WorldWideScience

Sample records for area plasma source

  1. Large area plasma source

    Science.gov (United States)

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

    2008-01-01

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

  2. Plasma and Ion Sources in Large Area Coatings: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2005-02-28

    Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enabling large area application of ions and plasmas, with ion energies ranging from a few eV to a few keV. Both semiconductortype large area (single wafer or batch processing with {approx} 1000 cm{sup 2}) and in-line web and glass-coating-type large area (> 10{sup 7} m{sup 2} annually) are considered. Characteristics and differences between plasma and ion sources are explained. The latter include gridded and gridless sources. Many examples are given, including sources based on DC, RF, and microwave discharges, some with special geometries like hollow cathodes and E x B configurations.

  3. Large-Area Permanent-Magnet ECR Plasma Source

    Science.gov (United States)

    Foster, John E.

    2007-01-01

    A 40-cm-diameter plasma device has been developed as a source of ions for material-processing and ion-thruster applications. Like the device described in the immediately preceding article, this device utilizes electron cyclotron resonance (ECR) excited by microwave power in a magnetic field to generate a plasma in an electrodeless (noncontact) manner and without need for an electrically insulating, microwave-transmissive window at the source. Hence, this device offers the same advantages of electrodeless, windowless design - low contamination and long operational life. The device generates a uniform, high-density plasma capable of sustaining uniform ion-current densities at its exit plane while operating at low pressure [magnetic field in this device is generated by a permanent-magnet circuit that is optimized to generate resonance surfaces. The microwave power is injected on the centerline of the device. The resulting discharge plasma jumps into a "high mode" when the input power rises above 150 W. This mode is associated with elevated plasma density and high uniformity. The large area and uniformity of the plasma and the low operating pressure are well suited for such material-processing applications as etching and deposition on large silicon wafers. The high exit-plane ion-current density makes it possible to attain a high rate of etching or deposition. The plasma potential is <3 V low enough that there is little likelihood of sputtering, which, in plasma processing, is undesired because it is associated with erosion and contamination. The electron temperature is low and does not vary appreciably with power.

  4. Plasma Sources for Medical Applications - A Comparison of Spot Like Plasmas and Large Area Plasmas

    Science.gov (United States)

    Weltmann, Klaus-Dieter

    2015-09-01

    Plasma applications in life science are currently emerging worldwide. Whereas today's commercially available plasma surgical technologies such as argon plasma coagulation (APC) or ablation are mainly based on lethal plasma effects on living systems, the newly emerging therapeutic applications will be based on selective, at least partially non-lethal, possibly stimulating plasma effects on living cells and tissue. Promising results could be obtained by different research groups worldwide revealing a huge potential for the application of low temperature atmospheric pressure plasma in fields such as tissue engineering, healing of chronic wounds, treatment of skin diseases, tumor treatment based on specific induction of apoptotic processes, inhibition of biofilm formation and direct action on biofilms or treatment of dental diseases. The development of suitable and reliable plasma sources for the different therapies requires an in-depth knowledge of their physics, chemistry and parameters. Therefore much basic research still needs to be conducted to minimize risk and to provide a scientific fundament for new plasma-based medical therapies. It is essential to perform a comprehensive assessment of physical and biological experiments to clarify minimum standards for plasma sources for applications in life science and for comparison of different sources. One result is the DIN-SPEC 91315, which is now open for further improvements. This contribution intends to give an overview on the status of commercial cold plasma sources as well as cold plasma sources still under development for medical use. It will discuss needs, prospects and approaches for the characterization of plasmas from different points of view. Regarding the manageability in everyday medical life, atmospheric pressure plasma jets (APPJ) and dielectric barrier discharges (DBD) are of special interest. A comprehensive risk-benefit assessment including the state of the art of commercial sources for medical use

  5. Electromagnetic, complex image model of a large area RF resonant antenna as inductive plasma source

    Science.gov (United States)

    Guittienne, Ph; Jacquier, R.; Howling, A. A.; Furno, I.

    2017-03-01

    A large area antenna generates a plasma by both inductive and capacitive coupling; it is an electromagnetically coupled plasma source. In this work, experiments on a large area planar RF antenna source are interpreted in terms of a multi-conductor transmission line coupled to the plasma. This electromagnetic treatment includes mutual inductive coupling using the complex image method, and capacitive matrix coupling between all elements of the resonant network and the plasma. The model reproduces antenna input impedance measurements, with and without plasma, on a 1.2× 1.2 m2 antenna used for large area plasma processing. Analytic expressions are given, and results are obtained by computation of the matrix solution. This method could be used to design planar inductive sources in general, by applying the termination impedances appropriate to each antenna type.

  6. Pulsed Plasma Electron Sources

    Science.gov (United States)

    Krasik, Yakov

    2008-11-01

    Pulsed (˜10-7 s) electron beams with high current density (>10^2 A/cm^2) are generated in diodes with electric field of E > 10^6 V/cm. The source of electrons in these diodes is explosive emission plasma, which limits pulse duration; in the case E Hadas and Ya. E. Krasik, Europhysics Lett. 82, 55001 (2008).

  7. Miniaturized cathodic arc plasma source

    Science.gov (United States)

    Anders, Andre; MacGill, Robert A.

    2003-04-15

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  8. OLED area illumination source

    Science.gov (United States)

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

    2008-03-25

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

  9. 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...

  10. Some plasma aspects and plasma diagnostics of ion sources.

    Science.gov (United States)

    Wiesemann, Klaus

    2008-02-01

    We consider plasma properties in the most advanced type of plasma ion sources, electron cyclotron resonance ion sources for highly charged ions. Depending on the operation conditions the plasma in these sources may be highly ionized, which completely changes its transport properties. The most striking difference to weakly ionized plasma is that diffusion will become intrinsically ambipolar. We further discuss means of plasma diagnostics. As noninvasive diagnostic methods we will discuss analysis of the ion beam, optical spectroscopy, and measurement of the x-ray bremsstrahlung continuum. From beam analysis and optical spectroscopy one may deduce ion densities, and electron densities and distribution functions as a mean over the line of sight along the axis (optical spectroscopy) or at the plasma edge (ion beam). From x-ray spectra one obtains information about the population of highly energetic electrons and the energy transfer from the driving electromagnetic waves to the plasma -- basic data for plasma modeling.

  11. The HelCat dual-source plasma device.

    Science.gov (United States)

    Lynn, Alan G; Gilmore, Mark; Watts, Christopher; Herrea, Janis; Kelly, Ralph; Will, Steve; Xie, Shuangwei; Yan, Lincan; Zhang, Yue

    2009-10-01

    The HelCat (Helicon-Cathode) device has been constructed to support a broad range of basic plasma science experiments relevant to the areas of solar physics, laboratory astrophysics, plasma nonlinear dynamics, and turbulence. These research topics require a relatively large plasma source capable of operating over a broad region of parameter space with a plasma duration up to at least several milliseconds. To achieve these parameters a novel dual-source system was developed utilizing both helicon and thermionic cathode sources. Plasma parameters of n(e) approximately 0.5-50 x 10(18) m(-3) and T(e) approximately 3-12 eV allow access to a wide range of collisionalities important to the research. The HelCat device and initial characterization of plasma behavior during dual-source operation are described.

  12. Plasma Cathode Electron Sources Physics, Technology, Applications

    CERN Document Server

    Oks, Efim

    2006-01-01

    This book fills the gap for a textbook describing this kind of electron beam source in a systematic and thorough manner: from physical processes of electron emission to examples of real plasma electron sources and their applications.

  13. Construction of Larger Area Density-Uniform Plasma with Collisional Inductively Coupled Plasma Cells

    Institute of Scientific and Technical Information of China (English)

    OUYANG Liang; LIU Wandong; BAI Xiaoyan; CHEN Zhipeng; WANG Huihui; LI LUO Chen; JI Liangliang; HU Bei

    2007-01-01

    The plasma density and electron temperature of a multi-source plasma system composed of several collisional inductively coupled plasma (ICP) cells were measured by a double-probe. The discharges of the ICP cells were shown to be independent of each other. Furthermore, the total plasma density at simultaneous multi-cell discharge was observed to be approximately equal to the summation of the plasma density when the cells discharge separately. Based on the linear summation phenomenon, it was shown that a larger area plasma with a uniform density and temperature profile could be constructed with multi-collisional ICP cells.

  14. The study of helicon plasma source.

    Science.gov (United States)

    Miao, Ting-Ting; Zhao, Hong-Wei; Liu, Zhan-Wen; Shang, Yong; Sun, Liang-Ting; Zhang, Xue-Zhen; Zhao, Huan-Yu

    2010-02-01

    Helicon plasma source is known as efficient generator of uniform and high density plasma. A helicon plasma source was developed for investigation of plasma neutralization and plasma lens in the Institute of Modern Physics in China. In this paper, the characteristics of helicon plasma have been studied by using Langmuir four-probe and a high argon plasma density up to 3.9x10(13) cm(-3) have been achieved with the Nagoya type III antenna at the conditions of the magnetic intensity of 200 G, working gas pressure of 2.8x10(-3) Pa, and rf power of 1200 W with a frequency of 27.12 MHz. In the experiment, the important phenomena have been found: for a given magnetic induction intensity, the plasma density became greater with the increase in rf power and tended to saturation, and the helicon mode appeared at the rf power between 200 and 400 W.

  15. Surface plasma source with saddle antenna radio frequency plasma generator.

    Science.gov (United States)

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  16. Saturn Plasma Sources and Associated Transport Processes

    Science.gov (United States)

    Blanc, M.; Andrews, D. J.; Coates, A. J.; Hamilton, D. C.; Jackman, C. M.; Jia, X.; Kotova, A.; Morooka, M.; Smith, H. T.; Westlake, J. H.

    2015-10-01

    This article reviews the different sources of plasma for Saturn's magnetosphere, as they are known essentially from the scientific results of the Cassini-Huygens mission to Saturn and Titan. At low and medium energies, the main plasma source is the H2O cloud produced by the "geyser" activity of the small satellite Enceladus. Impact ionization of this cloud occurs to produce on the order of 100 kg/s of fresh plasma, a source which dominates all the other ones: Titan (which produces much less plasma than anticipated before the Cassini mission), the rings, the solar wind (a poorly known source due to the lack of quantitative knowledge of the degree of coupling between the solar wind and Saturn's magnetosphere), and the ionosphere. At higher energies, energetic particles are produced by energy diffusion and acceleration of lower energy plasma produced by the interchange instabilities induced by the rapid rotation of Saturn, and possibly, for the highest energy range, by contributions from the CRAND process acting inside Saturn's magnetosphere. Discussion of the transport and acceleration processes acting on these plasma sources shows the importance of rotation-induced radial transport and energization of the plasma, and also shows how much the unexpected planetary modulation of essentially all plasma parameters of Saturn's magnetosphere remains an unexplained mystery.

  17. Hollow-Cathode Source Generates Plasma

    Science.gov (United States)

    Deininger, W. D.; Aston, G.; Pless, L. C.

    1989-01-01

    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  18. Sources of Pressure in Titan's Plasma Environment

    CERN Document Server

    Achilleos, N; Bertucci, C; Guio, P; Romanelli, N; Sergis, N

    2013-01-01

    In order to analyze varying plasma conditions upstream of Titan, we have combined a physical model of Saturn's plasmadisk with a geometrical model of the oscillating current sheet. During modeled oscillation phases where Titan is furthest from the current sheet, the main sources of plasma pressure in the near-Titan space are the magnetic pressure and, for disturbed conditions, the hot plasma pressure. When Titan is at the center of the sheet, the main source is the dynamic pressure associated with Saturn's cold, subcorotating plasma. Total pressure at Titan (dynamic plus thermal plus magnetic) typically increases by a factor of five as the current sheet center is approached. The predicted incident plasma flow direction deviates from the orbital plane of Titan by < 10 deg. These results suggest a correlation between the location of magnetic pressure maxima and the oscillation phase of the plasmasheet.

  19. Study of Coupling between a Plasma Source and Plasma Fluctuations

    Science.gov (United States)

    Berumen, Jorge; Chu, Feng; Hood, Ryan; Mattingly, Sean; Rogers, Anthony; Skiff, Fred

    2014-10-01

    An experimental study on the coupling between a plasma source and plasma fluctuations in a cylindrical, magnetized, singly-ionized Argon inductively-coupled gas discharge plasma that is weakly collisional is presented. Typical plasma conditions are n ~1010 cm-3 Te ~ 3 eV and B ~ 1 kG. Amplitude Modulation (AM) of the inductively-coupled RF plasma source is produced near the fundamental-mode ion-acoustic wave frequency (~1 kHz) to study the effects of the source-wave interaction and plasma production. Density fluctuation measurements are implemented using Laser-Induced Fluorescence techniques and Langmuir probes. We apply coherent detection with respect to the wave frequency to obtain the perturbed ion distribution function associated with the waves. Measurements of fluctuating I-V traces from a Langmuir probe array and antenna current load are also used to show the effects of the interaction. We would like to acknowledge DOE DE-FG02-99ER54543 for their financial support throughout this research.

  20. Meter scale plasma source for plasma wakefield experiments

    Science.gov (United States)

    Vafaei-Najafabadi, N.; Shaw, J. L.; Marsh, K. A.; Joshi, C.; Hogan, M. J.

    2012-12-01

    High accelerating gradients generated by a high density electron beam moving through plasma has been used to double the energy of the SLAC electron beam [1]. During that experiment, the electron current density was high enough to generate its own plasma without significant head erosion. In the newly commissioned FACET facility at SLAC, the peak current will be lower and without pre-ionization, head erosion will be a significant challenge for the planned experiments. In this work we report on our design of a meter scale plasma source for these experiments to effectively avoid the problem of head erosion. The plasma source is based on a homogeneous metal vapor gas column that is generated in a heat pipe oven [2]. A lithium oven over 30 cm long at densities over 1017 cm-3 has been constructed and tested at UCLA. The plasma is then generated by coupling a 10 TW short pulse Ti:Sapphire laser into the gas column using an axicon lens setup. The Bessel profile of the axicon setup creates a region of high intensity that can stretch over the full length of the gas column with approximately constant diameter. In this region of high intensity, the alkali metal vapor is ionized through multi-photon ionization process. In this manner, a fully ionized meter scale plasma of uniform density can be formed. Methods for controlling the plasma diameter and length will also be discussed.

  1. Meter scale plasma source for plasma wakefield experiments

    Energy Technology Data Exchange (ETDEWEB)

    Vafaei-Najafabadi, N.; Shaw, J. L.; Marsh, K. A.; Joshi, C.; Hogan, M. J. [Department of Electrical Engineering, University of California Los Angeles, Los Angeles, CA 90095 (United States); SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2012-12-21

    High accelerating gradients generated by a high density electron beam moving through plasma has been used to double the energy of the SLAC electron beam [1]. During that experiment, the electron current density was high enough to generate its own plasma without significant head erosion. In the newly commissioned FACET facility at SLAC, the peak current will be lower and without pre-ionization, head erosion will be a significant challenge for the planned experiments. In this work we report on our design of a meter scale plasma source for these experiments to effectively avoid the problem of head erosion. The plasma source is based on a homogeneous metal vapor gas column that is generated in a heat pipe oven [2]. A lithium oven over 30 cm long at densities over 10{sup 17} cm{sup -3} has been constructed and tested at UCLA. The plasma is then generated by coupling a 10 TW short pulse Ti:Sapphire laser into the gas column using an axicon lens setup. The Bessel profile of the axicon setup creates a region of high intensity that can stretch over the full length of the gas column with approximately constant diameter. In this region of high intensity, the alkali metal vapor is ionized through multi-photon ionization process. In this manner, a fully ionized meter scale plasma of uniform density can be formed. Methods for controlling the plasma diameter and length will also be discussed.

  2. Plasma-based EUV light source

    Science.gov (United States)

    Shumlak, Uri; Golingo, Raymond; Nelson, Brian A.

    2010-11-02

    Various mechanisms are provided relating to plasma-based light source that may be used for lithography as well as other applications. For example, a device is disclosed for producing extreme ultraviolet (EUV) light based on a sheared plasma flow. The device can produce a plasma pinch that can last several orders of magnitude longer than what is typically sustained in a Z-pinch, thus enabling the device to provide more power output than what has been hitherto predicted in theory or attained in practice. Such power output may be used in a lithography system for manufacturing integrated circuits, enabling the use of EUV wavelengths on the order of about 13.5 nm. Lastly, the process of manufacturing such a plasma pinch is discussed, where the process includes providing a sheared flow of plasma in order to stabilize it for long periods of time.

