (PSPWB) based on SPR in conjunction with an optical heterodyne technique. Experimentally, PSPWB showed a 125-fold improvement at least in the S-OIV detection as compared to conventional enzyme linked immunosorbent assay. Moreover, the detection limit of the PSPWB for the S-OIV detection was enhanced 250-fold in buffer at least in comparison with that of conventional rapid influenza diagnostic test.

  1. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  2. H$^{-}$ ion source for CERN's Linac4 accelerator: simulation, experimental validation and optimization of the hydrogen plasma

    CERN Document Server

    Mattei, Stefano; Lettry, Jacques

    2017-07-25

    Linac4 is the new negative hydrogen ion (H$^-$) linear accelerator of the European Organization for Nuclear Research (CERN). Its ion source operates on the principle of Radio-Frequency Inductively Coupled Plasma (RF-ICP) and it is required to provide 50~mA of H$^-$ beam in pulses of 600~$\\mu$s with a repetition rate up to 2 Hz and within an RMS emittance of 0.25~$\\pi$~mm~mrad in order to fullfil the requirements of the accelerator. This thesis is dedicated to the characterization of the hydrogen plasma in the Linac4 H$^-$ ion source. We have developed a Particle-In-Cell Monte Carlo Collision (PIC-MCC) code to simulate the RF-ICP heating mechanism and performed measurements to benchmark the fraction of the simulation outputs that can be experimentally accessed. The code solves self-consistently the interaction between the electromagnetic field generated by the RF coil and the resulting plasma response, including a kinetic description of charged and neutral species. A fully-implicit implementation allowed to si...

  3. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  4. Design of the 'half-size' ITER neutral beam source for the test facility ELISE

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, B. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany)], E-mail: bernd.heinemann@ipp.mpg.de; Falter, H.; Fantz, U.; Franzen, P.; Froeschle, M.; Gutser, R.; Kraus, W.; Nocentini, R.; Riedl, R.; Speth, E.; Staebler, A.; Wuenderlich, D. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany); Agostinetti, P. [Consorzio RFX, EURATOM Association, Corso Stati Uniti 4, I-35127 Padova (Italy); Jiang, T. [Southwestern Institute of Physics, ChengDu (China)

    2009-06-15

    In 2007 the radio frequency driven negative hydrogen ion source developed at IPP in Garching was chosen by the ITER board as the new reference source for the ITER neutral beam system. In order to support the design and the commissioning and operating phases of the ITER test facilities ISTF and NBTF in Padua, IPP is presently constructing a new test facility ELISE (Extraction from a Large Ion Source Experiment). ELISE will be operated with the so-called 'half-size ITER source' which is an intermediate step between the present small IPP RF sources (1/8 ITER size) and the full size ITER source. The source will have approximately the width but only half the height of the ITER source. The modular concept with 4 drivers will allow an easy extrapolation to the full ITER size with 8 drivers. Pulsed beam extraction and acceleration up to 60 kV (corresponding to pre-acceleration voltage of SINGAP) is foreseen. The aim of the design of the ELISE source and extraction system was to be as close as possible to the ITER design; it has however some modifications allowing a better diagnostic access as well as more flexibility for exploring open questions. Therefore one major difference compared to the source of ITER, NBTF or ISTF is the possible operation in air. Specific requirements for RF sources as found on IPP test facilities BATMAN and MANITU are implemented [A. Staebler, et al., Development of a RF-driven ion source for the ITER NBI system, SOFT Conference 2008, Fusion Engineering and Design, 84 (2009) 265-268].

  5. Upgrade of the BATMAN test facility for H{sup −} source development

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, B., E-mail: bernd.heinemann@ipp.mpg.de; Fröschle, M.; Falter, H.-D.; Fantz, U.; Franzen, P.; Kraus, W.; Nocentini, R.; Riedl, R.; Ruf, B. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-04-08

    The development of a radio frequency (RF) driven source for negative hydrogen ions for the neutral beam heating devices of fusion experiments has been successfully carried out at IPP since 1996 on the test facility BATMAN. The required ITER parameters have been achieved with the prototype source consisting of a cylindrical driver on the back side of a racetrack like expansion chamber. The extraction system, called “Large Area Grid” (LAG) was derived from a positive ion accelerator from ASDEX Upgrade (AUG) using its aperture size (ø 8 mm) and pattern but replacing the first two electrodes and masking down the extraction area to 70 cm2. BATMAN is a well diagnosed and highly flexible test facility which will be kept operational in parallel to the half size ITER source test facility ELISE for further developments to improve the RF efficiency and the beam properties. It is therefore planned to upgrade BATMAN with a new ITER-like grid system (ILG) representing almost one ITER beamlet group, namely 5 × 14 apertures (ø 14 mm). Additionally to the standard three grid extraction system a repeller electrode upstream of the grounded grid can optionally be installed which is positively charged against it by 2 kV. This is designated to affect the onset of the space charge compensation downstream of the grounded grid and to reduce the backstreaming of positive ions from the drift space backwards into the ion source. For magnetic filter field studies a plasma grid current up to 3 kA will be available as well as permanent magnets embedded into a diagnostic flange or in an external magnet frame. Furthermore different source vessels and source configurations are under discussion for BATMAN, e.g. using the AUG type racetrack RF source as driver instead of the circular one or modifying the expansion chamber for a more flexible position of the external magnet frame.

  6. Modelling of caesium dynamics in the negative ion sources at BATMAN and ELISE

    Science.gov (United States)

    Mimo, A.; Wimmer, C.; Wünderlich, D.; Fantz, U.

    2017-08-01

    The knowledge of Cs dynamics in negative hydrogen ion sources is a primary issue to achieve the ITER requirements for the Neutral Beam Injection (NBI) systems, i.e. one hour operation with an accelerated ion current of 40 A of D- and a ratio between negative ions and co-extracted electrons below one. Production of negative ions is mostly achieved by conversion of hydrogen/deuterium atoms on a converter surface, which is caesiated in order to reduce the work function and increase the conversion efficiency. The understanding of the Cs transport and redistribution mechanism inside the source is necessary for the achievement of high performances. Cs dynamics was therefore investigated by means of numerical simulations performed with the Monte Carlo transport code CsFlow3D. Simulations of the prototype source (1/8 of the ITER NBI source size) have shown that the plasma distribution inside the source has the major effect on Cs dynamics during the pulse: asymmetry of the plasma parameters leads to asymmetry in Cs distribution in front of the plasma grid. The simulated time traces and the general simulation results are in agreement with the experimental measurements. Simulations performed for the ELISE testbed (half of the ITER NBI source size) have shown an effect of the vacuum phase time on the amount and stability of Cs during the pulse. The sputtering of Cs due to back-streaming ions was reproduced by the simulations and it is in agreement with the experimental observation: this can become a critical issue during long pulses, especially in case of continuous extraction as foreseen for ITER. These results and the acquired knowledge of Cs dynamics will be useful to have a better management of Cs and thus to reduce its consumption, in the direction of the demonstration fusion power plant DEMO.

  7. Towards a realistic 3D simulation of the extraction region in ITER NBI relevant ion source

    Science.gov (United States)

    Mochalskyy, S.; Wünderlich, D.; Fantz, U.; Franzen, P.; Minea, T.

    2015-03-01

    The development of negative ion (NI) sources for ITER is strongly accompanied by modelling activities. The ONIX code addresses the physics of formation and extraction of negative hydrogen ions at caesiated sources as well as the amount of co-extracted electrons. In order to be closer to the experimental conditions the code has been improved. It includes now the bias potential applied to first grid (plasma grid) of the extraction system, and the presence of Cs+ ions in the plasma. The simulation results show that such aspects play an important role for the formation of an ion-ion plasma in the boundary region by reducing the depth of the negative potential well in vicinity to the plasma grid that limits the extraction of the NIs produced at the Cs covered plasma grid surface. The influence of the initial temperature of the surface produced NI and its emission rate on the NI density in the bulk plasma that in turn affects the beam formation region was analysed. The formation of the plasma meniscus, the boundary between the plasma and the beam, was investigated for the extraction potentials of 5 and 10 kV. At the smaller extraction potential the meniscus moves closer to the plasma grid but as in the case of 10 kV the deepest meniscus bend point is still outside of the aperture. Finally, a plasma containing the same amount of NI and electrons (nH- =ne =1017 m-3) , representing good source conditioning, was simulated. It is shown that at such conditions the extracted NI current can reach values of ˜32 mA cm-2 using ITER-relevant extraction potential of 10 kV and ˜19 mA cm-2 at 5 kV. These results are in good agreement with experimental measurements performed at the small scale ITER prototype source at the test facility BATMAN.

  8. Investigations on Cs-free alternatives for negative ion formation in a low pressure hydrogen discharge at ion source relevant parameters

    Science.gov (United States)

    Kurutz, U.; Friedl, R.; Fantz, U.

    2017-07-01

    Caesium (Cs) is applied in high power negative hydrogen ion sources to reduce a converter surface’s work function and thus enabling an efficient negative ion surface formation. Inherent drawbacks with the usage of this reactive alkali metal motivate the search for Cs-free alternative materials for neutral beam injection systems in fusion research. In view of a future DEMOnstration power plant, a suitable material should provide a high negative ion formation efficiency and comply with the RAMI issues of the system: reliability, availability, maintainability, inspectability. Promising candidates, like low work function materials (molybdenum doped with lanthanum (MoLa) and LaB6), as well as different non-doped and boron-doped diamond samples were investigated in this context at identical and ion source relevant parameters at the laboratory experiment HOMER. Negative ion densities were measured above the samples by means of laser photodetachment and compared with two reference cases: pure negative ion volume formation with negative ion densities of about 1× {10}15 {{{m}}}-3 and the effect of H- surface production using an in situ caesiated stainless steel sample which yields 2.5 times higher densities. Compared to pure volume production, none of the diamond samples did exhibit a measurable increase in H- densities, while showing clear indications of plasma-induced erosion. In contrast, both MoLa and LaB6 produced systematically higher densities (MoLa: ×1.60 LaB6: ×1.43). The difference to caesiation can be attributed to the higher work functions of MoLa and LaB6 which are expected to be about 3 eV for both compared to 2.1 eV of a caesiated surface.

  9. CW/Pulsed H- ion beam generation with PKU Cs-free 2.45 GHz microwave driven ion source

    Science.gov (United States)

    Peng, S. X.; Ren, H. T.; Xu, Y.; Zhang, T.; Zhang, A. L.; Zhang, J. F.; Zhao, J.; Guo, Z. Y.; Chen, J. E.

    2015-04-01

    Circular accelerators used for positron emission tomography (PET, i.e. accelerator used for make radio isotopes) need several mA of CW H- ion beam for their routine operation. Other facilities, like Space Radio-Environment Simulate Assembly (SPRESA), require less than 10 mA pulsed mode H- beam. Caesium free negative hydrogen ion source is a good choice for those facilities because of its compact structure, easy operation and low cost. Up to now, there is no H- source able to produce very intense H- beams with important variation of the duty factor[1]. Recently, a new version of 2.45 GHz microwave H- ion source was designed at PKU, based on lessons learnt from the previous one. This non cesiated source is very compact thanks to its permanent magnet configuration. Special attention was paid on the design of the discharge chamber structure, electron dumping and extraction system. Source test to produce H- ion beams in pulsed and CW mode was carried out on PKU ion source test bench. In CW mode, a 10.8 mA/30keV H- beam with rms emittance about 0.16 π.mm.mrad has been obtained with only 500 W rf power. The power efficiency reaches 21 mA/kW. In pulsed mode with duty factor of 10% (100Hz/1ms), this compact source can easily deliver 20 mA H- ion beam at 35 keV with rms emittance about 0.2 π.mm.mrad when RF power is set at 2.2 kW (peak power). Several hour successive running operation in both modes and totaling more than 200 hours proves its high quality. The outside dimension of this new H- source body is ϕ116 mm × 124 mm, and the entire H- source infrastructure, including rf matching section, plasma chamber and extraction system, is ϕ310 × 180 mm. The high voltage region is limited with in a ϕ310 mm × 230 mm diagram. Details are given in this paper.

  10. Negative Ion Sources: Magnetron and Penning

    CERN Document Server

    Faircloth, D.C.

    2013-12-16

    The history of the magnetron and Penning electrode geometry is briefly outlined. Plasma generation by electrical discharge-driven electron impact ionization is described and the basic physics of plasma and electrodes relevant to magnetron and Penning discharges are explained. Negative ions and their applications are introduced, along with their production mechanisms. Caesium and surface production of negative ions are detailed. Technical details of how to build magnetron and Penning surface plasma sources are given, along with examples of specific sources from around the world. Failure modes are listed and lifetimes compared.

  11. CW/Pulsed H{sup −} ion beam generation with PKU Cs-free 2.45 GHz microwave driven ion source

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S. X., E-mail: sxpeng@pku.edu.cn; Ren, H. T.; Xu, Y.; Zhang, T.; Zhang, J. F.; Zhao, J.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, People' s Republic of China (China); Zhang, A. L. [University of Chinese Academy of Sciences, Beijing 100049, People' s Republic of China (China); Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, People' s Republic of China (China); University of Chinese Academy of Sciences, Beijing 100049, People' s Republic of China (China)

    2015-04-08

    Circular accelerators used for positron emission tomography (PET, i.e. accelerator used for make radio isotopes) need several mA of CW H- ion beam for their routine operation. Other facilities, like Space Radio-Environment Simulate Assembly (SPRESA), require less than 10 mA pulsed mode H{sup −} beam. Caesium free negative hydrogen ion source is a good choice for those facilities because of its compact structure, easy operation and low cost. Up to now, there is no H{sup −} source able to produce very intense H{sup −} beams with important variation of the duty factor{sup [1]}. Recently, a new version of 2.45 GHz microwave H{sup −} ion source was designed at PKU, based on lessons learnt from the previous one. This non cesiated source is very compact thanks to its permanent magnet configuration. Special attention was paid on the design of the discharge chamber structure, electron dumping and extraction system. Source test to produce H{sup −} ion beams in pulsed and CW mode was carried out on PKU ion source test bench. In CW mode, a 10.8 mA/30keV H{sup −} beam with rms emittance about 0.16 π·mm·mrad has been obtained with only 500 W rf power. The power efficiency reaches 21 mA/kW. In pulsed mode with duty factor of 10% (100Hz/1ms), this compact source can easily deliver 20 mA H{sup −} ion beam at 35 keV with rms emittance about 0.2 π·mm·mrad when RF power is set at 2.2 kW (peak power). Several hour successive running operation in both modes and totaling more than 200 hours proves its high quality. The outside dimension of this new H{sup −} source body is ϕ116 mm × 124 mm, and the entire H{sup −} source infrastructure, including rf matching section, plasma chamber and extraction system, is ϕ310 × 180 mm. The high voltage region is limited with in a ϕ310 mm × 230 mm diagram. Details are given in this paper.

  12. Holography with surface plasma waves

    Science.gov (United States)

    Cowan, J. J.

    1976-01-01

    New technique utilizes reflection-type diffraction grating of type generally used in grating spectrometers. Grating is coated with thin layer of high-resolution recording medium, having absorption coefficient low enough to prevent incident light absorption before it is reflected by metal layer.

  13. Method of generating intense nuclear polarized beams by selective photodetachment of negative ions

    International Nuclear Information System (INIS)

    Hershcovitch, A.

    1986-01-01

    A novel method for production of nuclear polarized negative hydrogen ions by selective neutralization with a laser of negative hydrogen ions in a magnetic field is described. This selectivity is possible since a final state of the neutralized atom, and hence the neutralization energy, depends on its nuclear polarization. The main advantages of this scheme are the availability of multi-ampere negative ion sources and the possibility of neutralizing negative ions with very high efficiency. An assessment of the required laser power indicates that this method is in principle feasible with today's technology

  14. Initial operation of the CW 8X H- ion source discharge

    International Nuclear Information System (INIS)

    Smith, H.V. Jr.; Allison, P.; Geisik, C.; Schmitt, D.R.; Schneider, J.D.; Stelzer, J.E.

    1993-01-01

    A pulsed 8Χ source was built and the H - beam current, emittance, and power efficiency were measured. These results were promising, so a cooled, dc version designed for operation at arc power levels up to 30 kW was built. Testing of the CW 8Χ source discharge is underway. The design dc power loading on the cathode surface is 900 W/cm 2 , considerably higher than achieved in any pervious Penning surface-plasma source (SPS). Thus, the electrode surfaces are cooled with pressurized, hot water. We describe the source and present the initial operating experience and arc test results

  15. The front end test stand high performance H- ion source at Rutherford Appleton Laboratory.

    Science.gov (United States)

    Faircloth, D C; Lawrie, S; Letchford, A P; Gabor, C; Wise, P; Whitehead, M; Wood, T; Westall, M; Findlay, D; Perkins, M; Savage, P J; Lee, D A; Pozimski, J K

    2010-02-01

    The aim of the front end test stand (FETS) project is to demonstrate that chopped low energy beams of high quality can be produced. FETS consists of a 60 mA Penning Surface Plasma Ion Source, a three solenoid low energy beam transport, a 3 MeV radio frequency quadrupole, a chopper, and a comprehensive suite of diagnostics. This paper details the design and initial performance of the ion source and the laser profile measurement system. Beam current, profile, and emittance measurements are shown for different operating conditions.

  16. Spectroscopic measurements of an H- ion source discharge

    International Nuclear Information System (INIS)

    Keller, R.; Smith, H.V. Jr.

    1985-01-01

    Spectral emission lines from an H - Penning surface-plasma source (SPS), the 4X source, are examined in the visible and near ultraviolet. Electron distribution temperatures are deduced from integral line-strength measurements. These temperatures are surprisingly low, about 0.5 eV. Electron density values of about 1.5 x 10 14 cm -3 and H-atom energies between 2 and 2.6 eV are determined from the measured Balmer-line profiles. Assuming the H - energy is identical to the H-atom energy, an emittance limit of 0.006 π x cm x mrad is deduced for this source with a 5.4-mm aperture

  17. Solar energy converter using surface plasma waves

    Science.gov (United States)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

  18. A New 500-kV Ion Source Test Stand for HIF

    International Nuclear Information System (INIS)

    Sangster, T.C.; Ahle, L.E.; Halaxa, E.F.; Karpenko, V.P.; Oldaker, M. E.; Mitchell, J.W.; Beck, D.N.; Bieniosek, F.M.; Henestroza, E.; Kwan, J.W.

    2000-01-01

    One of the most challenging aspects of ion beam driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-msec, a pulse width of at least 20-msec, a flattop ripple of less than 0.1% and a repetition rate of at least 5-Hz. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 108 pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source. Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arc. This paper will describe the test stand design specifications as well as the details of the various subsystems and components

  19. Evaluation of negative ion distribution changes by image processing diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, K., E-mail: ikeda.katsunori@lhd.nifs.ac.jp; Nakano, H.; Tsumori, K.; Kisaki, M.; Nagaoka, K.; Tokuzawa, T.; Osakabe, M.; Takeiri, Y.; Kaneko, O. [National Institute for Fusion Science, 322-6 Oroshi Toki Gifu, 509-5292 (Japan); Geng, S. [The Graduate University for Advanced Studies, Toki Gifu, 509-5292 (Japan)

    2015-04-08

    Distributions of hydrogen Balmer-α (H{sub α}) intensity and its reduction behavior close to a plasma grid (PG) surface have been observed by a spectrally selective imaging system in an arc discharge type negative hydrogen ion source in National Institute for Fusion Science. H{sub α} reduction indicates a reduction of negative hydrogen ions because the mutual neutralization process between H{sup +} and H{sup −} ions causes the dominant excitation process for H{sub α} emission in the rich H{sup −} condition such as in ionic plasma. We observed a significant change in H{sub α} reduction distribution due to change in the bias voltage, which is used to suppress the electron influx. Small H{sub α} reduction in higher bias is likely because the production of negative ions is suppressed by the potential difference between the plasma and PG surface.

  20. Source Water Protection Contaminant Sources

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Simplified aggregation of potential contaminant sources used for Source Water Assessment and Protection. The data is derived from IDNR, IDALS, and US EPA program...

  1. Sources management

    International Nuclear Information System (INIS)

    Mansoux, H.; Gourmelon; Scanff, P.; Fournet, F.; Murith, Ch.; Saint-Paul, N.; Colson, P.; Jouve, A.; Feron, F.; Haranger, D.; Mathieu, P.; Paycha, F.; Israel, S.; Auboiroux, B.; Chartier, P.

    2005-01-01

    Organized by the section of technical protection of the French society of radiation protection ( S.F.R.P.), these two days had for objective to review the evolution of the rule relative to the sources of ionising radiations 'sealed and unsealed radioactive sources, electric generators'. They addressed all the actors concerned by the implementation of the new regulatory system in the different sectors of activities ( research, medicine and industry): Authorities, manufacturers, and suppliers of sources, holders and users, bodies involved in the approval of sources, carriers. (N.C.)

  2. Comments on H- volume production in Cs-seeded ion sources. Appendix I

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1986-01-01

    Considerable interest was generated at the IAEA Negative Ion Beam Workshop in Grenoble, France, in March, 1985, by a report from the Kurchatov Institute on the development of a 2-ampere steady-state H - ion source, in which the ions were volume-produced in a discharge in H 2 , seeded with Cs vapor. The mechanism primarily responsible for this remarkably high current from a volume production source was not yet understood, but it was tentatively presumed to involve the collisional energy transfer from electronically excited Cs 6p atoms into H 2 vibrations. In any case, it was apparently different from the surface-plasma interactions that have been assumed to control the H - production in the Dudnikov-Dimov type sources

  3. Synchrotron sources

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Ion source

    International Nuclear Information System (INIS)

    Saito, Fusao; Okuyama, Toshihisa; Suzuki, Yasuo.

    1996-01-01

    In a negative ion source having magnetic filters, bisecting magnetic fields are formed using electromagnets disposed at the outside of a plasma source. The position of the electromagnets is made adjustable and removable to optimize a negative ion generation efficiency. Further, a plurality of electromagnets are disposed in longitudinal direction of the plasma source, and the intensity of the magnetic fields of the filters in the longitudinal direction is made adjustable to control a beam distribution. Since uniform magnetic fields which bisect the plasma source can be formed by the electromagnets, and magnetomotive force of the electromagnets can be increased easily compared with that of permanent magnets, the magnetomotive force is changed to obtain appropriate filter magnetic fields easily. Then, optimum magnetic fields corresponding to the state of source plasmas can be generated by the control of the power source of the electromagnets, which also increases the negative ion drawing current density, thereby enabling to reduce the drawing area and size of the plasma source. (N.H.)

  5. Neutron source

    Science.gov (United States)

    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.

  6. Neutron source

    International Nuclear Information System (INIS)

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

    1975-01-01

    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

  7. Ion source

    International Nuclear Information System (INIS)

    1979-01-01

    The ion source comprises a cylindrically shaped chamber with a longitudinal outlet slot formed therein and two uniform anode wires which extend along the length of the chamber in the middle region thereof and which are symmetrically introduced with respect to the length axis of the chamber and the outlet groove, characterised in that at each outer end of the outlet groove at a nearly null potential or direct potential is introduced a mask, whereby the lowest distance between the inner and outer ends of the mask is equivalent to the breadth of the ion beam emitted from the source. (G.C.)

  8. Source Water Protection Basics

    Science.gov (United States)

    Defines drinking water sources (source water), identifies drinking water sources, and describes source water assessments and protection, roles of government and organizations in drinking water source protection

  9. Sourcing Excellence

    DEFF Research Database (Denmark)

    Adeyemi, Oluseyi

    2011-01-01

    the competitiveness of manufacturing companies (7). Over the last couple of years, supplier’s development is an evolution in supply chain management and there is a growing interest in generating approaches for meaningful development of suppliers and SDI. This would allow businesses to snatch long-term strategic......Sourcing Excellence is one of the key performance indicators (KPIs) in this world of ever changing sourcing strategies. Manufacturing companies need to access and diagnose the reliability and competencies of existing suppliers in order to coordinate and develop them. This would help in managing...... their relationships through the sharing and diversification of knowledge and skills. Meanwhile, this research will also strengthen the collaboration of researchers in the field of operations management to ascertain and adopt the right development tools for specific or groups of suppliers in manufacturing companies...

  10. Source rock

    Directory of Open Access Journals (Sweden)

    Abubakr F. Makky

    2014-03-01

    Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

  11. Tritium sources

    International Nuclear Information System (INIS)

    Glodic, S.; Boreli, F.

    1993-01-01

    Tritium is the only radioactive isotope of hydrogen. It directly follows the metabolism of water and it can be bound into genetic material, so it is very important to control levels of contamination. In order to define the state of contamination it is necessary to establish 'zero level', i.e. actual global inventory. The importance of tritium contamination monitoring increases with the development of fusion power installations. Different sources of tritium are analyzed and summarized in this paper. (author)

  12. Muon sources

    International Nuclear Information System (INIS)

    Parsa, Z.

    2001-01-01

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

  13. Sources manuscrites

    OpenAIRE

    2014-01-01

    I. SOURCES CONSULTÉES AUX ARCHIVES NATIONALES Série E 1. Minutes d’arrêts du Conseil, arrêts simples en finances 1602 : E 4a, E 4b. 1605 : E 8a, E 8b, E 8c-9a, E 9b, E 9c. 1608 : E 16a, E 16b, E 18a, E 18b, E 19a, E 19b. 1620 : E 63a E 63b, E 64a, E 64b-65a, E 65b. 1689 : E 579a, E 579b, E 580, E 581, E 582, E 583, E 584a, E 584b, E 585a, E 585b, E 586a, E 586b 1750 : E 1260a E 1260b, E 1261a E 1261b, E 1262a, E 1262b, E 1262e, E 1263a, E 1263b, E 1264a, E 1264b, E 1265a, E 1265b, E 1266a, E ...

  14. Surface plasma functionalization influences macrophage behavior on carbon nanowalls

    Energy Technology Data Exchange (ETDEWEB)

    Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Stancu, Claudia Elena [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Luculescu, Catalin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Dinescu, Gheorghe [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania)

    2015-03-01

    The surfaces of carbon nanowall samples as scaffolds for tissue engineering applications were treated with oxygen or nitrogen plasma to improve their wettability and to functionalize their surfaces with different functional groups. X-ray photoelectron spectroscopy and water contact angle results illustrated the effective conversion of the carbon nanowall surfaces from hydrophobic to hydrophilic and the incorporation of various amounts of carbon, oxygen and nitrogen functional groups during the treatments. The early inflammatory responses elicited by un-treated and modified carbon nanowall surfaces were investigated by quantifying tumor necrosis factor-alpha and macrophage inflammatory protein-1 alpha released by attached RAW 264.7 macrophage cells. Scanning electron microscopy and fluorescence studies were employed to investigate the changes in macrophage morphology and adhesive properties, while MTT assay was used to quantify cell proliferation. All samples sustained macrophage adhesion and growth. In addition, nitrogen plasma treatment was more beneficial for cell adhesion in comparison with un-modified carbon nanowall surfaces. Instead, oxygen plasma functionalization led to increased macrophage adhesion and spreading suggesting a more activated phenotype, confirmed by elevated cytokine release. Thus, our findings showed that the chemical surface alterations which occur as a result of plasma treatment, independent of surface wettability, affect macrophage response in vitro. - Highlights: • N{sub 2} and O{sub 2} plasma treatments alter the CNW surface chemistry and wettability. • Cells seeded on CNW scaffolds are viable and metabolically active. • Surface functional groups, independent of surface wettability, affect cell response. • O{sub 2} plasma treatment of CNW leads to a more activated macrophage phenotype.

  15. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    Pramana – Journal of Physics. Current Issue : Vol. 90, Issue 1 · Current Issue Volume 90 | Issue 1. January 2018. Home · Volumes & Issues · Special Issues · Forthcoming Articles · Search · Editorial Board · Information for Authors · Subscription ...

  16. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    Science.gov (United States)

    Belov, A. S.

    2008-02-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3He++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms.

  17. Radio-frequency quadrupole, RFQ-1

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Inner structure of RFQ-1, which in 1984 replaced the Cockcroft-Walton preinjector of Linac 1. It accelerated protons and negative hydrogen-ions to 520 keV during the period that Linac 1 was used for LEAR (1981-1996). The precision-machined modulated electrodes ("vanes") are shaped to first bunch the dc-beam from the ion source and then provide simultaneous acceleration and focusing of the beam. See also 8303511. For pictures of pre-installation RF tests, see 8202557, 8202558, 8202559.

  18. Generation of intense polarized beams by selective neutralization of negative ions

    International Nuclear Information System (INIS)

    Hershcovitch, A.I.; Hinds, E.A.

    1983-01-01

    A novel scheme is proposed. This method is based on selective neutralization by laser negative hydrogen ions in a magnetic field. This selectivity is based on the fact that the final state of the neutralized atom depends on nuclear polarization in the magnetic field. A two-scenario approach is to be followed: one in which the resulting neutral atom is in the ground state, and in the other the neutral atom is in the n = 2 level. Limiting factors are discussed. The main advantages of this scheme are the availability of multi-ampere negative ion sources and the possibility to neutralize negative ions with very high efficiency. 15 references, 2 figures

  19. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    International Nuclear Information System (INIS)

    Belov, A. S.

    2008-01-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3 He ++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms

  20. Pacemakers lower sources

    International Nuclear Information System (INIS)

    Greatbatch, W.

    1984-01-01

    Energy sources for cardiac facing are considered including radioisotope sources, in a broad conceptual and historical framework.The main guidelines for future development of energy sources are assessed

  1. VUV emission spectroscopy combined with H- density measurements in the ion source Prometheus I

    Science.gov (United States)

    Aleiferis, S.; Laulainen, J.; Svarnas, P.; Tarvainen, O.; Bacal, M.; Béchu, S.

    2017-08-01

    "Prometheus I" is a volume H- negative ion source, driven by a network of dipolar electron cyclotron resonance (ECR; 2.45 GHz) modules. The vacuum-ultraviolet (VUV) emission spectrum of low-temperature hydrogen plasmas may be related to molecular and atomic processes involved directly or indirectly in the production of negative ions. In this work, VUV spectroscopy has been performed in the above source, Prometheus I, both in the ECR zones and the bulk (far from ECR zones and surfaces) plasma. The acquired VUV spectra are correlated with the negative ion densities, as measured by means of laser photodetachment, and the possible mechanisms of negative ion production are considered. The well-established H- formation process of dissociative attachment to vibrationally excited molecules is evaluated, while an additional production path (i.e. neutral resonant ionization) is tested due to the recently attracted interest. The obtained results indicate that for the source Prometheus I, the dominant formation process is dissociative attachment.

  2. Multicharged ion sources

    International Nuclear Information System (INIS)

    Venikov, N.I.

    1979-01-01

    The main principles of action, beam parameters, basic problems and prospects for development of the available multicharged ion sources for various types of accelerators are considered. Descriptions of three types of Penneng sources (a source with coid cathodes, direct-heated source, and a source with a heated cathode), duoplasmatron, SHP source using electron-cyclotron resonance, electron-ray and laser sources are given. The problems productions for solid substance ions, lithium and beryllium ions in Penning sources, are considered as well as the problem of ion charge growth on passage of accelerated ion/or atom beam through a stripping target [ru

  3. Sources management; La gestion des sources

    Energy Technology Data Exchange (ETDEWEB)

    Mansoux, H.; Gourmelon; Scanff, P.; Fournet, F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay-aux-Roses (France); Murith, Ch. [Office Federal de la SantePublique (Switzerland); Saint-Paul, N. [NOVAR, 75 - Paris (France); Colson, P. [Electricite de France (EDF/DPN), 93 - Saint-Denis (France); Jouve, A.; Feron, F. [Direction Generale de al Surete Nucleaire et de la Radioprotection, 75 - Paris (France); Haranger, D. [Electricite de France (EDF), 75 - Paris (France); Mathieu, P. [Institut Pasteur, 75 - Paris (France); Paycha, F. [CHU Louis Mourier, Unitede Medecine Nucleaire Assistance Publique-Hopitaux de Paris, 92 - Colombes (France); Israel, S. [CEGELEC NDT et la gestion des sources radioactives (France); Auboiroux, B. [APAVE (France); Chartier, P. [DRIRE de Basse-Normandie, Div. Surete Nucleaire et Radioprotection, 14 - Caen (France)

    2005-07-01

    Organized by the section of technical protection of the French society of radiation protection ( S.F.R.P.), these two days had for objective to review the evolution of the rule relative to the sources of ionising radiations 'sealed and unsealed radioactive sources, electric generators'. They addressed all the actors concerned by the implementation of the new regulatory system in the different sectors of activities ( research, medicine and industry): Authorities, manufacturers, and suppliers of sources, holders and users, bodies involved in the approval of sources, carriers. (N.C.)

  4. Mesoscale, Sources and Models: Sources for Nitrogen in the Atmosphere

    DEFF Research Database (Denmark)

    Hertel, O.

    1994-01-01

    Projektet Mesoscales, Sources and Models: Sources for Nitrogen in the Atmosphere er opdelt i 3 delprojekter: Sources - farmland, Sources - sea og Sources - biogenic nitrogen.......Projektet Mesoscales, Sources and Models: Sources for Nitrogen in the Atmosphere er opdelt i 3 delprojekter: Sources - farmland, Sources - sea og Sources - biogenic nitrogen....

  5. Radioactive Ion Sources

    CERN Document Server

    Stora, T

    2013-01-01

    This chapter provides an overview of the basic requirements for ion sources designed and operated in radioactive ion beam facilities. The facilities where these sources are operated exploit the isotope separation online (ISOL) technique, in which a target is combined with an ion source to maximize the secondary beam intensity and chemical element selectivity. Three main classes of sources are operated, namely surface-type ion sources, arc discharge-type ion sources, and finally radio-frequency-heated plasma-type ion sources.

  6. Modeling Frequency Comb Sources

    Directory of Open Access Journals (Sweden)

    Li Feng

    2016-06-01

    Full Text Available Frequency comb sources have revolutionized metrology and spectroscopy and found applications in many fields. Stable, low-cost, high-quality frequency comb sources are important to these applications. Modeling of the frequency comb sources will help the understanding of the operation mechanism and optimization of the design of such sources. In this paper,we review the theoretical models used and recent progress of the modeling of frequency comb sources.

  7. THE CHANDRA SOURCE CATALOG

    International Nuclear Information System (INIS)

    Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G.; Grier, John D.; Hain, Roger M.; Harbo, Peter N.; He Xiangqun; Karovska, Margarita; Kashyap, Vinay L.; Davis, John E.; Houck, John C.; Hall, Diane M.

    2010-01-01

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

  8. Automated source classification of new transient sources

    Science.gov (United States)

    Oertel, M.; Kreikenbohm, A.; Wilms, J.; DeLuca, A.

    2017-10-01

    The EXTraS project harvests the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) onboard the ESA XMM-Newton mission since its launch. This includes a search for fast transients, missed by standard image analysis, and a search and characterization of variability in hundreds of thousands of sources. We present an automated classification scheme for new transient sources in the EXTraS project. The method is as follows: source classification features of a training sample are used to train machine learning algorithms (performed in R; randomForest (Breiman, 2001) in supervised mode) which are then tested on a sample of known source classes and used for classification.

  9. EPA's Radioactive Source Program

    International Nuclear Information System (INIS)

    Kopsick, D.

    2004-01-01

    The US EPA is the lead Federal agency for emergency responses to unknown radiological materials, not licensed, owned or operated by a Federal agency or an Agreement state (Federal Radiological Emergency Response Plan, 1996). The purpose of EPA's clean materials programme is to keep unwanted and unregulated radioactive material out of the public domain. This is achieved by finding and securing lost sources, maintaining control of existing sources and preventing future losses. The focus is on both, domestic and international fronts. The domestic program concentrates on securing lost sources, preventing future losses, alternative technologies like tagging of radioactive sources in commerce, pilot radioactive source roundup, training programs, scrap metal and metal processing facilities, the demolition industry, product stewardship and alternatives to radioactive devices (fewer radioactive source devices means fewer orphan sources). The international program consists of securing lost sources, preventing future losses, radiation monitoring of scrap metal at ports and the international scrap metal monitoring protocol

  10. Nonpoint Source: Forestry

    Science.gov (United States)

    Sources of nonpoint source (NPS) pollution associated with forestry activities include removal of streamside vegetation, road construction and use, timber harvesting, and mechanical preparation for the planting of trees. Information resources.

  11. Spallation Neutron Source (SNS)

    Data.gov (United States)

    Federal Laboratory Consortium — The SNS at Oak Ridge National Laboratory is a next-generation spallation neutron source for neutron scattering that is currently the most powerful neutron source in...

  12. 2011 NATA - Emissions Sources

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all emissions sources that were modeled in the 2011 National Air Toxics Assessment (NATA), inlcluding point, nonpoint, and mobile sources, and...

  13. Biogenic Emission Sources

    Science.gov (United States)

    Biogenic emissions sources come from natural sources and need to accounted for in photochemical grid models. They are computed using a model which utilizes spatial information on vegetation and land use.

  14. Digital intelligence sources transporter

    International Nuclear Information System (INIS)

    Zhang Zhen; Wang Renbo

    2011-01-01

    It presents from the collection of particle-ray counting, infrared data communication, real-time monitoring and alarming, GPRS and other issues start to realize the digital management of radioactive sources, complete the real-time monitoring of all aspects, include the storing of radioactive sources, transporting and using, framing intelligent radioactive sources transporter, as a result, achieving reliable security supervision of radioactive sources. (authors)

  15. Radioactive sources service

    CERN Multimedia

    2006-01-01

    Dear Users, A new web interface is now available for requesting radioactive sources: http://cern.ch/rp-sources/request This link is also available from the radioactive sources service main page: http://cern.ch/rp-sources From now on, please submit your request via the above interface, which has been developed in order to improve the service. Thank you in advance for your collaboration!

  16. Familiarity in Source Memory

    Science.gov (United States)

    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

  17. Spallation neutron sources

    International Nuclear Information System (INIS)

    Fraser, J.S.; Bartholomew, G.A.

    1983-01-01

    The principles and theory of spallation neutron sources are outlined and a comparison is given with other types of neutron source. A summary of the available accelerator types for spallation neutron sources and their advantages and disadvantages is presented. Suitable target materials are discussed for specific applications, and typical target assemblies shown. (U.K.)

  18. Sources of pulsed radiation

    International Nuclear Information System (INIS)

    Sauer, M.C. Jr.

    1981-01-01

    Characteristics of various sources of pulsed radiation are examined from the viewpoint of their importance to the radiation chemist, and some examples of uses of such sources are mentioned. A summary is given of the application of methods of physical dosimetry to pulsed sources, and the calibration of convenient chemical dosimeters by physical dosimetry is outlined. 7 figures, 1 table

  19. Sources for charged particles

    International Nuclear Information System (INIS)

    Arianer, J.

    1997-01-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

  20. Noise Source Location Optimization

    Directory of Open Access Journals (Sweden)

    Ed O’Keefe

    1994-01-01

    Full Text Available This article describes a method to determine locations of noise sources that minimize modal coupling in complex acoustic volumes. Using the acoustic source scattering capabilities of the boundary element method, predictions are made of mode shape and pressure levels due to various source locations. Combining knowledge of the pressure field with a multivariable function minimization technique, the source location generating minimum pressure levels can be determined. The analysis also allows for an objective comparison of “best/worst” locations. The technique was implemented on a personal computer for the U.S. Space Station, predicting 5–10 dB noise reduction using optimum source locations.

  1. DC source assemblies

    Science.gov (United States)

    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.

  2. Polarized source upgrading

    International Nuclear Information System (INIS)

    Clegg, T.B.; Rummel, R.L.; Carter, E.P.; Westerfeldt, C.R.; Lovette, A.W.; Edwards, S.E.

    1985-01-01

    The decision was made this past year to move the Lamb-shift polarized ion source which was first installed in the laboratory in 1970. The motivation was the need to improve the flexibility of spin-axis orientation by installing the ion source with a new Wien-filter spin precessor which is capable of rotating physically about the beam axis. The move of the polarized source was accomplished in approximately two months, with the accelerator being turned off for experiments during approximately four weeks of this time. The occasion of the move provided the opportunity to rewire completely the entire polarized ion source frame and to rebuild approximately half of the electronic chassis on the source. The result is an ion source which is now logically wired and carefully documented. Beams obtained from the source are much more stable than those previously available

  3. Wavelength sweepable laser source

    DEFF Research Database (Denmark)

    2014-01-01

    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  4. H- Ion Sources for High Intensity Proton Drivers

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dudnikov, Vadim [Muons, Inc., Batavia, IL (United States)

    2015-02-20

    Existing RF Surface Plasma Sources (SPS) for accelerators have specific efficiencies for H+ and H- ion generation around 3 to 5 mA/cm2 per kW, where about 50 kW of RF power is typically needed for 50 mA beam current production. The Saddle Antenna (SA) SPS described here was developed to improve H- ion production efficiency, reliability and availability for pulsed operation as used in the ORNL Spallation Neutron Source . At low RF power, the efficiency of positive ion generation in the plasma has been improved to 200 mA/cm2 per kW of RF power at 13.56 MHz. Initial cesiation of the SPS was performed by heating cesium chromate cartridges by discharge as was done in the very first versions of the SPS. A small oven to decompose cesium compounds and alloys was developed and tested. After cesiation, the current of negative ions to the collector was increased from 1 mA to 10 mA with RF power 1.5 kW in the plasma (6 mm diameter emission aperture) and up to 30 mA with 4 kW RF power in the plasma and 250 Gauss longitudinal magnetic field. The ratio of electron current to negative ion current was improved from 30 to 2. Stable generation of H- beam without intensity degradation was demonstrated in the aluminum nitride (AlN) discharge chamber for 32 days at high discharge power in an RF SPS with an external antenna. Some modifications were made to improve the cooling and cesiation stability. The extracted collector current can be increased significantly by optimizing the longitudinal magnetic field in the discharge chamber. While this project demonstrated the advantages of the pulsed version of the SA RF SPS as an upgrade to the ORNL Spallation Neutron Source, it led to a possibility for upgrades to CW machines like the many cyclotrons used for commercial applications. Four appendices contain important details of the work carried out under this grant.

  5. Orphan sources in Slovenia

    International Nuclear Information System (INIS)

    Janzekovic, H.; Cesarek, J.

    2005-01-01

    For decades the international standards and requirements postulate severe control over all lifecycle phases of radioactive sources in order to prevent risks associated with exposure of people and the environment. Despite this fact the orphan sources became a serious problem as a consequence of enlargement of economic transactions in many countries in Europe as well as in the world. The countries as well as international organisations, aware of this emerging problem, are trying to gain control over orphan sources using different approaches. These approaches include control over sources before they could become orphan sources. In addition, countries are also developing action plans in case that an orphan source could be found. The problems related to orphan sources in Slovenia is discussed based on the case studies from the last years. While in the nineties of the last century just a few cases of orphan sources were identified their number has increased substantially since 2003. The paper discusses the general reasons for the phenomena of orphan sources as well as the experience related to regaining control over orphan sources. (author)

  6. Point Pollution Sources Dimensioning

    Directory of Open Access Journals (Sweden)

    Georgeta CUCULEANU

    2011-06-01

    Full Text Available In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height of the source one takes into account the relation given by the proportionality factor, defined as ratio between the plume rise and physical height of the source. The plume rise depends on the gas exit velocity and gas temperature. That relation is necessary for diminishing the environmental pollution when the production capacity of the plant varies, in comparison with the nominal one.

  7. Microwave ion source

    Science.gov (United States)

    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.

  8. Global Sourcing Flexibility

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent

    2013-01-01

    sourcing flexibility. Here we draw on prior research in the fields of organizational flexibility, international business and global sourcing as well as case examples and secondary studies. In the second part of the paper, we discuss the implications of global sourcing flexibility for firm strategy...... flexibility. We finally discuss implications for management and international business research, within and beyond the domain of global services sourcing.......Recent studies show that flexibility is a key concern for firms that engage in the global sourcing of services. In this conceptual paper, we seek to explore two central aspects of global sourcing flexibility: In the first part of the paper, we provide a definition of the construct of global...

  9. Soldier System Power Sources

    Science.gov (United States)

    2006-12-31

    2004. 27 Soldier System Power Sources Final Project Report 23. Z. Jiang, R. Dougal, "Multiobjective MPPT /Charging Controller for Standalone PV Power...composed variously of batteries, fuel cells, and super capacitors, it developed control al- gorithms for those hybrid power sources, it assessed the...coupling, this model can control signal dependent source models. * Reference mission scenarios and test beds. A probabilistic load profile generator was

  10. Sources of atmospheric ammonia

    International Nuclear Information System (INIS)

    Harriss, R.C.; Michaels, J.T.

    1982-01-01

    The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States

  11. Pulsed spallation neutron sources

    International Nuclear Information System (INIS)

    Carpenter, J.M.

    1996-01-01

    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

  12. Pulsed spallation Neutron Sources

    International Nuclear Information System (INIS)

    Carpenter, J.M.

    1994-01-01

    This paper reviews the early history of pulsed spallation neutron source development at 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 provides a few examples of applications in fundamental condensed matter physics, materials science and technology

  13. Acoustic emission source modeling

    Directory of Open Access Journals (Sweden)

    Hora P.

    2010-07-01

    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  14. Properties of neutron sources

    International Nuclear Information System (INIS)

    1987-03-01

    The Conference presentations were divided into sessions devoted to the following topics: white neutron sources, primarily pulsed (6 papers); fast neutron fields (5 papers); Californium-252 prompt fission neutron spectra (14 papers); monoenergetic sources and filtered beams (11 papers); 14 MeV neutron sources (10 papers); selected special application (one paper); and a general interest session (4 papers). Individual abstracts were prepared separately for the papers

  15. Dynamic radioactive particle source

    Science.gov (United States)

    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.

  16. Source identification with GLAST

    International Nuclear Information System (INIS)

    Lonjou, Vincent; Knoedlseder, Juergen

    2007-01-01

    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

  17. Source Reference File

    Data.gov (United States)

    Social Security Administration — This file contains a national set of names and contact information for doctors, hospitals, clinics, and other facilities (known collectively as sources) from which...

  18. Source SDK development essentials

    CERN Document Server

    Bernier, Brett

    2014-01-01

    The Source Authoring Tools are the pieces of software used to create custom content for games made with Valve's Source engine. Creating mods and maps for your games without any programming knowledge can be time consuming. These tools allow you to create your own maps and levels without the need for any coding knowledge. All the tools that you need to start creating your own levels are built-in and ready to go! This book will teach you how to use the Authoring Tools provided with Source games and will guide you in creating your first maps and mods (modifications) using Source. You will learn ho

  19. Advanced Photon Source (APS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Photon Source (APS) at the U.S. Department of Energy's Argonne National Laboratoryprovides this nation's (in fact, this hemisphere's) brightest storage...

  20. Global Sourcing Flexibility

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent

    2013-01-01

    and operations against the backdrop of the theory-based definition of the construct. We discuss in particular the importance of global sourcing flexibility for operational performance stability, and the trade-off between specialization benefits, emerging from location and service provider specialization, versus...... the higher costs (but decreased risk for value chain disruption) embedded in a more flexible global sourcing model that allows the firm to replicate and/or relocate activities across multiple locations. We develop a model and propositions on facilitating and constraining conditions of global sourcing...... flexibility. We finally discuss implications for management and international business research, within and beyond the domain of global services sourcing....

  1. High current ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.

    1989-06-01

    The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be 'high', while in another area a current of 10 Amperes could 'low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper

  2. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  3. Sealed radioactive sources toolkit

    International Nuclear Information System (INIS)

    Mac Kenzie, C.

    2005-09-01

    The IAEA has developed a Sealed Radioactive Sources Toolkit to provide information to key groups about the safety and security of sealed radioactive sources. The key groups addressed are officials in government agencies, medical users, industrial users and the scrap metal industry. The general public may also benefit from an understanding of the fundamentals of radiation safety

  4. Soldier System Power Sources

    National Research Council Canada - National Science Library

    Dougal, Roger A; Gao, Lijun

    2006-01-01

    ... for those hybrid power sources, it assessed the value of recovering energy from partially spent primary cells, it developed more-efficient methods of capturing energy from photovoltaic sources, and it developed simulation-based tools for planning the carriage of sufficient electric energy to power specific suites of equipment as necessary to accomplish specific missions.

  5. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Creating Open Source Conversation

    Science.gov (United States)

    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…

  7. PORTABLE SOURCE OF RADIOACTIVITY

    Science.gov (United States)

    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. Belgrade waterworks groundwater source

    International Nuclear Information System (INIS)

    Sotic, A.; Dasic, M.; Vukcevic, G.; Vasiljevic, Lj.; Nikolic, S.

    2002-01-01

    Paper deals with Belgrade Waterworks groundwater source, its characteristics, conception of protection programme, contaminations on source and with parameters of groundwater quality degradation. Groundwaters present natural heritage with their strategic and slow renewable natural resources attributes, and as such they require priority in protection. It is of greatest need that existing source is to be protected and used optimally for producing quality drinkable water. The concept of source protection programme should be based on regular water quality monitoring, identification of contaminators, defining areas of their influences on the source and their permanent control. However, in the last 10 years, but drastically in the last 3, because of the overall situation in the country, it is very characteristic downfall in volume of business, organisation and the level of supply of the technical equipment

  9. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    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.

  10. Categorization of radiation sources

    International Nuclear Information System (INIS)

    2000-12-01

    The objective of this report is to develop a categorization scheme for radiation sources that could be relevant to decisions both in a retrospective application to bring sources under control and in a prospective sense to guide the application of the regulatory infrastructure. The Action Plan envisages that the preparation of guidance on national strategies and programmes for the detection and location of orphan sources and their subsequent management should commence after the categorization of sources has been carried out. In the prospective application of the system of notification, registration, and licensing, the categorization is relevant to prioritize a regulatory authority's resources and training activities; to guide the degree of detail necessary for a safety assessment; and to serve as a measure of the intensity of effort which a regulatory authority should apply to the safety and security of a particular type of source

  11. Piezotube borehole seismic source

    Science.gov (United States)

    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.

  12. Neutron sources and applications

    Energy Technology Data Exchange (ETDEWEB)

    Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    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.

  13. Neutron sources and applications

    International Nuclear Information System (INIS)

    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

  14. Global Sourcing of Services

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Petersen, Bent

    2013-01-01

    The global sourcing of services offers high returns but is also associated with high risks. The extent to which firms engage in ‘transformational’ global sourcing (i.e., global sourcing implying considerable changes in the home organization) chiefly depends on management's comfort zone which......, in turn, is determined by managers' risk perceptions, risk tolerance, and ability to employ risk-reducing measures. Many firms move into transformational global sourcing more or less deliberately. However, as the human asset specificity of the global sourcing operation increases, managers find themselves...... out of their comfort zones and a desire for a new collaborative architecture arises. An illustrative company case exemplifies the process of establishing such a collaborative architecture....

  15. Negative ion sources

    International Nuclear Information System (INIS)

    Ishikawa, Junzo; Takagi, Toshinori

    1983-01-01

    Negative ion sources have been originally developed at the request of tandem electrostatic accelerators, and hundreds of nA to several μA negative ion current has been obtained so far for various elements. Recently, the development of large current hydrogen negative ion sources has been demanded from the standpoint of the heating by neutral particle beam injection in nuclear fusion reactors. On the other hand, the physical properties of negative ions are interesting in the thin film formation using ions. Anyway, it is the present status that the mechanism of negative ion action has not been so fully investigated as positive ions because the history of negative ion sources is short. In this report, the many mechanisms about the generation of negative ions proposed so far are described about negative ion generating mechanism, negative ion source plasma, and negative ion generation on metal surfaces. As a result, negative ion sources are roughly divided into two schemes, plasma extraction and secondary ion extraction, and the former is further classified into the PIG ion source and its variation and Duoplasmatron and its variation; while the latter into reflecting and sputtering types. In the second half of the report, the practical negative ion sources of each scheme are described. If the mechanism of negative ion generation will be investigated more in detail and the development will be continued under the unified know-how as negative ion sources in future, the development of negative ion sources with which large current can be obtained for any element is expected. (Wakatsuki, Y.)

  16. Gadolinium-153 line sources

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, V.M. E-mail: kar@orip.niiar.simbirsk.su; Gordeev, J.N.; Karelin, E.A.; Gavrilov, V.D

    2000-11-15

    The technology for Gd-153 line source production has been developed at SSC RIAR. The source active core is made of Al-Gd{sub 2}O{sub 3} composition by means of one of the following ways: either collecting pressed pellets or filling the source body with the composition followed by sintering. The composition is prepared by gadolinium salt thermal destruction on aluminium particles. The method allows setting gadolinium mass fraction (from 0.02 to 6%) with high accuracy and uniformity of distribution in the composition volume of more than 95%.

  17. Categorization of radiation sources

    International Nuclear Information System (INIS)

    Antonova, M.

    2000-01-01

    Through one-parameter (factor) analysis it is proved a hypothesis that the value of a radiation source (RS) activity of an application correlates with the category (the rank) given to it by the IAEA categorization although it is based on other parameters of the RS applications (practices like devices with radiation sources in industry, science, medicine and agriculture). The principles of the new IAEA categorization, taking into account the potential harm the sources may cause and the necessary regulatory control, are described. (author)

  18. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  19. Tunable terahertz radiation source

    Science.gov (United States)

    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.

  20. Open source development

    DEFF Research Database (Denmark)

    Ulhøi, John Parm

    2004-01-01

    This paper addresses innovations based on open source or non-proprietary knowledge. Viewed through the lens of private property theory, such agency appears to be a true anomaly. However, by a further turn of the theoretical kaleidoscope, we will show that there may be perfectly justifiable reasons...... for not regarding open source innovations as anomalies. The paper is based on three sectorial and generic cases of open source innovation, which is an offspring of contemporary theory made possible by combining elements of the model of private agency with those of the model of collective agency. In closing...

  1. Microfabricated diffusion source

    Science.gov (United States)

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

    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.

  2. AGS polarized H- source

    International Nuclear Information System (INIS)

    Kponou, A.; Alessi, J.G.; Sluyters, T.

    1985-01-01

    The AGS polarized H - source is now operational. During a month-long experimental physics run in July 1984, pulses equivalent to 15 μA x 300 μs (approx. 3 x 10 10 protons) were injected into the RFQ preaccelerator. Beam polarization, measured at 200 MeV, was approx. 75%. After the run, a program to increase the H - yield of the source was begun and significant progress has been made. The H - current is now frequently 20 to 30 μA. A description of the source and some details of our operating experience are given. We also briefly describe the improvement program

  3. Vacuum Arc Ion Sources

    CERN Document Server

    Brown, I.

    2013-12-16

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

  4. Environmental Data Sources

    Data.gov (United States)

    Kansas Data Access and Support Center — This database includes gauging stations, climatic data centers, and storet sites. The accuracy of the locations is dependent on the source data for each of the...