  3. Plasma sources of solar system magnetospheres

    CERN Document Server

    Blanc, Michel; Chappell, Charles; Krupp, Norbert

    2016-01-01

    This volume reviews what we know of the corresponding plasma source for each intrinsically magnetized planet. Plasma sources fall essentially in three categories: the solar wind, the ionosphere (both prevalent on Earth), and the satellite-related sources. Throughout the text, the case of each planet is described, including the characteristics, chemical composition and intensity of each source. The authors also describe how the plasma generated at the source regions is transported to populate the magnetosphere, and how it is later lost. To summarize, the dominant sources are found to be the solar wind and sputtered surface ions at Mercury, the solar wind and ionosphere at Earth (the relative importance of the two being discussed in a specific introductory chapter), Io at Jupiter and – a big surprise of the Cassini findings – Enceladus at Saturn. The situation for Uranus and Neptune, which were investigated by only one fly-by each, is still open and requires further studies and exploration. In the final cha...

  4. A Microfabricated Inductively Coupled Plasma Excitation Source

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-Qing; PU Yong-Ni; SUN Rong-Xia; TANG Yu-Jun; CHEN Wen-Jun; LOU Jian-Zhong; MA Wen

    2008-01-01

    A novel miniaturization of inductively coupled plasma(ICP)source based on printed circuit produced using micro-fabrication techniques is presented.The basic parameters of the novel ICP,including its radio frequency,power loss,size,and argon consumption are less than 1% of that for the case of atmospheric pressure ICP source.For example,at 100 Pa of argon gas pressure,the present ICP source can be ignited by using the rf power less than 3.5 W.Potential applications of the ICP is discussed.

  5. Plasma wake field XUV radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Prono, Daniel S. (Los Alamos, NM); Jones, Michael E. (Los Alamos, NM)

    1997-01-01

    A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.

  6. Assistant Anode in a Cathodic Arc Plasma Source

    Institute of Scientific and Technical Information of China (English)

    张涛; Paul K. Chu; 张荟星; Ian G. Brown

    2001-01-01

    The performance and characteristics of a cathodic arc plasma source, consisting of a titanium cathode, an anode with and without a tungsten mesh, and a coil producing a focusing magnetic field between the anode and cathode,are investigated. The high transparency and large area of the mesh allow a high plasma flux to penetrate the anode from the cathodic arc. The mesh helps to decrease the arc resistance and the ignition voltage of the cathodic arc in the focusing magnetic field, and to increase the life of the source, which means that the source makes the cathodic arc easily and greatly stabilized during the operation when a focusing magnetic field exists in the source.

  7. Burning plasmas in ITER for energy source

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Nobuyuki [Atomic Energy Commission, Tokyo (Japan)

    2002-10-01

    Fusion research and development has two aspects. One is an academic research on science and technology, i.e., discovery and understanding of unexpected phenomena and, development of innovative technology, respectively. The other is energy source development to realize fusion as a viable energy future. Fusion research has been made remarkable progress in the past several decades, and ITER will soon realize burning plasma that is essential for both academic research and energy development. With ITER, scientific research on unknown phenomena such as self-organization of the plasma in burning state will become possible and it contributes to create a variety of academic outcome. Fusion researchers will have a responsibility to generate actual energy, and electricity generation immediately after the success of burning plasma control experiment in ITER is the next important step that has to be discussed seriously. (author)

  8. Speciation analysis by gas chromatography with plasma source spectrometric detection

    Science.gov (United States)

    Łobiński, Ryszard; Adams, Freddy C.

    State-of-the-art species-selective analysis by gas chromatography (GC) with plasma source spectrometric detection is discussed for organometal and organometalloid compounds. Various plasmas, inductively coupled plasma, microwave induced plasma, capacitatively coupled plasma, direct current plasma and alternating current plasma, are characterized and critically compared as sources of radiation for atomic emission spectrometry and sources of ions for mass spectrometry. Interfaces between gas chromatography (packed, wide-bore, capillary and multicapillary) and plasma source spectrometry are characterized. Particular emphasis is given to applications of GC with plasma source detection to real-world analytical problems, which are comprehensively reviewed. The use of plasmas for the acquisition of auxiliary molecular information such as empirical formulae and structural information is discussed. Recent developments relating to sample preparation and presentation to the hyphenated system are addressed. The most significant trends in speciation analysis are highlighted.

  9. 21 CFR 640.74 - Modification of Source Plasma.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Modification of Source Plasma. 640.74 Section 640...) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the Director, Center for Biologics Evaluation and Research, Food...

  10. Plasma-Based Ion Beam Sources

    Energy Technology Data Exchange (ETDEWEB)

    Loeb, H. W.

    2005-07-01

    Ion beam sources cover a broad spectrum of scientific and technical applications delivering ion currents between less than 1 mA and about 100 A at acceleration voltages between 100 V and 100 kV. The ions are mostly generated by electron collisions in a gas discharge and then extracted from the discharge plasma, focused and post-accelerated by single- or multi-aperture electrode systems. Some important applications require the neutralization of the exhausted beam either by charge exchange or by admixture of electrons. In the first part of the paper, the theory of ionization by electron impact, the energy and carrier balances in the plasma, and the extraction and focusing mechanisms will be outlined. The principles of the preferred gas discharges and of the ion beam sources based on them are discussed; i.e. of the Penning, bombardment, arc, duoplasmatron, radio frequency, and microwave types. In the second part of the paper, the special requirements of the different applications are described together with the related source hardware. One distinguishes: 1. Single-aperture ion sources producing protons, heavy ions, isotope ions, etc. for particle accelerators, ion microprobes, mass spectrometers, isotope separators, etc.; quality determinative quantities are brightness, emittance, energy width, etc. 2. Broad-beam multi-aperture injector sources for fusion machines with positive or negative deuterium ions; very high beam densities, small portions of molecular ions, flat beam profiles with small divergence angles, etc. are required. 3. Broad-beam multi-aperture ion thrusters for space propulsion operated with singly charged xenon ions; high efficiencies, reliable operation, and long lifetimes are most important. Spin-offs are applied in industry for material processing. Referring to these applications, the following sources will be described in some detail: 1. Cold cathode and filament driven sources, capillary arc and plasmatron types, microwave and ECR-sources. 2

  11. Ions beams and ferroelectric plasma sources

    Science.gov (United States)

    Stepanov, Anton

    Near-perfect space-charge neutralization is required for the transverse compression of high perveance ion beams for ion-beam-driven warm dense matter experiments, such as the Neutralized Drift Compression eXperiment (NDCX). Neutralization can be accomplished by introducing a plasma in the beam path, which provides free electrons that compensate the positive space charge of the ion beam. In this thesis, charge neutralization of a 40 keV, perveance-dominated Ar+ beam by a Ferroelectric Plasma Source (FEPS) is investigated. First, the parameters of the ion beam, such as divergence due to the extraction optics, charge neutralization fraction, and emittance were measured. The ion beam was propagated through the FEPS plasma, and the effects of charge neutralization were inferred from time-resolved measurements of the transverse beam profile. In addition, the dependence of FEPS plasma parameters on the configuration of the driving pulser circuit was studied to optimize pulser design. An ion accelerator was constructed that produced a 30-50 keV Ar + beam with pulse duration ion source showed that the dependence of beam radius on Q was consistent with space charge expansion. It was concluded that the beam was perveance-dominated with a charge neutralization fraction of approximately zero in the absence of neutralizing plasma. Since beam expansion occurred primarily due to space charge, the decrease in effective perveance due to neutralization by FEPS plasma can be inferred from the reduction in beam radius. Results on propagation of the ion beam through FEPS plasma demonstrate that after the FEPS is triggered, the beam radius decreases to its neutralized value in about 5 mus. The duration of neutralization was about 10 mus at a charging voltage VFEPS = 5.5 kV and 35 mus at VFEPS = 6.5 kV. With VFEPS = 6.5 kV, the transverse current density profile 33 cm downstream of the source had a Gaussian shape with xrms =5 mm, which corresponds to a half-angle divergence of 0.87°. The

  12. Magnetic plasma confinement for laser ion source.

    Science.gov (United States)

    Okamura, M; Adeyemi, A; Kanesue, T; Tamura, J; Kondo, K; Dabrowski, R

    2010-02-01

    A laser ion source (LIS) can easily provide a high current beam. However, it has been difficult to obtain a longer beam pulse while keeping a high current. On occasion, longer beam pulses are required by certain applications. For example, more than 10 micros of beam pulse is required for injecting highly charged beams to a large sized synchrotron. To extend beam pulse width, a solenoid field was applied at the drift space of the LIS at Brookhaven National Laboratory. The solenoid field suppressed the diverging angle of the expanding plasma and the beam pulse was widened. Also, it was observed that the plasma state was conserved after passing through a few hundred gauss of the 480 mm length solenoid field.

  13. Plasma source mass spectrometry in experimental nutrition.

    Science.gov (United States)

    Barnes, R M

    1998-01-01

    The development and commercial availability of plasma ion source, specifically inductively coupled plasma, mass spectrometers (ICP-MS) have significantly extended the potential application of stable isotopes for nutritional modeling. The status of research and commercial ICP-MS instruments, and their applications and limitations for stable isotopic studies are reviewed. The consequences of mass spectroscopic resolution and measurement sensitivity obtainable with quadrupole, sector, time-of-flight, and trap instruments on stable isotope analysis are examined. Requirements for reliable isotope measurements with practical biological samples including tissues and fluids are considered. The possibility for stable isotope analysis in chemically separated compounds (speciation) also is explored. On-line compound separations by chromatography or electrophoresis, for example, have been combined instrumentally with ICP-MS. Som possibilities and requirements are described for stable isotope speciation analysis.

  14. 四川地区供血浆人群隐匿性乙型肝炎病毒感染的研究%Study of occult hepatitis B virus infection among the source plasma donors in Sichuan area, China

    Institute of Scientific and Technical Information of China (English)

    张燕; 曾飞翔; 何学新; 何培德; 刘丽; 程皓; 马异云; 杨汇川

    2011-01-01

    Objective To investigate the prevalence rate of occult hepatitis B virus infection ( OBI) among source plasma donors in Sichuan area,and to evaluate the residual risk of HBV in source plasma under current standards. Methods A total of 135 542 donations,collected from 56 620 donors from July 2007 to July 2009,were tested by PCR kits and ELISA kits for HBV DNA and HBsAg respectively according to the instruction of the kits. PCR positive samples were further analysed by Roche COBAS AmpliScreen,imported ELISA kits,HBsAg neutralization tests and quantitative determination of HBV DNA. Results 12 donations were detected as HBV DNA( + )/ HBsAg(-) ,for a rate of 0.008 9% (12/135 542). The HBV DNA loads were lower than 1 000 IU/ml. The donations of HBV DNA( + ) were tested by imported ELISA reagents and by HBsAg confirmation. The test results demonstrated that 5 of them were positive for HBsAg, and the rest 7 donations (collected from 6 donors) were determined as plasma of OBI with the same serological pattern of HbsAg ( -)/ HbeAg( -)/ HbcAb( + ). Further trace analysis for 2 ~ 9 months showed no change in ELISA and NAT test results. Conclusion There were HBV infected donors in the populations of source plasma donors with negative HBsAg. Based on this study,the prevalence rate of OBI in the population of source plasma donors in Sichuan area was 0. 010 6% (6/56 620) .lower than several reported OBI rate of voluntary whole blood donors in China. The residual risk of HBV in source plasma tested by domestic HBsAg ELISA reagents was higher than using imported ELISA reagents. Application of nucleic acid technology could further enhance the safety of source plasma.%目的 了解四川地区供血浆人群隐匿性乙型肝炎病毒感染(OBI)情况,分析现行标准下原料血浆的HBV残余风险.方法 采用实时荧光PCR和ELISA法,对四川地区10个单采血浆站2007年7月~2009年7月筛查合格的56 620名次供浆者的135 542份原料血浆标本作HBV NAT和HBs

  15. Laser-produced plasma source system development

    Science.gov (United States)

    Fomenkov, Igor V.; Brandt, David C.; Bykanov, Alexander N.; Ershov, Alexander I.; Partlo, William N.; Myers, David W.; Böwering, Norbert R.; Vaschenko, Georgiy O.; Khodykin, Oleh V.; Hoffman, Jerzy R.; Vargas L., Ernesto; Simmons, Rodney D.; Chavez, Juan A.; Chrobak, Christopher P.

    2007-03-01

    This paper describes the development of laser produced plasma (LPP) technology as an EUV source for advanced scanner lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193 nm immersion technology for critical layer patterning below 32 nm beginning with beta generation scanners in 2009. This paper describes the development status of subsystems most critical to the performance to meet joint scanner manufacturer requirements and semiconductor industry standards for reliability and economic targets for cost of ownership. The intensity and power of the drive laser are critical parameters in the development of extreme ultraviolet LPP lithography sources. The conversion efficiency (CE) of laser light into EUV light is strongly dependent on the intensity of the laser energy on the target material at the point of interaction. The total EUV light generated then scales directly with the total incident laser power. The progress on the development of a short pulse, high power CO2 laser for EUV applications is reported. The lifetime of the collector mirror is a critical parameter in the development of extreme ultra-violet LPP lithography sources. The deposition of target materials and contaminants, as well as sputtering of the collector multilayer coating and implantation of incident particles can reduce the reflectivity of the mirror substantially over the exposure time even though debris mitigation schemes are being employed. The results of measurements of high energy ions generated by a short-pulse CO2 laser on a laser-produced plasma EUV light source with Sn target are presented. Droplet generation is a key element of the LPP source being developed at Cymer for EUV lithography applications. The main purpose of this device is to deliver small quantities of liquid target material as droplets to the laser focus. The EUV light in such configuration is obtained as a result of creating a highly ionized plasma from the material of the

  16. SurfaceWater Source Protection Areas (SPAs)

    Data.gov (United States)

    Vermont Center for Geographic Information — Source Protection Area (SPA) boundaries have been located on RF 24000 & RF 25000 scale USGS topographic maps by Water Supply Division (DEC) and VT Dept of Health...

  17. Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

    Science.gov (United States)

    Rawat, R. S.

    2015-03-01

    The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 1010 J/m3. The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

  18. Sheath overlap during very large scale plasma source ion implantation

    Science.gov (United States)

    Cluggish, B. P.; Munson, C. P.

    1998-12-01

    Measurements of plasma source ion implantation have been performed on a large target of complex geometry. The target consists of 1000 aluminum, automotive piston surrogates mounted on four racks; total surface area is over 16 m2. The four racks are positioned parallel to each other, 0.25 m apart, in an 8 m3 vacuum chamber. The racks of pistons are immersed in a capacitive radio frequency plasma, with an argon gas pressure of 20-65 mPa. Langmuir probe measurements indicate that the plasma density profile is highly nonuniform, due to particle losses to the racks of pistons. The plasma ions are implanted into the pistons by pulse biasing the workpiece to negative voltages as low as -18 kV for up to 20 μs. During the voltage pulse, the high-voltage sheaths from adjacent racks of pistons converge towards each other. At plasma densities less than 109 cm-3 the sheaths are observed to overlap. Measurements of the sheath overlap time are compared with standard analytic theory and with simulations run with a two-dimensional particle-in-cell code.

  19. A New Atmospheric Pressure Microwave Plasma Source (APMPS)

    Institute of Scientific and Technical Information of China (English)

    LIU Liang; ZHANG Guixin; LI Yinan; ZHU Zhijie; WANG Xinxin; LUO Chengmu

    2008-01-01

    An atmospheric pressure microwave plasma source (APMPS) that can generate a large volume of plasma at an atmospheric pressure has been developed at Tsinghua University. This paper presents the design of this APMPS, the theoretical consideration of microwave plasma ignition and the simulation results, including the distributions of the electric field and power density inside the cavity as well as the accuracy of the simulation results. In addition, a method of producing an atmospheric pressure microwave plasma and some relevant observations of the plasma are also provided. It. is expected that this research would be useful for further developing atmospheric pressure microwave plasma sources and expanding the scope of their applications.

  20. Spectroscopic characterization of atmospheric pressure um-jet plasma source

    CERN Document Server

    Bibinov, Nikita; Bahre, Hendrik; Awakowicz, Peter; der Gathen, Volker Schulz-von

    2011-01-01

    A radio frequency um-jet plasma source is studied using He/O2 mixture. This um-jet can be used for different applications as a source of chemical active species e.g. oxygen atoms, molecular metastables and ozone. Using absolutely-calibrated optical emission spectroscopy and numerical simulation, the gas temperature in active plasma region and plasma parameters (electron density and electron distribution function) are determined. Concentrations of oxygen atoms and ozone in the plasma channel and in the effluent of the plasma source are measured using emission and absorption spectroscopy. To interpret the measured spatial distributions, the steady-state species' concentrations are calculated using determined plasma parameters and gas temperature. At that the influence of the surface processes and gas flow regime on the loss of the active species in the plasma source are discussed. The measured spatial distributions of oxygen atom and ozone densities are compared with the simulated ones.

  1. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Nolan, P. L.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Abdo, A. A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Antolini, E.; Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Atwood, W. B.; Belfiore, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Axelsson, M. [Department of Astronomy, Stockholm University, SE-106 91 Stockholm (Sweden); Baldini, L.; Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bignami, G. F., E-mail: digel@stanford.edu, E-mail: Gino.Tosti@pg.infn.it, E-mail: jean.ballet@cea.fr, E-mail: tburnett@u.washington.edu [Istituto Universitario di Studi Superiori (IUSS), I-27100 Pavia (Italy); and others

    2012-04-01

    We present the second catalog of high-energy {gamma}-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely {gamma}-ray-producing source classes.

  2. Fermi Large Area Telescope Second Source Catalog

    Science.gov (United States)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M; Allafort, A.; Antolini, E; Bonnell, J.; Cannon, A.; Celik O.; Corbet, R.; Davis, D. S.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Harding, A. K.; Hays, E.; Johnson, T. E.; McConville, W.; McEnery, J. E; Perkins, J. S.; Racusin, J. L; Scargle, J. D.; Stephens, T. E.; Thompson, D. J.; Troja, E.

    2012-01-01

    We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24-month period. The Second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in 5 energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 11eV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely gamma-ray-producing source classes.

  3. Extraction of ions and electrons from audio frequency plasma source

    Directory of Open Access Journals (Sweden)

    N. A. Haleem

    2016-09-01

    Full Text Available Herein, the extraction of high ion / electron current from an audio frequency (AF nitrogen gas discharge (10 – 100 kHz is studied and investigated. This system is featured by its small size (L= 20 cm and inner diameter = 3.4 cm and its capacitive discharge electrodes inside the tube and its high discharge pressure ∼ 0.3 Torr, without the need of high vacuum system or magnetic fields. The extraction system of ion/electron current from the plasma is a very simple electrode that allows self-beam focusing by adjusting its position from the source exit. The working discharge conditions were applied at a frequency from 10 to 100 kHz, power from 50 – 500 W and the gap distance between the plasma meniscus surface and the extractor electrode extending from 3 to 13 mm. The extracted ion/ electron current is found mainly dependent on the discharge power, the extraction gap width and the frequency of the audio supply. SIMION 3D program version 7.0 package is used to generate a simulation of ion trajectories as a reference to compare and to optimize the experimental extraction beam from the present audio frequency plasma source using identical operational conditions. The focal point as well the beam diameter at the collector area is deduced. The simulations showed a respectable agreement with the experimental results all together provide the optimizing basis of the extraction electrode construction and its parameters for beam production.

  4. Fermi Large Area Telescope Second Source Catalog

    Science.gov (United States)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Bignami, G. F.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bottacini, E.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Campana, R.; Cañadas, B.; Cannon, A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Ceccanti, M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chipaux, R.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Corbet, R.; Cutini, S.; D'Ammando, F.; Davis, D. S.; de Angelis, A.; DeCesar, M. E.; DeKlotz, M.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Enoto, T.; Escande, L.; Fabiani, D.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Iafrate, G.; Itoh, R.; Jóhannesson, G.; Johnson, R. P.; Johnson, T. E.; Johnson, A. S.; Johnson, T. J.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Landriu, D.; Latronico, L.; Lemoine-Goumard, M.; Lionetto, A. M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Marelli, M.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Minuti, M.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Pinchera, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Romani, R. W.; Roth, M.; Rousseau, R.; Ryde, F.; Sadrozinski, H. F.-W.; Salvetti, D.; Sanchez, D. A.; Saz Parkinson, P. M.; Sbarra, C.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Shaw, M. S.; Shrader, C.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Tinebra, F.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vandenbroucke, J.; Van Etten, A.; Van Klaveren, B.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Werner, M.; Winer, B. L.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zimmer, S.

    2012-04-01

    We present the second catalog of high-energy γ-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely γ-ray-producing source classes. We dedicate this paper to the memory of our colleague Patrick Nolan, who died on 2011 November 6. His career spanned much of the history of high-energy astronomy from space and his work on the Large Area Telescope (LAT) began nearly 20 years ago when it was just a concept. Pat was a central member in the operation of the LAT collaboration and he is greatly missed.

  5. The Gridless Plasma Ion Source(GIS)for Plasma Ion Assisted Optical Coating

    Institute of Scientific and Technical Information of China (English)

    尤大伟; 李晓谦; 王宇; 林永昌

    2004-01-01

    High-quality optical coating is a key technology for modern optics. Ion-assisted deposition technology was used to improve the vaporized coating in 1980's. The GIS (gridless ion source), which is an advanced plasma source for producing a high-quality optical coating in large area, can produce a large area uniformity>1000 mm(diameter), a high ion current density ~ 0.5mA/cm2, 20 eV ~ 200 eV energetic plasma ions and can activate reactive gas and film atoms. Now we have developed a GIS system. The GIS and the plasma ion-assisted deposition technology are investigated to achieve a high-quality optical coating. The GIS is a high power and high current source with a power of I kW ~ 7.5 kW, a current of 10 A ~ 70 A and an ion density of 200μA/cm2 ~ 500μA/cm2. Because of the special magnetic structure, the plasma-ion extraction efficiency has been improved to obtain a maximum ion density of 500μA/cm2 in the medium power (~ 4 kW) level. The GIS applied is of a special cathode structure, so that the GIS operation can be maintained under a rather low power and the lifetime of cathode will be extended. The GIS has been installed in the LPSX-1200 type box coating system. The coated TiO2, SiO2 films such as antireflective films with the system have the same performance reported by Leybold Co, 1992, along with a controllable refractive index and film structure.

  6. Antitumor action of non thermal plasma sources, DBD and Plasma Gun, alone or in combined protocols

    Science.gov (United States)

    Robert, Eric; Brullé, Laura; Vandamme, Marc; Riès, Delphine; Le Pape, Alain; Pouvesle, Jean-Michel

    2012-10-01

    The presentation deals with the assessment on two non thermal plasma sources developed and optimized for oncology applications. The first plasma source is a floating-electrode dielectric barrier discharge powered at a few hundreds of Hz which deliver air-plasma directly on the surface of cell culture medium in dishes or on the skin or organs of mice bearing cancer tumors. The second plasma source, so called Plasma Gun, is a plasma jet source triggered in noble gas, transferred in high aspect ratio and flexible capillaries, on targeting cells or tumors after plasma transfer in air through the ``plasma plume'' generated at the capillary outlet. In vitro evidence for massive cancer cell destruction and in vivo tumor activity and growth rate reductions have been measured with both plasma sources. DNA damages, cell cycle arrests and apoptosis induction were also demonstrated following the application of any of the two plasma source both in vitro and in vivo. The comparison of plasma treatment with state of the art chemotherapeutic alternatives has been performed and last but not least the benefit of combined protocols involving plasma and chemotherapeutic treatments has been evidenced for mice bearing orthotopic pancreas cancer and is under evaluation for the colon tumors.

  7. Capillary plasma jet: A low volume plasma source for life science applications

    Energy Technology Data Exchange (ETDEWEB)

    Topala, I., E-mail: ionut.topala@uaic.ro, E-mail: tmnagat@ipc.shizuoka.ac.jp [Alexandru Ioan Cuza University of Iasi, Faculty of Physics, Iasi Plasma Advanced Research Center (IPARC), Bd. Carol I No. 11, Iasi 700506 (Romania); Nagatsu, M., E-mail: ionut.topala@uaic.ro, E-mail: tmnagat@ipc.shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan)

    2015-02-02

    In this letter, we present results from multispectroscopic analysis of protein films, after exposure to a peculiar plasma source, i.e., the capillary plasma jet. This plasma source is able to generate very small pulsed plasma volumes, in kilohertz range, with characteristic dimensions smaller than 1 mm. This leads to specific microscale generation and transport of all plasma species. Plasma diagnosis was realized using general electrical and optical methods. Depending on power level and exposure duration, this miniature plasma jet can induce controllable modifications to soft matter targets. Detailed discussions on protein film oxidation and chemical etching are supported by results from absorption, X-ray photoelectron spectroscopy, and microscopy techniques. Further exploitation of principles presented here may consolidate research interests involving plasmas in biotechnologies and plasma medicine, especially in patterning technologies, modified biomolecule arrays, and local chemical functionalization.

  8. Focused ion beams using a high-brightness plasma source

    Science.gov (United States)

    Guharay, Samar

    2002-10-01

    High-brightness ion beams, with low energy spread, have merits for many new applications in microelectronics, materials science, and biology. Negative ions are especially attractive for the applications that involve beam-solid interactions. When negative ions strike a surface, especially an electrically isolated surface, the surface charging voltage is limited to few volts [1]. This property can be effectively utilized to circumvent problems due to surface charging, such as device damage and beam defocusing. A compact plasma source, with the capability to deliver either positive or negative ion beams, has been developed. H- beams from this pulsed source showed brightness within an order of magnitude of the value for beams from liquid-metal ion sources. The beam angular intensity is > 40 mAsr-1 and the corresponding energy spread is 1 Acm-2 and a spot size of 100 nm. Such characteristics of focused beam parameters, using a dc source, will immediately open up a large area of new applications. [1] P. N. Guzdar, A. S. Sharma, S. K. Guharay, "Charging of substrates irradiated by particle beams" Appl. Phys. Lett. 71, 3302 (1997). [2] S. K. Guharay, E. Sokolovsky, J. Orloff, "Characteristics of ion beams from a Penning source for focused ion beam applications" J. Vac. Sci Technol. B17, 2779 (1999).

  9. Fermi Large Area Telescope Second Source Catalog

    CERN Document Server

    ,

    2011-01-01

    We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24-month period. The Second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in 5 energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we att...

  10. Cysteine as a Biological Probe for Comparing Plasma Sources

    Science.gov (United States)

    Lackmann, Jan-Wilm; Golda, Judith; Kogelheide, Friederike; Held, Julian; Schulz-von-der-Gathen, Volker; Stapelmann, Katharina

    2016-09-01

    A large variety of plasma sources are available in the plasma medicine community. While enabling to choose the most promising source for a certain biomedical application, comparison of the different sources with a focus on their effect on biological targets is rather challenging. To allow for better comparison of various sources, the recent European COST action MP1101 was used to design the COST reference microplasma jet. Cysteine is a promising candidate investigate the impact of plasma from various sources on a standardized biological molecule, which is especially relevant for the investigations on a molecular level after plasma treatment. The simple structure of cysteine allows for a more in-depth analysis of each chemical group after plasma treatment and enables a comparison between different plasma sources and treatment parameters on each chemical group. The model itself has already been successfully established using a dielectric barrier discharge. Here, additional plasma sources are compared by the means of their impact on cysteine samples, showing e.g. the influence of feed-gas variations by adding oxygen or nitrogen admixture This work was supported by the German Research Foundation (DFG) with the packet grant PAK816 (PlaCID).

  11. Shunting arc plasma source for pure carbon ion beama)

    Science.gov (United States)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  12. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  13. Physical limitations in ferromagnetic inductively coupled plasma sources

    CERN Document Server

    Bliokh, Yury P; Slutsker, Yakov Z

    2012-01-01

    The Ferromagnetic Inductively Coupled Plasma (FICP) source, which is a version of the common inductively coupled plasma sources, has a number of well known advantages such as high efficiency, high level of ionization, low minimal gas pressure, very low required driver frequency, and even a possibility to be driven by single current pulses. We present an experimental study of such an FICP source which showed that above a certain value of the driving pulse power the properties of this device changed rather drastically. Namely, the plasma became non-stationary and non-uniform contrary to the stationary and uniform plasmas typical for this kind of plasma sources. In this case the plasma appeared as a narrow dense spike which was short compared to the driving pulse. The local plasma density could exceed the neutral atoms density by a few orders of magnitude. When that happened, the afterglow plasma decay time after the end of the pulse was long compared to an ordinary case with no plasma spike. Experiments were pe...

  14. Counter-facing plasma guns for efficient extreme ultra-violet plasma light source

    Science.gov (United States)

    Kuroda, Yusuke; Yamamoto, Akiko; Kuwabara, Hajime; Nakajima, Mitsuo; Kawamura, Tohru; Horioka, Kazuhiko

    2013-11-01

    A plasma focus system composed of a pair of counter-facing coaxial guns was proposed as a long-pulse and/or repetitive high energy density plasma source. We applied Li as the source of plasma for improvement of the conversion efficiency, the spectral purity, and the repetition capability. For operation of the system with ideal counter-facing plasma focus mode, we changed the system from simple coaxial geometry to a multi-channel configuration. We applied a laser trigger to make synchronous multi-channel discharges with low jitter. The results indicated that the configuration is promising to make a high energy density plasma with high spectral efficiency.

  15. Ferroelectric Plasma Source for Heavy Ion Beam Charge Neutralization

    CERN Document Server

    Efthimion, Philip; Gilson, Erik P; Grisham, Larry; Logan, B G; Waldron, William; Yu, Simon

    2005-01-01

    Plasmas are employed as a medium for charge neutralizing heavy ion beams to allow them to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ~ 0.1-1 m would be suitable. To produce 1 meter plasma, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO3 to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) will be covered with ceramic. High voltage (~ 1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. A prototype ferroelectric source 20 cm long produced plasma densities ~ 5x1011 cm-3. The source was integrated into the experiment and successfully charge neutralized the K ion beam. Presently, the 1 meter source ...

  16. Design and Construction of a Microwave Plasma Ion Source

    CERN Document Server

    Çınar, Kamil

    2011-01-01

    This thesis is about the designing and constructing a microwave ion source. The ions are generated in a thermal and dense hydrogen plasma by microwave induction. The plasma is generated by using a microwave source with a frequency of 2.45 GHz and a power of 700 W. The generated microwave is pulsing with a frequency of 50 Hz. The designed and constructed microwave system generates hydrogen plasma in a pyrex plasma chamber. Moreover, an ion extraction unit is designed and constructed in order to extract the ions from the generated hydrogen plasma. The ion beam extraction is achieved and ion currents are measured. The plasma parameters are determined by a double Langmuir probe and the ion current is measured by a Faraday cup. The designed ion extraction unit is simulated by using the dimensions of the designed and constructed ion extraction unit in order to trace out the trajectories of the extracted ions.

  17. Physical investigation of a quad confinement plasma source

    Science.gov (United States)

    Knoll, Aaron; Lucca Fabris, Andrea; Young, Christopher; Cappelli, Mark

    2016-10-01

    Quad magnetic confinement plasma sources are novel magnetized DC discharges suitable for applications in a broad range of fields, particularly space propulsion, plasma etching and deposition. These sources contain a square discharge channel with magnetic cusps at the four lateral walls, enhancing plasma confinement and electron residence time inside the device. The magnetic field topology is manipulated using four independent electromagnets on each edge of the channel, tuning the properties of the generated plasma. We characterize the plasma ejected from the quad confinement sources using a combination of traditional electrostatic probes and non-intrusive laser-based diagnostics. Measurements show a strong ion acceleration layer located 8 cm downstream of the exit plane, beyond the extent of the magnetic field. The ion velocity field is investigated with different magnetic configurations, demonstrating how ion trajectories may be manipulated. C.Y. acknowledges support from the DOE NSSA Stewardship Science Graduate Fellowship under contract DE-FC52-08NA28752.

  18. Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources

    Energy Technology Data Exchange (ETDEWEB)

    Geddes, Cameron G.R.; Cormier-Michel, Estelle; Esarey, Eric H.; Schroeder, Carl B.; Vay, Jean-Luc; Leemans, Wim P.; Bruhwiler, David L.; Cary, John R.; Cowan, Ben; Durant, Marc; Hamill, Paul; Messmer, Peter; Mullowney, Paul; Nieter, Chet; Paul, Kevin; Shasharina, Svetlana; Veitzer, Seth; Weber, Gunther; Rubel, Oliver; Ushizima, Daniela; Bethel, Wes; Wu, John

    2009-03-20

    Compared to conventional particle accelerators, plasmas can sustain accelerating fields that are thousands of times higher. To exploit this ability, massively parallel SciDAC particle simulations provide physical insight into the development of next-generation accelerators that use laser-driven plasma waves. These plasma-based accelerators offer a path to more compact, ultra-fast particle and radiation sources for probing the subatomic world, for studying new materials and new technologies, and for medical applications.

  19. Studies on plasma production in a large volume system using multiple compact ECR plasma sources

    Science.gov (United States)

    Tarey, R. D.; Ganguli, A.; Sahu, D.; Narayanan, R.; Arora, N.