  5. EPA Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  6. Nonlinear Source Emulator

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem

    and remains the prime source of energy in non-terrestrial applications such as those in sky-explorers. However, a renewable energy source is expensive, bulky, and its performance is weather dependent, which make testing of downstream converters very difficult. As a result, a nonlinear source emulator (NSE...... of a proposed NSE system with high dynamic performance. The goal of the work is to achieve a state-of-the art transient time of 10 µs. In order to produce the arbitrary nonlinear curve, the exponential function of a typical diode is used, but the diode can be replaced by other nonlinear curve reference...... simulation of nonlinear source systems with higher output power. In this work, a module will consist of two fundamental units: an isolated power supply and an NSE. The isolated power supply has to possess a very low circuit input-to-output capacitance (very low Cio) in order to reduce the effect...

  7. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G.; Thorn, A.

    2013-12-16

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  8. National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Hulbert, S.L.; Lazarz, N.M.

    1991-04-01

    This report discussion research being conducted at the National Synchrotron light source. In particular, this report contains operations summaries; symposia, workshops, and projects; NSLS highlights; and abstracts of science at the NSLS

  9. Sodium and Food Sources

    Science.gov (United States)

    ... Disease Cholesterol High Blood Pressure Million Hearts® WISEWOMAN Sodium and Food Sources Recommend on Facebook Tweet Share ... food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: More ...

  10. New renewable energy sources

    International Nuclear Information System (INIS)

    2001-06-01

    This publication presents a review of the technological, economical and market status in the field of new renewable energy sources. It also deals briefly with the present use of energy, external conditions for new renewable energy sources and prospects for these energy sources in a future energy system. The renewable energy sources treated here are ''new'' in the sense that hydroelectric energy technology is excluded, being fully developed commercially. This publication updates a previous version, which was published in 1996. The main sections are: (1) Introduction, (2) Solar energy, (3) Bio energy, (4) Wind power, (5) Energy from the sea, (6) Hydrogen, (7) Other new renewable energy technologies and (8) New renewable s in the energy system of the future

  11. Sources of pollution

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Sources of pollution. Domestic wastewater (Sewage). Organic matter; Nitrogen & phosphorus; Pathogens, viruses, …. Agricultural runoff. Nitrogen & phosphorus; Pesticides; Industrial effluents; Organics (oil &grease, pigments, phenols, organic matter ….) Heavy ...

  12. Nonpoint Source: Agriculture

    Science.gov (United States)

    Agricultural runoff as a nonpoint source category of pollution. Resouces to learn more a bout conservation practices to reduce water quality impacts from storm water run off and ground water infiltration

  13. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  14. Field emission electron source

    Science.gov (United States)

    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.

  15. Radio frequency ion source

    CERN Document Server

    Shen Guan Ren; Gao Fu; LiuNaiYi

    2001-01-01

    The study on Radio Frequency Ion Source is mainly introduced, which is used for CIAE 600kV ns Pulse Neutron Generator; and obtained result is also presented. The RF ion source consists of a diameter phi 25 mm, length 200 mm, coefficient of expansion =3.5 mA, beam current on target >=1.5 mA, beam spot =100 h.

  16. Reactor Neutron Sources

    International Nuclear Information System (INIS)

    Aksenov, V.L.

    1994-01-01

    The present status and the prospects for development of reactor neutron sources for neutron scattering research in the world are considered. The fields of application of neutron scattering relative to synchrotron radiation, the creation stages of reactors (steady state and pulsed) and their position in comparison with spallation neutron sources at present and in the foreseen future are discussed. (author). 15 refs.; 8 figs.; 3 tabs

  17. Dosimetry of industrial sources

    International Nuclear Information System (INIS)

    Vega C, H.R.; Rodriguez J, R.; Manzanares A, E.; Hernandez V, R.; Ramirez G, J.; Rivera M, T.

    2007-01-01

    The gamma rays are produced during the disintegration of the atomic nuclei, its high energy allows them to cross thick materials. The capacity to attenuate a photons beam allows to determine the density, in line, of industrial interest materials as the mining. By means of two active dosemeters and a TLDs group (passive dosimetry) the dose rates of two sources of Cs-137 used for determining in line the density of mining materials were determined. With the dosemeters the dose levels in diverse points inside the grave that it harbors the sources and by means of calculations the isodoses curves were determined. In the phase of calculations was supposed that both sources were punctual and the isodose curves were calculated for two situations: naked sources and in their Pb packings. The dosimetry was carried out around two sources of 137 Cs. The measured values allowed to develop a calculation procedure to obtain the isodoses curves in the grave where the sources are installed. (Author)

  18. Characteristics and locations of sources

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.; Poellaenen, R.; Toivonen, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    Ten artificial radiation sources were placed in the terrain in order to test the capability of airborne measuring teams to detect them. One of the sources was a line source, others were point sources (three of them collimated). The radionuclides used in the sources were {sup 60}Co, {sup 137}Cs, {sup 99m}Tc and {sup 192}Ir. The source activities ranged from about 26 MBq (one of the cobalt sources) to 0.56 TBq (iridium). (au).

  19. Open source posturography.

    Science.gov (United States)

    Rey-Martinez, Jorge; Pérez-Fernández, Nicolás

    2016-12-01

    The proposed validation goal of 0.9 in intra-class correlation coefficient was reached with the results of this study. With the obtained results we consider that the developed software (RombergLab) is a validated balance assessment software. The reliability of this software is dependent of the used force platform technical specifications. Develop and validate a posturography software and share its source code in open source terms. Prospective non-randomized validation study: 20 consecutive adults underwent two balance assessment tests, six condition posturography was performed using a clinical approved software and force platform and the same conditions were measured using the new developed open source software using a low cost force platform. Intra-class correlation index of the sway area obtained from the center of pressure variations in both devices for the six conditions was the main variable used for validation. Excellent concordance between RombergLab and clinical approved force platform was obtained (intra-class correlation coefficient =0.94). A Bland and Altman graphic concordance plot was also obtained. The source code used to develop RombergLab was published in open source terms.

  20. Open Source Telecommunication Companies

    Directory of Open Access Journals (Sweden)

    Peter Liu

    2007-08-01

    Full Text Available Little is known about companies whose core business is selling telecommunications products that lever open source projects. Open source telecommunications (OST companies operate in markets that are very different from typical software product markets. The telecommunications market is regulated, vertically integrated, and proprietary designs and special chips are widely used. For a telecommunications product to be useful, it must interact with both access network products and core network products. Due to specifications in Service Agreements Levels, penalties for failures of telecommunications products are very high. This article shares information that is not widely known, including a list of OST companies and the open source projects on which they depend, the size and diversity of venture capital investment in OST companies, the nature of the commercial product-open source software and company-project relationships, ways in which OST companies make money, benefits and risks of OST companies, and competition between OST companies. Analysis of this information provides insights into the ways in which companies can build business models around open source software. These findings will be of interest to entrepreneurs, top management teams of incumbent companies that sell telecommunications products, and those who care about Ontario's ability to compete globally.

  1. Extraction of negative lithium ions from a lithium-containing hydrogen plasma

    International Nuclear Information System (INIS)

    Wada, M.; Sasao, M.

    1996-01-01

    Negative lithium ions (Li - ) were extracted from a 6-cm-diam 7-cm-long negative hydrogen ion (H - ) source to simulate the condition of Li - extraction from a Li vapor introduced ion source for the neutral beam heating. The amount of the Li - current extracted from a hydrogen plasma with Li vapor was comparable to that extracted from a pure Li plasma. However, the amount of the H - current decreased as the H 2 gas pressure in the source decreased due to a getter-pump effect of Li during the introduction of Li vapor. A heat shield installed to keep a high wall temperature was effective in mitigating the pressure decrease. However, the H - current extracted from the ion source equipped with the heat shield became 20% of the original value, as Li vapor was injected into the ion source. copyright 1996 American Institute of Physics

  2. Intense fusion neutron sources

    Science.gov (United States)

    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.

  3. INEEL Source Water Assessment

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Alternative energy sources

    Energy Technology Data Exchange (ETDEWEB)

    Michaelides, Efstathios E. (Stathis) [Texas Christian Univ., Forth Worth, TX (United States). Dept. of Engineering

    2012-07-01

    Alternative Energy Sources is designed to give the reader, a clear view of the role each form of alternative energy may play in supplying the energy needs of the human society in the near and intermediate future (20-50 years). The two first chapters on energy demand and supply and environmental effects, set the tone as to why the widespread use of alternative energy is essential for the future of human society. The third chapter exposes the reader to the laws of energy conversion processes, as well as the limitations of converting one energy form to another. The sections on exergy give a succinct, quantitative background on the capability/potential of each energy source to produce power on a global scale. The fourth, fifth and sixth chapters are expositions of fission and fusion nuclear energy. The following five chapters (seventh to eleventh) include detailed descriptions of the most common renewable energy sources - wind, solar, geothermal, biomass, hydroelectric - and some of the less common sources, such as tidal and wave energy. The emphasis of these chapters is on the global potential of each source; the engineering/technical systems that are currently used in harnessing the potential of each one of these energy sources; the technological developments that will contribute to wider utilization of the sources; and the environmental effects associated with their current and their wider use. The last three chapters are: energy storage, which is the main limitation of the wider use of solar and wind power and will become an important issue if renewable energy sources are to be used widely; energy conservation, which appears to be everyone's favorite issue, but by itself is not a solution to our energy challenge; and energy economics, a necessary consideration in market-driven economies. The fourteen chapters in the book have been chosen so that one may fit a semester University course around this book. At the end of every chapter, there are 12-20 problems

  5. Sources et bibliographie

    OpenAIRE

    2015-01-01

    SOURCES Sources Archivistiques Archives nationales (AN) Série AP. Archives personnelles et familiales AP/09. Fonds privés d’avocats. 304/ AP. Maurice Garçon. 334/AP. Bluet. 417/AP. Georges Coulon. 470/AP. Alexandre Millerand. 476/AP. Chauveau- Lagarde. 488/AP. Joseph Denaïs. 505/AP. Edgar Faure. 516/AP. Bourdeau de Fontenay. 556/AP. Gabriel Olivier. 596/AP. Georges Calzant. Série BB. Ministère de la Justice BB29 : Enregistrement général de la correspondance BB29/723-724. Matricule des avoués ...

  6. Renewable energy sources (promotion)

    International Nuclear Information System (INIS)

    Cook, F.

    1986-01-01

    Permission to present a Bill to establish an independent commission directly responsible for the research, development and demonstration of clean, renewable, alternative sources of energy (to nuclear energy) is requested. The paragraphs of the preamble to the Bill are summarized by the Member seeking permission. The main reason for promoting renewable energy sources is opposition to the nuclear industry. One objection was raised. However, permission was granted to present the Bill and it was read for the first time with a second reading ordered for 7 March 1986. The Bill itself is not reprinted but the permission and question are reported verbatim. (U.K.)

  7. Open source molecular modeling.

    Science.gov (United States)

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Valorization of ECR sources

    CERN Document Server

    2003-01-01

    One way to limit the size of particle accelerators is to use intense multicharged ion beams. Thus, compact, low cost and reliable sources have been developed. These sources are based on the electron cyclotron resonance (ECR) principle and need no cathode nor filament. A prototype named Nanogan has been developed for the Spiral project of the Ganil accelerator (Caen, France). Then, this technology has been transferred toward other research domains and industrial applications, like the ion implantation in micro-electronics components. (J.S.)

  9. Power source facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro

    1998-09-29

    The present invention concerns a power plant, in which power is supplied from an ordinary system battery to an ordinary DC bus system when all of the AC power sources should be lost and a generator is driven by a steam turbine. A generator is connected with an ordinary system battery charger by way of a channel. If all of power sources should be lost, the ordinary system battery charger is driven by using emergency steam turbine generator facilities, and reactor steams are supplied thereby enabling to supply power to the ordinary system DC bus system for a long period of time. (N.H.)

  10. Sources of Financial Sociability

    DEFF Research Database (Denmark)

    Thompson, Grahame

    2011-01-01

    This article investigates the sources of sociability in modern financial systems as a prelude to assessing the prospects for financial regulation. Three sources are identified: sociality dependent upon contract, upon relational interdependency, and upon the operation of will and passion. Each...... of the article which is to explore further the nature of ‘irrationality’ as manifest in financial crises. When the contours of both these aspects of financial calculation have been elaborated, the article moves on to consider how they might shape regulatory responses to the seeming inevitability of financial...

  11. Alternate energy sources

    International Nuclear Information System (INIS)

    Stevens-Guille, P.D.

    1975-01-01

    The author highlights the interesting points made by the speeches during the conference on Energy and its Future in Southern Africa. He also draws attention to potential alternate energy sources such as power from tides, ocean waves, ocean temperature differences and geothermal power

  12. Tandem Terminal Ion Source

    International Nuclear Information System (INIS)

    None

    2000-01-01

    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

  13. New sources of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly.

  14. International Entrepreneurship and Sourcing

    DEFF Research Database (Denmark)

    Servais, Per; Zucchella, Antonella; Palamera, Giada

    2006-01-01

    This contribution focuses on international sourcing as an entrepreneurial act and aims at demonstrating that it is actually at the core of internationalization processes of small firms, both established and international new ventures. Another issue of this research is to understand how these firms...

  15. Alternative Energy Sources

    CERN Document Server

    Michaelides, Efstathios E (Stathis)

    2012-01-01

    Alternative Energy Sources is designed to give the reader, a clear view of the role each form of alternative energy may play in supplying the energy needs of the human society in the near and intermediate future (20-50 years).   The two first chapters on energy demand and supply and environmental effects, set the tone as to why the widespread use of alternative energy is essential for the future of human society. The third chapter exposes the reader to the laws of energy conversion processes, as well as the limitations of converting one energy form to another. The sections on exergy give a succinct, quantitative background on the capability/potential of each energy source to produce power on a global scale. The fourth, fifth and sixth chapters are expositions of fission and fusion nuclear energy. The following five chapters (seventh to eleventh) include detailed descriptions of the most common renewable energy sources – wind, solar, geothermal, biomass, hydroelectric – and some of the less common sources...

  16. Risks of energy sources

    International Nuclear Information System (INIS)

    Pop-Jordanov, J.; Pop-Jordanova, N.

    1989-09-01

    The paper is devoted to comparative health and environmental risks of different energy sources and their influence to public perception, social acceptability and decision-making. The technical heights of the risks, expressed in the number of fatalities of labor and public per unit energy output, from fossil, nuclear and renewable sources are analysed and compared. The complete energy cycle from mining to waste disposal, as well as the future trends, are taken into account. A comparison of the risks of different energy systems with the anticipated global and national energy shares by source is also presented. Furthermore, detailed studies of the non-technical dimensions of the energy risks are performed. Using a modified attitude-behaviour model, the cognitive structure underlying the positions towards different energy options is investigated. Estimating the diverse acting of the risk components, the consequent changes in the rank ordering of the energy sources are deduced. Finally, adding the psychological components nuclear reaches the highest place. In this respect, a unified multidimensional space for the representation of various technological risks is introduced. It affords a comparison of the risks not only by their technical height, but also by other characteristics (involuntary, fearfulness etc.). Finally, it was pointed out that in considering the risk characteristics and constraints, as well as the external fields, a system approach has to be used, taking into account the risks simultaneously with the benefits. 12 refs, 4 figs, 2 tabs

  17. OMNIDIRECTIONAL SOUND SOURCE

    DEFF Research Database (Denmark)

    1996-01-01

    A sound source comprising a loudspeaker (6) and a hollow coupler (4) with an open inlet which communicates with and is closed by the loudspeaker (6) and an open outlet, said coupler (4) comprising rigid walls which cannot respond to the sound pressures produced by the loudspeaker (6). According...

  18. Open-Source Colorimeter

    Science.gov (United States)

    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

  19. Y-source inverter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Town, Graham; Loh, Poh Chiang

    2014-01-01

    This paper introduces a new 3-phase Y-source inverter whose gain is presently not matched by classical impedance-network-based inverters operating at the same duty ratio. The proposed network uses a tightly coupled transformer with three windings. By squeezing the shoot-through range while keeping...

  20. Acoustic emission source modeling

    Czech Academy of Sciences Publication Activity Database

    Hora, Petr; Červená, Olga

    2010-01-01

    Roč. 4, č. 1 (2010), s. 25-36 ISSN 1802-680X R&D Projects: GA ČR GA101/09/1630 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustic emission source * wave propagation * FEM Subject RIV: BI - Acoustics

  1. Sourcing made easy.

    Science.gov (United States)

    2005-09-01

    MDT Sourcing is a free online service for buyers seeking the range of services used in the design, manufacture and marketing of finished medical devices. Take up of the service has been good since its launch earlier this year. Some of the latest requests for quotations are outlined here.

  2. New sources of radiation

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly

  3. Organizing for Global Sourcing

    DEFF Research Database (Denmark)

    Bals, Lydia; Turkulainen, Virpi

    Research on Purchasing Organization is dominated by studies on centralization versus decentralization. While global sourcing relates to the integrated activities of purchasing and other functions in line with the company’s strategic objectives and while it has been put forward that hybrid organiz...

  4. Electrochemical Power Sources

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Electrochemical Power Sources - Rechargeable Batteries. A K Shukla S K Martha. General Article Volume 6 Issue 7 July 2001 pp 52-63. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Californium source transfer

    International Nuclear Information System (INIS)

    Wallace, C.R.

    1995-01-01

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

  6. Safe handling of radiation sources

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    This chapter discussed the subjects related to the safe handling of radiation sources: type of radiation sources, method of use: transport within premises, transport outside premises; Disposal of Gamma Sources

  7. Beam characterization at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

    Science.gov (United States)

    Aza, E.; Schiesko, L.; Wimmer, C.; Wünderlich, D.; Fantz, U.

    2017-08-01

    The properties of the negative hydrogen ion beam produced by the scaled prototype ITER NBI source at the BATMAN testbed were investigated by means of two beam diagnostics: Beam Emission Spectroscopy (BES) and a calorimeter. Two modifications to the prototype were applied. The first was the installation of a second Cs oven at the bottom part of the backplate in addition to the standard one at the upper part of the backplate varying the Cs evaporation asymmetry inside the source. The second consisted in the replacement of the cylindrical driver with a larger racetrack-shaped RF driver and placing a single Cs oven in a central position at the backplate of the driver. The resulting beam characteristics are discussed and compared with those obtained with the previous source design. The position of the Cs oven and the different driver size and geometry appear not to influence the beam profile and the beam deflection for a well-conditioned source.

  8. Sources of groundwater contamination

    International Nuclear Information System (INIS)

    Assaf, H.; Al-Masri, M. S.

    2007-09-01

    In spite of the importance of water for life, either for drinking, irrigation, industry or other wide uses in many fields, human beings seem to contaminate it and make it unsuitable for human uses. This is due to disposal of wastes in the environment without treatment. In addition to population increase and building expanding higher living costs, industrial and economical in growth that causes an increase in water consumption. All of these factors have made an increase pressure on our water environment quantitatively and qualitatively. In addition, there is an increase of potential risks to the water environmental due to disposal of domestic and industrial wastewater in areas near the water sources. Moreover, the use of unacceptable irrigation systems may increase soil salinity and evaporation rates. The present report discusses the some groundwater sources and problem, hot and mineral waters that become very important in our life and to our health due to its chemical and radioactivity characteristics.(authors)

  9. Atom beam source

    International Nuclear Information System (INIS)

    Franks, J.

    1984-01-01

    Ion beam V etching may give rise to undesirable effects such as uneven erosion and ion migration in dielectrics, even when the surface is neutralized by electron flooding. The effects appear due to a remaining charge imbalance on a microscopic scale, which is absent when bombarding with an uncharged beam. Saddle field sources provide a convenient means of producing energetic neutral beams of inert and reactive gases (which may be dissociated into radicals). The construction and characteristics of the sources are described and a mechanism of internal neutralization proposed. Evidence is given that uncharged beams introduce less damage than equivalent ion beams. Disruptive effects may be initiated by charge accumulation or possibly by neutralization processes which occur when ions closely approach the target surface. (author)

  10. Microdosimetry of internal sources

    International Nuclear Information System (INIS)

    Roesch, W.C.

    1976-01-01

    Microdosimetry has been limited to irradiations characterized by uniform probabilities of charged-particle production. New methods are here presented for dealing with particles emitted by radionuclides embedded in the irradiated medium; these particles seldom emerge uniformly, because the radionuclides are not dispersed uniformly. In particular, emission from radionuclides that are agglomerated into particulates is extremely nonuniform. Microdosimetric distributions for these internal emitters can be calculated by: (1) determining the probability density in specific energy due to single energy deposition events by charged particles from a point source, (2) combining these densities by Fourier-transform methods, and (3) using existing numerical methods to evaluate the Fourier result. Examples are given calculated for 239 Pu alpha particles from point sources (particulates) and from particulates uniformly distributed through all space, a half space, and a sphere

  11. Synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    van Steenbergen, A.

    1979-01-01

    As a result of the exponential growth of the utilization of synchrotron radiation for research in the domain of the material sciences, atomic and molecular physics, biology and technology, a major construction activity has been generated towards new dedicated electron storage rings, designed optimally for synchrotron radiation applications, also, expansion programs are underway at the existing facilities, such as DORIS, SPEAR, and VEPP. In this report the basic properties of synchrotron radiation will be discussed, a short overview will be given of the existing and new facilities, some aspects of the optimization of a structure for a synchrotron radiation source will be discussed and the addition of wigglers and undulators for spectrum enhancement will be described. Finally, some parameters of an optimized synchrotron radiation source will be given.

  12. Cold source economic study

    International Nuclear Information System (INIS)

    Fuster, Serge.

    1975-01-01

    This computer code is intended for the statement of the general economic balance resulting from using a given cold source. The balance includes the investments needed for constructing the various materials, and also production balances resulting from their utilization. The case of either using an open circuit condenser on sea or river, or using air cooling systems with closed circuits or as auxiliaries can be dealt with. The program can be used to optimize the characteristics of the various parts of the cold source. The performance of the various materials can be evaluated for a given situation from using very full, precise economic balances, these materials can also be classified according to their possible uses, the outer constraints being taken into account (limits for heat disposal into rivers or seas, water temperature, air temperature). Technical choices whose economic consequences are important have been such clarified [fr

  13. The advanced photon source

    International Nuclear Information System (INIS)

    Galayda, J.N.

    1995-01-01

    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

  14. Osmotic Acoustic Source

    Science.gov (United States)

    2017-09-25

    one side of the radiating surface that is on the order of one meter the length and width of the plane of the enclosure. The walls of the enclosure...DEPARTMENT OF THE NAVY OFFICE OF COUNSEL NAVAL UNDERSEA WARFARE CENTER DIVISION 1176 HOWELL STREET NEWPORT Rl 02841-1708...across a semi-permeable membrane. (2) Description of the Prior Art [0004] Low frequency acoustic sources such as in a range of one to ten Hertz are

  15. Feed sources for livestock

    OpenAIRE

    Zanten, van, H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as la...

  16. Stutter seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Gumma, W. H.; Hughes, D. R.; Zimmerman, N. S.

    1980-08-12

    An improved seismic prospecting system comprising the use of a closely spaced sequence of source initiations at essentially the same location to provide shorter objective-level wavelets than are obtainable with a single pulse. In a preferred form, three dynamite charges are detonated in the same or three closely spaced shot holes to generate a downward traveling wavelet having increased high frequency content and reduced content at a peak frequency determined by initial testing.

  17. Contested sources of authority

    DEFF Research Database (Denmark)

    Kyed, Helene Maria; Buur, Lars

    2006-01-01

    In Mozambique, the current legal framework institutionalizes a rural–urban differentiation of local governance, allowing for elected representation in thirty-three urban settings and the recognition of ‘community authorities’ in rural areas. This article deals with the latter by exploring the imp...... on which legitimization was based defies any generalized Weberian dichotomy between traditional and modern/state types of office. Different sources of legitimacy sometimes foregrounded administrative needs and at other times maintained what became defined as traditional....

  18. The Advanced Neutron Source

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1989-01-01

    The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge in the late 1990's. The centerpiece of the ANS will be a steady-state research reactor of unprecedented thermal neutron flux (φ th ∼ 9·10 19 m -2 ·s -1 ) accompanied by extensive and comprehensive equipment and facilities for neutron-based research. 5 refs., 5 figs

  19. Background sources at PEP

    International Nuclear Information System (INIS)

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, γ-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs

  20. Sources and diagenet..

    African Journals Online (AJOL)

    The inter-site differences in 13C and 151V could be related to the sources of OM. In the Msasani Bay the material is derived from seagrasses while in the Dar es salaam harbour and Msimbazi micro-bay, large proportion is derived from the continent. Other parameters ofOC, nitrogen and C/N ratios for these three sites show ...

  1. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... is dedicated to vortex rings. Source rings are only briefly mentioned....

  2. Proton beam source

    International Nuclear Information System (INIS)

    Auslender, V.L.; Lazarev, V.N.; Panfilov, A.D.

    1979-01-01

    A proton pulse source with penning discharge and a cathode needle in the discharge chamber is described. The source is simple in design and has a great service life. An electromagnet induces a magnetic field of the order of 700 Oe along the axis of the discharge chamber. In this field the discharge is ignited between the left and right cathodes when a positive voltage is applied to the anode. A hole in the recess of the right cathode serves to provide the injection of plasma into the accelerating gap. The cathodes and the anode unit are set into a sleeve welded to magnet poles. Through a magnetic circuit this unit is placed on a high-voltage ceramic insulator. For extraction and initial shaping of an ion beam with a divergence angle of 3 0 use is made of extraction electrodes which form the Pierce optics. Further shaping of the ion beam is realized by an electrostatic lens. Tungsten grids in the holes of grounded electrodes increase the focusing effect of the lens. At the input of the first accelerating gap of an accelerator the described source provides an ion peak current of 140 mA at 65% content of protons and a normalized emittance of no more than 4x10 -5 cmxrad

  3. Inverted magnetron ion source

    International Nuclear Information System (INIS)

    Singh, B.; Boyarsky, D.

    1985-01-01

    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

  4. Future Synchrotron Radiation Sources

    CERN Document Server

    Winick, Herman

    2003-01-01

    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, micr...

  5. Introscopy using gamma sources

    International Nuclear Information System (INIS)

    Gromov, Yu.V.; Leonov, B.I.; Najorov, A.N.; Smirnov, N.N.; Firstov, V.G.

    1978-01-01

    A method is described of working with standard 170 Tm, 75 Se, 192 Ir, 137 Cs and 60 Co sources at the activity of 1-4000 Ci, during television gamma introscopy of steel products. Experiments involving the RI-10T introscope are carried out to determine prospects of using various radiation sources. The results of using X-ray instruments for control of steel products are also shown for comparison. In introscopy of X-rayed steel products over 25 mm thick, spreading of the edge of the detected groove image is shown to be comparable when using X radiation and gamma radiation of standard sources. Sensitivity of control by fluorographic introscope in X-raying and gamma irradiation of products over 25 mm thick will presumably be the same owing to the detector storage capacity. The use of commercial gamma flaw detecting instruments together with a television introscope permits to reliably reveal defects of 0.5-2.0 mm in size, eliminating possible instability of operation of X-ray instruments, particularly in field conditions

  6. Negative ion beam extraction in ROBIN

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Gourab, E-mail: bansal@ipr.res.in [Institute for Plasma Research (IPR), Bhat, Gandhinagar, Gujarat 382428 (India); Gahlaut, Agrajit; Soni, Jignesh; Pandya, Kaushal; Parmar, Kanu G.; Pandey, Ravi; Vuppugalla, Mahesh; Prajapati, Bhavesh; Patel, Amee; Mistery, Hiren [Institute for Plasma Research (IPR), Bhat, Gandhinagar, Gujarat 382428 (India); Chakraborty, Arun; Bandyopadhyay, Mainak; Singh, Mahendrajit J.; Phukan, Arindam; Yadav, Ratnakar K.; Parmar, Deepak [ITER-India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujarat 380025 (India)

    2013-10-15

    Highlights: ► A RF based negative hydrogen ion beam test bed has been set up at IPR, India. ► Ion source has been successfully commissioned and three campaigns of plasma production have been carried out. ► Extraction system (35 kV) has been installed and commissioning has been initiated. Negative ion beam extraction is immediate milestone. -- Abstract: The RF based single driver −ve ion source experiment test bed ROBIN (Replica Of BATMAN like source in INDIA) has been set up at Institute for Plasma Research (IPR), India in a technical collaboration with IPP, Garching, Germany. A hydrogen plasma of density 5 × 10{sup 12} cm{sup −3} is expected in driver region of ROBIN by launching 100 kW RF power into the driver by 1 MHz RF generator. The cesiated source is expected to deliver a hydrogen negative ion beam of 10 A at 35 kV with a current density of 35 mA/cm{sup 2} as observed in BATMAN. In first phase operation of the ROBIN ion source, a hydrogen plasma has been successfully generated (without extraction system) by coupling 80 kW RF input power through a matching network with high power factor (cos θ > 0.8) and different plasma parameters have been measured using Langmuir probes and emission spectroscopy. The plasma density of 2.5 × 10{sup 11} cm{sup −3} has been measured in the extraction region of ROBIN. For negative hydrogen ion beam extraction in second phase operation, extraction system has been assembled and installed with ion source on the vacuum vessel. The source shall be first operated in volume mode for negative ion beam extraction. The commissioning of the source with high voltage power supply has been initiated.

  7. Natural sources of ionizing radiations

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

  8. Quasi-Y-source inverter

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    This paper introduces a new inverter topology called a “quasi-Y-source inverter”. The proposed inverter inherits all the advantages of the original Y-source inverter. In addition, the new topology draws continuous current from the source which is required for many renewable sources. It also has dc...

  9. Source Monitoring in Alzheimer's Disease

    Science.gov (United States)

    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…

  10. Global sourcing of advanced services

    OpenAIRE

    Ørberg Jensen, Peter D.; Petersen, Bent

    2011-01-01

    In this exploratory study we take a strategic management approach to global sourcing of advanced services. We discuss in which ways conventional sourcing differs from strategic sourcing and what impels firms to aim for the latter (or, prevent them from doing so). Potentially, strategic global sourcing of services has high returns, but is also associated with high risks and needs for organizational changes. Strategic global sourcing may therefore be outside firms’ “comfort zone”...

  11. Chandra Source Catalog: User Interface

    Science.gov (United States)

    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.

  12. Selective structural source identification

    Science.gov (United States)

    Totaro, Nicolas

    2018-04-01

    In the field of acoustic source reconstruction, the inverse Patch Transfer Function (iPTF) has been recently proposed and has shown satisfactory results whatever the shape of the vibrating surface and whatever the acoustic environment. These two interesting features are due to the virtual acoustic volume concept underlying the iPTF methods. The aim of the present article is to show how this concept of virtual subsystem can be used in structures to reconstruct the applied force distribution. Some virtual boundary conditions can be applied on a part of the structure, called virtual testing structure, to identify the force distribution applied in that zone regardless of the presence of other sources outside the zone under consideration. In the present article, the applicability of the method is only demonstrated on planar structures. However, the final example show how the method can be applied to a complex shape planar structure with point welded stiffeners even in the tested zone. In that case, if the virtual testing structure includes the stiffeners the identified force distribution only exhibits the positions of external applied forces. If the virtual testing structure does not include the stiffeners, the identified force distribution permits to localize the forces due to the coupling between the structure and the stiffeners through the welded points as well as the ones due to the external forces. This is why this approach is considered here as a selective structural source identification method. It is demonstrated that this approach clearly falls in the same framework as the Force Analysis Technique, the Virtual Fields Method or the 2D spatial Fourier transform. Even if this approach has a lot in common with these latters, it has some interesting particularities like its low sensitivity to measurement noise.

  13. SYNCHROTRON RADIATION SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Contact ionization ion source

    International Nuclear Information System (INIS)

    Hashmi, N.; Van Der Houven Van Oordt, A.J.

    1975-01-01

    An ion source in which an apertured or foraminous electrode having a multiplicity of openings is spaced from one or more active surfaces of an ionisation electrode, the active surfaces comprising a material capable of ionising by contact ionization a substance to be ionized supplied during operation to the active surface or surfaces comprises means for producing during operation a magnetic field which enables a stable plasma to be formed in the space between the active surface or surfaces and the apertured electrode, the field strength of the magnetic field being preferably in the range between 2 and 8 kilogauss. (U.S.)

  15. Alternative energy sources

    International Nuclear Information System (INIS)

    Chapman, P.

    1978-01-01

    It is suggested that the development of alternative energy sources has made them more attractive than nuclear power, due to their characteristics, such as small scale and short lead times, moderate costs and minimal environmental impact. The objectives of energy policy are discussed in relation to forecasts of energy demand. Tables show (a) projected useful energy demands UK; (b) patterns of end-use of energy; (c) costs of heating fuels; (d) net present value of gas purchases; (e) useful-energy by end-use analysis; and (f) primary fuel summary 2025. The contributions of hydro, nuclear, waves, solar, oil, gas and coal are estimated to 2025. (U.K.)

  16. PLANTS, SOURCE FOR BIOFUELS

    Directory of Open Access Journals (Sweden)

    Irina Ramona PECINGINĂ

    2016-12-01

    Full Text Available The most affordable alternative energy sources to fossil plants with hydropower are some oils that accumulate in different organs other accumulating carbohydrates with high energy value. They are known worldwide and cultivated a number of plant species entering the oilseeds, which provides significant production of edible oil (soybean, sunflower, etc. Vegetable oils or their product derived biodiesel fuels are potential diesel engines, representing an alternative to fuels. The most promising suitable for the production of oil crops "with short circuit "or biodiesel are fruits and seeds, both herbaceous and tree.

  17. Current HPM Source Research

    Science.gov (United States)

    Spencer, T. A.

    2003-12-01

    Advanced research continues in the field of High Power Microwaves (HPM), which have potential applications ranging from long distance communications, radar, environmental waste clean up, bio-toxin neutralization, fusion heating, as well as a host of others. Current HPM sources being studied are the Magnetically Insulated Line Oscillator, Relativistic Klystron Oscillator, and Relativistic Magnetron, and experimental and computational comparisons will be presented. Relevant components to be discussed are recent cathode results, recent antenna results, as well as the discussion of a HPM air breakdown experiment to be conducted in the near future.

  18. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  19. Internal sources dosimetry

    International Nuclear Information System (INIS)

    Savio, Eduardo

    1994-01-01

    The absorbed dose, need of estimation in risk evaluation in the application of radiopharmaceuticals in Nuclear Medicine practice,internal dosimetry,internal and external sources. Calculation methodology,Marinelli model,MIRD system for absorbed dose calculation based on biological parameters of radiopharmaceutical in human body or individual,energy of emitted radiations by administered radionuclide, fraction of emitted energy that is absorbed by target body.Limitation of the MIRD calculation model. A explanation of Marinelli method of dosimetry calculation,β dosimetry. Y dosimetry, effective dose, calculation in organs and tissues, examples. Bibliography .

  20. Central radio sources

    International Nuclear Information System (INIS)

    Phinney, E.S.

    1985-01-01

    The compact radio sources in the nuclei of most active galaxies lie closer to their centers of activity than any other region accessible to observation, excepting only the broad emission line region. They provide uniquely strong evidence for bulk motion of matter at relativistic velocities, encouraging the belief that the activity originates in a gravitational potential well whose escape velocity is of the order of the speed of light. The observational facts are reviewed as well as several theoretical pictures of them. Those places where systematic observations could help to distinguish the true theoretical picture from the many competing forgeries are emphasized. 76 references

  1. Data source handbook

    CERN Document Server

    Warden, Pete

    2011-01-01

    If you''re a developer looking to supplement your own data tools and services, this concise ebook covers the most useful sources of public data available today. You''ll find useful information on APIs that offer broad coverage, tie their data to the outside world, and are either accessible online or feature downloadable bulk data. You''ll also find code and helpful links. This guide organizes APIs by the subjects they cover-such as websites, people, or places-so you can quickly locate the best resources for augmenting the data you handle in your own service. Categories include: Website tools

  2. Organizing for Global Sourcing

    DEFF Research Database (Denmark)

    Bals, Lydia; Turkulainen, Virpi

    Research on Purchasing Organization is dominated by studies on centralization versus decentralization. While global sourcing relates to the integrated activities of purchasing and other functions in line with the company’s strategic objectives and while it has been put forward that hybrid...... organizations are on the rise, the exact ways in which companies employ hybrid organizations in this context have not been studied in further detail. By presenting a multi-year case study from 2010 to 2013 at a pharmaceutical company, we elaborate on the existing knowledge regarding hybrid organizations...

  3. Compact synchrotron light sources

    CERN Document Server

    Weihreter, Ernst

    1996-01-01

    This book covers a new niche in circular accelerator design, motivated by the promising industrial prospects of recent micromanufacturing methods - X-ray lithography, synchrotron radiation-based micromachining and microanalysis techniques. It describes the basic concepts and the essential challenges for the development of compact synchrotron radiation sources from an accelerator designer's point of view and gives an outline of the actual state of the art. The volume is intended as an introduction and as a reference for physicists, engineers and managers involved in this rapidly developing fiel

  4. GPC Single Source Letter

    Science.gov (United States)

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  5. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  6. [Microbial sources of pigments].

    Science.gov (United States)

    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.

  7. Optimization of neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, E.B.

    1993-11-09

    I consider here the optimization of the two component neutron source, allowing beam species and energy to vary. A simple model is developed, based on the earlier publications, that permits the optimum to be obtained simply. The two component plasma, with one species of hot ion (D{sup +} or T{sup +}) and the complementary species of cold ion, is easy to analyze in the case of a spatially uniform cold plasma, as to good approximation the total number of hot ions is important but not their spatial distribution. Consequently, the optimization can ignore spatial effects. The problem of a plasma with both types of hot ions and cold ions is rather more difficult, as the neutron production by hot-hot interactions is sensitive to their spatial distributions. Consequently, consideration of this problem will be delayed to a future memorandum. The basic model is that used in the published articles on the two-component, beam-plasma mirror source. I integrate the Fokker-Planck equation analytically, obtaining good agreement with previous numerical results. This simplifies the optimization, by providing a functional form for the neutron production. The primary result is expressed in terms of the power efficiency: watts of neutrons/watts of primary power. The latter includes the positive ion neutralization efficiency. At 150 keV, the present model obtains an efficiency of 0.66%, compared with 0.53% of the earlier calculation.

  8. Plasma source ion implantation

    International Nuclear Information System (INIS)

    Conrad, J.R.; Forest, C.

    1986-01-01

    The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

  9. Neutron source multiplication method

    International Nuclear Information System (INIS)

    Clayton, E.D.

    1985-01-01

    Extensive use has been made of neutron source multiplication in thousands of measurements of critical masses and configurations and in subcritical neutron-multiplication measurements in situ that provide data for criticality prevention and control in nuclear materials operations. There is continuing interest in developing reliable methods for monitoring the reactivity, or k/sub eff/, of plant operations, but the required measurements are difficult to carry out and interpret on the far subcritical configurations usually encountered. The relationship between neutron multiplication and reactivity is briefly discussed and data presented to illustrate problems associated with the absolute measurement of neutron multiplication and reactivity in subcritical systems. A number of curves of inverse multiplication have been selected from a variety of experiments showing variations observed in multiplication during the course of critical and subcritical experiments where different methods of reactivity addition were used, with different neutron source detector position locations. Concern is raised regarding the meaning and interpretation of k/sub eff/ as might be measured in a far subcritical system because of the modal effects and spectrum differences that exist between the subcritical and critical systems. Because of this, the calculation of k/sub eff/ identical with unity for the critical assembly, although necessary, may not be sufficient to assure safety margins in calculations pertaining to far subcritical systems. Further study is needed on the interpretation and meaning of k/sub eff/ in the far subcritical system

  10. Moving Sources Detection System

    International Nuclear Information System (INIS)

    Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Normand, Stephane

    2013-06-01

    To monitor radioactivity passing through a pipe or in a given container such as a train or a truck, radiation detection systems are commonly employed. These detectors could be used in a network set along the source track to increase the overall detection efficiency. However detection methods are based on counting statistics analysis. The method usually implemented consists in trigging an alarm when an individual signal rises over a threshold initially estimated in regards to the natural background signal. The detection efficiency is then proportional to the number of detectors in use, due to the fact that each sensor is taken as a standalone sensor. A new approach is presented in this paper taking into account the temporal periodicity of the signals taken by all distributed sensors as a whole. This detection method is not based only on counting statistics but also on the temporal series analysis aspect. Therefore, a specific algorithm is then developed in our lab for this kind of applications and shows a significant improvement, especially in terms of detection efficiency and false alarms reduction. We also plan on extracting information from the source vector. This paper presents the theoretical approach and some preliminary results obtain in our laboratory. (authors)

  11. Open source clustering software.

    Science.gov (United States)

    de Hoon, M J L; Imoto, S; Nolan, J; Miyano, S

    2004-06-12

    We have implemented k-means clustering, hierarchical clustering and self-organizing maps in a single multipurpose open-source library of C routines, callable from other C and C++ programs. Using this library, we have created an improved version of Michael Eisen's well-known Cluster program for Windows, Mac OS X and Linux/Unix. In addition, we generated a Python and a Perl interface to the C Clustering Library, thereby combining the flexibility of a scripting language with the speed of C. The C Clustering Library and the corresponding Python C extension module Pycluster were released under the Python License, while the Perl module Algorithm::Cluster was released under the Artistic License. The GUI code Cluster 3.0 for Windows, Macintosh and Linux/Unix, as well as the corresponding command-line program, were released under the same license as the original Cluster code. The complete source code is available at http://bonsai.ims.u-tokyo.ac.jp/mdehoon/software/cluster. Alternatively, Algorithm::Cluster can be downloaded from CPAN, while Pycluster is also available as part of the Biopython distribution.

  12. Population: sources and trends.

    Science.gov (United States)

    Keane, J G

    1986-01-01

    Most of the data on US immigration flows do not come from the Census Bureau; rather, data from the Immigration and Naturalization Service, on the number of legal migrants entering the country, and from the Office of Refugee Resettlement on the number of refugees entering the country is used. Between 1970 and 1980, the foreign-born population in the US grew by some 4.5 million persons or an astounding 46%. The foreign-born population in the US is concentrated in a few geographic areas; 3.6 million, or 1/4 of the foreign-born, live in California, and New York and Florida together have another 1/4 of the foreign-born population. The concentration of the foreign-born population is very pronounced in metropolitan areas. Mexico supplied the largest fraction of the foreign-born population in the 1980 census. Over 5 out of every 6 or 84% of the foreign-born persons who came to the US before 1950 were born in Europe or Canada. The shift from Europe as the main source of immigration was marked by a shift to Latin America and Asia as the principal sources of recent migrants to the US. The Census Bureau has made a number of projections using different scenarios for fertility, mortality, and immigration. The middle migration series, roughly consistent with current levels of legal immigration, shows that the population would grow to about 311 million by 2080 from a current level of 237 million.

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

    Science.gov (United States)

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

    2016-01-01

    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. 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. 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.

  14. New source review for stationary sources of air pollution

    National Research Council Canada - National Science Library

    Committee on Changes in New Source Review Programs for Stationary Sources of Air Pollution; National Research Council; Division on Earth and Life Studies; National Research Council; National Academy of Sciences

    2006-01-01

    The Clean Air Act established a pair of programsâ€"known as New Source Review (NSR)â€"that regulate large stationary sources of air pollution, such as factories and electricity-generating facilities...

  15. Accessing vs Sourcing Knowledge

    DEFF Research Database (Denmark)

    Awate, Snehal; Larsen, Marcus M.; Mudambi, Ram

    2015-01-01

    Research and development (R&D) internationalization is on the rise for advanced economy multinationals (AMNEs) as well as emerging economy multinationals (EMNEs). We study EMNE R&D internationalization by comparing it to that by AMNEs in the context of an emerging, knowledge-intensive industry. We...... find that these two are fundamentally different processes. While the internationalization of AMNEs' R&D activities can largely be explained in terms of the twin strategies of competence exploitation and competence creation, EMNE R&D internationalization is rooted in the firms' overall catch up strategy...... to get on par with industry leaders. An in-depth comparison of knowledge flows reveals that within AMNEs, headquarters often serves the primary source of knowledge for R&D subsidiaries. In contrast, within EMNEs, headquarters accesses knowledge from R&D subsidiaries in advanced economies for innovation...

  16. Swiss Light Source SLS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    The Paul Scherrer Institute has begun work on the implementation of the Swiss Synchrotron Light Source (SLS). The construction of this facility, which will have international scope, is intended to provide a national focus for co-operation between various disciplines and for research in material sciences. Although basic research in physics and chemistry, biology, medicine and environmental sciences would seem to be in the foreground, industrial users also have an interest in the SLS. At present, this mainly centres on investigations into the structure of biological and chemical molecules, the use of high-performance methods of analysis, and the manufacture and investigation of microstructures. SLS is planned to be taken into service with an initial experimental installation by the middle of 2001. In this brochure an overview is presented on the main characteristics of the SLS facility and on its significance as a tool for interdisciplinary research.

  17. High brightness electron sources

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. PRAMU. Contamination sources

    International Nuclear Information System (INIS)

    Asenjo, Armando R.

    2000-01-01

    Mining and milling activities have been carried out in Argentina during the last 40 years, and nowadays National Atomic Energy Commission (CNEA) of Argentina is undertaking the Uranium Mining Environmental Restoration Project (PRAMU). The aim of this project is to achieve that in all the places where uranium mining activities were developed, to restore the environment as much as it is possible, according to the legislation in force. The sites which are studied are: Malargue (Mendoza province), Cordoba (Cordoba province), Los Gigantes (Cordoba province), Huemul (Mendoza province), Pichinan (Chubut province), Tonco (Salta province), La Estela (San Luis province), Los Colorados (La Rioja province). In order to develop the restoration project in each site, one of the first task to be performed is to know quantities and the chemical, physicals and radiological characteristics of the contamination sources. In the present paper the activities of PRAMU in this field, are informed. (author)

  19. Infrared source test

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Arctic Aerosols and Sources

    DEFF Research Database (Denmark)

    Nielsen, Ingeborg Elbæk

    2017-01-01

    carbon, which is the most efficient aerosol to absorb radiation, is found to be one of the largest contributors to global warming. Aerosols are emitted from both anthropogenic and natural sources and the major components of atmospheric particulate matter include sulfate, organic aerosols, nitrate...... at the Villum Research Station, Station Nord in North Greenland. Laboratory studies of a conventional wood stove showed that particle emissions were strongly dependent on the intensity of burn rate. The burning cycle was divided into three phases, where the first phase, the fuel addition, resulted in short-lived...... but high emissions of levoglucosan and organic aerosols. The second phase, the intermediate phase, was dominated by black carbon and only to a minor extent organic aerosols and levoglucosan. The final burn out phase was generally represented by low concentrations of all species and overall the full cycle...

  1. Swiss Light Source SLS

    International Nuclear Information System (INIS)

    1999-09-01

    The Paul Scherrer Institute has begun work on the implementation of the Swiss Synchrotron Light Source (SLS). The construction of this facility, which will have international scope, is intended to provide a national focus for co-operation between various disciplines and for research in material sciences. Although basic research in physics and chemistry, biology, medicine and environmental sciences would seem to be in the foreground, industrial users also have an interest in the SLS. At present, this mainly centres on investigations into the structure of biological and chemical molecules, the use of high-performance methods of analysis, and the manufacture and investigation of microstructures. SLS is planned to be taken into service with an initial experimental installation by the middle of 2001. In this brochure an overview is presented on the main characteristics of the SLS facility and on its significance as a tool for interdisciplinary research

  2. Sources et bibliographie

    OpenAIRE

    2017-01-01

    Sources manuscrites Archives nationales JJ 97, JJ 111 (registres du Trésor des Chartes) P 490 ; P 492 ; P 493 ; P 13782 ; P 14022 ; P 14023 (Chambre des comptes, Forez, anciens aveux, 1214-1514 et titres du Forez, 1173-1519). Archives départementales de la Loire Série B B 1171 ; B 1189 ; B 1190 ; B 1353 ; B 1571 ; B 1717 ; B 1724 ; B 1839 ; B 1842 ; B 1844 ; B 1850 ; B 1851 ; B 1852 ; B 1853 ; B 1854 ; B 1856 ; B 1858 ; B 1860 ; B 1861 ; B 1862 ; B 1864 ; B 1865 ; B 1866 ; B 1867 ; B 1869 ; B...

  3. Mobile Source Observation Database (MSOD)

    Science.gov (United States)

    The Mobile Source Observation Database (MSOD) is a relational database developed by the Assessment and Standards Division (ASD) of the U.S. EPA Office of Transportation and Air Quality (formerly the Office of Mobile Sources).

  4. SOFTWARE OPEN SOURCE, SOFTWARE GRATIS?

    Directory of Open Access Journals (Sweden)

    Nur Aini Rakhmawati

    2006-01-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Berlakunya Undang – undang Hak Atas Kekayaan Intelektual (HAKI, memunculkan suatu alternatif baru untuk menggunakan software open source. Penggunaan software open source menyebar seiring dengan isu global pada Information Communication Technology (ICT saat ini. Beberapa organisasi dan perusahaan mulai menjadikan software open source sebagai pertimbangan. Banyak konsep mengenai software open source ini. Mulai dari software yang gratis sampai software tidak berlisensi. Tidak sepenuhnya isu software open source benar, untuk itu perlu dikenalkan konsep software open source mulai dari sejarah, lisensi dan bagaimana cara memilih lisensi, serta pertimbangan dalam memilih software open source yang ada. Kata kunci :Lisensi, Open Source, HAKI

  5. EV-GHG Mobile Source

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EV-GHG Mobile Source Data asset contains measured mobile source GHG emissions summary compliance information on light-duty vehicles, by model, for certification...

  6. Helping Residents Protect Water Sources

    Science.gov (United States)

    Building on the successful early engagement of the Plain Sect agricultural community, the Eastern Lancaster County Source Water Protection Collaborative is expanding its efforts to involve local residents in the work of protecting drinking water sources.

  7. Sources for charged particles; Les sources de particules chargees

    Energy Technology Data Exchange (ETDEWEB)

    Arianer, J.

    1997-09-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.).

  8. Mot-croisé : Source(s.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Cherel

    2006-03-01

    Full Text Available    Le point de vue de l’informatique. Le source (contraction de code source d'un logiciel informatique est sa forme la plus compréhensible pour les êtres humains. Les ordinateurs utilisent la forme exécutable (ou binaire du logiciel, qui est créé à partir du source par le biais d'un compilateur. Quand on installe un programme, on installe un exécutable. Tous les logiciels ont leur source, qui est soit distribué librement (logiciels open source , ou ouverts, ou bien ...

  9. Global Sourcing and Firm Selection

    DEFF Research Database (Denmark)

    Kohler, Wilhelm; Smolka, Marcel

    2014-01-01

    We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms.......We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms....

  10. Experience with synchrotron radiation sources

    International Nuclear Information System (INIS)

    Krinsky, S.

    1987-01-01

    The development of synchrotron radiation sources is discussed, emphasizing characteristics important for x-ray microscopy. Bending magnets, wigglers and undulators are considered as sources of radiation. Operating experience at the national Synchrotron Light Source on the VUV and XRAY storage rings is reviewed, with particular consideration given to achieved current and lifetime, transverse bunch dimensions, and orbit stability. 6 refs., 3 figs

  11. Trust Revision for Conflicting Sources

    Science.gov (United States)

    2017-02-01

    flicting evidence for various reasons, including errors and decep- tion. When conflicting evidence is received, some sources produce more accurate... conflicting opinions coming from different information sources . In the model, the analyst assigns a trust opinion to each of the information sources , where a

  12. Authorship Attribution of Source Code

    Science.gov (United States)

    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…

  13. The SLC polarized electron source

    International Nuclear Information System (INIS)

    Clendenin, J.E.

    1990-10-01

    A polarized electron source consisting of a 3-electrode photocathode gun and a flashlamp-pumped dye laser has been designed and built for the SLC and is currently undergoing commissioning. The source is described, and the operating configuration is discussed. The present status of the source and future plans are briefly indicated. 7 refs., 4 figs

  14. Source-space ICA for MEG source imaging.

    Science.gov (United States)

    Jonmohamadi, Yaqub; Jones, Richard D

    2016-02-01

    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. 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. 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. 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.

  15. Defining Open Source

    Directory of Open Access Journals (Sweden)

    Russ Nelson

    2007-09-01

    Full Text Available The Open Source Initiative and the Free Software Foundation share a common goal: that everyone should be free to modify and redistribute the software they commonly use. 'Should' is of course a normative word. For the FSF, 'should' is a moral imperative. Anything else is an immoral restriction on people's activities, just as are restrictions on speech, press, movement, and religion. For the OSI, freedom is a necessary precondition for a world where "software doesn't suck", in the words of a founder of the OSI. The FSF started from its founder's GNU Manifesto widely published in 1985. Given the manifesto's hostility to copyright, and given the failure of the Free Software Foundation to gain any traction amongst commercial users of software even with a 13-year head start, a group of people gathered together in 1998 to talk about a new strategy to get the corporate world to listen to hackers. They were impressed by Eric Raymond's Cathedral and the Bazaar's take-up among business leaders.

  16. Hydrocarbons: source of energy

    International Nuclear Information System (INIS)

    Imarisio, G.; Frias, M.; Bemtgen, J.M.

    1989-01-01

    Hydrocarbons are at present the single most important source of energy, since they are the most versatile and widely used. It is expected that their importance will extend well into the next century and therefore it is essential to provide for all those improvements which will extend their availability and usefulness. The sub-programme ''Optimization of the production and utilization of hydrocarbons'' (within the Non-Nuclear Energy R and D Programme of the European Communities) is pursuing a number of R and D topics aimed at the above-mentioned results. It is implemented by means of shared-cost R and D contracts. At this first Seminar held in Lyon (France) from 21-23 September, 1988, all contractors of the sub-programme presented the state of progress of their R and D projects. These proceedings comprise all the papers presented at the Seminar. The section on oilfield exploration includes a report of work on the interpretation of nuclear logs by means of mathematical models. (author)

  17. Pi a source book

    CERN Document Server

    Berggren, Lennart; Borwein, Peter

    2004-01-01

    This book documents the history of pi from the dawn of mathematical time to the present. One of the beauties of the literature on pi is that it allows for the inclusion of very modern, yet accessible, mathematics. The articles on pi collected herein include selections from the mathematical and computational literature over four millennia, a variety of historical studies on the cultural significance of the number, and an assortment of anecdotal, fanciful, and simply amusing pieces. For this new edition, the authors have updated the original material while adding new material of historical and cultural interest. There is a substantial exposition of the recent history of the computation of digits of pi, a discussion of the normality of the distribution of the digits, new translations of works by Viete and Huygen, as well as Kaplansky's never-before-published "Song of Pi." From the reviews of earlier editions: "Few mathematics books serve a wider potential readership than does a source book and this particular on...