    2017-01-01

    This paper presents a scheme for large volume plasma production using multiple highly portable compact ECR plasma sources (CEPS) (Ganguli et al 2016 Plasma Source Sci. Technol. 25 025026). The large volume plasma system (LVPS) described in the paper is a scalable, cylindrical vessel of diameter  ≈1 m, consisting of source and spacer sections with multiple CEPS mounted symmetrically on the periphery of the source sections. Scaling is achieved by altering the number of source sections/the number of sources in a source section or changing the number of spacer sections for adjusting the spacing between the source sections. A series of plasma characterization experiments using argon gas were conducted on the LVPS under different configurations of CEPS, source and spacer sections, for an operating pressure in the range 0.5-20 mTorr, and a microwave power level in the range 400-500 W per source. Using Langmuir probes (LP), it was possible to show that the plasma density (~1  -  2  ×  1011 cm-3) remains fairly uniform inside the system and decreases marginally close to the chamber wall, and this uniformity increases with an increase in the number of sources. It was seen that a warm electron population (60-80 eV) is always present and is about 0.1% of the bulk plasma density. The mechanism of plasma production is discussed in light of the results obtained for a single CEPS (Ganguli et al 2016 Plasma Source Sci. Technol. 25 025026).

  20. Modelling the plasma plume of an assist source in PIAD

    Science.gov (United States)

    Wauer, Jochen; Harhausen, Jens; Foest, Rüdiger; Loffhagen, Detlef

    2016-09-01

    Plasma ion assisted deposition (PIAD) is a technique commonly used to produce high-precision optical interference coatings. Knowledge regarding plasma properties is most often limited to dedicated scenarios without film deposition. Approaches have been made to gather information on the process plasma in situ to detect drifts which are suspected to cause limits in repeatability of resulting layer properties. Present efforts focus on radiance monitoring of the plasma plume of an Advanced Plasma Source (APSpro, Bühler) by optical emission spectroscopy to provide the basis for an advanced plasma control. In this contribution modelling results of the plume region are presented to interpret these experimental data. In the framework of the collisional radiative model used, 15 excited neutral argon states in the plasma are considered. Results of the species densities show good consistency with the measured optical emission of various argon 2 p - 1 s transitions. This work was funded by BMBF under grant 13N13213.

  1. Matching network for RF plasma source

    Science.gov (United States)

    Pickard, Daniel S.; Leung, Ka-Ngo

    2007-11-20

    A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

  2. Laser-Produced Plasmas and Radiation Sources.

    Science.gov (United States)

    1980-01-31

    Vlases, H. Rutkowski, A. Hertzberg, A. Hoffman, L. Steinhauer, J. Dawson, D.R. Cohn, W. Halverson, B. Lax, J.D. Daugherty, J.E. Eninger , E.R. Pugh, T.K...Meeting, Albuquerque (October 1974). J.D. Daugherty, J.E. Eninger , D.R. Cohn, and W. Halverson, "Scaling of Laser Heated Plasmas Confined in Long Solenoids...Cohn, H.E. Eninger , W. Halverson, and D.J. Rose, "Stress, Dissipation, and Neutronics Constraints on ’fagnets for Laser-Solenoid Reactors," APS Plasma

  3. A Plasma Ion Source for ISOLTRAP

    CERN Document Server

    Skov, Thomas Guldager

    2016-01-01

    In this report, my work testing the new Penning ion source as a summer student at ISOLTRAP is described. The project was composed of three stages: (1) Setting up a test laboratory in building 275, (2) characterizing the ion source, and (3) implementing and testing the source in the ISOLTRAP setup. After setting up the test laboratory, the ion source was tested in a constant pressure environment with produced ion currents in the range of nA . An extensive scan of the source ion current versus operating parameters (pressure, voltage) was performed. A setup with pulsed gas flow was also tested, allowing a reduction of the gas load on the vacuum system. The behavior of the ion source together with the ISOLTRAP setup was also investigated, allowing to understand current limitations and future directions of improvement.

  4. Multicapillary cathode controlled by a ferroelectric plasma source

    Science.gov (United States)

    Gleizer, J. Z.; Hadas, Y.; Krasik, Ya. E.

    2008-06-01

    We present results of high-current microsecond and sub-microsecond duration electron beam generation in a ~200 kV diode with a multicapillary dielectric cathode (MCDC) assisted by a ferroelectric plasma source (FPS). Electron beam current densities are achieved up to 40 A/cm2. It was shown that the operation of the MCDC is determined by the parameters of the plasma flow generated by the FPS. Also, it was found that the high resistivity of the plasma produced inside the capillaries allows effective de-coupling of individual capillary plasma discharges which results in uniform electron beam generation.

  5. Characteristics of Cylindrical Microwave Plasma Source at Low Pressure

    Science.gov (United States)

    Park, Seungil; Youn, S.; Kim, S. B.; Yoo, S. J.

    2016-10-01

    A microwave plasma source with a cylindrical resonance cavity has been proposed to generate the plasma at low pressure. This plasma source consists of magnetron, waveguide, antenna, and cavity. The microwave generating device is a commercial magnetron with 1 kW output power at the frequency of 2.45 GHz. The microwave is transmitted through the rectangular waveguide with the whistle shape, and coupled to the cavity by the slot antenna. The resonant mode of the cylindrical cavity is the TE111 mode. The operating pressure is between 0.1 Torr and 0.3 Torr with the Argon and nitrogen gas. The electron temperature and electron number density of argon plasma were measured with the optical emission spectroscopy measurement. And Ar1s5 metastable density was measured using tunable diode laser absorption spectroscopy (TDLAS). The plasma diagnostic results of a cylindrical microwave plasma source would be described in this study. This work was supported by R&D Program of ``Plasma Advanced Technology for Agriculture and Food (Plasma Farming)'' through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

  6. Combined Gas-Liquid Plasma Source for Nanoparticle Synthesis

    Science.gov (United States)

    Burakov, V. S.; Kiris, V. V.; Nevar, A. A.; Nedelko, M. I.; Tarasenko, N. V.

    2016-09-01

    A gas-liquid plasma source for the synthesis of colloidal nanoparticles by spark erosion of the electrode material was developed and allowed the particle synthesis regime to be varied over a wide range. The source parameters were analyzed in detail for the electrical discharge conditions in water. The temperature, particle concentration, and pressure in the discharge plasma were estimated based on spectroscopic analysis of the plasma. It was found that the plasma parameters did not change signifi cantly if the condenser capacitance was increased from 5 to 20 nF. Purging the electrode gap with argon reduced substantially the pressure and particle concentration. Signifi cant amounts of water decomposition products in addition to electrode elements were found in the plasma in all discharge regimes. This favored the synthesis of oxide nanoparticles.

  7. Inertial Electrostatic Confinement (IEC) Fusion using Helicon Injected Plasma Source

    Science.gov (United States)

    Miley, George; Ahern, Drew; Bowman, Jaerd

    2016-10-01

    The use of an external plasma source with the IEC has the advantage that the background pressure in the IEC chamber can be low. This then enables a deep potential well formation for ion confinement. Also unit efficiency is increase due to minimization of ion losses through charge exchange. This technique is under study experimentally for use in a plasma jet propulsion unit and as an IEC type neutron source. Current work has studied the effect of locating the IEC grids off-center in the vacuum chamber, near the plasma entrance from the Helicon. With double grids, the relative potentials employed are also key factors in device performance. Electron emitters are added for space charge neutralization in the case of plasma jet propulsion. Plasma simulations are used to supplement the experiments. Specifically, the electric field and the magnetic field effects on energetic ion trajectories are examined for varying configurations. Funding by NASA, Air Force Research Lab and NPL Associates.

  8. Alternative modeling methods for plasma-based Rf ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Veitzer, Seth A., E-mail: veitzer@txcorp.com; Kundrapu, Madhusudhan, E-mail: madhusnk@txcorp.com; Stoltz, Peter H., E-mail: phstoltz@txcorp.com; Beckwith, Kristian R. C., E-mail: beckwith@txcorp.com [Tech-X Corporation, Boulder, Colorado 80303 (United States)

    2016-02-15

    Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H{sup −} source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. In particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H{sup −} ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two

  9. Alternative modeling methods for plasma-based Rf ion sources

    Science.gov (United States)

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

    2016-02-01

    Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H- source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. In particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H- ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two-temperature MHD models

  10. 77 FR 6463 - Revisions to Labeling Requirements for Blood and Blood Components, Including Source Plasma...

    Science.gov (United States)

    2012-02-08

    ... Requirements for Blood and Blood Components, Including Source Plasma; Correction AGENCY: Food and Drug... Blood Components, Including Source Plasma,'' which provided incorrect publication information...

  11. Development of a long-slot microwave plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, Y., E-mail: euo1304@mail4.doshisha.ac.jp; Kasuya, T.; Miyamoto, N.; Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2016-02-15

    A 20 cm long 10 cm wide microwave plasma source was realized by inserting two 20 cm long 1.5 mm diameter rod antennas into the plasma. Plasma luminous distributions around the antennas were changed by magnetic field arrangement created by permanent magnets attached to the source. The distributions appeared homogeneous in one direction along the antenna when the spacing between the antenna and the source wall was 7.5 mm for the input microwave frequency of 2.45 GHz. Plasma density and temperature at a plane 20 cm downstream from the microwave shield were measured by a Langmuir probe array at 150 W microwave power input. The measured electron density and temperature varied over space from 3.0 × 10{sup 9} cm{sup −3} to 5.8 × 10{sup 9} cm{sup −3}, and from 1.1 eV to 2.1 eV, respectively.

  12. Multicomponent Consideration of Electron Fraction of ECR Source Plasma

    CERN Document Server

    Shirkov, G D

    1999-01-01

    The development of physical model and mathematical simulation methods of electron and ion accumulation and production in the ECR ion source is presented. New equations represent electrons in the ECR plasma as a multicomponent media. In the result any kind of experimental or analytical electron distribution function can be approximated with a series of Maxwellian distributions with different temperatures and partial weights. Main positive plasma potential is introduced into consideration in addition to the negative potential dip for highly charged ion confinement. This potential regulates the loss rate of primary cold electrons from the plasma volume and completes the total picture of ECR plasma behavior. The first test of new model and code with recent experimental data of RIKEN 18 GHz ECR source has shown some new opportunities for investigators to study the ECR ion sources.

  13. High electronegativity multi-dipolar electron cyclotron resonance plasma source for etching by negative ions

    DEFF Research Database (Denmark)

    Stamate, Eugen; Draghici, M.

    2012-01-01

    A large area plasma source based on 12 multi-dipolar ECR plasma cells arranged in a 3 x 4 matrix configuration was built and optimized for silicon etching by negative ions. The density ratio of negative ions to electrons has exceeded 300 in Ar/SF6 gas mixture when a magnetic filter was used...... to reduce the electron temperature to about 1.2 eV. Mass spectrometry and electrostatic probe were used for plasma diagnostics. The new source is free of density jumps and instabilities and shows a very good stability for plasma potential, and the dominant negative ion species is F-. The magnetic field...... in plasma volume is negligible and there is no contamination by filaments. The etching rate by negative ions measured in Ar/SF6/O-2 mixtures was almost similar with that by positive ions reaching 700 nm/min. (C) 2012 American Institute of Physics...

  14. Negative ion production in the RF multiaperture surface-plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Abdrashitov, G.; Belchenko, Yu., E-mail: Belchenko@inp.nsk.su; Dranichnikov, A.; Gorbovsky, A.; Kapitonov, V.; Kolmogorov, V.; Kondakov, A.; Konstantinov, S.; Sanin, A.; Selivanov, A.; Selivanov, P.; Shikhovtsev, I.; Stupishin, N.; Tiunov, M. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Ivanov, A.; Sotnikov, O. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Binderbauer, M.; Putvinski, S.; Smirnov, A.; Sevier, L. [Tri Alpha Energy Inc., Rancho Santa Margarita, CA 92688 (United States)

    2015-04-08

    The experiments on negative hydrogen ion beam production in a multi-aperture long-pulse surface-plasma source are described. H- ions are produced on the surface of a plasma grid covered by cesium and illuminated by fast plasma particles. The source uses a radio-frequency driver to generate plasma. A composite magnet system made of external permanent magnets confines and filters electrons in the plasma region, and deflects them in the extraction area. A multiaperture, multi-electrode ion optical system is used for beam formation. The electrode heating and cooling during long pulses is accomplished by circulating a heat transfer fluid through channels drilled in the electrodes bodies. H- ions extraction through a single aperture and 21 apertures was performed and studied. A stable H- beam with the current up to 0.7 A, energy up to 74 kV, and pulse duration up to 7 s was routinely obtained.

  15. Industrial application of electron sources with plasma emitters

    CERN Document Server

    Belyuk, S I; Rempe, N G

    2001-01-01

    Paper contains a description, operation, design and parameters of electron sources with plasma emitters. One presents examples of application of these sources as part of automated electron-beam welding lines. Paper describes application of such sources for electron-beam deposition of composite powders. Electron-beam deposition is used to rebuild worn out part and to increase strength of new parts of machines and tools. Paper presents some examples of rebuilding part and the advantages gained in this case

  16. Effect of plasma grid bias on extracted currents in the RF driven surface-plasma negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Belchenko, Yu., E-mail: belchenko@inp.nsk.su; Ivanov, A.; Sanin, A.; Sotnikov, O.; Shikhovtsev, I. [Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2016-02-15

    Extraction of negative ions from the large inductively driven surface-plasma negative ion source was studied. The dependencies of the extracted currents vs plasma grid (PG) bias potential were measured for two modifications of radio-frequency driver with and without Faraday screen, for different hydrogen feeds and for different levels of cesium conditioning. The maximal PG current was independent of driver modification and it was lower in the case of inhibited cesium. The maximal extracted negative ion current depends on the potential difference between the near-PG plasma and the PG bias potentials, while the absolute value of plasma potential in the driver and in the PG area is less important for the negative ion production. The last conclusion confirms the main mechanism of negative ion production through the surface conversion of fast atoms.

  17. Candidate plasma-facing materials for EUV lithography source components

    Science.gov (United States)

    Hassanein, Ahmed; Burtseva, Tatiana; Brooks, Jeff N.; Konkashbaev, Isak K.; Rice, Bryan J.

    2003-06-01

    Material selection and lifetime issues for extreme ultraviolet (EUV) lithography are of critical importance to the success of this technology for commercial applications. This paper reviews current trends in production and use of plasma-facing electrodes, insulators, and wall materials for EUV type sources. Ideal candidate materials should be able to: withstand high thermal shock from the short pulsed plasma; withstand high thermal loads without structural failure; reduce debris generation during discharge; and be machined accurately. We reviewed the literature on current and proposed fusion plasma-facing materials as well as current experience with plasma gun and other simulation devices. Both fusion and EUV source materials involve issues of surface erosion by particle sputtering and heat-induced evaporation/melting. These materials are either bare structural materials or surface coatings. EUV materials can be divided into four categories: wall, electrode, optical, and insulator materials. For electric discharge sources, all four types are required, whereas laser-produced plasma EUV sources do not require electrode and insulator materials. Several types of candidate alloy and other materials and methods of manufacture are recommended for each component of EUV lithography light sources.

  18. A highly reliable trigger for vacuum ARC plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Bernardet, H.; Godechot, X.; Jarjat, F. [SODERN, Limeil-Brevannes (France)

    1996-08-01

    The authors have developed a reliable electrical trigger and its associated circuitry to fire vacuum arc plasma or ion source. They tested different embodiments of the trigger device in order to get a highly reliable one, which is able to perform more than 1.2 x 10{sup 6} shots at 60 A and 6.5 ps pulse length. The evolution of the ion current emitted has been recorded as a function of the number of shots. They have also investigated in which direction the plasma jet is emitted : axially or radially. This device can be used to fire a vacuum arc plasma or ion source by plasma injection. It has obvious advantage to be placed outside the cathode and therefore would ease maintenance of vacuum arc devices.

  19. Are Spicules the Primary Source of Hot Coronal Plasma?

    Science.gov (United States)

    Klimchuk, James A.

    2011-01-01

    The recent discovery of Type II spicules has generated considerable excitement. It has even been suggested that these ejections can account for a majority of the hot plasma observed in the corona, thus obviating the need for "coronal" heating. If this is the case, however, then there should be observational consequences. We have begun to examine some of these consequences and find reason to question the idea that spicules are the primary source of hot coronal plasma.

  20. e+e- Plasma Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Hartouni, Ed P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-12-06

    This note addresses the idea of a photon source that is based on an e+e- plasma created by co-propagating beams of e+ and e-. The plasma has a well-defined temperature, and the thermal distribution of the charged particles is used to average over the relative velocity cross section multiplied by the relative velocity. Two relevant cross sections are the direct “free-free” annihilation of e+e- pairs in the plasma, and the radiative recombination of e+e- pairs into positronium (Ps) which subsequently undergoes annihilation.