  18. Novel laser ion sources

    CERN Document Server

    Fournier, P; Kugler, H; Lisi, N; Scrivens, R; Rodríguez, F V; Düsterer, S; Sauerbrey, R; Schillinger, H; Theobald, W; Veisz, L; Tisch, J W G; Smith, R A

    2000-01-01

    Development in the field of high-power laser systems with repetition rates of several Hz and energies of few joules is highly active and opening, giving new possibilities for the design of laser ions sources. Preliminary investigations on the use of four different laser and target configurations are presented: (1) A small CO/sub 2/ laser (100 mJ, 10.6 mu m) focused onto a polyethylene target to produce C ions at 1 Hz repetition rate (CERN). (2) An excimer XeCl laser (6 J, 308 nm) focused onto solid targets (Frascati). (3) A femtosecond Ti: sapphire laser (250 mJ, 800 nm) directed onto a solid targets (Jena). (4) A picosecond Nd: yttrium-aluminum-garnet (0.3 J, 532 nm) focused into a dense medium of atomic clusters and onto solid targets (London). The preliminary experimental results and the most promising schemes will be discussed with respect to the scaling of the production of high numbers of highly charged ions. Different lasers are compared in terms of current density at 1 m distance for each charge state...

  19. The Advanced Neutron Source

    International Nuclear Information System (INIS)

    Peretz, F.J.

    1990-01-01

    The Advanced Neutron Source (ANS) is to be a multipurpose neutron research center, constructed around a high-flux reactor now being designed at the Oak Ridge National Laboratory (ORNL). Its primary purpose is to place the United States in the forefront of neutron scattering in the twenty-first century. Other research programs include nuclear and fundamental physics, isotope production, materials irradiation, and analytical chemistry. The ANS will be a unique and invaluable research tool because of the unprecedented neutron flux available from the high-intensity research reactor. But this reactor would be ineffective without world-class research facilities that allow the fullest utilization of the available neutrons. And, in turn, those research facilities will not produce new and exciting science without a broad population of users from all parts of the nation and the world, placed in a stimulating environment in which experiments can be effectively conducted and in which scientific exchange is encouraged. This paper discusses the measures being taken to ensure that the design of the ANS focuses not only on the reactor, but on providing the experiment and user support facilities needed to allow its effective use

  20. Neutron guides on pulsed sources

    International Nuclear Information System (INIS)

    Carlile, C.J.; Johnson, M.W.; Williams, W.G.

    1979-11-01

    A survey of the physics of neutron guides has been applied to their installation on pulsed neutron sources, particularly the Spallation Neutron Source (SNS) at the Rutherford Laboratory. Guides on pulsed sources generally view smaller source areas than those on continuous sources, and furthermore their lengths are fixed primarily by time-of-flight resolution requirements. These differences have been accounted for in the design of guides for two SNS instruments A Monte Carlo computer code has been used in the optimisation and simulation of the guide geometries. (author)

  1. Large source test stand for H-(D-) ion source

    International Nuclear Information System (INIS)

    Larson, R.; McKenzie-Wilson, R.

    1981-01-01

    The Brookhaven National Laboratory Neutral Beam Group has constructed a large source test stand for testing of the various source modules under development. The first objective of the BNL program is to develop a source module capable of delivering 10A of H - (D - ) at 25 kV operating in the steady state mode with satisfactory gas and power efficiency. The large source test stand contains gas supply and vacuum pumping systems, source cooling systems, magnet power supplies and magnet cooling systems, two arc power supplies rated at 25 kW and 50 kW, a large battery driven power supply and an extractor electrode power supply. Figure 1 is a front view of the vacuum vessel showing the control racks with the 36'' vacuum valves and refrigerated baffles mounted behind. Figure 2 shows the rear view of the vessel with a BNL Mk V magnetron source mounted in the source aperture and also shows the cooled magnet coils. Currently two types of sources are under test: a large magnetron source and a hollow cathode discharge source

  2. Radioactive source recovery program responses to neutron source emergencies

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  3. Radiation sources working group summary

    International Nuclear Information System (INIS)

    Fazio, M.V.

    1998-01-01

    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

  4. Plume rise from multiple sources

    International Nuclear Information System (INIS)

    Briggs, G.A.

    1975-01-01

    A simple enhancement factor for plume rise from multiple sources is proposed and tested against plume-rise observations. For bent-over buoyant plumes, this results in the recommendation that multiple-source rise be calculated as [(N + S)/(1 + S)]/sup 1/3/ times the single-source rise, Δh 1 , where N is the number of sources and S = 6 (total width of source configuration/N/sup 1/3/ Δh 1 )/sup 3/2/. For calm conditions a crude but simple method is suggested for predicting the height of plume merger and subsequent behavior which is based on the geometry and velocity variations of a single buoyant plume. Finally, it is suggested that large clusters of buoyant sources might occasionally give rise to concentrated vortices either within the source configuration or just downwind of it

  5. Coaxial slow source

    International Nuclear Information System (INIS)

    Brooks, R.D.; Jarboe, T.R.

    1990-01-01

    Field reversed configurations (FRCs) are a class of compact toroid with not toroidal field. The field reversed theta pinch technique has been successfully used for formation of FRCs since their inception in 1958. In this method an initial bias field is produced. After ionization of the fill gas, the current in the coil is rapidly reversed producing the radial implosion of a current sheath. At the ends of the coil the reversed field lines rapidly tear and reconnect with the bias field lines until no more bias flux remains. At this point, vacuum reversed field accumulates around the configuration which contracts axially until an equilibrium is reached. When extrapolating the use of such a technique to reactor size plasmas two main shortcomings are found. First, the initial bias field, and hence flux in a given device, which can be reconnected to form the configuration is limited from above by destructive axial dynamics. Second, the voltages required to produce rapid current reversal in the coil are very large. Clearly, a low voltage formation technique without limitations on flux addition is desirable. The Coaxial Slow Source (CSS) device was designed to meet this need. It has two coaxial theta pinch coils. Coaxial coil geometry allows for the addition of as much magnetic flux to the annular plasma between them as can be generated inside the inner coil. Furthermore the device can be operated at charging voltages less than 10 kV and on resistive diffusion, rather than implosive time scales. The inner coil is a novel, concentric, helical design so as to allow it to be cantilevered on one end to permit translation of the plasma. Following translation off the inner coil the Annular Field Reversed Configuration would be re-formed as a true FRC. In this paper we investigate the formation process in the new parallel configuration., CSSP, in which the inner and outer coils are connected in parallel to the main capacitor bank

  6. Portable source identification device

    Science.gov (United States)

    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.

  7. Portable Source Identification Device

    International Nuclear Information System (INIS)

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

    2005-01-01

    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

  8. Industrial ion sources broadbeam gridless ion source technology

    CERN Document Server

    Zhurin, Viacheslav V

    2012-01-01

    Due to the large number of uses of ion sources in academia and industry, those who utilize these sources need up to date and coherent information to keep themselves abreast of developments and options, and to chose ideal solutions for quality and cost-effectiveness. This book, written by an author with a strong industrial background and excellent standing, is the comprehensive guide users and developers of ion sources have been waiting for. Providing a thorough refresher on the physics involved, this resource systematically covers the source types, components, and the operational parameters.

  9. Leakage of caesium braquitherapy sources

    International Nuclear Information System (INIS)

    Lozada, J.A.

    1998-01-01

    In several Venezuelan public hospitals where cervix uteri tumours are treated by intracavitary radiotherapy, that use manual after loading Fletcher method, with Caesium 137 sources, the use of improper source holders, locally manufactured from pieces of drainage plastic tubing, which deteriorated and created a corrosive environment all around the sources, omission of manufacturer's recommendations regarding corrosion information, source storage, inspection and testing, violation of International Atomic Energy Agency Radiation Protection Procedures, and lack of proper regulatory control, resulted integrity damage to about sixty special form sources (ISO2919 C 63322), leakage of Cs-137 from a supposed insoluble refractory active content (caesium silicoaluminate), and contamination of applicators, floors and bedding. When the situation was detected by means removal contamination tests, after routine inspections, the sources were removed from the hospitals, decontaminated by means of immersion in 3% EDTA solution in ultrasonic bath, subjected to leaking assessment tests, and the ones that passed were placed in low cost stainless steel source holders, designed and built by the instituto Venezolano de Investigaciones Cientificas (IVIC) returned to the hospitals. The leaking sources were removed from use and considered radioactive waste. In order to avoid the occurrence of similar situations, all the importers of such sources are now required to send them to IVIC for testing and placement in proper source holders, before they are shipped to the hospitals. (author)

  10. A source of innovation.

    Science.gov (United States)

    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

  11. Disintegrins from Hematophagous Sources

    Directory of Open Access Journals (Sweden)

    Ivo M. B. Francischetti

    2012-04-01

    Full Text Available 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., Amblyomma sp., 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

  12. DESIGN OF ALTERNATIVE ENERGY SOURCES

    Directory of Open Access Journals (Sweden)

    Popa Stefania

    2013-11-01

    Full Text Available By energy sources we understand technologies and materials used to obtain various forms of energy necessary for the development of society. These sources must be in adequate quantities and be conveniently exploited in terms of technical, economic and sustainable perspective. Alternative energy uses the inherent power of natural sources like wind, tides, the sun. Alternative energy is a term used for some energy sources and energy storage technologies. Generally it indicates energies that are nontraditional and have low impact to the environment. The alternative energy term is used in contrast with the term fossil fuel according to some sources, while other sources use it with the meaning of renewable energy purposes.

  13. Ion sources for electrostatic accelerators

    International Nuclear Information System (INIS)

    Hellborg, R.

    1998-01-01

    Maybe the most important part of an electrostatic accelerator system, and also often the most tricky part is the ion source. There has been a rapid growth in activity in ion-source research and development during the last two to three decades. Some of these developments have also been of benefit to electrostatic accelerator users. In this report some of the different types of ion sources used in electrostatic accelerators are described. The list is not complete but more an overview of some of the more commonly used sources. The description is divided into two groups; positive ion sources for single stage electrostatic accelerators and negative ion sources for two stages (i.e. tandem) accelerators

  14. Editorial: Open Source in Government

    Directory of Open Access Journals (Sweden)

    Dru Lavigne

    2009-04-01

    Full Text Available Last summer, the Center for Strategic and International Studies published the sixth update to their Open Source Policy survey. The survey "tracks governmental policies on the use of open source software as reported in the press or other media." The report lists 275 open source policy initiatives. It also breaks down by country and by government level whether the policy on the use of open source is considered to be advisory, preferential, or mandatory. The editorial theme for the May issue of the OSBR is "open source in government" and we are pleased that the authors have drawn upon their experiences to provide insight into public policy regarding open source for many parts of the world.

  15. Convolutive Blind Source Separation Methods

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Larsen, Jan; Kjems, Ulrik

    2008-01-01

    During the past decades, much attention has been given to the separation of mixed sources, in particular for the blind case where both the sources and the mixing process are unknown and only recordings of the mixtures are available. In several situations it is desirable to recover all sources from...... the recorded mixtures, or at least to segregate a particular source. Furthermore, it may be useful to identify the mixing process itself to reveal information about the physical mixing system. In some simple mixing models each recording consists of a sum of differently weighted source signals. However, in many...... real-world applications, such as in acoustics, the mixing process is more complex. In such systems, the mixtures are weighted and delayed, and each source contributes to the sum with multiple delays corresponding to the multiple paths by which an acoustic signal propagates to a microphone...

  16. Radiation sources and technical services

    International Nuclear Information System (INIS)

    Stonek, K.; Satorie, Z.; Vyskocil, I.

    1981-01-01

    Work is briefly described of the department for sealed sources production of the Institute, including leak testing and surface contamination of sealed sources. The department also provides technical services including the inspections of sealed sources used in medicine and geology and repair of damaged sources. It carries out research of the mechanical and thermal strength of sealed sources and of the possibility of reprocessing used 226 Ra sources. The despatch department is responsible for supplying the entire country with home and imported radionuclides. The department of technical services is responsible for testing imported radionuclides, assembling materials testing, industrial and medical irradiation devices, and for the collection and storage of low-level wastes on a national scale. (M.D.)

  17. Embedded EZ-Source Inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chiang; Gao, F.

    2008-01-01

    Z-source inverters are recent topological options proposed for buck-boost energy conversion with a number of possible voltage and current-type circuitries already reported in the literature. Comparing them, a common feature noted is their inclusion of a LC impedance network, placed between the dc...... input source and inverter bridge. This impedance network allows the output end of a voltage-type Z-source inverter to be shorted for voltage-boosting without causing a large current flow, and the terminal current of a current-type inverter to be interrupted for current boosting without introducing over......-voltage oscillations to the system. Therefore, Z-source inverters are in effect safer and less complex, and can be implemented using only passive elements with no additional active semiconductor needed. Believing in the prospects of Z-source inverters, this paper contributes by introducing a new family of embedded EZ-source...

  18. Source-circuit design overview

    Science.gov (United States)

    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.

  19. Open source software and libraries

    OpenAIRE

    Randhawa, Sukhwinder

    2008-01-01

    Open source software is, software that users have the ability to run, copy, distribute, study, change, share and improve for any purpose. Open source library software’s does not need the initial cost of commercial software and enables libraries to have greater control over their working environment. Library professionals should be aware of the advantages of open source software and should involve in their development. They should have basic knowledge about the selection, installation and main...

  20. Ion sources for medical accelerators

    Science.gov (United States)

    Barletta, W. A.; Chu, W. T.; Leung, K. N.

    1998-02-01

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

  1. Advanced LIGO: sources and astrophysics

    International Nuclear Information System (INIS)

    Creighton, Teviet

    2003-01-01

    Second-generation detectors in LIGO will take us from the discovery phase of gravitational-wave observations to the phase of true gravitational-wave astrophysics, with hundreds or thousands of potential sources. This paper surveys the most likely and interesting potential sources for Advanced LIGO, and the astrophysical processes that each one will probe. I conclude that binary inspiral signals are expected, while continuous signals from pulsars are plausible but not guaranteed. Other sources, such as core-collapse bursts, cosmic strings and primordial stochastic backgrounds, are speculative sources for Advanced LIGO, but also potentially the most interesting, since they push the limits of our theoretical knowledge

  2. Microseismic sources of rotational type

    Science.gov (United States)

    Pasternak, Elena; Dyskin, Arcady; He, Junxian

    2017-04-01

    Traditionally the sources of seismic and microseismic events are related to shear fractures. The analysis of the seismic moment tensors of the sources associated with rock fracturing and hydraulic fracturing in the laboratory experiments and in-situ reveals that while there exist tensile and compressive sources, the shear sources prevail. The appearance of multiple shear sources, accompanied rock fracturing contradicts the results of the direct experiments suggesting that the rock as well as other materials not exhibiting clear plastic flow fail in tension. This contradiction is conventionally resolved by assuming the presence of multiple pre-existing shear fractures (faults or microfaults) whose sudden sliding provides microseismic events of shear type. We consider alternative mechanisms associated with bending of links between rotating particles and fragments of geomaterial and bending of bridges connecting opposite sides of hydraulic fractures. In both cases the fracturing is caused by the action of moments (or moment stresses) leading to bending, while at microscale the failure is associated with tensile microstresses leading to formation of tensile microcracks. In other words, at microscale the moment-related failure is failure in tension, as routinely observed in materials even in compression. It is easy to demonstrate that from a distance the sources of rotational type are equivalent to a standard double couple, similar to the one associated with shear fracturing. In other words what is currently interpreted as shear microseismic sources can in fact be rotational sources. This calls for new methods of detecting and interpreting microseismic sources; some possible methods are discussed.

  3. The status of the spallation neutron source ion source

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  4. INTERNET SOURCES Sources of Militaria on the World Wide Web

    African Journals Online (AJOL)

    INTERNET SOURCES. Sources of Militaria on the World Wide Web. KIM WALKER. Assistant Librarian, National Monuments Council. Having an interest in military-type topics is one thing, finding information on the web to quench your thirst for knowledge is another. The World Wide Web (WWW) is a uni- versal electronic ...

  5. BEST medical radioisotope production cyclotrons

    Science.gov (United States)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Gelbart, W. Z.; Johnson, Richard R.

    2013-04-01

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 μA to 1000 μA, depending on the cyclotron energy and application [1].

  6. BEST medical radioisotope production cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Johnson, Richard R. [Best Cyclotron Systems Inc., 7-8765 Ash Street, Vancouver, British Columbia, V6P 6T3 (Canada); Gelbart, W. Z. [Advanced System Designs Inc., 5295 Bear Bay Road, Garden Bay, BC, V0N 1S1 (Canada)

    2013-04-19

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 {mu}A to 1000 {mu}A, depending on the cyclotron energy and application.

  7. Source Segregation and Collection of Source-Segregated Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Matsufuji, Y.

    2011-01-01

    The Segregation of individual material fractions at the waste source and keeping the fractions separate for collection is one of the key issues in modern waste management. In most cases the waste is just kept segregated from other waste according to certain criteria that improve the possibility...... the more important it is to consider source segregation of the waste, since the amount of waste links to the possibility of obtaining manageable amounts of segregated waste with reasonable logistics as well as to the manpower that can be allocated at the source to perform source segregation of waste...... in wastes segregation addressing: - Purpose of source segregation. - Segregation criteria and guidance. - Segregation potentials and efficiencies. - Systems for collecting segregated fraction....

  8. C-188 cobalt-60 sealed source integrity: source monitoring

    International Nuclear Information System (INIS)

    Defalco, G.M.; Shah, V.

    1995-01-01

    The integrity of C-188 cobalt-60 sealed sources used for radiation processing will be a key factor in the continued industrial acceptance and growth of gamma irradiation technology. Given the public's relatively poor understanding of most nuclear topics and the news media's tendency to sensationalize events, it is appropriate for suppliers and users of gamma technology to be vigilant and conservative regarding the application of cobalt-60 sources to industrial purposes. Nordion's recent decision to extend the optional warranty on its C-188 cobalt-60 sealed source from 15 years to 20 years is based on over 30 years of data generated from its on-going SOURCE SURVEILLANCE PROGRAM. This paper presents an overview of the C-188 SOURCE SURVEILLANCE PROGRAM. (author)

  9. On non-radiating sources

    Science.gov (United States)

    Musafir, Ricardo E.

    2013-08-01

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

  10. Radiation Safety and Orphan Sources

    International Nuclear Information System (INIS)

    Janzekovic, H.; Krizman, M.

    2006-01-01

    The wide spread use of radioactive and particularly of nuclear materials which started in the last century very quickly also demonstrated negative sides. The external exposure and radiotoxicity of these materials could be easily used in a malevolent act. Due to the fact that these materials could not be detected without special equipment designed for that purpose, severe control over their use in all phases of a life cycle is required. An orphan source is a radioactive source which is not under regulatory control, either because it has never been under regulatory or because it has been abandoned, lost, misplaced, stolen or transferred without proper authorization. In the last ten years a few international conferences were dedicated to the improvement of the safety and security of radioactive sources. Three main tasks are focused, the maintenance of data bases related to events with orphan sources and the publications of such events, the preparation of recommendations and guidelines to national regulatory bodies in order to prevent and detect the events related to orphan sources as well as to develop the response strategies to radiological or nuclear emergency, appraisals of the national strategies of radioactive sources control. Concerning Slovenia, strengthening control over orphan sources in Slovenia started after the adoption of new legislation in 2002. It was carried out through several tasks with the aim to prevent orphan sources, as well as to identify the sources which could be potentially orphan sources. The comprehensive methodology was developed by the Slovenian nuclear safety administration (S.N.S.A.) based on international guidelines as well as on the study of national lesson learned cases. The methodology was developed and used in close cooperation with all parties involved, namely other regulatory authorities, police, customs, agency for radioactive waste management (A.R.A.O.), technical support organisations (T.S.O.), users of source, authorised

  11. Analyzing and Interpreting Historical Sources

    DEFF Research Database (Denmark)

    Kipping, Matthias; Wadhwani, Dan; Bucheli, Marcelo

    2014-01-01

    on social scientific methods as well as the practice and reflections of historians, the chapter describes analytical and interpretive process based on three basic elements, illustrating them with exemplars from management research: source criticism to identify possible biases and judge the extent to which....... The chapter contributes to the creation of a language for describing the use of historical sources in management research....

  12. Status of spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    Existing and planned facilities using proton accelerator driven spallation neutron source are reviewed. These include new project of neutron science proposed from Japan Atomic Energy Research Institute. The present status of facility requirement and accelerator technology leads us to new era of neutron science such as neutron scattering research and nuclear transmutation study using very intense neutron source. (author)

  13. Hooded arc ion-source

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    The positioning system for the hooded arc ion-source, shown prior to mounting, consists of four excentric shafts to locate the ion-source and central electrodes. It will be placed on the axis of the SC and introduced into the vacuum tank via the air locks visible in the foreground.

  14. Urban Sources of Air Pollution

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.

    1998-01-01

    A discusion of the relative importance of different mobile sources, effects of driving on emissions, history of emissions standards, and technological methods to reduce emissions.......A discusion of the relative importance of different mobile sources, effects of driving on emissions, history of emissions standards, and technological methods to reduce emissions....

  15. Accelerator based continuous neutron source.

    CERN Document Server

    Shapiro, S M; Ruggiero, A G

    2003-01-01

    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 pr...

  16. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium.

  17. High current polarized proton sources

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, J.G.

    1988-01-01

    Polarized proton sources are now being used more frequently on linacs. In pulsed operation up to 10 mA of /rvec H//sup +/ and 0.4 mA of /rvec H//sup /minus// have been produced. The present status of these sources, and developments to reach even higher intensities, are reviewed. 39 refs., 1 tab.

  18. Distributed source coding of video

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Van Luong, Huynh

    2015-01-01

    A foundation for distributed source coding was established in the classic papers of Slepian-Wolf (SW) [1] and Wyner-Ziv (WZ) [2]. This has provided a starting point for work on Distributed Video Coding (DVC), which exploits the source statistics at the decoder side offering shifting processing...

  19. The cohesiveness of sourcing teams

    DEFF Research Database (Denmark)

    Lidegaard, Nina

    2015-01-01

    Sourcing teams are introduced as an approach to achieving the interdepartmental integration necessary for companies to address the complexity of strategic sourcing. Companies aim at facilitating teams capable of balancing the goals and tasks of the team with departmental expectations; however...

  20. Ion source requirements for pulsed spallation neutron sources

    International Nuclear Information System (INIS)

    Alonso, J.R.

    1995-10-01

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

  1. Testing earthquake source inversion methodologies

    KAUST Repository

    Page, Morgan T.

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquakerelated computations, such as ground motion simulations and static stress change calculations.

  2. Impedance source power electronic converters

    CERN Document Server

    Liu, Yushan; Ge, Baoming; Blaabjerg, Frede; Ellabban, Omar; Loh, Poh Chiang

    2016-01-01

    Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding control methods. Presents the latest power conversion solutions that aim to advance the role of pow...

  3. Impedance Source Power Electronic Converters

    DEFF Research Database (Denmark)

    Liu, Yushan; Abu-Rub, Haitham; Ge, Baoming

    Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable...... and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key...... features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding...

  4. Embedded EZ-Source Inverters

    DEFF Research Database (Denmark)

    Chiang Loh, Poh; Gao, Feng; Blaabjerg, Frede

    2010-01-01

    Z-source inverters are recent topological options proposed for buck–boost energy conversion with a number of possible voltage- and current-type circuitries already reported in the literature. Comparing them, a common feature noted is their inclusion of an LC impedance network, placed between the dc...... input source and inverter bridge. This impedance network allows the output end of a voltage-type Z-source inverter to be shorted for voltage boosting without causing a large current flow and the terminal current of a current-type inverter to be interrupted for current boosting without introducing...... overvoltage oscillations to the system. Therefore, Z-source inverters are, in effect, safer and less complex and can be implemented using only passive elements with no additional active semiconductor needed. Believing in the prospects of Z-source inverters, this paper contributes by introducing a new family...

  5. A-Source Impedance Network

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Galigekere, Veda Prakash

    2016-01-01

    A novel A-source impedance network is proposed in this letter. The A-source impedance network uses an autotransformer for realizing converters for any application that demand a very high dc voltage gain. The network utilizes a minimal turns ratio compared to other Magnetically Coupled Impedance S...... with an example single-switch 400 W dc-dc converter. For the closed-loop control design and stability assessment, a small signal model and its analysis of the proposed network are also presented in brief....... Source (MCIS) networks to attain a high voltage gain. In addition, the proposed converter draws a continuous current from the source, and hence it is suitable for many types of renewable energy sources. The derived network expressions and theoretical analysis are finally validated experimentally...

  6. TRIUMF: Technology transfer

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    In our occasional series highlighting the increasingly important area of technology transfer and industrial spinoff from high energy physics, this month the CERN Courier focuses on TRIUMF in Vancouver, Canada's major national facility for research in subatomic physics, a particularly illustrative example of the rewards and challenges involved. TRIUMF is based on a 520 MeV negative hydrogen ion cyclotron meson factory operated by a consortium of Canadian universities. Although the primary funding from the Canadian government is earmarked for support of basic research, the laboratory has always fostered applications of the technologies available, supporting them with funds from other sources. At first this ''applied programme'' involved simply the provision of particle beams for other scientific, medical and industrial uses - protons for the development of neutrondeficient radioisotopes, neutrons for activation analysis, pions for cancer therapy, and muons for chemistry and condensed-matter physics. Twenty five years on, the technology transfer process has resulted not only in a significantly expanded internal applied programme, with many areas of activity quite independent of the big cyclotron, but also in a number of successful commercial operations in the Vancouver area. Radioisotope production has been a particularly fruitful source for technology transfer, the early development work leading to two important initiatives - the establishment of a commercial radioisotope production facility on site and the inauguration of a positron emission tomography (PET) program at the University of British Columbia nearby. In 1979 Atomic Energy of Canada Ltd's isotope production division (now Nordion International Inc.) decided to establish a western Canadian facility at TRIUMF, to produce the increasingly important neutron-deficient radioisotopes obtainable with accelerator beams, primarily for medical applications. This would complement their

  7. Sealed source peer review plan

    International Nuclear Information System (INIS)

    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

  8. Spectrometers for compact neutron sources

    Science.gov (United States)

    Voigt, J.; Böhm, S.; Dabruck, J. P.; Rücker, U.; Gutberlet, T.; Brückel, T.

    2018-03-01

    We discuss the potential for neutron spectrometers at novel accelerator driven compact neutron sources. Such a High Brilliance Source (HBS) relies on low energy nuclear reactions, which enable cryogenic moderators in very close proximity to the target and neutron optics at comparably short distances from the moderator compared to existing sources. While the first effect aims at increasing the phase space density of a moderator, the second allows the extraction of a large phase space volume, which is typically requested for spectrometer applications. We find that competitive spectrometers can be realized if (a) the neutron production rate can be synchronized with the experiment repetition rate and (b) the emission characteristics of the moderator can be matched to the phase space requirements of the experiment. MCNP simulations for protons or deuterons on a Beryllium target with a suitable target/moderator design yield a source brightness, from which we calculate the sample fluxes by phase space considerations for different types of spectrometers. These match closely the figures of todays spectrometers at medium flux sources. Hence we conclude that compact neutron sources might be a viable option for next generation neutron sources.

  9. Diversity employment and recruitment sources

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Designing of RF ion source and the power sources system

    International Nuclear Information System (INIS)

    Rusdiyanto.