  1. Simple filtered repetitively pulsed vacuum arc plasma source

    Science.gov (United States)

    Chekh, Yu.; Zhirkov, I. S.; Delplancke-Ogletree, M. P.

    2010-02-01

    A very simple design of cathodic filtered vacuum arc plasma source is proposed. The source without filter has only four components and none of them require precise machining. The source operates in a repetitively pulsed regime, and for laboratory experiments it can be used without water cooling. Despite the simple construction, the source provides high ion current at the filter outlet reaching 2.5% of 400 A arc current, revealing stable operation in a wide pressure range from high vacuum to oxygen pressure up to more than 10-2 mbar. There is no need in complicated power supply system for this plasma source, only one power supply can be used to ignite the arc, to provide the current for the arc itself, to generate the magnetic field in the filter, and provide its positive electric biasing without any additional high power resistance.

  2. 21 CFR 640.64 - Collection of blood for Source Plasma.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Collection of blood for Source Plasma. 640.64... (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.64 Collection of blood for Source Plasma. (a) Supervision. All blood for the collection of Source Plasma...

  3. Counter-facing plasma guns for efficient extreme ultra-violet plasma light source

    Directory of Open Access Journals (Sweden)

    Kuroda Yusuke

    2013-11-01

    Full Text Available A plasma focus system composed of a pair of counter-facing coaxial guns was proposed as a long-pulse and/or repetitive high energy density plasma source. We applied Li as the source of plasma for improvement of the conversion efficiency, the spectral purity, and the repetition capability. For operation of the system with ideal counter-facing plasma focus mode, we changed the system from simple coaxial geometry to a multi-channel configuration. We applied a laser trigger to make synchronous multi-channel discharges with low jitter. The results indicated that the configuration is promising to make a high energy density plasma with high spectral efficiency.

  4. Mirror-field confined compact plasma source using permanent magnet for plasma processings.

    Science.gov (United States)

    Goto, Tetsuya; Sato, Kei-Ichiro; Yabuta, Yuki; Sugawa, Shigetoshi

    2016-12-01

    A mirror-field confined compact electron cyclotron resonance (ECR) plasma source using permanent magnets was developed, aiming for the realization of high-quality plasma processings where high-density reactive species are supplied to a substrate with minimizing the ion bombardment damages. The ECR position was located between a microwave transmissive window and a quartz limiter, and plasmas were transported from the ECR position to a midplane of the magnetic mirror field through the quartz limiter. Thus, a radius of core plasma could be determined by the limiter, which was 15 mm in this study. Plasma parameters were investigated by the Langmuir probe measurement. High-density plasma larger than 10(11) cm(-3) could be produced by applying 5.85-GHz microwave power of 10 W or more. For the outside region of the core plasma where a wafer for plasma processings will be set at, the ion current density was decreased dramatically with distance from the core plasma and became smaller by approximately two orders of magnitude that in the core plasma region for the radial position of 40 mm, suggesting the realization of reduction in ion bombardment damages.

  5. Mirror-field confined compact plasma source using permanent magnet for plasma processings

    Science.gov (United States)

    Goto, Tetsuya; Sato, Kei-ichiro; Yabuta, Yuki; Sugawa, Shigetoshi

    2016-12-01

    A mirror-field confined compact electron cyclotron resonance (ECR) plasma source using permanent magnets was developed, aiming for the realization of high-quality plasma processings where high-density reactive species are supplied to a substrate with minimizing the ion bombardment damages. The ECR position was located between a microwave transmissive window and a quartz limiter, and plasmas were transported from the ECR position to a midplane of the magnetic mirror field through the quartz limiter. Thus, a radius of core plasma could be determined by the limiter, which was 15 mm in this study. Plasma parameters were investigated by the Langmuir probe measurement. High-density plasma larger than 1011 cm-3 could be produced by applying 5.85-GHz microwave power of 10 W or more. For the outside region of the core plasma where a wafer for plasma processings will be set at, the ion current density was decreased dramatically with distance from the core plasma and became smaller by approximately two orders of magnitude that in the core plasma region for the radial position of 40 mm, suggesting the realization of reduction in ion bombardment damages.

  6. Dense plasma focus (DPF) accelerated non radio isotopic radiological source

    Energy Technology Data Exchange (ETDEWEB)

    Rusnak, Brian; Tang, Vincent

    2017-01-31

    A non-radio-isotopic radiological source using a dense plasma focus (DPF) to produce an intense z-pinch plasma from a gas, such as helium, and which accelerates charged particles, such as generated from the gas or injected from an external source, into a target positioned along an acceleration axis and of a type known to emit ionizing radiation when impinged by the type of accelerated charged particles. In a preferred embodiment, helium gas is used to produce a DPF-accelerated He2+ ion beam to a beryllium target, to produce neutron emission having a similar energy spectrum as a radio-isotopic AmBe neutron source. Furthermore, multiple DPFs may be stacked to provide staged acceleration of charged particles for enhancing energy, tunability, and control of the source.

  7. Neutron Source from Laser Plasma Acceleration

    Science.gov (United States)

    Jiao, Xuejing; Shaw, Joseph; McCary, Eddie; Downer, Mike; Hegelich, Bjorn

    2016-10-01

    Laser driven electron beams and ion beams were utilized to produce neutron sources via different mechanism. On the Texas Petawatt laser, deuterized plastic, gold and DLC foil targets of varying thickness were shot with 150 J , 150 fs laser pulses at a peak intensity of 2 ×1021W /cm2 . Ions were accelerated by either target normal sheath acceleration or Breakout Afterburner acceleration. Neutrons were produced via the 9Be(d,n) and 9Be(p,n) reactions when accelerated ions impinged on a Beryllium converter as well as by deuteron breakup reactions. We observed 2 ×1010 neutron per shot in average, corresponding to 5 ×1018n /s . The efficiencies for different targets are comparable. In another experiment, 38fs , 0.3 J UT3 laser pulse interacted with mixed gas target. Electrons with energy 40MeV were produced via laser wakefield acceleration. Neutron flux of 2 ×106 per shot was generated through bremsstrahlung and subsequent photoneutron reactions on a Copper converter.

  8. A low-energy linear oxygen plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre; Yushkov, Georgy Yu.

    2007-01-08

    A new version of a Constricted Plasma Source is described,characterized by all metal-ceramic construction, a linear slit exit of180 mm length, and cw-operation (typically 50 kHz) at an average power of1.5 kW. The plasma source is here operated with oxygen gas, producingstreaming plasma that contains mainly positive molecular and atomic ions,and to a much lesser degree, negative ions. The maximum total ion currentobtained was about 0.5 A. The fraction of atomic ions reached more than10 percent of all ions when the flow rate was less then 10 sccm O2,corresponding to a chamber pressure of about 0.5 Pa for the selectedpumping speed. The energy distribution functions of the different ionspecies were measured with a combinedmass spectrometer and energyanalyzer. The time-averaged distribution functions were broad and rangedfrom about 30eV to 90 eV at 200 kHz and higher frequencies, while theywere only several eV broad at 50 kHz and lower frequencies, with themaximum located at about 40 eV for the grounded anode case. This maximumwas shifted down to about 7 eV when the anode was floating, indicatingthe important role of the plasma potential for the ion energy for a givensubstrate potential. The source could be scaled to greater length and maybe useful for functionalization of surfaces and plasma-assisteddeposition of compound films.

  9. Study on Performance Parameters of the Plasma Source for a Short-Conduction-Time Plasma Opening Switch

    Institute of Scientific and Technical Information of China (English)

    LUO Weixi; ZENG Zhengzhong; WANG Liangping; LEI Tianshi; HU Yixiang; HUANG Tao; SUN Tieping

    2012-01-01

    Plasma source performance parameters, including plasma ejection density and velocity, greatly affect the operation of a short-conduction-time plasma opening switch (POS). In this paper, the plasma source used in the POS of Qiangguang I generator is chosen as the study object. At first the POS working process is analyzed. The result shows that the opening performance of the POS can be improved by increasing the plasma ejection velocity and decreasing the plasma density. The influence of the cable plasma gun structure and number on the plasma ejection parameters is experimentally investigated with two charge collectors. Finally a semi-empirical model is proposed to describe the experimental phenomenon.

  10. Modeling of plasma transport and negative ion extraction in a magnetized radio-frequency plasma source

    Science.gov (United States)

    Fubiani, G.; Garrigues, L.; Hagelaar, G.; Kohen, N.; Boeuf, J. P.

    2017-01-01

    Negative ion sources for fusion are high densities plasma sources in large discharge volumes. There are many challenges in the modeling of these sources, due to numerical constraints associated with the high plasma density, to the coupling between plasma and neutral transport and chemistry, the presence of a magnetic filter, and the extraction of negative ions. In this paper we present recent results concerning these different aspects. Emphasis is put on the modeling approach and on the methods and approximations. The models are not fully predictive and not complete as would be engineering codes but they are used to identify the basic principles and to better understand the physics of the negative ion sources.

  11. RF Plasma modeling of the Linac4 H− ion source

    CERN Document Server

    Mattei, S; Hatayama, A; Lettry, J; Kawamura, Y; Yasumoto, M; Schmitzer, C

    2013-01-01

    This study focuses on the modelling of the ICP RF-plasma in the Linac4 H− ion source currently being constructed at CERN. A self-consistent model of the plasma dynamics with the RF electromagnetic field has been developed by a PIC-MCC method. In this paper, the model is applied to the analysis of a low density plasma discharge initiation, with particular interest on the effect of the external magnetic field on the plasma properties, such as wall loss, electron density and electron energy. The use of a multi-cusp magnetic field effectively limits the wall losses, particularly in the radial direction. Preliminary results however indicate that a reduced heating efficiency results in such a configuration. The effect is possibly due to trapping of electrons in the multi-cusp magnetic field, preventing their continuous acceleration in the azimuthal direction.

  12. Three Filtered Vacuum Arc Plasma Sources Deposition & Implantation System

    Institute of Scientific and Technical Information of China (English)

    WU Xian-ying; ZHANG Hui-xing; LI Qiang

    2004-01-01

    A deposition & implantation system, which includes three filtered vacuum arc plasma sources, has been built. Vacuum arc discharge is used to produce high-density metal plasma; Curved magnetic filtering technique is used to transfer the plasma into out-of-sight vacuum chamber and reduce macro-particles from the vacuum arc plasma in order to drastically reduce the macro-particles contamination of the films. The up to 30 kV negative bias applied to the target can be used for ion implantation in order to improve the film adhesion; or for ion sputtering to clear the substrate surface. The 0 to 300 V negative bias can be used to adjust the ion energy which forming films. The system is designed for various thin films synthesizing, such as single-layer, compound layer, multi-layer films. It's principle, components and applications are described in the literature.

  13. Modeling of negative ion transport in a plasma source

    Science.gov (United States)

    Riz, David; Paméla, Jérôme

    1998-08-01

    A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The ion trajectory is calculated by numerically solving the 3-D motion equation, while the atomic processes of destruction, of elastic collision H-/H+ and of charge exchange H-/H0 are handled at each time step by a Monte-Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided if they are produced at a distance lower than 2 cm from the plasma grid in the case of «volume production» (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

  14. Modeling of negative ion transport in a plasma source (invited)

    Science.gov (United States)

    Riz, David; Paméla, Jérôme

    1998-02-01

    A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The H-/D- trajectory is calculated by numerically solving the 3D motion equation, while the atomic processes of destruction, of elastic collision with H+/D+ and of charge exchange with H0/D0 are handled at each time step by a Monte Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have been allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that, in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided they are produced at a distance lower than 2 cm from the plasma grid in the case of volume production (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

  15. Intense ion beam generation, plasma radiation source and plasma opening switch research

    Science.gov (United States)

    Hammer, D. A.; Coleman, M. D.; Qi, N.; Similon, P. L.; Sudan, R. N.

    1989-04-01

    This report describes research on intense ion beam diodes, plasma opening switches and dense z-pinch plasma radiators. Laser induced fluorescence spectroscopy has been used to map the electrostatic potential profile in a plasma-prefilled magnetically insulated ion diode. In a simple planar diode, the measured profile is inconsistent with the electrons being confined in a sheath near the cathode by the magnetic field. Rather, the profile implies the presence of electrons throughout the accelerating gap. A theoretical model of the penetration of current and magnetic field into a plasma, and of the current-driven effective collision frequency has been developed. The snowplow action of the rising magnetic field causes a steep rise in the plasma density at the leading edge. The subsequent multistreaming of the ions caused by ion reflection at the current layer could lead to ion heating through collective effects. The two-dimensional electron flow in the plasma cathode vacuum gap is also treated. Dense z-pinch plasma radiation source experiments have been initiated on the LION accelerator using gas puff and fine wire loads. The x-pinch was found to be a more effective way to generate soft x-rays than a single wire pinch or a gas puff implosion. Plasma opening switch experiments being initiated, and plasma anode ion diode development work being terminated are also briefly described.

  16. Plasma ion sources and ion beam technology inmicrofabrications

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Lili [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ion beam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ion beam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ion beam with various ion species, a FEI two-lens electron (2LE) column for SEM imaging, and a five-axis manipulator system for sample positioning. An all-electrostatic two-lens column has been designed to focus the ion beam extracted from the source. Based on the Munro ion optics simulation, beam spot sizes as small as 100 nm can be achieved at beam energies between 5 to 35 keV if a 5 μm-diameter extraction aperture is used. Smaller beam spot sizes can be obtained with smaller apertures at sacrifice of some beam current. The FEI 2LE column, which utilizes Schottky emission, electrostatic focusing optics, and stacked-disk column construction, can provide high-resolution (as small as 20 nm) imaging capability, with fairly long working distance (25

  17. A large-area RF source for negative hydrogen ions

    Science.gov (United States)

    Frank, P.; Feist, J. H.; Kraus, W.; Speth, E.; Heinemann, B.; Probst, F.; Trainham, R.; Jacquot, C.

    1998-08-01

    In a collaboration with CEA Cadarache, IPP is presently developing an rf source, in which the production of negative ions (H-/D-) is being investigated. It utilizes PINI-size rf sources with an external antenna and for the first step a small size extraction system with 48 cm2 net extraction area. First results from BATMAN (Ba¯varian T_est Ma¯chine for N_egative Ions) show (without Cs) a linear dependence of the negative ion yield with rf power, without any sign of saturation. At elevated pressure (1.6 Pa) a current density of 4.5 mA/cm2 H- (without Cs) has been found so far. At medium pressure (0.6 Pa) the current density is lower by approx. a factor of 5, but preliminary results with Cesium injection show a relative increase by almost the same factor in this pressure range. Langmuir probe measurements indicate an electron temperature Te>2 eV close to the plasma grid with a moderate magnetic filter (700 Gcm). Attempts to improve the performance by using different magnetic configurations and different wall materials are under way.

  18. 200 North Aggregate Area source AAMS report

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    This report presents the results of an aggregate area management study (AAMS) for the 200 North Aggregate Area in the 200 Areas of the US Department of Energy (DOE) Hanford Site in Washington State. This scoping level study provides the basis for initiating Remedial Investigation/Feasibility Study (RI/FS) activities under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS) under RCRA. This report also integrates select RCRA treatment, storage, or disposal (TSD) closure activities with CERCLA and RCRA past practice investigations.

  19. Kinetic models for the VASIMR thruster helicon plasma source

    Science.gov (United States)

    Batishchev, Oleg; Molvig, Kim

    2001-10-01

    Helicon gas discharge [1] is widely used by industry because of its remarkable efficiency [2]. High energy and fuel efficiencies make it very attractive for space electrical propulsion applications. For example, helicon plasma source is used in the high specific impulse VASIMR [3] plasma thruster, including experimental prototypes VX-3 and upgraded VX-10 [4] configurations, which operate with hydrogen (deuterium) and helium plasmas. We have developed a set of models for the VASIMR helicon discharge. Firstly, we use zero-dimensional energy and mass balance equations to characterize partially ionized gas condition/composition. Next, we couple it to one-dimensional hybrid model [6] for gas flow in the quartz tube of the helicon. We compare hybrid model results to a purely kinetic simulation of propellant flow in gas feed + helicon source subsystem. Some of the experimental data [3-4] are explained. Lastly, we discuss full-scale kinetic modeling of coupled gas and plasmas [5-6] in the helicon discharge. [1] M.A.Lieberman, A.J.Lihtenberg, 'Principles of ..', Wiley, 1994; [2] F.F.Chen, Plas. Phys. Contr. Fus. 33, 339, 1991; [3] F.Chang-Diaz et al, Bull. APS 45 (7) 129, 2000; [4] J.Squire et al., Bull. APS 45 (7) 130, 2000; [5] O.Batishchev et al, J. Plasma Phys. 61, part II, 347, 1999; [6] O.Batishchev, K.Molvig, AIAA technical paper 2000-3754, -14p, 2001.

  20. Oscillating plasma bubbles. III. Internal electron sources and sinks

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2012-08-15

    An internal electron source has been used to neutralize ions injected from an ambient plasma into a spherical grid. The resultant plasma is termed a plasma 'bubble.' When the electron supply from the filament is reduced, the sheath inside the bubble becomes unstable. The plasma potential of the bubble oscillates near but below the ion plasma frequency. Different modes of oscillations have been observed as well as a subharmonic and multiple harmonics. The frequency increases with ion density and decreases with electron density. The peak amplitude occurs for an optimum current and the instability is quenched at large electron densities. The frequency also increases if Langmuir probes inside the bubble draw electrons. Allowing electrons from the ambient plasma to enter, the bubble changes the frequency dependence on grid voltage. It is concluded that the net space charge density in the sheath determines the oscillation frequency. It is suggested that the sheath instability is caused by ion inertia in an oscillating sheath electric field which is created by ion bunching.

  1. The ITER full size plasma source device design

    Energy Technology Data Exchange (ETDEWEB)

    Sonato, P. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy)], E-mail: piergiorgio.sonato@igi.cnr.it; Agostinetti, P.; Anaclerio, G.; Antoni, V.; Barana, O.; Bigi, M.; Boldrin, M. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy); Cavenago, M. [INFN, Legnaro, Padova (Italy); Dal Bello, S.; Palma, M. Dalla [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy); Daniele, A. [ENEA, Frascati, Roma (Italy); D' Arienzo, M.; De Lorenzi, A.; Ferro, A.; Fiorentin, A.; Gaio, E.; Gazza, E.; Grando, L.; Fantini, F.; Fellin, F. [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy)] (and others)

    2009-06-15

    In the framework of the strategy for the development and the procurement of the NB systems for ITER, it has been decided to build in Padova a test facility, including two experimental devices: a full size plasma source with low voltage extraction and a full size NB injector at full beam power (1 MV). These two different devices will separately address the main scientific and technological issues of the 17 MW NB injector for ITER. In particular the full size plasma source of negative ions will address the ITER performance requirements in terms of current density and uniformity, limitation of the electron/ion ratio and stationary operation at full current with high reliability and constant performances for the whole operating time up to 1 h. The required negative ion current density to be extracted from the plasma source ranges from 290 A/m{sup 2} in D{sub 2} (D{sup -}) and 350 A/m{sup 2} in H{sub 2} (H{sup -}) and these values should be obtained at the lowest admissible neutral pressure in the plasma source volume, nominally at 0.3 Pa. The electron to ion ratio should be limited to less than 1 and the admissible ion inhomogeneity extracted from the grids should be better than 10% on the whole plasma cross-section having a surface exposed to the extraction grid of the order of 1 m{sup 2}. The main design choices will be presented in the paper as well as an overview of the design of the main components and systems.

  2. Plasma shape control by pulsed solenoid on laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, M. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Ikeda, S. [Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Romanelli, M. [Cornell University, Ithaca, NY 14850 (United States); Kumaki, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Waseda University, Shinjuku, Tokyo 169-0072 (Japan); Fuwa, Y. [RIKEN, Wako, Saitama 351-0198 (Japan); Kyoto University, Uji, Kyoto 611-0011 (Japan); Kanesue, T. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Hayashizaki, N. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); Lambiase, R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okamura, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-09-21

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  3. Plasma shape control by pulsed solenoid on laser ion source

    Science.gov (United States)

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-09-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  4. Measurement of the Internal Magnetic Field of Plasmas using an Alpha Particle Source

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Zweben; D.S. Darrow; P.W. Ross; J.L. Lowrance; G. Renda

    2004-05-13

    The internal magnetic fields of plasmas can be measured under certain conditions from the integrated v x B deflection of MeV alpha particles emitted by a small radioactive source. This alpha source and large-area alpha particle detector would be located inside the vacuum vessel but outside the plasma. Alphas with a typical energy of 5.5 MeV (241Am) can reach the center of almost all laboratory plasmas and magnetic fusion devices, so this method can potentially determine the q(r) profile of tokamaks or STs. Orbit calculations, background evaluations, and conceptual designs for such a vxB (or ''AVB'') detector are described.

  5. Hydrogen Plasma Generation with 200 MHz RF Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeongtae; Park, Kwangmook; Seo, Dong Hyuk; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The ion source for the system is required to be rugged with 2000 hours maintenance free operation time because it is installed in the vessel filled with SF6 gas at the pressure of 10 bar. A 200 MHz RF ion source is considered as an ion source. It is a simple construction and provides long life operation. The specifications of the ion source are 5 kV extraction voltage and 1 mA beam current referenced to the proton. RF ion source has been developed and undergone a performance test. Results of the test are presented. 200 MHz RF ion source is designated and manufactured. First of all test stand test of ion source are set up for a performance test of ion source. It includes a RF ion source, a 200-MHz RF system, beam extraction system, vacuum system, beam extraction system, and beam diagnostic system. At pressure of 1.2E-5 torr, hydrogen plasma is generated with net RF power 70 W. Pyrex tube surrounded by an inductive coil takes the role of vessel and discharge is enhanced with field of permanent magnets.

  6. High Current, High Density Arc Plasma as a New Source for WiPAL

    Science.gov (United States)

    Waleffe, Roger; Endrizzi, Doug; Myers, Rachel; Wallace, John; Clark, Mike; Forest, Cary; WiPAL Team

    2016-10-01

    The Wisconsin Plasma Astrophysics Lab (WiPAL) has installed a new array of nineteen plasma sources (plasma guns) on its 3 m diameter, spherical vacuum vessel. Each gun is a cylindrical, molybdenum, washer-stabilized, arc plasma source. During discharge, the guns are maintained at 1.2 kA across 100 V for 10 ms by the gun power supply establishing a high density plasma. Each plasma source is fired independently allowing for adjustable plasma parameters, with densities varying between 1018 -1019 m-3 and electron temperatures of 5-15 eV. Measurements were characterized using a 16 tip Langmuir probe. The plasma source will be used as a background plasma for the magnetized coaxial plasma gun (MCPG), the Terrestrial Reconnection Experiment (TREX), and as the plasma source for a magnetic mirror experiment. Temperature, density, and confinement results will be presented. This work is supported by the DoE and the NSF.

  7. Laboratory Plasma Source as an MHD Model for Astrophysical Jets

    Science.gov (United States)

    Mayo, Robert M.

    1997-01-01

    The significance of the work described herein lies in the demonstration of Magnetized Coaxial Plasma Gun (MCG) devices like CPS-1 to produce energetic laboratory magneto-flows with embedded magnetic fields that can be used as a simulation tool to study flow interaction dynamic of jet flows, to demonstrate the magnetic acceleration and collimation of flows with primarily toroidal fields, and study cross field transport in turbulent accreting flows. Since plasma produced in MCG devices have magnetic topology and MHD flow regime similarity to stellar and extragalactic jets, we expect that careful investigation of these flows in the laboratory will reveal fundamental physical mechanisms influencing astrophysical flows. Discussion in the next section (sec.2) focuses on recent results describing collimation, leading flow surface interaction layers, and turbulent accretion. The primary objectives for a new three year effort would involve the development and deployment of novel electrostatic, magnetic, and visible plasma diagnostic techniques to measure plasma and flow parameters of the CPS-1 device in the flow chamber downstream of the plasma source to study, (1) mass ejection, morphology, and collimation and stability of energetic outflows, (2) the effects of external magnetization on collimation and stability, (3) the interaction of such flows with background neutral gas, the generation of visible emission in such interaction, and effect of neutral clouds on jet flow dynamics, and (4) the cross magnetic field transport of turbulent accreting flows. The applicability of existing laboratory plasma facilities to the study of stellar and extragalactic plasma should be exploited to elucidate underlying physical mechanisms that cannot be ascertained though astrophysical observation, and provide baseline to a wide variety of proposed models, MHD and otherwise. The work proposed herin represents a continued effort on a novel approach in relating laboratory experiments to

  8. Tin LPP plasma control in the argon cusp source

    Science.gov (United States)

    McGeoch, Malcolm W.

    2016-03-01

    The argon cusp plasma has been introduced [1,2] for 500W class tin LPP exhaust control in view of its high power handling, predicted low tin back-scatter from a beam dump, and avoidance of hydrogen usage. The physics of tin ion control by a plasma is first discussed. Experimentally, cusp stability and exhaust disc geometry have previously been proved at full scale [2], the equivalent of 300W-500W usable EUV. Here we verify operation of the plasma barrier that maintains a high argon density next to the collector, for its protection, and a low density in the long path toward the intermediate focus, for efficiency. A pressure differential of 2Pa has been demonstrated in initial work. Other aspects of tin LPP plasma control by the cusp have now been demonstrated using tin ions from a low Hz 130mJ CO2 laser pulse onto a solid tin surface at the cusp center. Plasma is rejected at the design to match a specified exhaust power is discussed. In view of this work, argon cusp exhaust control appears to be very promising for 500W class tin LPP sources.

  9. Efficient cesiation in RF driven surface plasma negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Belchenko, Yu.; Ivanov, A.; Konstantinov, S.; Sanin, A., E-mail: sanin@inp.nsk.su; Sotnikov, O. [Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2016-02-15

    Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (∼0.5 G) provides an enhanced H{sup −} production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H{sup −} production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H{sup −} yield to the high value. The effect of H{sup −} yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H{sup −} yield recovery due to sputtering of cesium from the deteriorated layers is discussed.

  10. High Power Light Gas Helicon Plasma Source For VASMIR

    Science.gov (United States)

    Squire, J. P.; Chang-Diaz, F. R.; Glover, T. W.; Jacobson, V. T.; McCaskill, G. E.; Winter, D. S.; Baity, F. W.; Carter, M. D.; Goulding, R. H.

    2004-01-01

    The VASIMR space propulsion development effort relies on a high power (greater than 10kW) helicon source to produce a dense flowing plasma (H, D and He) target for ion cyclotron resonance (ICR) acceleration of the ions. Subsequent expansion in an expanding magnetic field (magnetic nozzle) converts ion lunetic energy to directed momentum. This plasma source must have critical features to enable an effective propulsion device. First, it must ionize most of the input neutral flux of gas, thus producing a plasma stream with a high degree of ionization for application of ICR power. This avoids propellant waste and potential power losses due to charge exchange. Next, the plasma stream must flow into a region of high magnetic field (approximately 0.5 T) for efficient ICR acceleration. Third, the ratio of input power to plasma flux must be low, providing an energy per ion-electron pair approaching 100 eV. Lastly, the source must be robust and capable of very long life-times (years). In our helicon experiment (VX-10) we have measured a ratio of input gas to plasma flux near 100%. The plasma flows from the helicon region (B approximately 0.1 T) into a region with a peak magnetic field of 0.8 T. The energy input per ion-electron pair has been measured at 300 plus or minus 100 eV. Recent results at Oak Ridge National Laboratory (ORNL) show an enhanced efficiency mode of operation with a high power density, over 5 kW in a 5 cm diameter tube. Our helicon is presently 9 cm in diameter and operates up to 3.5 kW of input power. An upgrade to a power level of 10 kW is underway. Much of our recent work has been with a Boswell double-saddle antenna design. We are also converting the antenna design to a helical type. With these modifications, we anticipate an improvement in the ionization efficiency. This paper presents the results from scaling the helicon in the VX-10 device from 3.5 to 10 kW. We also compare the operation with a double-saddle to a helical antenna design. Finally, we

  11. Dynamics of Ion Beam Charge Neutralization by Ferroelectric Plasma Sources

    Science.gov (United States)

    Stepanov, Anton D.; Gilson, Erik P.; Grisham, Larry R.; Kaganovich, Igor D.; Davidson, Ronald C.; Ji, Qing; Persaud, Arun; Seidl, Peter A.; Schenkel, Thomas

    2016-10-01

    Ferroelectric Plasma Sources (FEPSs) can generate plasma that provides effective space-charge neutralization of intense high-perveance ion beams. Here we present experimental results on charge neutralization of a high-perveance 38 keV Ar+ beam by a FEPS plasma. By comparing the measured beam radius with the envelope model for space-charge expansion, it is shown that a charge neutralization fraction of 98% is attainable. The transverse electrostatic potential of the ion beam is reduced from 15 V before neutralization to 0.3 V, implying that the energy of the neutralizing electrons is below 0.3 eV. Near-complete charge neutralization is established 5 μs after the driving pulse is applied to the FEPS, and can last for 35 μs. It is argued that the duration of neutralization is much longer than a reasonable lifetime of the plasma produced in the sub- μs surface discharge. Measurements of current flow in the driving circuit of the FEPS suggest that plasma can be generated for tens of μs after the high voltage pulse is applied. This is confirmed by fast photography of the plasma in the 1-meter long FEPS on NDCX-II, where effective charge neutralization of the beam was achieved with the optimized FEPS timing. This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0209CH11466 (PPPL) and DE-AC0205CH11231 (LBNL).

  12. 77 FR 7 - Revisions to Labeling Requirements for Blood and Blood Components, Including Source Plasma

    Science.gov (United States)

    2012-01-03

    ...) Revisions to Labeling Requirements for Blood and Blood Components, Including Source Plasma AGENCY: Food and... requirements for blood and blood components, including Source Plasma, into one section of the Code of Federal..., and Source Plasma,'' which amended Sec. 606.121(d)(2) by adding ``or in solid black,''...

  13. Element Abundances and Source Plasma Temperatures of Solar Energetic Particles

    Science.gov (United States)

    Reames, Donald V.

    2016-11-01

    Thirty years ago Breneman and Stone [1] observed that the enhancement or suppression of element abundances in large solar energetic-particle (SEP) events varies as a power of the mass-to-charge ratio, A/Q, of the elements. Since Q during acceleration or transport may depend upon the source plasma temperature T, the pattern of element enhancements can provide a best-fit measure of T. The small SEP events we call 3He-rich or “impulsive” show average enhancements, relative to coronal abundances, rising as the 3.6 power of A/Q to a factor of ∼1000 for (76magnetic reconnection on open field lines in solar flares and jets. It has been recently found that the large shock-accelerated “gradual” SEP events have a broad range of source plasma temperatures; 69% have coronal temperatures of T seed population containing residual impulsive suprathermal ions. Most of the large event-to-event abundance variations and their time variation are largely explained by variations in T magnified by A/Q-dependent fractionation during transport. However, the non-thermal variance of impulsive SEP events (∼30%) exceeds that of the ∼3 MK gradual events (∼10%) so that several small impulsive events must be averaged together with the ambient plasma to form the seed population for shock acceleration in these events.

  14. Large area radiation source for water and wastewater treatment

    Science.gov (United States)

    Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh

    2011-06-01

    There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

  15. Particle flux at the outlet of an Ecr plasma source; Flujos de particulas a la salida de una fuente de plasma ECR

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Gonzalez D, J. [ININ, Departamento de Fisica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The necessity of processing big material areas this has resulted in the development of plasma sources with the important property to be uniform in these areas. Also the continuous diminution in the size of substrates to be processed have stimulated the study of models which allow to predict the control of energy and the density of the ions and neutral particles toward the substrate. On the other hand, there are other applications of the plasma sources where it is very necessary to understand the effects generated by the energetic fluxes of ions and neutrals. These fluxes as well as another beneficial effects can improve the activation energy for the formation and improvement of the diffusion processes in the different materials. In this work, using the drift kinetic approximation is described a model to calculate the azimuthal and radial fluxes in the zone of materials processing of an Ecr plasma source type. The results obtained are compared with experimental results. (Author)

  16. A compact and continuously driven supersonic plasma and neutral source.

    Science.gov (United States)

    Asai, T; Itagaki, H; Numasawa, H; Terashima, Y; Hirano, Y; Hirose, A

    2010-10-01

    A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.

  17. Endosomal recycling controls plasma membrane area during mitosis.

    Science.gov (United States)

    Boucrot, Emmanuel; Kirchhausen, Tomas

    2007-05-08

    The shape and total surface of a cell and its daughters change during mitosis. Many cells round up during prophase and metaphase and reacquire their extended and flattened shape during cytokinesis. How does the total area of plasma membrane change to accommodate these morphological changes and by what mechanism is control of total membrane area achieved? Using single-cell imaging methods, we have found that the amount of plasma membrane in attached cells in culture decreases at the beginning of mitosis and recovers rapidly by the end. Clathrin-based endocytosis is normal throughout all phases of cell division, whereas recycling of internalized membranes back to the cell surface slows considerably during the rounding up period and resumes at the time at which recovery of cell membrane begins. Interference with either one of these processes by genetic or chemical means impairs cell division. The total cell-membrane area recovers even in the absence of a functional Golgi apparatus, which would be needed for export of newly synthesized membrane lipids and proteins. We propose a mechanism by which modulation of endosomal recycling controls cell area and surface expression of membrane-bound proteins during cell division.