    1978-01-01

    An RF ion source prototype is being developed for the particle accelerator at the Gama Research Centre. Supply of the gas is fed into the plasma chamber by means of neadle valve system. Magnetic field strength of about 500 gauss is applied to the system to improve the ionization efficiency. Components and spare parts of the RF ion source are made based on locally available materials and are discussed in this report. (author)

  11. Open source firewall implementation : replacing traditional firewall with open source

    OpenAIRE

    Thakur, Amit

    2015-01-01

    The prime focus of thesis is to substitute a real life solution of a router-based firewall with an open source solution having an easy, manageable, and centralized GUI and integrated built-in network extensions. The thesis compares three popular open source firewalls, namely Untangle, pfSense and Zeroshell, in order to meet security requirements. These three firewalls were installed in a VMware environment and tested for installation, stability, built-in components, security level, GUI interf...

  12. Spallation neutron source and other high intensity froton sources

    International Nuclear Information System (INIS)

    Weiren Chou

    2003-01-01

    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 and D program is included in an appendix

  13. The Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    White, William E., E-mail: wewhite@slac.stanford.edu; Robert, Aymeric; Dunne, Mike [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-21

    The present status of the Linac Coherent Light Source as a user facility is presented. Opportunities and challenges as well as the scientific impact of X-ray free-electron lasers are discussed. 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.

  14. Renewable energy sources. Erneuerbare Energien

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    To judge future trends in work on the exploitation of renewable energy sources for overall energy supply, it is necessary to know the following: the rules that nature abides by, the principles of technical exploitation of these energies, and the basic data for the current state of development. The above information is compiled in this publication for those renewable energy sources on which topical discussion centres: solar radiation and wind. For the remaining renowable energy sources (e.g. biomass, tidal power, geothermal energy), some examples of use are mentioned and advanced literature is indicated. (orig./HSCH).

  15. Patients experience of source isolation

    DEFF Research Database (Denmark)

    Johansen, Kamilla; Pedersen, Didde; Kragbak, Nina

    2014-01-01

    Patients´ experience of source isolation - a literature review Title: Patients experience of source isolation – a literature review Authors: Nina Kragbak*, Didde Pedersen*, Kamilla Johansen* and Peter E. Jensen** *students, **lecturer, bachelor in science and Ph.D., at VIA University College....... Physical environment: Some patients felt lonely and imprison, while other patients enjoyed time alone and not having to worry about other patients. A view to the life outside the physical boundaries of the isolation helped to avoid boredom. Importance of relatives: Relatives were a major source of comfort...

  16. The cohesiveness of sourcing teams

    DEFF Research Database (Denmark)

    Lidegaard, Nina

    2015-01-01

    Sourcing teams are introduced as an approach to achieving the interdepartmental integration necessary for companies to address the complexity of strategic sourcing. Companies aim at facilitating teams capable of balancing the goals and tasks of the team with departmental expectations; however......, the practical implementation is often unsuccessful leading to poor performance. Originating in PSM literature, factors influencing sourcing team performance are categorised into three: top management support, organisational structures, and those related to team members. In this paper, the concept...... of cohesiveness is introduced as an explanatory factor and, consequently, linkages between team cohesiveness and team performance are proposed....

  17. Recent progress in ion sources

    International Nuclear Information System (INIS)

    Osher, J.E.

    1975-01-01

    This paper is intended to survey recent developments in ion sources, particularly work reported at the ''Symposium on Ion Sources and the Formation of Ion Beams'' held in Berkeley in October 1974. The approach here will be to subdivide this topic into three main areas; briefly list and discuss notable progress in each; and finally add some additional detail through a few specific, selected examples. The major items of progress discussed include development of large-area plasma surfaces for multiple- aperture ion sources, a significant increase in available negative-ion current densities, and improved general agreement between extraction electrode design and performance. (U.S.)

  18. The Sources and Solutions: Wastewater

    Science.gov (United States)

    Wastewater treatment plants process water from homes and businesses, which contains nitrogen and phosphorus from human waste, food and certain soaps and detergents, and they can be a major source of nutrient pollution.

  19. Hot Hydrogen Heat Source Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a  hot hydrogen heat source that would produce  a high temperature hydrogen flow which would be comparable to that produced...

  20. Polar source analysis : technical memorandum

    Science.gov (United States)

    2017-09-29

    The following technical memorandum describes the development, testing and analysis of various polar source data sets. The memorandum also includes recommendation for potential inclusion in future releases of AEDT. This memorandum is the final deliver...

  1. Navy Heat Source Safety Tests

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C. G.; Cartmill, W. B.

    1975-06-18

    The purpose of these tests was to validate the integrity of the Navy Heat Source after imposing conditions which might, in the extreme, be encountered singly or serially so that safety would be assured.

  2. sources of the chemical elements

    African Journals Online (AJOL)

    THE GEOCHEMISTRY OF BANDED IRON. FORMATIONS IN THE SUKUMALAND GREENSTONE. BELT OF GEITA, NORTHERN TANZANIA: EVIDENCE. FOR MIXING OF HYDROTHERMAL AND CLASTIC. SOURCES OF THE CHEMICAL ELEMENTS. MAH Maboko. Department of Geology, University of Dar es Salaam.

  3. Perspectives on Open Source Software

    National Research Council Canada - National Science Library

    Hissam, Scott

    2001-01-01

    Open source software (OSS) is emerging as the software community's next "silver bullet" and appears to be playing a significant role in the acquisition and development plans of the Department of Defense (DoD) and industry...

  4. Intermediate-energy light sources

    CERN Document Server

    Corbett, W

    2003-01-01

    Increasingly, atomic scale information underlies scientific and technological progress in disciplines ranging from pharmaceutical development to materials synthesis to environmental remediation. While a variety of research tools are used to provide atomic scale information, synchrotron radiation has proved invaluable in this quest. The rapid growth of soft- and hard X-ray synchrotron light sources stands as stark testimony to the importance and utility of synchrotron radiation. Starting from just a handful of synchrotron light sources in the early 1970s, this burgeoning field now includes over 70 proposed, in-construction, or operating facilities in 23 countries on five continents. Along the way, synchrotron light facilities have evolved from small laboratories extracting light parasitically from storage rings designed for high-energy physics research to large, dedicated sources using the latest technology to produce extraordinarily bright photon beams. The basic layout of a multi-GeV storage ring light sourc...

  5. Data Sources for the Analyses

    Data.gov (United States)

    U.S. Environmental Protection Agency — Links are provided for the National Wetlands Inventory, National Hydrography Dataset, and the WorldClim-Global Climate Data source data websites. This dataset is...

  6. Mobile Source Observation Database (MSOD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Mobile Source Observation Database (MSOD) is a relational database being developed by the Assessment and Standards Division (ASD) of the US Environmental...

  7. Synchrotron light source data book

    International Nuclear Information System (INIS)

    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

  8. The sources of radiation exposure

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1992-01-01

    Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)

  9. Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs

    Science.gov (United States)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2012-02-01

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

  11. Zukunft des IT-Sourcing

    OpenAIRE

    von Jouanne-Diedrich, Holger; Zarnekow, Rüdiger; Brenner, Walter

    2006-01-01

    Im Oktober 2005 wurden in Kooperation mit der Analystenfirma Gartner zwei Workshops in Frankfurt am Main und in München zum Thema Sourcing & Benchmarking durchgeführt. Diese wurde vom Autor H. v. Jouanne-Diedrich mit moderiert und wissenschaftlich begleitet. Thema war die Zukunft des IT-Sourcing, deren Management sich zunehmend den Herausforderungen einer Industrialisierung der IT stellen muss. Die 30 teilnehmenden Personen stammten dabei sowohl aus den Geschäftsbereichen als auch aus Bereich...

  12. Open Source Vulnerability Database Project

    Directory of Open Access Journals (Sweden)

    Jake Kouns

    2008-06-01

    Full Text Available This article introduces the Open Source Vulnerability Database (OSVDB project which manages a global collection of computer security vulnerabilities, available for free use by the information security community. This collection contains information on known security weaknesses in operating systems, software products, protocols, hardware devices, and other infrastructure elements of information technology. The OSVDB project is intended to be the centralized global open source vulnerability collection on the Internet.

  13. Source Test and Characterization Program

    OpenAIRE

    Russell, Ray; Ardila, David; Rudy, Richard; Kim, Daryl; Crawford, Kirk; Laag, Edward

    2015-01-01

    Several recently completed and ongoing programs have demonstrated the value of stable internal source of illumination for on-orbit responsivity trending and calibration update processes. A prime example was the SPIRIT III sensor on the Midcourse Space Experiment in the mid-90s which used grain of wheat bulbs as stimulation sources for the infrared focal plane arrays. As more recent programs have continued to prove, being able to monitor the responses of each pixel in an array over time enable...

  14. Astrometry of southern radio sources

    Science.gov (United States)

    White, Graeme L.; Jauncey, David L.; Harvey, Bruce R.; Savage, Ann; Gulkis, Samuel; Preston, Robert A.

    1991-01-01

    An overview is presented of a number of astrometry and astrophysics programs based on radio sources from the Parkes 2.7 GHz catalogs. The programs cover the optical identification and spectroscopy of flat-spectrum Parkes sources and the determination of their milliarcsecond radio structures and positions. Work is also in progress to tie together the radio and Hipparcos positional reference frames. A parallel program of radio and optical astrometry of southern radio stars is also under way.

  15. Ring insertions as light sources

    International Nuclear Information System (INIS)

    Green, G.K.

    1975-01-01

    Bending magnets can be inserted in the long straight sections of electron storage rings to produce synchrotron radiation. If the design is carefully proportioned, the bending magnets create only a small perturbation of the properties of the ring. The resulting spectra have favorable optical properties as sources for spectroscopy and diffraction studies. The characteristics of the source are discussed, and the geometrical requirements of the magnets are presented

  16. Management of disused teletherapy sources

    International Nuclear Information System (INIS)

    Benitez-Navarro, J.C.; Salgado, M.; Madrazo, S.; Jova, L.; Castillo, R.

    2001-01-01

    Disused radiotherapy sources represent a large waste problem in most developing countries. Improperly controlled and stored such kind of sources has caused many accidents around the world. Some of these accidents resulted in human deaths and/or contamination of large areas (e.g. Brazil, Turkey, Thailand). According to the potential harm the sources may cause, teletherapy sources belong to category 1. In order to reduce the risk associated with high activity sources the first priority would be to bring under appropriate controls. It is important to have a proper infrastructure for their safe management in the country. The CPHR is responsible for centralized collection, transportation, conditioning and long-term storage of disused radioactive sources in Cuba. Radiotherapy sources may have high concentration of radionuclides in extremely small volumes. The radionuclides most commonly used in teletherapy sources are 60 Co and 137 Cs. In sealed radioactive sources metallic cobalt is always used, meanwhile Cesium can only be used as a chemical compound. An updated inventory of all stored wastes and disused radioactive sources is kept at CPHR. The current inventory of stored teletherapy units is presented. For disused sealed radiation sources with high activity (e.g. 60 Co and 137 Cs used for teletherapy) the only management option, except returning the source to the manufacturer, is long term interim storage (several decades) awaiting future disposal. Due to the high cost of disposal, sources conditioned for interim storage should have the flexibility to accommodate future waste acceptance criteria. Furthermore conditioning by complete embedding in concrete may be counterproductive with regard to efficient utilization of repository space. Consequently any conditioning process for interim storage should be carried out with the possibility of retrieving the source for further conditioning without imposing undue cost. A competent company manufactures the metallic containers

  17. The Compact Light Source A Miniature Synchrotron Light Source

    CERN Document Server

    Ruth, Ronald D

    2005-01-01

    During the past 30 years, synchrotron light sources have become the x-ray probe of choice for physicists, chemists, biologists and research physicians. With their high-quality, intense x-ray beams, these national research facilities have spawned a broad array of applications. Past research at Stanford Linear Accelerator Center has led to a new x-ray source concept that can substantially reduce the size of the required synchrotron.* This research has spawned a new corporation, Lyncean Technologies, Inc. which is now developing the Compact Light Source (CLS). The CLS is a tunable, homelab x-ray source with up to three beamlines that can be used like the x-ray beamlines at the synchrotrons-but it is about 200 times smaller than a synchrotron light source. The compact size is achieved using a laser undulator and a miniature electron-beam storage ring. The photon flux on a sample will be comparable to the flux of highly productive synchrotron beamlines. At Lyncean Technologies, Inc. we have constructed a prototype...

  18. Cold source vessel development for the advanced neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P.T.; Lucas, A.T. [Oak Ridge National Lab., TN (United States)

    1995-09-01

    The Advanced Neutron Source (ANS), in its conceptual design phase at Oak Ridge National Laboratory (ORNL), will be a user-oriented neutron research facility that will produce the most intense flux of neutrons in the world. Among its many scientific applications, the productions of cold neutrons is a significant research mission for the ANS. The cold neutrons come from two independent cold sources positioned near the reactor core. Contained by an aluminum alloy vessel, each cold source is a 410 mm diameter sphere of liquid deuterium that functions both as a neutron moderator and a cryogenic coolant. With nuclear heating of the containment vessel and internal baffling, steady-state operation requires close control of the liquid deuterium flow near the vessel`s inner surface. Preliminary thermal-hydraulic analyses supporting the cold source design are being performed with multi-dimensional computational fluid dynamics simulations of the liquid deuterium flow and heat transfer. This paper presents the starting phase of a challenging program and describes the cold source conceptual design, the thermal-hydraulic feasibility studies of the containment vessel, and the future computational and experimental studies that will be used to verify the final design.

  19. High-resolution angular and displacement sensing based on the excitation of surface plasma waves.

    Science.gov (United States)

    Margheri, G; Mannoni, A; Quercioli, F

    1997-07-01

    The possibility of building angular and displacement sensors based on the phenomenon of attenuated total reflection (ATR) is explored both numerically and experimentally. ATR occurs when a surface wave is excited by an incoming TM electromagnetic wave through a resonant phase-matching process, as in the Kretschmann coupling scheme. The reflected intensity strongly depends on the angle of incidence of the beam. We first show some computations of the sensitivity and the linearity of an ATR-based sensor, then proceed to the experiment, illustrating how an angular resolution of the order of 0.1 arc sec can be obtained with moderate effort. Finally we show how the sensor, combined with a simple optical arrangement, can be used to detect and measure nanometric displacements, as those provided by piezoelectric actuators.

  20. Microstructural characterization and tribological behavior of surface plasma Zr-Er alloying on TC11 alloy

    Science.gov (United States)

    Wei, Dongbo; Zhang, Pingze; Liu, Yingchao; Chen, Xiaohu; Ding, Feng; Li, Fengkun

    2018-02-01

    The Zr coating and Zr-Er coating are grown on TC11 substrate by double-glow plasma surface metallurgy technique, followed by the wear tests at ambient temperature and 500 °C. The data of nanohardness and elastic modulus of the samples are collected by the nano-indentation test. The adhesion strength of coatings is investigated by means of the scratch test. The study of wear resistance is performed using a ball-on-disc wear test system by running against the Si3N4 ball and measured by scanning electron microscope (SEM) and X-ray diffraction (XRD). Experimental results indicate that the nanohardness of the Zr coating and Zr-Er coating are 5.94 GPa and 7.98 GPa, respectively, which are 1.79 times and 2.41 times greater than that of TC11 substrate. Zr coating and Zr-Er coating realize the metallurgical bonding with TC11 substrate with continuous and compact structure. Compared with the Zr coating and TC11, the Zr-Er coating presents the lowest specific wear rates, which are 1.689 × 10‑6 mm3 Nm‑1 and 1.851 × 10‑6 mm3 Nm‑1 at ambient temperature and 500 °C respectively, indicating the excellent and improved wear resistance of TC11.

  1. Study of surface plasma coating of 4340 steel with different microstructure for high temperature use

    International Nuclear Information System (INIS)

    Carrer, Isabela Reis; Abdalla, Antonio Jorge; Barboza, Miguel Justino Ribeiro; Suzuki, Paulo Atsushi

    2010-01-01

    This paper has as main objective the formation of different microstructures by the specific heat treatments and applies the plasma thermochemical treatments to increase surface hardness. These two types of treatments will be evaluated in creep mechanical properties in steel 4340 for aeronautic uses. It will be evaluated, at first, the influence of heat treatments that changes the material microstructure. It was prepared specimen with three kinds of different microstructures (ferritic- perlitic, bainitic and martensitic), have been formed by the different heat treatments. After that, part of specimen will be submitted to plasma coating to evaluate the influence of this kind of surface treatment on creep properties. To better understand the microstructure and the relations between his properties, it was realized microscopic analyses, hardness tests and X-ray diffraction. (author)

  2. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification.

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F; Tardy, Blaise L; Dagastine, Raymond; Orbell, John D; Schutz, Jürg A; Duke, Mikel C

    2016-07-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  3. Sources

    OpenAIRE

    2017-01-01

    1 - Archives départementales de l’Isère (AD38) Série B, Chambre des comptes du Dauphiné B 2611 (1331)B 2635 (1213-1282)B 3006, fos 743v°-744r°B 3120, fos 220-221v° (1339)B 3138 (1398)B 3139 1251)B 3158 (1231)B 3159 (1214-1284)B 3551B 3637-B 3698B 3735 (1257)B 3791 (1262)B 3850 (1298-1379)B 3978 (1270-1331)B 4000 (1290)B 4077B 4079 (1242-1247-1428)B 4083 (1263)B 4086 (1235-1306)B 4454 (1364-1433) Série B, visites du maître des œuvres delphinales Libri visitationis receptionis castrorum et domo...

  4. Source misattributions may increase the accuracy of source judgments.

    Science.gov (United States)

    Lyle, Keith B; Johnson, Marcia K

    2007-07-01

    Misattribution of remembered information from one source to another is commonly associated with false memories, but we demonstrate that it also may underlie memories that accord with past events. Participants imagined drawings of objects in four different locations. For each, a drawing of a similarly shaped object was seen in the same location, a different location, or not seen. When tested on memory for objects' origin (seen/imagined) and location, more false "seen" responses, but also more correct location responses, were given to imagined objects if a similar object had been seen, versus not seen, in the same location. We argue that misattribution of feature information (e.g., shape, location) from seen objects to similar imagined ones increased false memories of seeing objects but also increased correct location memories, provided the misattributed location matched the imagined objects' location. Thus, consistent with the source-monitoring framework, imperfect source-attribution processes underlie false and true memories.

  5. Miniature field deployable terahertz source

    Science.gov (United States)

    Mayes, Mark G.

    2006-05-01

    Developments in terahertz sources include compacted electron beam systems, optical mixing techniques, and multiplication of microwave frequencies. Although significant advances in THz science have been achieved, efforts continue to obtain source technologies that are more mobile and suitable for field deployment. Strategies in source development have approached generation from either end of the THz spectrum, from up-conversion of high-frequency microwave to down-conversion of optical frequencies. In this paper, we present the design of a THz source which employs an up-conversion method in an assembly that integrates power supply, electronics, and radiative component into a man-portable unit for situations in which a lab system is not feasible. This unit will ultimately evolve into a ruggedized package suitable for use in extreme conditions, e.g. temporary security check points or emergency response teams, in conditions where THz diagnostics are needed with minimal planning or logistical support. In order to meet design goals of reduced size and complexity, the inner workings of the unit ideally would be condensed into a monolithic active element, with ancillary systems, e.g. user interface and power, coupled to the element. To attain these goals, the fundamental component of our design is a THz source and lens array that may be fabricated with either printed circuit board or wafer substrate. To reduce the volume occupied by the source array, the design employs a metamaterial composed of a periodic lattice of resonant elements. Each resonant element is an LC oscillator, or tank circuit, with inductance, capacitance, and center frequency determined by dimensioning and material parameters. The source array and supporting electronics are designed so that the radiative elements are driven in-phase to yield THz radiation with a high degree of partial coherence. Simulation indicates that the spectral width of operation may be controlled by detuning of critical dimensions

  6. Modelling Choice of Information Sources

    Directory of Open Access Journals (Sweden)

    Agha Faisal Habib Pathan

    2013-04-01

    Full Text Available This paper addresses the significance of traveller information sources including mono-modal and multimodal websites for travel decisions. The research follows a decision paradigm developed earlier, involving an information acquisition process for travel choices, and identifies the abstract characteristics of new information sources that deserve further investigation (e.g. by incorporating these in models and studying their significance in model estimation. A Stated Preference experiment is developed and the utility functions are formulated by expanding the travellers' choice set to include different combinations of sources of information. In order to study the underlying choice mechanisms, the resulting variables are examined in models based on different behavioural strategies, including utility maximisation and minimising the regret associated with the foregone alternatives. This research confirmed that RRM (Random Regret Minimisation Theory can fruitfully be used and can provide important insights for behavioural studies. The study also analyses the properties of travel planning websites and establishes a link between travel choices and the content, provenance, design, presence of advertisements, and presentation of information. The results indicate that travellers give particular credence to governmentowned sources and put more importance on their own previous experiences than on any other single source of information. Information from multimodal websites is more influential than that on train-only websites. This in turn is more influential than information from friends, while information from coachonly websites is the least influential. A website with less search time, specific information on users' own criteria, and real time information is regarded as most attractive

  7. Compton Sources of Electromagnetic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

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

  8. Searching for Orphan radiation sources

    International Nuclear Information System (INIS)

    Bystrov, Evgenij; Antonau, Uladzimir; Gurinovich, Uladzimir; Kazhamiakin, Valery; Petrov, Vitaly; Shulhovich, Heorhi; Tischenko, Siarhei

    2008-01-01

    Full text: The problem of orphan sources cannot be left unaddressed due high probability of accidental exposure and use of sources for terrorism. Search of objects of this kind is complex particularly when search territory is large. This requires devices capable of detecting sources, identifying their radionuclide composition, and correlating scan results to geographical coordinates and displaying results on a map. Spectral radiation scanner AT6101C can fulfill the objective of search for gamma and neutron radiation sources, radionuclide composition identification, correlation results to geographical coordinates and displaying results on a map. The scanner consists of gamma radiation scintillation detection unit based on NaI(Tl) crystal, neutron detection unit based on two He 3 counters, GPS receiver and portable ruggedized computer. Built-in and application software automates entire scan process, saving all results to memory for further analysis with visual representation of results as spectral information diagrams, count rate profile and gamma radiation dose rates on a geographical map. The scanner informs operator with voice messages on detection of radiation sources, identification result and other events. Scanner detection units and accessories are packed in a backpack. Weighing 7 kg, the scanner is human portable and can be used for scan inside cars. The scanner can also be used for radiation mapping and inspections. (author)

  9. Procedures: Source Term Measurement Program

    International Nuclear Information System (INIS)

    Dyer, N.C.; Keller, J.H.; Nieschmidt, E.B.; Motes, B.J.

    1977-10-01

    The report contains procedures for the Source Term Measurement Project being performed by Idaho National Engineering Laboratory for the Nuclear Regulatory Commission. This work is being conducted for the Office of Nuclear Regulatory Research in support of requirements of the Effluent Treatment Systems Branch of the Office of Nuclear Reactor Regulation. This project is designed to obtain source term information at operating light water reactors to update the parameters used in NRC calculational models (GALE codes). Detailed procedures and methods used for collection and analysis of samples are presented. This provides a reference base to supplement a series of reports to be issued by the Source Term Measurements Project which will present data obtained from measurements in specific nuclear power stations. Reference to appropriate parts of these procedures will be made as required

  10. Source and LINAC3 studies

    CERN Document Server

    Bellodi, G

    2017-01-01

    In the framework of the LHC Ion Injector Upgrade pro-gramme (LIU), several activities have been carried out in2016 to improve the ion source and Linac3 performance,with the goal to increase the beam current routinely deliv-ered to LEIR. The extraction region of the GTS-LHC ionsource was upgraded with enlarged vacuum chamber aper-tures and the addition of an einzel lens, yielding highertransmission through the rest of the machine. Also, a seriesof experiments have been performed to study the effects ofdouble frequency mixing on the afterglow performance ofthe source after installation of a Travelling Wave Tube Am-plifier (TWTA) as secondary microwave source at variablefrequency. Measurements have been carried out at a dedi-cated oven test stand for better understanding of the ionsource performance. Finally, several MD sessions werededicated to the study and characterization of the strippingfoils, after evidence of degradation in time was discoveredin the 2015 run.

  11. Miniature x-ray source

    Science.gov (United States)

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

    2000-01-01

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  12. Materials for spallation neutron sources

    International Nuclear Information System (INIS)

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

    1996-03-01

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

  13. Compact portable electric power sources

    Energy Technology Data Exchange (ETDEWEB)

    Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

    1997-02-01

    This report provides an overview of recent advances in portable electric power source (PEPS) technology and an assessment of emerging PEPS technologies that may meet US Special Operations Command`s (SOCOM) needs in the next 1--2- and 3--5-year time frames. The assessment was performed through a literature search and interviews with experts in various laboratories and companies. Nineteen PEPS technologies were reviewed and characterized as (1) PEPSs that meet SOCOM requirements; (2) PEPSs that could fulfill requirements for special field conditions and locations; (3) potentially high-payoff sources that require additional R and D; and (4) sources unlikely to meet present SOCOM requirements. 6 figs., 10 tabs.

  14. Sourcing teams and interdepartmental integration

    DEFF Research Database (Denmark)

    Lidegaard, Nina; Ellegaard, Chris; Møller, Morten Munkgaard

    2015-01-01

    Internal integration is often mentioned as a prerequisite for conducting strategic sourcing, as multiple functional departments must collaborate on creating value-creating activities amongst them. Though it is one of many possibilities, the use of cross-functional teams is often the most commonly...... indicate that informal integration mechanisms not promoted by management or the organizational structure may contribute to the overall level of integration.......Internal integration is often mentioned as a prerequisite for conducting strategic sourcing, as multiple functional departments must collaborate on creating value-creating activities amongst them. Though it is one of many possibilities, the use of cross-functional teams is often the most commonly...... proposed solution to ensure internal integration. This paper presents an exploratory case study evaluating the use of internal integration mechanisms in a cross-functional sourcing process. Two commodity categories are examined. One is organised in a cross-functional team, while the other is not. Findings...

  15. Graphite moderated 252Cf source

    International Nuclear Information System (INIS)

    Sajo B, L.; Barros, H.; Greaves, E. D.; Vega C, H. R.

    2014-08-01

    The thorium molten salt reactor is an attractive and affordable nuclear power option for developing countries with insufficient infrastructure and limited technological capability. In the aim of personnel training and experience gathering at the Universidad Simon Bolivar there is in progress a project of developing a subcritical thorium liquid fuel reactor. The neutron source to run this subcritical reactor is a 252 Cf source and the reactor will use high-purity graphite as moderator. Using the MCNP5 code the neutron spectra of the 252 Cf in the center of the graphite moderator has been estimated along the channel where the liquid thorium salt will be inserted; also the ambient dose equivalent due to the source has been determined around the moderator. (Author)

  16. SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-30

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

  17. Tikal obsidian: sources and typology

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  18. Sourcing teams and interdepartmental integration

    DEFF Research Database (Denmark)

    Lidegaard, Nina; Ellegaard, Chris; Møller, Morten Munksgaard

    2015-01-01

    proposed solution to ensure internal integration. This paper presents an exploratory case study evaluating the use of internal integration mechanisms in a cross-functional sourcing process. Two commodity categories are examined. One is organised in a cross-functional team, while the other is not. Findings......Internal integration is often mentioned as a prerequisite for conducting strategic sourcing, as multiple functional departments must collaborate on creating value-creating activities amongst them. Though it is one of many possibilities, the use of cross-functional teams is often the most commonly...