  18. Data requirements and data sources for biodiversity priority area selection

    Indian Academy of Sciences (India)

    P H Williams; C R Margules; D W Hilbert

    2002-07-01

    The data needed to prioritize areas for biodiversity protection are records of biodiversity features – species, species assemblages, environmental classes – for each candidate area. Prioritizing areas means comparing candidate areas, so the data used to make such comparisons should be comparable in quality and quantity. Potential sources of suitable data include museums, herbariums and natural resource management agencies. Issues of data precision, accuracy and sampling bias in data sets from such sources are discussed and methods for treating data to minimize bias are reviewed.

  19. Study of negative ion transport phenomena in a plasma source

    Science.gov (United States)

    Riz, D.; Paméla, J.

    1996-07-01

    NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H-/H+) and charge exchanges (H-/H0). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NI produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter.

  20. Study of negative ion transport phenomena in a plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Riz, D.; Pamela, J. [Departement de Recherches sur la Fusion Controlee C. E., Cadarache, 13108 St-Paul-lez-Durance Cedex (France)

    1996-07-01

    NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H{sup {minus}}/H{sup +}) and charge exchanges (H{sup {minus}}/H{sup 0}). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NI produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter. {copyright} {ital 1996 American Institute of Physics.}

  1. Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China.

    Science.gov (United States)

    Wang, Y; Bian, J M; Wang, S N; Nie, S Y

    The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River.

  2. Element Abundances and Source Plasma Temperatures of Solar Energetic Particles

    CERN Document Server

    Reames, Donald V

    2016-01-01

    Thirty years ago Breneman and Stone observed that the enhancement or suppression of element abundances in large solar energetic-particle (SEP) events varies as a power of the mass-to-charge ratio, A/Q, of the elements. Since Q during acceleration or transport may depend upon the source plasma temperature T, the pattern of element enhancements can provide a best-fit measure of T. The small SEP events we call 3He-rich or "impulsive" show average enhancements, relative to coronal abundances, rising as the 3.6 power of A/Q to a factor of ~1000 for (76<=Z<=82)/O and temperature in the range 2-4 MK. This acceleration is believed to occur in islands of magnetic reconnection on open field lines in solar flares and jets. It has been recently found that the large shock-accelerated "gradual" SEP events have a broad range of source plasma temperatures; 69% have coronal temperatures of T < 1.6 MK, while 24% have T ~ 3 MK, the latter suggesting a seed population containing residual impulsive suprathermal ions. Mos...

  3. Development of atmospheric pressure large area plasma jet for sterilisation and investigation of molecule and plasma interaction

    Science.gov (United States)

    Zerbe, Kristina; Iberler, Marcus; Jacoby, Joachim; Wagner, Christopher

    2016-09-01

    The intention of the project is the development and improvement of an atmospheric plasma jet based on various discharge forms (e.g. DBD, RF, micro-array) for sterilisation of biomedical equipment and investigation of biomolecules under the influence of plasma stress. The major objective is to design a plasma jet with a large area and an extended length. Due to the success on small scale plasma sterilisation the request of large area plasma has increased. Many applications of chemical disinfection in environmental and medical cleaning could thereby be complemented. Subsequently, the interaction between plasma and biomolecules should be investigated to improve plasma strerilisation. Special interest will be on non equilibrium plasma electrons affecting the chemical bindings of organic molecules.

  4. Plasma expansion across a transverse magnetic field in a negative hydrogen ion source for fusion

    Science.gov (United States)

    Fantz, U.; Schiesko, L.; Wünderlich, D.

    2014-08-01

    High power negative hydrogen ion sources operating at 0.3 Pa are a key component of the neutral beam injection systems for the international fusion experiment ITER. To achieve the required large ion current at a tolerable number of co-extracted electrons the source is equipped with a magnetic filter field (up to 10 mT). The IPP prototype source (1/8 of the area of the ITER source) has been equipped with a flexible magnetic filter frame to perform filter field studies (position, polarity, strength). Axial profiles of the plasma parameters are measured with two Langmuir probes, positioned in the upper and the lower half of the expansion chamber. In addition to the expected decrease in electron temperature and density a vertical drift develops the direction depending on the polarity of the field. Without field no drift is observed. The drift is less pronounced in caesium seeded discharges and almost vanishes in deuterium, indicating an influence of the ion mass on the drift. A comparison with results from a half-size ITER source reveals that the plasma is much more uniform in the large source.

  5. A tandem mirror plasma source for a hybrid plume plasma propulsion concept

    Science.gov (United States)

    Yang, T. F.; Miller, R. H.; Wenzel, K. W.; Krueger, W. A.; Chang, F. R.

    1985-01-01

    This paper describes a tandem mirror magnetic plasma confinement device to be considered as a hot plasma source for the hybrid plume rocket concept. The hot plasma from this device is injected into an exhaust duct, which will interact with an annular layer of hypersonic neutral gas. Such a device can be used to study the dynamics of the hybrid plume and to experimentally verify the numerical predictions obtained with computer codes. The basic system design is also geared toward being lightweight and compact, as well as having high power density (i.e., several kW/sq cm) at the exhaust. This feature is aimed toward the feasibility of 'space testing'. The plasma is heated by microwaves. A 50 percent heating efficiency can be obtained by using two half-circle antennas. The preliminary Monte Carlo modeling of test particles result reported here indicates that interaction does take place in the exhaust duct. Neutrals gain energy from the ion, which confirms the hybrid plume concept.

  6. Waveguide slot-excited long racetrack electron cyclotron resonance plasma source for roll-to-roll (scanning) processing.

    Science.gov (United States)

    You, H-J

    2013-07-01

    We present a SLot-excited ANtenna (SLAN) long racetrack ECR plasma source that is utilized for roll-to-roll plasma processing such as thin film encapsulation of large-area OLED (organic light emitting diode) panel or modification of fabric surfaces. This source is designed to be long, and to operate under high density uniform plasma with sub-milli-torr pressures. The above features are accomplished by a slot-excited long racetrack resonator with a toroidal geometry of magnetic field ECR configuration, and reinforced microwave electric distributions along the central region of plasma chamber. Also, a new feature has been added to the source. This is to employ a tail plunger, which allows the microwave electric field and the uniformity of the plasma profile to be easily adjustable. We have successfully generated Ar plasmas operating with the microwave power of 0.5-3 kW in the pressure range of 0.2-10 mTorr. The plasma is uniform (racetrack-SLAN source.

  7. Compact tunable Compton x-ray source from laser-plasma accelerator and plasma mirror

    CERN Document Server

    Tsai, Hai-En; Shaw, Joseph; Li, Zhengyan; Arefiev, Alexey V; Zhang, Xi; Zgadzaj, Rafal; Henderson, Watson; Khudik, V; Shvets, G; Downer, M C

    2014-01-01

    We present results of the first tunable Compton backscattering (CBS) x-ray source that is based on the easily aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The LPA is driven in the blowout regime by 30 TW, 30 fs laser pulses, and produces high-quality, tunable, quasi-monoenergetic electron beams. A thin plastic film near the gas jet exit efficiently retro-reflects the LPA driving pulse with relativistic intensity into oncoming electrons to produce $2\\times10^{7}$ CBS x-ray photons per shot with 10-20 mrad angular divergence and 50 % (FWHM) energy spread without detectable bremsstrahlung background. The x-ray central energy is tuned from 75 KeV to 200 KeV by tuning the LPA e-beam central energy. Particle-in-cell simulations of the LPA, the drive pulse/PM interaction and CBS agree well with measurements.

  8. MAGNETIC FIELD GRADIENT EFFECTS ON ION FLUX BEHAVIORS IN ECR PLASMA SOURCES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The available electron cyclotron resonance plasma source has been simulated in two-dimensional configuration space (z, r) and three-dimensional velocity space (Vz, Vr Vθ). The simulation is focused on the magnetic field gradient effects on ion flux behaviors in electron cyclotron resonance plasma sources. The simulation results show that, when the magnetic field gradients increase, electron temperature, plasma density, ionization rate, and ion flux in Zdirection would decrease, while ion energy and plasma potential would increase.

  9. Note: Triggering behavior of a vacuum arc plasma source.

    Science.gov (United States)

    Lan, C H; Long, J D; Zheng, L; Dong, P; Yang, Z; Li, J; Wang, T; He, J L

    2016-08-01

    Axial symmetry of discharge is very important for application of vacuum arc plasma. It is discovered that the triggering method is a significant factor that would influence the symmetry of arc discharge at the final stable stage. Using high-speed multiframe photography, the transition processes from cathode-trigger discharge to cathode-anode discharge were observed. It is shown that the performances of the two triggering methods investigated are quite different. Arc discharge triggered by independent electric source can be stabilized at the center of anode grid, but it is difficult to achieve such good symmetry through resistance triggering. It is also found that the triggering process is highly correlated to the behavior of emitted electrons.

  10. Counter-facing plasma focus system as a repetitive and/or long-pulse high energy density plasma source

    Science.gov (United States)

    Aoyama, Yutaka; Nakajima, Mitsuo; Horioka, Kazuhiko

    2009-11-01

    A plasma focus system composed of a pair of counter-facing coaxial plasma guns is proposed as a long-pulse and/or repetitive high energy density plasma source. A proof-of-concept experiment demonstrated that with an assist of breakdown and outer electrode connections, current sheets evolved into a configuration for stable plasma confinement at the center of the electrodes. The current sheets could successively compress and confine the high energy density plasma every half period of the discharge current, enabling highly repetitive light emissions in extreme ultraviolet region with time durations in at least ten microseconds.

  11. A microwave plasma source for VUV atmospheric photochemistry

    Science.gov (United States)

    Tigrine, S.; Carrasco, N.; Vettier, L.; Cernogora, G.

    2016-10-01

    Microwave plasma discharges working at low pressure are nowadays a well-developed technique mainly used to provide radiation at different wavelengths. The aim of this work is to show that those discharges are an efficient windowless vacuum ultra-violet (VUV) photon source for planetary atmospheric photochemistry experiments. To do this, we use a surfatron-type discharge with a neon gas flow in the mbar pressure range coupled to a photochemical reactor. Working in the VUV range allows nitrogen-dominated atmospheres to be focused on (λ  <  100 nm). The experimental setup makes sure that no energy sources (electrons, metastable atoms) other than the VUV photons interact with the reactive medium. Neon has two resonance lines at 73.6 and 74.3 nm that behave differently depending on the pressure or power conditions. In parallel, the VUV photon flux emitted at 73.6 nm has been experimentally estimated in different pressure and power conditions, and varies in a large range between 2  ×  1013 ph s-1 cm-2 and 4  ×  1014 ph s-1 cm-2, which is comparable to a VUV synchrotron photon flux. Our first case study is the atmosphere of Titan and its N2-CH4 atmosphere. With this VUV source, the production of HCN and C2N2, two major Titan compounds, is detected, ensuring the suitability of the source for atmospheric photochemistry experiments.

  12. Inclined slot-excited annular electron cyclotron resonance plasma source for hyperthermal neutral beam generation.

    Science.gov (United States)

    You, H-J; Kim, D-W; Koo, M; Jang, S-O; Jung, Y-H; Hong, S-H; Lee, B-J

    2011-01-01

    An inclined slot-excited antenna (ISLAN) electron cyclotron resonance (ECR) plasma source is newly designed and constructed for higher flux hyperthermal neutral beam (HNB) generation. The developed ISLAN source is modified from vertical slot-excited antenna (VSLAN) source in two aspects: one is the use of inclined slots instead of vertical slots, and the other is a cusp magnetic field configuration rather than a toroidal configuration. Such modifications allow us to have more uniform arrangement of slots and magnets, then enabling plasma generation more uniform and thinner. Moreover, ECR plasma allows higher ionization rate, enabling plasma density higher even in submillitorr pressures, therefore decreasing the collision rate and∕or the reionization rate of the reflected atoms while passing through the plasma, and eventually getting higher flux of HNBs. In this paper, we report the design features and the plasma characteristics of the ISLAN source by doing plasma measurements and electromagnetic simulations. It was found that ISLAN source can be a high potential source for larger flux HNB generation; the source was found to give higher plasma densities and better uniformities than inductively coupled plasma source, particularly in low pressure ranges. Also, it is important that using ISLAN gives easier matching and better stability, i.e., ISLAN shows similar field patterns and good plasma symmetries irrespective of the variations of the mean diameter of the ring resonator and∕or the presence of a limiter or a reflector, and the operating pressures.

  13. Quasi-steady carbon plasma source for neutral beam injector.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2014-02-01

    Carbon plasma is successfully sustained during 1000 s without any carrier gas in the bucket type ionization chamber with cusp magnetic field. Every several seconds, seed plasmas having ∼3 ms duration time are injected into the ionization chamber by a shunting arch plasma gun. The weakly ionized carbon plasma ejected from the shunting arch is also ionized by 2.45 GHz microwave at the electron cyclotron resonance surface and the plasma can be sustained even in the interval of gun discharges. Control of the gun discharge interval allows to keep high pressure and to sustain the plasma for long duration.

  14. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources

    Science.gov (United States)

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

    2016-02-01

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  15. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Sudhir, Dass, E-mail: dass.sudhir@iter-india.org; Bandyopadhyay, M.; Chakraborty, A. [ITER-India, Institute for Plasma Research, A-29 GIDC, Sec-25, Gandhinagar, 382016 Gujarat (India)

    2016-02-15

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  16. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources.

    Science.gov (United States)

    Sudhir, Dass; Bandyopadhyay, M; Chakraborty, A

    2016-02-01

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  17. Ferroelectric plasma sources for NDCX-II and heavy ion drivers

    Science.gov (United States)

    Gilson, E. P.; Davidson, R. C.; Efthimion, P. C.; Kaganovich, I. D.; Kwan, J. W.; Lidia, S. M.; Ni, P. A.; Roy, P. K.; Seidl, P. A.; Waldron, W. L.; Barnard, J. J.; Friedman, A.

    2014-01-01

    A barium titanate ferroelectric cylindrical plasma source has been developed, tested and delivered for the Neutralized Drift Compression Experiment NDCX-II at Lawrence Berkeley National Laboratory (LBNL). The plasma source design is based on the successful design of the NDCX-I plasma source. A 7 kV pulse applied across the 3.8 mm-thick ceramic cylinder wall produces a large polarization surface charge density that leads to breakdown and plasma formation. The plasma that fills the NDCX-II drift section upstream of the final-focusing solenoid has a plasma number density exceeding 1010 cm-3 and an electron temperature of several eV. The operating principle of the ferroelectric plasma source are reviewed and a detailed description of the installation plans is presented. The criteria for plasma sources with larger number density will be given, and concepts will be presented for plasma sources for driver applications. Plasma sources for drivers will need to be highly reliable, and operate at several Hz for millions of shots.

  18. Analysis of plasma distribution near the extraction region in surface produced negative ion sources.

    Science.gov (United States)

    Fukano, A; Hatayama, A

    2014-02-01

    In study of a negative ion source, it is important to understand the plasma characteristics near the extraction region. A recent experiment in the NIFS-R&D ion source has suggested that a "double ion plasma layer" which is a region consisting of hydrogen positive and negative ions exists near the plasma grid (PG). Density distribution of plasma near the extraction region is studied analytically. It is shown that the density distribution depends on an amount of the surface produced negative ions and the double ion plasma layer is formed near the PG surface for the case of strong surface production.

  19. Fermi Large Area Telescope Bright Gamma-ray Source List

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /KIPAC, Menlo Park /SLAC; Ajello, M.; /KIPAC, Menlo Park /SLAC; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Bechtol, K.; /KIPAC, Menlo Park /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /KIPAC, Menlo Park /SLAC; Bignami, G.F.; /Pavia U.; Bloom, Elliott D.; /KIPAC, Menlo Park /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /KIPAC, Menlo Park /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /IASF, Milan /IASF, Milan /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /KIPAC, Menlo Park /SLAC /ASDC, Frascati /NASA, Goddard /Maryland U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /UC, Santa Cruz /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /NASA, Goddard; /more authors..

    2009-05-15

    Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

  20. Content Area Textbooks as Sources for Vocabulary Learning

    Directory of Open Access Journals (Sweden)

    Bambang Yudi Cahyono

    2016-02-01

    Full Text Available This study examines the potential of content area textbooks as a lexical environment for incidental vocabulary learning. The two questions proposed are how many rarely-used words content area textbooks contain within a particular number of words, and how different or similar the frequency of rarely-used words is in the linguistic studies and non-linguistic studies textbooks. This study concludes that content area textbooks contain a relatively high frequency of words within Nat3 and Nat4 levels. The high percentage of rarely-used words indicates that content area textbooks are rich sources for vocabulary learning. The findings also suggest that different kinds of textbooks in the content courses can be rich lexical environments for the study of second language vocabulary

  1. 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)

  2. 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).