  19. Sources of remotely sensed data

    Science.gov (United States)

    Applications Branch, EROS Data Center

    1978-01-01

    NCIC was established within the USGS to provide a single-point contact source for cartographic-related information, including remotely sensed data. A computerized indexing system, the Aerial Photography Summary Record System (APSRS), shows all holding for Federal agencies, with the long range goal of including data acquired on the state and local levels and (eventually) by private industry. The system directs the used to a particular agency which holds coverage over a particular unit area, based on the 7 1/2 minute USGS quadrangle system. The data will remain in the hands of the source agency.

  20. Γ-Z-Source Inverters

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Li, Ding; Blaabjerg, Frede

    2013-01-01

    Voltage-type Γ-Z-source inverters are proposed in this letter. They use a unique Γ-shaped impedance network for boosting their output voltage in addition to their usual voltage-buck behavior. Comparing them with other topologies, the proposed inverters use lesser components and a coupled transfor......Voltage-type Γ-Z-source inverters are proposed in this letter. They use a unique Γ-shaped impedance network for boosting their output voltage in addition to their usual voltage-buck behavior. Comparing them with other topologies, the proposed inverters use lesser components and a coupled...

  1. Neutron diffraction on pulsed sources

    Science.gov (United States)

    Aksenov, V. L.; Balagurov, A. M.

    2016-03-01

    The current capabilities of and major scientific problems solved by time-of-flight neutron diffraction are reviewed. The reasons for the rapid development of the method over the last two decades have been mainly the emergence of third-generation pulsed sources with a megawatt time-averaged power and advances in neutron optical devices and detector systems. The paper discusses some historical aspects of time-of-flight neutron diffraction and examines the contribution to this method from F L Shapiro, the centennial of whose birth was celebrated in 2015. The state of the art with respect to neutron sources for studies on extracted beams is reviewed in a special section.

  2. Penetration Tester's Open Source Toolkit

    CERN Document Server

    Faircloth, Jeremy

    2011-01-01

    Great commercial penetration testing tools can be very expensive and sometimes hard to use or of questionable accuracy. This book helps solve both of these problems. The open source, no-cost penetration testing tools presented do a great job and can be modified by the user for each situation. Many tools, even ones that cost thousands of dollars, do not come with any type of instruction on how and in which situations the penetration tester can best use them. Penetration Tester's Open Source Toolkit, Third Edition, expands upon existing instructions so that a professional can get the most accura

  3. Magnetogasdynamics of double radio sources

    International Nuclear Information System (INIS)

    Nepveu, M.

    1979-01-01

    The magnetogasdynamical behaviour of plasmoids moving through an ambient gas is investigated numerically with a two-dimensional code, based on the SHASTA scheme. The astrophysical importance of this study lies in the observed extended extragalactic radio sources. It is assumed that plasma clouds with cylinder symmetry are ejected from the nucleus of a galaxy. Their large-scale evolution in the intergalactic medium (IGM) is followed. The gas dynamics of an ejected cloud, the magnetogasdynamics of ejected clouds, the Christiansen-Pacholczyk-Scott picture for radio galaxies and the shear layers in double radio sources are studied. (Auth.)

  4. The SLAC polarized electron source

    International Nuclear Information System (INIS)

    Tang, H.; Alley, R.; Frisch, J.

    1995-06-01

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

  5. Ion-source development at Argonne

    Science.gov (United States)

    Bilquist, P. J.; Yntema, J. L.

    Brief descriptions are given of the ion source test stand, the ANIS source, a copy of the SNIC source, and the Chapman inverted sputter source. Relative performance is discussed, particularly for the inverted sputter source. Beam currents are given for several ion species.

  6. A review of polarized ion sources

    International Nuclear Information System (INIS)

    Schmor, P.W.

    1995-06-01

    The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

  7. On Hubbell's rectangular source integral

    International Nuclear Information System (INIS)

    Stalker, John

    2001-01-01

    The integral H(a,b)=∫ 0 b ∫ 0 a dx dy/(1+x 2 +y 2 ) arises naturally in the study of radiation from a rectangular source and has been studied by many authors. This paper introduces a new series expansion which is rapidly convergent for large a and b

  8. Image Makers: Reporters or Sources.

    Science.gov (United States)

    Petruzzello, Marion C.

    To explore how news sources are used by media to create a social image of women during key suffrage events of 1858, 1920, and 1970, the front page stories of the "New York Times" were reviewed for 1 week prior to and 1 week following each of these events: May 14, 1858, the Eighth National Women's Rights Convention in New York City;…

  9. Leveraging Synergiesn in Global Sourcing

    DEFF Research Database (Denmark)

    Englyst, Linda; Stegmann Mikkelsen, Ole; Johansen, John

    2005-01-01

    Leveraging synergies in global sourcing is not a straightforward task, and requires a balanced approach to organizing, taking into consideration a number of situational factors. These include, but are not limited to, strategic significance, product specificity, market complexity, coherency and th...... case company, investigated through a historical review and explorative interviews regarding recent experiences and improvement ideas....

  10. Mismatch sources in LDMOS devices

    NARCIS (Netherlands)

    Andricciola, Pietro; Andricciola, P.; Tuinhout, Hans

    2010-01-01

    This paper discusses the influence of different sources of DC parametric mismatch in an LDMOS. By comparing measurements and statistical simulations the impact on mismatch of the most important fluctuation causes is qualitatively evaluated. We demonstrate that, whereas the shape of the doping

  11. Trends in EEG source localization.

    Science.gov (United States)

    Koles, Z J

    1998-02-01

    The concepts underlying the quantitative localization of the sources of the EEG inside the brain are reviewed along with the current and emerging approaches to the problem. The concepts mentioned include monopolar and dipolar source models and head models ranging from the spherical to the more realistic based on boundary and finite elements. The forward and inverse problems in electroencephalography are discussed, including the non-uniqueness of the inverse problem. The approaches to the solution of the inverse problem described include single and multiple time-slice localization, equivalent dipole localization and the weighted minimum norm. The multiple time-slice localization approach is highlighted as probably the best available at this time and is discussed in terms of the spatiotemporal model of the EEG. The effect of noise corruption, artifacts and the number of recording electrodes on the accuracy of source localization is also mentioned. It is suggested that the main appeal of the minimum norm is that it does not assume a model for the sources and provides an estimate of the current density everywhere in the three dimensional volume of the head.

  12. Synchrotron-driven spallation sources

    CERN Document Server

    Bryant, P J

    1996-01-01

    The use of synchrotrons for pulsed neutron spallation sources is an example of scientific and technological spin-off from the accelerator development for particle physics. Accelerator-driven sources provide an alternative to the continuous-flux, nuclear reactors that currently furnish the majority of neutrons for research and development. Although the present demand for neutrons can be adequately met by the existing reactors, this situation is unlikely to continue due to the increasing severity of safety regulations and the declared policies of many countries to close down their reactors within the next decade or so. Since the demand for neutrons as a research tool is, in any case,expected to grow, there has been a corresponding interest in sources that are synchrotron-driven or linac-driven with a pulse compression ring and currently several design studies are being made. These accelerator-driven sources also have the advantage of a time structure with a high peak neutron flux. The basic requirement is for a...

  13. Synthetic aperture controlled source electromagnetics

    NARCIS (Netherlands)

    Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

    2010-01-01

    Controlled?source electromagnetics (CSEM) has been used as a de?risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect.

  14. Organizational Dysfunctions: Sources and Areas

    Directory of Open Access Journals (Sweden)

    Jacek Pasieczny

    2016-12-01

    Full Text Available Objective:The purpose of this article is to identify and describe various types and sources of organizational dysfunctions. Research Design & Methods: The findings are based on literature review and an ongoing empirical research project conducted in private sector organisations. The empirical study can be situated within interpretative approach. In this qualitative project open interviews and observations were used to collect data. Findings: The study indicates that various types and sources of organizational dysfunctions can be identified in organizations operating in Poland. The sources of dysfunctions may be found both within the organization and its environment. Regardless of its specific features, most of the dysfunctions may be interpreted as an undesirable goal displacement. Very often areas of these dysfunctions are strongly interconnected and create a system that hinders organizational performance. Yet, it is difficult to study these phenomena as respondents are unwilling, for various reasons, to disclose the problems faced by their organizations. Implications & Recommendations: The results imply that the issue of organisational dysfunctions requires open, long-lasting and comparative studies. Recommendations for further studies are formulated in the last section of the paper. Contribution & Value Added: The paper provides insight into "the dark side of organising" by identifying sources and areas of dysfunctions. It also reveals difficulties connected with conducting research on dysfunctions in the Polish context.

  15. Open Source and Open Standards

    NARCIS (Netherlands)

    Koper, Rob

    2006-01-01

    Publication reference: Koper, R. (2008). Open Source and Open Standards. In J. M. Spector, M. Merrill, J. van Merriënboer & M. P. Driscol (Eds.), Handbook of Research on Educational Communications and Technology (3rd ed., pp. 355-368). New York: Routledge.

  16. High efficiency atomic hydrogen source

    International Nuclear Information System (INIS)

    Lagomarsino, V.; Bassi, D.; Bertok, E.; De Paz, M.; Tommasini, F.

    1974-01-01

    This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

  17. Source Code Analysis Laboratory (SCALe)

    Science.gov (United States)

    2012-04-01

    Samba and NFS. The Windows VMs can be remotely accessed from within the CERT network by using Remote Desktop Protocol (RDP) and the Linux VMs by...File Server • Samba • NFS RDP SSH Other VMs CMU/SEI-2012-TN-013 | 10 Source code being analyzed is copied onto the file server, where it is

  18. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    Prince Consort Road, London, SW7 2AZ, UK. E-mail: .... In this section I broadly and qualitatively describe guidelines for the construction of ... The master os- cillator is a mode-locked fibre laser, which has been shown to be compact and robust short pulse sources [22]. The saturable absorber is often a semiconductor.

  19. pollution sources and environmental impacts

    International Nuclear Information System (INIS)

    2008-01-01

    The second conference on analytical nuclear and conventional technics and their applications which took place in Meknes (Morocco) under the theme ''pollution sources and environmental impacts'' from 27 to 29 Novenber 2008 discussed the various aspects of the use of analytical techniques applied to issues of environmental pollution [fr

  20. Escaping "localisms" in IT sourcing

    DEFF Research Database (Denmark)

    Mola, L.; Carugati, Andrea

    2012-01-01

    Organizations are limited in their choices by the institutional environment in which they operate. This is particularly true for IT sourcing decisions that go beyond cost considerations and are constrained by traditions, geographical location, and social networks. This article investigates how...

  1. Moessbauer spectroscopy of implanted sources

    International Nuclear Information System (INIS)

    Niesen, L.

    1983-01-01

    A review is given of the field of Moessbauer spectroscopy of ion-implanted sources. After an introduction to the various aspects of the ion-implantation method, the following topics are treated: final site selection of implanted impurities; trapping of defects at implanted ions; on-line implantation; implantation in metals, semiconductors and insulators. (Auth.)

  2. Organizing for External Knowledge Sourcing

    DEFF Research Database (Denmark)

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings o...

  3. Methods for evaluating information sources

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2012-01-01

    The article briefly presents and discusses 12 different approaches to the evaluation of information sources (for example a Wikipedia entry or a journal article): (1) the checklist approach; (2) classical peer review; (3) modified peer review; (4) evaluation based on examining the coverage...

  4. Contamination sources, prevention, and research

    Science.gov (United States)

    Contamination is defined as anything other than cotton in cotton lint. Worldwide, contamination is on the rise and plastic contamination has increased at a faster rate than contamination overall. In the U.S., there are many sources of plastic contaminants, such as plastic trash that collects in cott...

  5. Holophonic synthesis of musical sources

    OpenAIRE

    Menzies, Dylan

    2007-01-01

    The composition of a soundfield containing complex nearfield sources has interesting musical applications. A method is presented here using freefield expansions about exterior points of a harmonic multipole field. A derivation and verification are included. Binaural rendering is the natural method for displaying such soundfields. Some possible musical applications are discussed.

  6. Open Source Wifi Hotspot Implementation

    Directory of Open Access Journals (Sweden)

    Tyler Sondag

    2007-06-01

    Full Text Available The goal of this paper is to describe a design—including the hardware, software, and configuration––for an open source wireless network. The network designed will require authentication. While care will be taken to keep the authentication exchange secure, the network will otherwise transmit data without encryption.

  7. Occasioning change through HR sourcing

    NARCIS (Netherlands)

    van Balen, Mitchell; Bondarouk, Tatiana; Strohmeier, Stefan; Diederichsen, Anke

    2010-01-01

    This article describes how structuration theory can be used to analyze changes as invoked by two HR Sourcing arrangements: HR Shared Service Centers and HR Outsourcing. This approach allows us to under-stand changing responsibilities, altered HR processes, and the adaptation of web-based tools for

  8. Alpha sources deposit by sublimation

    International Nuclear Information System (INIS)

    Amoudry, F.; Eloy, J.F.

    1983-09-01

    We studied and realized a device able to perform some very thin substracts used for alpha spectrometry measurements. Sources are prepared by sublimation of the sample in a vacuum container. The energy required for this sublimation is furnished by a laser beam [fr

  9. Renewable Energy Sources Brno '93

    International Nuclear Information System (INIS)

    1993-01-01

    The proceedings contain 27 contributions dealing with unconventional energy sources. The numbers of contributions in the individual classes of topics indicate that interest has mostly concentrated on the direct utilization of solar energy, whereas wind energy, hydroelectric energy and geothermal energy receive less attention and the use of biomass is at the margin of interest. (J.B.)

  10. (SPWM) Voltage Source Inverter (VSI)

    African Journals Online (AJOL)

    The quest to achieve less-distorted dc-ac power conversion has resulted in the proliferation of many multilevel inverter configurations. This paper presents an experimental report of a simplified topology for single-phase, SPWM, three-level voltage source inverter wit R-L load. To keep the power circuit component count to a ...

  11. OSGeo - Open Source Geospatial Foundation

    Directory of Open Access Journals (Sweden)

    Margherita Di Leo

    2012-09-01

    Full Text Available L'esigenza nata verso la fine del 2005 di selezionare ed organizzare più di 200 progetti FOSS4G porta alla nascita nel Febbraio2006 di OSGeo (the Open Source Geospatial Foundation, organizzazione internazionale la cui mission è promuovere lo sviluppo collaborativo di software libero focalizzato sull'informazione geografica (FOSS4G.Open   Source   Geospatial   Foundation (OSGeoThe Open Source Geospatial Foundation (OSGeo  is  a  not-for-profit  organization, created  in  early  2006  to  the  aim  at  sup-porting   the   collaborative   development of  geospatial  open  source  software,  and promote its widespread use. The founda-tion provides financial, organizational and legal support to the broader open source geospatial community. It also serves as an independent  legal  entity  to  which  com-munity  members  can  contribute  code, funding  and  other  resources,  secure  in the knowledge that their contributions will be maintained for public benefit. OSGeo also  serves  as  an  outreach  and  advocacy organization for the open source geospa-tial  community,  and  provides  a  common forum  and  shared  infrastructure  for  im-proving  cross-project  collaboration.  The foundation's projects are all freely available and  useable  under  an  OSI-certified  open source license. The Italian OSGeo local chapter is named GFOSS.it     (Associazione     Italiana     per l'informazione Geografica Libera.

  12. Radioactive sources in chemical laboratories

    International Nuclear Information System (INIS)

    Janzekovic, H.; Krizman, M.

    2007-01-01

    Radioactive sources including all radioactive materials exceeding exemption levels have to be registered in national databases according to international standards based on the recommendations ICRP 60 and a proper licensing should take place as described for example in the 96/29/EURATOM. In spite of that, unregistered sources could be found, usually due to the fact that the owner is not aware of radiation characteristics of sources. The material inventories of chemical laboratories are typical and most frequent example where radioactive sources could be found. Five different types of sources could be identified. The most frequent type are chemicals, namely thorium and uranium compounds. They are used not due to their radioactivity but due to their chemical properties. As for all other sources a stringent control is necessary in order to assure their safe use. Around hundred of stored radioactive chemical items were found during inspections of such laboratories performed by the Slovenian Nuclear Safety Administration or qualified experts in a period December 2006 - July 2007. Users of such chemicals are usually not aware that thorium and uranium chemicals are radioactive and, as unsealed sources, they could be easily spilled out and produce contamination of persons, surfaces, equipment etc. The external exposure as well as the internal exposure including exposure due to inhalation could be present. No knowledge about special precautions is usually present in laboratories and leads to underestimating of a potential risk and unintentional exposure of the laboratory personnel, students etc. Due to the long decay times in decay series of Th -232, U-238 and U- 235 the materials are also radioactive today. Even more, in case of thorium chemicals the radioactivity increased substantially from the time of their production. The implementation of safety measures has been under way and includes a survey of the qualified experts, establishment of organizational structure in a

  13. Open Burning Sources of Air Pollution

    Science.gov (United States)

    This slide presentation will focus on Open Burning Sources f Air Pollution, with sections on Sources, Pollutants, Perspective, Quantification. The various sources of domestic and international open burning pollutants will be discussed. The focus pollutants and their effects wil...

  14. EPA Region 1 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of...

  15. Land Streamer Surveying Using Multiple Sources

    KAUST Repository

    Mahmoud, Sherif

    2014-12-11

    Various examples are provided for land streamer seismic surveying using multiple sources. In one example, among others, a method includes disposing a land streamer in-line with first and second shot sources. The first shot source is at a first source location adjacent to a proximal end of the land streamer and the second shot source is at a second source location separated by a fixed length corresponding to a length of the land streamer. Shot gathers can be obtained when the shot sources are fired. In another example, a system includes a land streamer including a plurality of receivers, a first shot source located adjacent to the proximal end of the land streamer, and a second shot source located in-line with the land streamer and the first shot source. The second shot source is separated from the first shot source by a fixed overall length corresponding to the land streamer.

  16. Pulsating X-ray sources

    International Nuclear Information System (INIS)

    Trumper, J.

    1986-01-01

    The discovery of pulsating X-ray sources in close binary systems was one of the major achievements of the Uhuru satellite. Today one knows about two dozens of these sources with pulsational periods between 69 ms and 835 s. In most cases the X-ray source orbits an early-type star of high mass having a rather large optical luminosity. There are a few exceptions: GX1+4 is associated with a late-type (M6) giant, 4U1616-67 has a comparison of very low mass (≤ 0.1 M/sub sub solar/), and Her X-1 is a borderline case, since its counterpart HZ Her is an A-F star of -- 2/sub sub solar/. It is clear that the X-ray sources in these systems are rotating magnetized neutron stars accreting from their normal companion, probably in most cases via Roche lobe overflow which leads to the formation of an accretion disk. In some cases (e.g. Vela X-1) the accretion proceeds via a stellar wind. Pulsations occur because in the immediate vicinity of the neutron star the matter is funneled by the strong magnetic field onto the polar caps where a hot and very luminous plasma is formed. Typical luminosities are huge, namely of the order of 10/sup 37/ erg/s which are radiated at effective temperatures of -- 10/sup 8/ K. Much has been learned about these systems and about neutron stars from studies of pulse arrival times and source spectra. The author briefly summarizes some of the major results and discusses some very recent results obtained with EXOSAT

  17. Control of sealed radioactive sources in Peru

    International Nuclear Information System (INIS)

    Ramirez Quijada, R.

    2001-01-01

    The paper describes the inventory of radioactive sources in Peru and assesses the control. Three groups of source conditions are established: controlled sources, known sources, and lost and orphan sources. The potential risk, described as not significant, for producing accidents is established and the needed measures are discussed. The paper concludes that, while the control on sealed sources is good, there is still room for improvement. (author)

  18. Handling of radioactive sources in Ecuador

    International Nuclear Information System (INIS)

    Benitez, Manuel

    2000-01-01

    This document describes the following aspects: sealed and unsealed radioactive sources, radiation detectors, personnel and area monitoring, surface pollution, radioactive wastes control and radioactive sources transferring. (The author)

  19. TSUNAMI INFORMATION SOURCES - PART 4

    Directory of Open Access Journals (Sweden)

    Robert L. Wiegel

    2006-01-01

    Full Text Available I have expanded substantially my list of information sources on: tsunami generation (sources, impulsive mechanisms, propagation, effects of nearshore bathymetry, and wave run-up on shore - including physical (hydraulic modeling and numerical modeling. This expanded list includes the subjects of field investigations of tsunamis soon after an event; damage effects in harbors on boats, ships, and facilities; tsunami wave-induced forces; damage by tsunami waves to structures on shore; scour/erosion; hazard mitigation; land use planning; zoning; siting, design, construction and maintenance of structures and infrastructure; public awareness and education; distant and local sources; tsunami warning and evacuation programs; tsunami probability and risk criteria. A few references are on "sedimentary signatures" useful in the study of historic and prehistoric tsunamis (paleo-tsunamis. In addition to references specifically on tsunamis, there are references on long water wave and solitary wave theory; wave refraction, diffraction, and reflection; shelf and basin free and forced oscillations (bay and harbor response; seiches; edge waves; Mach- reflection of long water waves ("stem waves"; wave run-up on shore; energy dissipation. All are important in understanding tsunamis, and in hazard mitigation. References are given on subaerial and submarine landslide (and rockfall generated waves in reservoirs, fjords, bays, and ocean; volcano explosive eruptions/collapse; underwater and surface explosions; asteroid impact. This report is in two parts: 1 Bibliographies, books and pamphlets, catalogs, collections, journals and newsletters, maps, organizations, proceedings, videos and photos; 2 Articles, papers, reports listed alphabetically by author.Many papers on the Indian Ocean (Sumatra tsunami of 26 December 2004, were given at the 22nd IUGG International Tsunami Symposium, Chania, Crete, 27-29 June 2005, but had not been published at the date of this report. For

  20. Neutron diffraction on pulsed sources

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.

    2016-01-01

    The possibilities currently offered and major scientific problems solved by time-of-flight neutron diffraction are reviewed. The reasons for the rapid development of the method over the last two decades has been mainly the emergence of third generation pulsed sources with a MW time-averaged power and advances in neutron-optical devices and detector systems. The paper discusses some historical aspects of time-of-flight neutron diffraction and examines the contribution to this method by F.L.Shapiro whose 100th birth anniversary was celebrated in 2015. The state of the art with respect to neutron sources for studies on output beams is reviewed in a special section. [ru

  1. Resonance Ionization Laser Ion Sources

    CERN Document Server

    Marsh, B

    2013-01-01

    The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

  2. Inverse source problems in elastodynamics

    Science.gov (United States)

    Bao, Gang; Hu, Guanghui; Kian, Yavar; Yin, Tao

    2018-04-01

    We are concerned with time-dependent inverse source problems in elastodynamics. The source term is supposed to be the product of a spatial function and a temporal function with compact support. We present frequency-domain and time-domain approaches to show uniqueness in determining the spatial function from wave fields on a large sphere over a finite time interval. The stability estimate of the temporal function from the data of one receiver and the uniqueness result using partial boundary data are proved. Our arguments rely heavily on the use of the Fourier transform, which motivates inversion schemes that can be easily implemented. A Landweber iterative algorithm for recovering the spatial function and a non-iterative inversion scheme based on the uniqueness proof for recovering the temporal function are proposed. Numerical examples are demonstrated in both two and three dimensions.

  3. Review of available power sources

    International Nuclear Information System (INIS)

    Beard, Carl

    2006-01-01

    Klystrons and triodes have been the accepted choice for particle accelerators because they produce high power RF and offer high gain (60 dB) with efficiencies of ∼50%. Although fairly new to the market, inductive output tubes (IOTs) have become available at L-band frequencies and have maintained their high efficiency. The development of superconducting RF at the L-band frequency allows IOTs to become the choice for future accelerator programs. Due to the operational nature of SRF technology in energy recovery mode, there is no longer the requirement for large amounts of RF power from single sources. This report reviews some of the developments in RF power sources suitable for energy recovery linacs (ERLs)

  4. The new Munich neutron source

    International Nuclear Information System (INIS)

    Herrmann, W.A.

    1998-01-01

    The Munich FRM II neutron source currently under construction is to replace the FRM I research reactor in Munich, also known as 'atomic egg'. The project is executed by the Free State of Bavaria as a construction project of the Munich Technical University and managed by the University. As main contractor for the construction project, Siemens AG is also co-applicant in the licensing procedure under the Atomic Energy Act for the construction phase. The project is carried out to build a modern high flux neutron source required for a broad range of applications in research and technology mainly with thermal and cold neutrons. The 'neutron gap' existing in Germany is to be closed with the FRM II. As a national research installation, the FRM II is available to all interested scientists from a variety of disciplines. (orig.) [de

  5. The ILC polarized electron source

    CERN Document Server

    Brachmann, Axel; Garwin, Edward; Kirby, Robert; Luh Dah An; Maruyama, Takashi; Prepost, Richard; Schultz, David; Sheppard, John

    2005-01-01

    The SLC polarized electron source (PES) can meet the expected requirements of the International Linear Collider (ILC) for polarization, charge and lifetime. However, experience with newer and successful PES designs at JLAB, Mainz and elsewhere can be incorporated into a first-generation ILC source that will emphasize reliability and stability without compromising the photocathode performance. The long pulse train for the ILC may introduce new challenges for the PES, and in addition more reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler load-lock system. The outline of the R&D program currently taking shape at SLAC and elsewhere is discussed. The principal components of the proposed ILC PES, including the laser system necessary for operational tests, are described.

  6. Management of disused sealed sources

    International Nuclear Information System (INIS)

    Lukauskas, D.; Skridaila, N.

    2003-01-01

    The report presents the requirements on management of disused sealed sources in Lithuania; disused sealed source disposal facilities; performed safety analysis and planed repository safety improvements. The requirements on pre-disposal management of Disused Sealed Sources (DSS) are presented. The requirements on disposal of short lived VLLW and LILW (A, B and C classes) radioactive waste approved in 2002-2003. Generic Waste Acceptance Criteria for Near Surface Disposal, P-2003-01 approved in 2003. Requirements on disposal of Low and intermediate level long lived waste do not exist (D and E classes). Requirements for the disposal of disused sealed sources (F class) do not exist. Disposal method for the F class - Near Surface or Deep geological repository, depending on the waste acceptance criteria. Only one repository for institutional radioactive waste exist in Lithuania - Maisiagala repository. It is near surface RADON type disposal facility, built in 1963 and closed in 1988. It was constructed of the monolithic reinforced concrete with the dimensions 5 m x 15 m x 3 m, the thickness of the sidewalls is about 0.25 m and the thickness of the bottom is about 0.2 m. The overall volume is about 200 m 3 . At time of closure only three fifths of the volume had been filled. The empty two fifths of the vault were filled with concrete, then with sand, then with the concrete (0.01 m), hot bitumen and the 0.05 m asphalt layers. Monolithic concrete that was covered with bitumen and 0.05 m thick layer of asphalt closed the vault. Sand layer the thickness of which was not less than 1.2 m formed the cap. Disused radioactive sources embedded in a biological shielding were buried together with their shielding, the sources without the shielding were buried in two stainless steel containers. The total activity of buried radioactive nuclides is 3.42.10 -15 Bq (calculated according the documentation). There are some uncertainties about the inventory: from 1963 to 1973. After the

  7. High efficiency optoelectronic terahertz sources

    Science.gov (United States)

    Lampin, Jean-François; Peytavit, Emilien; Akalin, Tahsin; Ducournau, G.; Hindle, Francis; Mouret, Gael

    2010-08-01

    We have developed a new generation of optoelectronic large bandwidth terahertz sources based on TEM horn antennas monolithically integrated with several types of photodetectors: low-temperature grown GaAs (LTG-GaAs) planar photoconductors, vertically integrated LTG-GaAs photoconductors on silicon substrate and uni-travelling-carrier photodiodes. Results of pulsed (time-domain) and photomixing (CW, frequency domain) experiments are presented.

  8. Refurbishment and open source software

    CSIR Research Space (South Africa)

    Mabuza, S

    2006-11-01

    Full Text Available  Linux  Thin Client   LTSP (Linux Terminal Server Project)  12 Linux Applications for Old  computers  Linux LiveCD Router  FreeS/WAN  Print Server 13 Examples of OSS use on  Refurbished computers Open Source Centre – Soweto Tux...

  9. Silicon sources for rice crop

    Directory of Open Access Journals (Sweden)

    Pereira Hamilton Seron

    2004-01-01

    Full Text Available Although silicon is not an essential nutrient, its application is beneficial for plant growth and development. To evaluate silicon sources in relation to agronomic efficiency and economic viability in rice crops (Oryza sativa L., a greenhouse experiment was conducted, Quartzipsamment soil, in a completely randomized experimental design (n = 4. Treatments were 12 silicon sources and a control. Silicon was applied at the rate of 125 kg Si ha-1. Data were compared to a standard response curve for Si using the standard source Wollastonite at rates of 0, 125, 250, 375, and 500 kg Si ha-1. All treatments received CaCO3 and MgCO3 to balance pH, Ca and Mg. One hundred and fifty days after sowing, evaluations on dry matter yield in the above-ground part of plants, grain yield, and Si contents in the soil and plant tissues were performed. Wollastonite had linear response, increasing silicon in the soil and plants with increasing application rates. Differences between silicon sources in relation to Si uptake were observed. Phosphate slag provided the highest Si uptake, followed by Wollastonite and electric furnace silicates which however, did not show differed among themselves. The highest Si accumulation in grain was observed for stainless steel, which significantly differed from the control, silicate clay, Wollastonite, and AF2 (blast furnace of the company 2 slag. Silicate clay showed the lowest Si accumulation in grain and did not differ from the control, AF2 slag, AF1 slag, schist ash, schist, and LD4 (furnace steel type LD of the company 4 slag.

  10. Data Sources for Human Behavior

    Science.gov (United States)

    2009-08-06

    D t S fa a ources or Human Behavior Elizabeth Mezzacappa, Ph.D. & Kenneth Short, Ph.D. Target Behavioral Response Laboratory/Stress and Motivated...to 00-00-2009 4. TITLE AND SUBTITLE Data Sources for Human Behavior Presented at the Focus 2010 Human Social Cultural Behavioral Conference...understanding human behavior for M&S efforts. This presentation falls under the presentation top are of "Socio-cultural data acquisition, extraction

  11. Earthquake sources near Uturuncu Volcano

    Science.gov (United States)

    Keyson, L.; West, M. E.

    2013-12-01

    Uturuncu, located in southern Bolivia near the Chile and Argentina border, is a dacitic volcano that was last active 270 ka. It is a part of the Altiplano-Puna Volcanic Complex, which spans 50,000 km2 and is comprised of a series of ignimbrite flare-ups since ~23 ma. Two sets of evidence suggest that the region is underlain by a significant magma body. First, seismic velocities show a low velocity layer consistent with a magmatic sill below depths of 15-20 km. This inference is corroborated by high electrical conductivity between 10km and 30km. This magma body, the so called Altiplano-Puna Magma Body (APMB) is the likely source of volcanic activity in the region. InSAR studies show that during the 1990s, the volcano experienced an average uplift of about 1 to 2 cm per year. The deformation is consistent with an expanding source at depth. Though the Uturuncu region exhibits high rates of crustal seismicity, any connection between the inflation and the seismicity is unclear. We investigate the root causes of these earthquakes using a temporary network of 33 seismic stations - part of the PLUTONS project. Our primary approach is based on hypocenter locations and magnitudes paired with correlation-based relative relocation techniques. We find a strong tendency toward earthquake swarms that cluster in space and time. These swarms often last a few days and consist of numerous earthquakes with similar source mechanisms. Most seismicity occurs in the top 10 kilometers of the crust and is characterized by well-defined phase arrivals and significant high frequency content. The frequency-magnitude relationship of this seismicity demonstrates b-values consistent with tectonic sources. There is a strong clustering of earthquakes around the Uturuncu edifice. Earthquakes elsewhere in the region align in bands striking northwest-southeast consistent with regional stresses.

  12. Renewable energy sources and ecology

    International Nuclear Information System (INIS)

    Panajotova, Yu.

    1998-01-01

    The share of renewable energy sources (RES) in the world energy balance is estimated from 1-2 to 10% of the total primary energy sources consumption. In EU since 1990 until now the power energy production from these sources is growing continuously by over 3% annually. The features of the updated Environmental Strategy for Bulgaria (ESB) elaborated with the World Bank in 1994 are: increasing the energy efficiency; utilising RES; granting preference to the regional energy concept and establishing regional energy centres based on the EU experience. In ESB the basic priorities are linked with disease factors - pollutants as lead in the air and soils (from leaded petrol, resp. from metallurgical enterprises), dust particles in the air (from household heating, industry and thermo-electric power stations) and sulfur dioxide and other gases (also from energy sector and industry). There is consistent policy for harmonization of the Bulgarian standards with those of the WHO. Among the implemented projects preference is granting to ones concerning new energy saving technologies and RES. Bulgaria got an environmental protection law harmonized with the international legislation and adapted to the economic situation inflicted by the market economy transition. The development of RES needs high investment cost and has low efficiency factor compared to the classical methods of energy production. Implementation of Environmental Action Programme (EAP) in Bulgaria with an international co-operation includes: solid wastes management; water sources management; water pollution problems; soil degradation; transport and environment; nuclear safety and nuclear waste problems and full value utilization of the RES. The Ministry of Environment and local Authorities have to develop their policies and implementing them by a range of activities to identify pollution control strategies, to identify areas where the greatest environmental benefits can be achieved at least cost and to incorporate the

  13. Sources of Regional Banks Capitalization

    Directory of Open Access Journals (Sweden)

    Olga Sergeevna Miroshnichenko

    2018-03-01

    Full Text Available Searching of sources to increase the capitalization of Russian banks is an important economic problem for both the national and regional economy. Moreover, a strong capital base allows to credit institutions to meet the demands of economic agents for banking service. The research focuses on the choice of sources of regulatory capital for the banks of Tyumen region in the context of changing supervisory requirements in the period of 2005–2016, in different phases of the business cycle. We apply econometric methods of statistical information using IBM SPSS Statistics software. We have calculated the individual correlations of regional banks’ capital with gross domestic product (GDP (excluding gross regional product (GRP and GRP (with the exception of the effect of GDP. These calculations have shown that the capital of regional banks is related only to GDP. The increase in the capital of regional banks is accompanied by a change in its structure: the share of authorized capital has halved, and the share of subordinated debt has grown. All sources of capital, other than the reserve fund, are related to GDP. Authorized capital is associated with the profit of profitable lending institutions; retained earnings in the capital of regional banks — with the aggregated amount of risks of the banking system of the Russian Federation. Subordinated debt, like capital as a whole, is negatively affected by the profitability of the banking sector. The change in the capital of regional banks is determined by the change in retained earnings, subordinated debt and reserve fund. Modelling of these relations has allowed to obtain a system of equations. This system synthesizes linear regression models of changing the capital of regional banks in the context of their sourcing. The results of this study are significant for theoretical justification and practical development of a balanced financial policy of regional banks. Our research will contribute to

  14. Tracing the source of campylobacteriosis.

    Directory of Open Access Journals (Sweden)

    Daniel J Wilson

    2008-09-01

    Full Text Available Campylobacter jejuni is the leading cause of bacterial gastro-enteritis in the developed world. It is thought to infect 2-3 million people a year in the US alone, at a cost to the economy in excess of US $4 billion. C. jejuni is a widespread zoonotic pathogen that is carried by animals farmed for meat and poultry. A connection with contaminated food is recognized, but C. jejuni is also commonly found in wild animals and water sources. Phylogenetic studies have suggested that genotypes pathogenic to humans bear greatest resemblance to non-livestock isolates. Moreover, seasonal variation in campylobacteriosis bears the hallmarks of water-borne disease, and certain outbreaks have been attributed to contamination of drinking water. As a result, the relative importance of these reservoirs to human disease is controversial. We use multilocus sequence typing to genotype 1,231 cases of C. jejuni isolated from patients in Lancashire, England. By modeling the DNA sequence evolution and zoonotic transmission of C. jejuni between host species and the environment, we assign human cases probabilistically to source populations. Our novel population genetics approach reveals that the vast majority (97% of sporadic disease can be attributed to animals farmed for meat and poultry. Chicken and cattle are the principal sources of C. jejuni pathogenic to humans, whereas wild animal and environmental sources are responsible for just 3% of disease. Our results imply that the primary transmission route is through the food chain, and suggest that incidence could be dramatically reduced by enhanced on-farm biosecurity or preventing food-borne transmission.

  15. Tracing the source of campylobacteriosis.

    Science.gov (United States)

    Wilson, Daniel J; Gabriel, Edith; Leatherbarrow, Andrew J H; Cheesbrough, John; Gee, Steven; Bolton, Eric; Fox, Andrew; Fearnhead, Paul; Hart, C Anthony; Diggle, Peter J

    2008-09-26

    Campylobacter jejuni is the leading cause of bacterial gastro-enteritis in the developed world. It is thought to infect 2-3 million people a year in the US alone, at a cost to the economy in excess of US $4 billion. C. jejuni is a widespread zoonotic pathogen that is carried by animals farmed for meat and poultry. A connection with contaminated food is recognized, but C. jejuni is also commonly found in wild animals and water sources. Phylogenetic studies have suggested that genotypes pathogenic to humans bear greatest resemblance to non-livestock isolates. Moreover, seasonal variation in campylobacteriosis bears the hallmarks of water-borne disease, and certain outbreaks have been attributed to contamination of drinking water. As a result, the relative importance of these reservoirs to human disease is controversial. We use multilocus sequence typing to genotype 1,231 cases of C. jejuni isolated from patients in Lancashire, England. By modeling the DNA sequence evolution and zoonotic transmission of C. jejuni between host species and the environment, we assign human cases probabilistically to source populations. Our novel population genetics approach reveals that the vast majority (97%) of sporadic disease can be attributed to animals farmed for meat and poultry. Chicken and cattle are the principal sources of C. jejuni pathogenic to humans, whereas wild animal and environmental sources are responsible for just 3% of disease. Our results imply that the primary transmission route is through the food chain, and suggest that incidence could be dramatically reduced by enhanced on-farm biosecurity or preventing food-borne transmission.

  16. Source to Accretion Disk Tilt

    OpenAIRE

    Montgomery, M. M.; Martin, E. L.

    2010-01-01

    Many different system types retrogradely precess, and retrograde precession could be from a tidal torque by the secondary on a misaligned accretion disk. However, a source to cause and maintain disk tilt is unknown. In this work, we show that accretion disks can tilt due to a force called lift. Lift results from differing gas stream supersonic speeds over and under an accretion disk. Because lift acts at the disk's center of pressure, a torque is applied around a rotation axis passing through...

  17. Source rock hydrocarbons. Present status

    International Nuclear Information System (INIS)

    Vially, R.; Maisonnier, G.; Rouaud, T.

    2013-01-01

    This report first presents the characteristics of conventional oil and gas system, and the classification of liquid and gaseous non conventional hydrocarbons, with the peculiar case of coal-bed methane. The authors then describe how source rock hydrocarbons are produced: production of shale oils and gases (horizontal drilling, hydraulic fracturing, exploitation) and of coal-bed methane and coal mine methane. In the next part, they address and discuss the environmental impact of source rock hydrocarbon production: installation footprint, water resource management, drilling fluids, fracturing fluids composition, toxicity and recycling, air pollution, induced seismicity, pollutions from other exploitation and production activities. They propose an overview of the exploitation and production of source rock gas, coal-bed gas and other non conventional gases in the world. They describe the current development and discuss their economic impacts: world oil context and trends in the USA, in Canada and other countries, impacts on the North American market, on the world oil industry, on refining industries, on the world oil balance. They analyse the economic impacts of non conventional gases: development potential, stakes for the world gas trade, consequence for gas prices, development opportunities for oil companies and for the transport sector, impact on CO 2 emissions, macro-economic impact in the case of the USA

  18. Neutron sources for radiation oncology

    International Nuclear Information System (INIS)

    D'omyina, E.A.; Yivankova, V.S.

    2011-01-01

    The authors discuss the peculiarities of biologic effect of fast neutrons from the perspective of overcoming radioresistance of the tumor cells. Retrospective radiobiological and clinical data obtained during treatment of cancer with fast neutrons at Oncology Institute of Academy of Medical Sciences of Ukraine (now National Cancer Institute of Ministry of Health of Ukraine) are reported. It was proven that neutron therapy allows to achieve a positive effect in patients with primary tumors and relapses. 252 Cf neutrons indicated to treatment of the tumors poorly sensitive to gamma-radiation were used. 252 Cf sources were used in combination radiotherapy for cancer of endometrium and uterine cervix. The sources were introduced to the cavity and fornix of the vagina. The treatment was performed by means of alternation of distance and intracavitary radiation therapy. Complete tumor regression was achieved in almost all patients. Radiation reactions were easily controlled during the treatment. Investigation of longterm results of treatment with 252 Cf sources demonstrated that their application allowed to achieve a high and prolonged relapse-free effect.

  19. Repeated Earthquakes in the Vrancea Subcrustal Source and Source Scaling

    Science.gov (United States)

    Popescu, Emilia; Otilia Placinta, Anica; Borleasnu, Felix; Radulian, Mircea

    2017-12-01

    The Vrancea seismic nest, located at the South-Eastern Carpathians Arc bend, in Romania, is a well-confined cluster of seismicity at intermediate depth (60 – 180 km). During the last 100 years four major shocks were recorded in the lithosphere body descending almost vertically beneath the Vrancea region: 10 November 1940 (Mw 7.7, depth 150 km), 4 March 1977 (Mw 7.4, depth 94 km), 30 August 1986 (Mw 7.1, depth 131 km) and a double shock on 30 and 31 May 1990 (Mw 6.9, depth 91 km and Mw 6.4, depth 87 km, respectively). The probability of repeated earthquakes in the Vrancea seismogenic volume is relatively large taking into account the high density of foci. The purpose of the present paper is to investigate source parameters and clustering properties for the repetitive earthquakes (located close each other) recorded in the Vrancea seismogenic subcrustal region. To this aim, we selected a set of earthquakes as templates for different co-located groups of events covering the entire depth range of active seismicity. For the identified clusters of repetitive earthquakes, we applied spectral ratios technique and empirical Green’s function deconvolution, in order to constrain as much as possible source parameters. Seismicity patterns of repeated earthquakes in space, time and size are investigated in order to detect potential interconnections with larger events. Specific scaling properties are analyzed as well. The present analysis represents a first attempt to provide a strategy for detecting and monitoring possible interconnections between different nodes of seismic activity and their role in modelling tectonic processes responsible for generating the major earthquakes in the Vrancea subcrustal seismogenic source.

  20. Ultrafast X-ray Sources

    International Nuclear Information System (INIS)

    Neil, George

    2010-01-01

    Since before the scattering of X-rays off of DNA led to the first understanding of the double helix structure, sources of X-rays have been an essential tool for scientists examining the structure and interactions of matter. The resolution of a microscope is proportional to the wavelength of light so x-rays can see much finer structures than visible light, down to single atoms. In addition, the energy of X-rays is resonant with the core atomic levels of atoms so with appropriate wavelengths the placement of specific atoms in a large molecule can be determined. Over 10,000 scientists use synchrotron sources, storage rings of high energy electrons, each year worldwide. As an example of such use, virtually every picture of a protein or drug molecule that one sees in the scientific press is a reconstruction based on X-ray scattering of synchrotron light from the crystallized form of that molecule. Unfortunately those pictures are static and proteins work through configuration (shape) changes in response to energy transfer. To understand how biological systems work requires following the energy flow to these molecules and tracking how shape changes drive their interaction with other molecules. We'd like to be able to freeze the action of these molecules at various steps along the way with an X-ray strobe light. How fast does it have to be? To actually get a picture of a molecule in a fixed configuration requires X-ray pulses as short as 30 femtoseconds (1/30 of a millionth of a millionth of a second). To capture the energy flow through changes in electronic levels requires a faster strobe, less than 1 femtosecond And to acquire such information in smaller samples with higher accuracy demands brighter and brighter X-rays. Unfortunately modern synchrotrons (dubbed 3rd Generation Light Sources) cannot deliver such short bright pulses of X-rays. An entirely new approach is required, linear-accelerator (linac-)-based light sources termed 4th or Next Generation Light Sources

  1. Characterization of ISOLDE ion source and ion source chemistry

    CERN Document Server

    Barbeau, Marion

    2014-01-01

    This report presents results of measurements made with the ISOLDE OFF-LINE mass separator [1]. The first part shows measurements of the ionization characteristics of noble gases in a VADIS ion source. The goal of the measurements was to determine the dependency of the extractable current of first and second noble gases ions with the electron energy. In the second part, investigation on in-target chemistry are presented. Here, the effect of injected sulfur hexafluoride ($SF_6$) on the release of oxygen from aluminium oxide ($Al_2 O_3$) was studied.

  2. Iranian Light Source Facility, A third generation light source laboratory

    Directory of Open Access Journals (Sweden)

    J Rahighi

    2015-09-01

    Full Text Available The Iranian Light Source Facility (ILSF project is the first large scale accelerator facility which is currently under planning in Iran. On the basis of the present design, circumference of the 3 GeV storage ring is 528 m. Beam current and natural beam emittance are 400 mA and 0.477 nm.rad, respectively. Some prototype accelerator components such as high power solid state radio frequency amplifiers, low level RF system, thermionic RF gun, H-type dipole and quadruple magnets, magnetic measurement laboratory and highly stable magnet power supplies have been constructed at ILSF R&D laboratory

  3. Higher Social Intelligence Can Impair Source Memory

    Science.gov (United States)

    Barber, Sarah J.; Franklin, Nancy; Naka, Makiko; Yoshimura, Hiroki

    2010-01-01

    Source monitoring is made difficult when the similarity between candidate sources increases. The current work examines how individual differences in social intelligence and perspective-taking abilities serve to increase source similarity and thus negatively impact source memory. Strangers first engaged in a cooperative storytelling task. On each…

  4. SoFiA: Source Finding Application

    NARCIS (Netherlands)

    Serra, Paolo; Westmeier, Tobias; Giese, Nadine; Jurek, Russell; Flöer, Lars; Popping, Attila; Winkel, Benjamin; van der Hulst, Thijs; Meyer, Martin; Koribalski, Bärbel; Staveley-Smith, Lister; Courtois, Hélène

    2014-01-01

    SoFiA is a flexible source finding pipeline designed to detect and parameterise sources in 3D spectral-line data cubes. SoFiA combines several powerful source finding and parameterisation algorithms, including wavelet denoising, spatial and spectral smoothing, source mask optimisation, spectral

  5. When to make proprietary software open source

    NARCIS (Netherlands)

    Caulkins, J.P.; Feichtinger, G.; Grass, D.; Hartl, R.F.; Kort, P.M.; Seidl, A.

    Software can be distributed closed source (proprietary) or open source (developed collaboratively). While a firm cannot sell open source software, and so loses potential sales revenue, the open source software development process can have a substantial positive impact on the quality of a software,

  6. 48 CFR 13.102 - Source list.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Source list. 13.102... AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Procedures 13.102 Source list. (a) Contracting... as their primary sources of vendor information. Offices maintaining additional vendor source files or...

  7. 21 CFR 640.60 - Source Plasma.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Source Plasma. 640.60 Section 640.60 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human blood...

  8. 28 CFR 104.47 - Collateral sources.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Collateral sources. 104.47 Section 104.47... Amount of Compensation for Eligible Claimants. § 104.47 Collateral sources. (a) Payments that constitute collateral source compensation. The amount of compensation shall be reduced by all collateral source...

  9. Sources of underwater sound and their characterization

    NARCIS (Netherlands)

    Ainslie, M.A.; Jong, C.A.F. de

    2016-01-01

    Because of the history of sonar and sonar engineering, the concept of “source level” is widely used to characterize anthropogenic sound sources, but is it useful for sources other than sonar transmitters? The concept and applicability of source level are reviewed for sonar, air guns, explosions,

  10. Practical open source software for libraries

    CERN Document Server

    Engard, Nicole

    2010-01-01

    Open source refers to an application whose source code is made available for use or modification as users see fit. This means libraries gain more flexibility and freedom than with software purchased with license restrictions. Both the open source community and the library world live by the same rules and principles. Practical Open Source Software for Libraries explains the facts and dispels myths about open source. Chapters introduce librarians to open source and what it means for libraries. The reader is provided with links to a toolbox full of freely available open source products to use in

  11. Negative ion sources for tandem accelerator

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    1980-08-01

    Four kinds of negative ion sources (direct extraction Duoplasmatron ion source, radial extraction Penniing ion source, lithium charge exchange ion source and Middleton-type sputter ion source) have been installed in the JAERI tandem accelerator. The ion sources can generate many negative ions ranging from Hydrogen to Uranium with the exception of Ne, Ar, Kr, Xe and Rn. Discussions presented in this report include mechanisms of negative ion formation, electron affinity and stability of negative ions, performance of the ion sources and materials used for negative ion production. Finally, the author will discuss difficult problems to be overcome in order to get any negative ion sufficiently. (author)

  12. ALTERNATIVE SOURCES OF ENERGY - ALTERNATIVE SOURCES OF POLLUTION?

    Directory of Open Access Journals (Sweden)

    Marius-Razvan SURUGIU

    2007-06-01

    Full Text Available In many countries of the world investments are made for obtaining energy efficiency, pursuing to increase the generation of non-polluting fuels due to the fact that energy is vital for any economy. The increase in non-polluting fuels and in renewable energy generation might lead to diminishing the dependence of countries less endowed with conventional energy resources on oil and natural gas from Russia or from Arab countries. Nevertheless, environmental issues represent serious questions facing the mankind, requiring the identification, prevention, and why not, their total solving.European Union countries depend on imports of energy, especially on oil imports. At the same time, the European Union countries record a high volume of greenhouse gas emissions, substances adding to global warming. The transport sector is the main consumer of fossil fuels and generator of greenhouse gas emissions. Therefore, diversifying the energy supply used in the transport sector with less polluting sources is an essential objective of the European Union policy in the transport, energy and environment sector. Road transports’ is the sector recording the highest consumption of energy and the highest volume of greenhouse gas emissions.The use of ecologic fuels in the transport sector is an important factor for achieving the objectives of European policies in the field. It is yet to be seen to what extent alternative energy sources are damaging to the environment, as it is a known fact that even for them is recorded a certain level of negative externalities.

  13. Procedures for calibration of brachytherapy sources

    International Nuclear Information System (INIS)

    Alfonso Laguardia, R.; Alonso Samper, J.L.; Morales Lopez, J.L.; Saez Nunez, D.G.

    1997-01-01

    Brachytherapy source strength verification is a responsibility of the user of these source, in fact of the Medical Physicists in charge of this issue in a Radiotherapy Service. The calibration procedures in the users conditions are shown. Specifics methods for source strength determination are recommended, both for High Dose Rate (HDR) sources with Remote Afterloading equipment and for Low Dose Rate sources. The The results of the calibration of HDR Remote After loaders are indicated

  14. The HYPE Open Source Community

    Science.gov (United States)

    Strömbäck, L.; Pers, C.; Isberg, K.; Nyström, K.; Arheimer, B.

    2013-12-01

    The Hydrological Predictions for the Environment (HYPE) model is a dynamic, semi-distributed, process-based, integrated catchment model. It uses well-known hydrological and nutrient transport concepts and can be applied for both small and large scale assessments of water resources and status. In the model, the landscape is divided into classes according to soil type, vegetation and altitude. The soil representation is stratified and can be divided in up to three layers. Water and substances are routed through the same flow paths and storages (snow, soil, groundwater, streams, rivers, lakes) considering turn-over and transformation on the way towards the sea. HYPE has been successfully used in many hydrological applications at SMHI. For Europe, we currently have three different models; The S-HYPE model for Sweden; The BALT-HYPE model for the Baltic Sea; and the E-HYPE model for the whole Europe. These models simulate hydrological conditions and nutrients for their respective areas and are used for characterization, forecasts, and scenario analyses. Model data can be downloaded from hypeweb.smhi.se. In addition, we provide models for the Arctic region, the Arab (Middle East and Northern Africa) region, India, the Niger River basin, the La Plata Basin. This demonstrates the applicability of the HYPE model for large scale modeling in different regions of the world. An important goal with our work is to make our data and tools available as open data and services. For this aim we created the HYPE Open Source Community (OSC) that makes the source code of HYPE available for anyone interested in further development of HYPE. The HYPE OSC (hype.sourceforge.net) is an open source initiative under the Lesser GNU Public License taken by SMHI to strengthen international collaboration in hydrological modeling and hydrological data production. The hypothesis is that more brains and more testing will result in better models and better code. The code is transparent and can be changed

  15. PERSPECTIVE: Dust, fertilization and sources

    Science.gov (United States)

    Remer, Lorraine A.

    2006-11-01

    fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the

  16. Advanced Light Source control system

    International Nuclear Information System (INIS)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs

  17. Compact x-ray source and panel

    Science.gov (United States)

    Sampayon, Stephen E [Manteca, CA

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  18. [Source data management in clinical researches].

    Science.gov (United States)

    Ho, Effie; Yao, Chen; Zhang, Zi-bao; Liu, Yu-xiu

    2015-11-01

    Source data and its source documents are the foundation of clinical research. Proper source data management plays an essential role for compliance with regulatory and GCP requirements. Both paper and electronic source data co-exist in China. Due to the increasing use of electronic technology in pharmaceutical and health care industry, electronic data source becomes an upcoming trend with clear advantages. To face new opportunities and to ensure data integrity, quality and traceability from source data to regulatory submission, this document demonstrates important concepts, principles and best practices during managing source data. It includes but not limited to: (1) important concepts of source data (e.g., source data originator, source data elements, source data identifier for audit trail, etc.); (2) various modalities of source data collection in paper and electronic methods (e.g., paper CRF, EDC, Patient Report Outcomes/eCOA, etc.); (3) seven main principles recommended in the aspect of data collection, traceability, quality standards, access control, quality control, certified copy and security during source data management; (4) a life cycle from source data creation to obsolete is used as an example to illustrate consideration and implementation of source data management.

  19. Shielding around spallation neutron sources

    International Nuclear Information System (INIS)

    Fragopoulou, M; Manolopoulou, M; Stoulos, S; Brandt, R; Westmeier, W; Krivopustov, M; Sosnin, A; Golovatyuk, S; Zamani, M

    2006-01-01

    Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors for which a substantial amount of shielding measurements have been performed. Although the main part of the cost for a spallation station is the cost of the shielding, measurements regarding shielding for the high energy neutron region are still very scarce. In this work calculation of the neutron interaction length in polyethylene moderator for different neutron energies is presented. Measurements which were carried out in Nuclotron accelerator at the Laboratory of High Energies (Joint Institute for Nuclear Research, Dubna) and comparison with calculation are also presented. The measurements were performed with Solid State Nuclear Track Detectors (SSNTDs)

  20. LINAC4 - The Ion Source

    CERN Document Server

    Haugaa, Olav

    2013-01-01

    My summer student project has been split in three parts. During the first 4-5 weeks I was involved in the design of the filtermagnets for the IS02 with the simulation tool Opera. After this, I have performed data analysis of the plasma light emission in the IS01 source with the software Matlab and I took part in the development of a Fortran code for plasma simulations. In all projects, understanding plasma physics has been essential and the learning outcome related to this field has been very high.