  3. Source formulation for electron-impact ionization for fluid plasma simulations

    DEFF Research Database (Denmark)

    Müller, S.H.; Holland, C.; Tynan, G.R.;

    2009-01-01

    The derivation of the correct functional form of source terms in plasma fluid theory is revisited. The relation between the fluid source terms and atomic physics differential cross sections is established for particle-impact ionization. It is shown that the interface between atomic and plasma...

  4. Color Developing Capacity of Plasma-treated Water as a Source of Nitrite for Meat Curing

    OpenAIRE

    2015-01-01

    The interaction of plasma with liquid generates nitrogen species including nitrite (NO− 2). Therefore, the color developing capacity of plasma-treated water (PTW) as a nitrite source for meat curing was investigated in this study. PTW, which is generated by surface dielectric barrier discharge in air, and the increase of plasma treatment time resulted in increase of nitrite concentration in PTW. The PTW used in this study contains 46 ppm nitrite after plasma treatment for 30 min. To evaluate ...

  5. Terahertz Light Source and User Area at FACET

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Li, S.Z.; Litos, M.; Fisher, A.D.; Hogan, M.J.; /SLAC

    2011-11-08

    FACET at SLAC provides high charge, high peak current, low emittance electron beam that is bunched at THz wavelength scale during its normal operation. A THz light source based coherent transition radiation (CTR) from this beam would potentially be the brightest short-pulse THz source ever constructed. Efforts have been put into building this photon source together with a user area, to provide a platform to utilize this unique THz radiation for novel nonlinear and ultrafast phenomena researches and experiments. Being a long-time underutilized portion of the electromagnetic spectrum, terahertz (100 GHz {approx} 10 THz) spectral range is experiencing a renaissance in recent years, with broad interests from chemical and biological imaging, material science, telecommunication, semiconductor and superconductor research, etc. Nevertheless, the paucity of THz sources especially strong THz radiation hinders both its commercial applications and nonlinear processes research. FACET - Facilities for Accelerator science and Experimental Test beams at SLAC - provides 23 GeV electron beam with peak currents of {approx} 20 kA that can be focused down to 100 {mu}m{sup 2} transversely. Such an intense electron beam, when compressed to sub-picosecond longitudinal bunch length, coherently radiates high intensity EM fields well within THz frequency range that are orders of magnitude stronger than those available from laboratory tabletop THz sources, which will enable a wide variety of THz related research opportunities. Together with a description of the FACET beamline and electron beam parameters, this paper will report FACET THz radiation generation via coherent transition radiation and calculated photon yield and power spectrum. A user table is being set up along the THz radiation extraction sites, and equipped with various signal diagnostics including THz power detector, Michelson interferometer, sample stages, and sets of motorized optical components. This setup will also be

  6. Plasma ignition schemes for the SNS radio-frequency driven H- source

    Energy Technology Data Exchange (ETDEWEB)

    Schenkel, T.; Staples, J.W.; Thomae, W.; Reijonen, J.; Gough, R.A.; Leung, K.N.; Keller, R.

    2001-09-06

    The H{sup -} ion source for the Spallation Neutron Source (SNS) is a cesiated, radio-frequency driven (2 MHz) multicusp volume source which operates at a duty cycle of 6% (1 ms pulses and 60 Hz). In pulsed RF driven plasma sources, ignition of the plasma affects the stability of source operation and the antenna lifetime. We are reporting on investigations of different ignition schemes, based on secondary electron generation in the plasma chamber by UV light, a hot filament, a low power RF plasma (cw, 13.56 MHz), as well as source operation solely with the high power (40 kW) 2 MHz RF. We find that the dual frequency, single antenna scheme is most attractive for the operating conditions of the SNS H{sup -} source.

  7. Methane Emissions from Point and Area Sources in California

    Science.gov (United States)

    Peischl, J.; Ryerson, T. B.; Frost, G. J.; Holloway, J. S.; McKeen, S. A.; Neuman, J.; Nowak, J. B.; Pollack, I. B.; Roberts, J. M.; Trainer, M.; Parrish, D. D.

    2010-12-01

    Airborne measurements of methane (CH4), carbon monoxide (CO), sulfur dioxide, ammonia, and nitric oxides were made aboard the NOAA WP-3D during May and June 2010, during the CalNex (Research at the Nexus of Air Quality and Climate Change) field campaign based out of Ontario, California. Emission ratios of CH4 to these other trace gas species are calculated from observations downwind of point sources and compared to national emissions inventories. Further, background urban ratios of CH4 to CO are established, and enhancements from known area CH4 sources, such as rice paddies and cattle ranches, are analyzed. Finally, significant methane emissions from point sources not in emissions inventories are examined.

  8. Comparing Jupiter and Saturn: dimensionless input rates from plasma sources within the magnetosphere

    Directory of Open Access Journals (Sweden)

    V. M. Vasyliūnas

    2008-06-01

    Full Text Available The quantitative significance for a planetary magnetosphere of plasma sources associated with a moon of the planet can be assessed only by expressing the plasma mass input rate in dimensionless form, as the ratio of the actual mass input to some reference value. Traditionally, the solar wind mass flux through an area equal to the cross-section of the magnetosphere has been used. Here I identify another reference value of mass input, independent of the solar wind and constructed from planetary parameters alone, which can be shown to represent a mass input sufficiently large to prevent corotation already at the source location. The source rate from Enceladus at Saturn has been reported to be an order of magnitude smaller (in absolute numbers than that from Io at Jupiter. Both reference values, however, are also smaller at Saturn than at Jupiter, by factors ~40 to 60; expressed in dimensionless form, the estimated mass input from Enceladus may be larger than that from Io by factors ~4 to 6. The magnetosphere of Saturn may thus, despite a lower mass input in kg s−1, intrinsically be more heavily mass-loaded than the magnetosphere of Jupiter.

  9. Application of source-receptor models to determine source areas of biological components (pollen and butterflies

    Directory of Open Access Journals (Sweden)

    M. Alarcón

    2010-01-01

    Full Text Available The source-receptor models allow the establishment of relationships between a receptor point (sampling point and the probable source areas (regions of emission through the association of concentration values at the receptor point with the corresponding atmospheric back-trajectories, and, together with other techniques, to interpret transport phenomena on a synoptic scale. These models are generally used in air pollution studies to determine the areas of origin of chemical compounds measured at a sampling point, and thus be able to target actions to reduce pollutants. However, until now, few studies have applied these types of models to describe the source areas of biological organisms. In Catalonia there are very complete records of pollen (data from the Xarxa Aerobiològica de Catalunya, Aerobiology Network of Catalonia and butterflies (data from the Catalan Butterfly Monitoring Scheme, a biological material that is also liable to be transported long distances and whose areas of origin could be interesting to know. This work presents the results of the use of the Seibert et al. model applied to the study of the source regions of: (1 certain pollen of an allergic nature, observed in Catalonia and the Canary Islands, and (2 the migratory butterfly Vanessa cardui, observed in Catalonia. Based on the results obtained we can corroborate the suitability of these models to determine the area of origin of several species, both chemical and biological, therefore expanding the possibilities of applying the original model to the wider field of Aerobiology.

  10. Tracing lead pollution sources in abandoned mine areas using stable Pb isotope ratios.

    Science.gov (United States)

    Yoo, Eun-Jin; Lee, Jung-A; Park, Jae-Seon; Lee, Khanghyun; Lee, Won-Seok; Han, Jin-Seok; Choi, Jong-Woo

    2014-02-01

    This study focused on Pb isotope ratios of sediments in areas around an abandoned mine to determine if the ratios can be used as a source tracer. For pretreatment, sediment samples were dissolved with mixed acids, and a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Nu plasma II) was used to investigate the Pb isotopic composition of the samples. The measured isotope ratios were then corrected for instrumental mass fractionation by measuring the (203)Tl/(205)Tl ratio. Repeated measurements with the NIST SRM 981 reference material showed that the precision of all ratios was below 104 ppm (±2σ) for 50 ng/g. The isotope ratios ((207)Pb/(206)Pb) found were 0.85073 ± 0.0004~0.85373 ± 0.0003 for the main stream, while they were 0.83736 ± 0.0010 for the tributary and 0.84393 ± 0.0002 for the confluence. A binary mixing equation for isotope ratios showed that the contributions of mine lead to neighboring areas were up to 60%. Therefore, Pb isotope ratios can be a good source tracer for areas around abandoned mines.

  11. Cold plasma source for bacterial inactivation at atmospheric pressure

    DEFF Research Database (Denmark)

    Chen, Weifeng; Stamate, Eugen; Mejlholm, Ole

    A dielectric-barrier discharge system for cold plasma production was built for bacterial inactivation purpose. The eect of cold plasma treatment on sensory properties of seafood products was studied to establish how the sensory properties (e.g. appearance, texture) of seafood were aected by diere...

  12. An Electrothermal Plasma Source Developed for Simulation of Transient Heat Loads in Future Large Fusion Devices

    Science.gov (United States)

    Gebhart, Trey; Baylor, Larry; Winfrey, Leigh

    2016-10-01

    The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a possible transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime, which is driven by a DC capacitive discharge. The current travels through the 4mm bore of a boron nitride liner and subsequently ablates and ionizes the liner material. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have a duration of 1ms at full-width half maximum. The peak currents and maximum source energies seen in this system are 2kA and 5kJ. The goal of this work is to show that the ET source produces electron densities and heat fluxes that are comparable to transient events in future large magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each test shot using infrared imaging and optical spectroscopy techniques. This work will compare the ET source output (heat flux, temperature, and density) with and without an applied magnetic field. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  13. The minimization of non-equilibrium plasma source at high pressure

    Institute of Scientific and Technical Information of China (English)

    BAI MinDi; QIU XiuMei; LIU Dong; YANG Bo; ZHOU JianGang; XUE XiaoHong; GU JianLong

    2008-01-01

    The density of plasma produced by atmospheric non-equilibrium plasma source is the function of en-ergy dissipation rate in ionization electric field and gas particles momentum. The experiment shows that the plasma density highly rises with the increasing of energy dissipation rate and gas particles momentum. When the energy dissipation rate of activation field is 2.18 Wh/m3 and the average gas particles momentum is 109×10-22 g·m/s, the air throughput of plasma source whose volume is only 2.5 cm3 can be up to 12 m3/h and the density of plasma can be up to 1010 cm-3. The research can develop a method of producing minitype plasma source which is low energy consumption but high ion concert-tration used for chemical industry, environmental engineering and military.

  14. An ultracompact X-ray source based on a laser-plasma undulator.

    Science.gov (United States)

    Andriyash, I A; Lehe, R; Lifschitz, A; Thaury, C; Rax, J-M; Krushelnick, K; Malka, V

    2014-08-22

    The capability of plasmas to sustain ultrahigh electric fields has attracted considerable interest over the last decades and has given rise to laser-plasma engineering. Today, plasmas are commonly used for accelerating and collimating relativistic electrons, or to manipulate intense laser pulses. Here we propose an ultracompact plasma undulator that combines plasma technology and nanoengineering. When coupled with a laser-plasma accelerator, this undulator constitutes a millimetre-sized synchrotron radiation source of X-rays. The undulator consists of an array of nanowires, which are ionized by the laser pulse exiting from the accelerator. The strong charge-separation field, arising around the wires, efficiently wiggles the laser-accelerated electrons. We demonstrate that this system can produce bright, collimated and tunable beams of photons with 10-100 keV energies. This concept opens a path towards a new generation of compact synchrotron sources based on nanostructured plasmas.

  15. Design of a high particle flux hydrogen helicon plasma source for used in plasma materials interaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, Richard Howell [ORNL; Chen, Guangye [ORNL; Meitner, Steven J [ORNL; Baity Jr, F Wallace [ORNL; Caughman, John B [ORNL; Owen, Larry W [ORNL

    2009-01-01

    Existing linear plasma materials interaction (PMI) facilities all use plasma sources with internal electrodes. An rf-based helicon source is of interest because high plasma densities can be generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. Work has begun at Oak Ridge National Laboratory (ORNL) to develop a large (15 cm) diameter helicon source producing hydrogen plasmas with parameters suitable for use in a linear PMI device: n(e) >= 10(19)m(-3), T(e) = 4-10 eV, particle flux Gamma(p) > 10(23) m(-3) s(-1), and magnetic field strength |B| up to I T in the source region. The device, whose design is based on a previous hydrogen helicon source operated at ORNL[1], will operate at rf frequencies in the range 10 - 26 MHz, and power levels up to similar to 100 kW. Limitations in cooling will prevent operation for pulses longer than several seconds, but a major goal will be the measurement of power deposition on device structures so that a later steady state version can be designed. The device design, the diagnostics to be used, and results of rf modeling of the device will be discussed. These include calculations of plasma loading, resulting currents and voltages in antenna structures and the matching network, power deposition profiles, and the effect of high |B| operation on power absorption.

  16. Data sources on landscape structure in a highly industrialized area

    Directory of Open Access Journals (Sweden)

    Mazurek Kinga

    2015-03-01

    Full Text Available Landscape may be described as a part of space characterized by a certain physiognomy, which is a dynamic system subject to evolution. An important factor influencing the type and condition of the landscape is human activity which shapes or rebuilds its structure. Interesting results may be obtained on comparison of archival cartographic materials with contemporary studies and zoning plans. The Upper Silesian Coal Basin is a region with a clearly transformed landscape. The determinant of the geographical environment transformation here is the anthropogenic factor. The study area includes the upper part of the Kłodnica catchment (229.6 sq km. The study is a review, and its aim is to systematize data sources used in the research on the transformation of landscape structure of a heavily industrialized area. In the first half of the nineteenth century created the "Urmesstischblätter" in the scale of 1:25 000. Afterwards preparations began to take new topographic images of the country (the "Messtischblätter". In the 1990s initiated the development of a new topographic map (in the scale of 1:10 000. Recent data source is for example the project CORINE Land Cover 2006. There are many of various sources of data on land cover. An important aspect is the proper selection of documents and maps, and their proper interpretation.

  17. A plasma source driven predator-prey like mechanism as a potential cause of spiraling intermittencies in linear plasma devices

    Science.gov (United States)

    Reiser, D.; Ohno, N.; Tanaka, H.; Vela, L.

    2014-03-01

    Three-dimensional global drift fluid simulations are carried out to analyze coherent plasma structures appearing in the NAGDIS-II linear device (nagoya divertor plasma Simulator-II). The numerical simulations reproduce several features of the intermittent spiraling structures observed, for instance, statistical properties, rotation frequency, and the frequency of plasma expulsion. The detailed inspection of the three-dimensional plasma dynamics allows to identify the key mechanism behind the formation of these intermittent events. The resistive coupling between electron pressure and parallel electric field in the plasma source region gives rise to a quasilinear predator-prey like dynamics where the axisymmetric mode represents the prey and the spiraling structure with low azimuthal mode number represents the predator. This interpretation is confirmed by a reduced one-dimensional quasilinear model derived on the basis of the findings in the full three-dimensional simulations. The dominant dynamics reveals certain similarities to the classical Lotka-Volterra cycle.

  18. A plasma source driven predator-prey like mechanism as a potential cause of spiraling intermittencies in linear plasma devices

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, D. [Research Center Jülich GmbH, Institute for Energy and Climate Research—Plasma Physics, D-52425 Jülich (Germany); Ohno, N. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tanaka, H. [National Institute for Fusion Science, Toki 509-5292 (Japan); Vela, L. [Physics Department, Universidad Carlos III de Madrid, Avda de la Universidad 30, 28911-Leganés, Madrid (Spain)

    2014-03-15

    Three-dimensional global drift fluid simulations are carried out to analyze coherent plasma structures appearing in the NAGDIS-II linear device (nagoya divertor plasma Simulator-II). The numerical simulations reproduce several features of the intermittent spiraling structures observed, for instance, statistical properties, rotation frequency, and the frequency of plasma expulsion. The detailed inspection of the three-dimensional plasma dynamics allows to identify the key mechanism behind the formation of these intermittent events. The resistive coupling between electron pressure and parallel electric field in the plasma source region gives rise to a quasilinear predator-prey like dynamics where the axisymmetric mode represents the prey and the spiraling structure with low azimuthal mode number represents the predator. This interpretation is confirmed by a reduced one-dimensional quasilinear model derived on the basis of the findings in the full three-dimensional simulations. The dominant dynamics reveals certain similarities to the classical Lotka-Volterra cycle.

  19. Investigation of helium ion production in constricted direct current plasma ion source with layered-glows

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yuna [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Yeong-Shin [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-02-15

    Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He{sup 2+} by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm{sup 2} and power density of 0.52 mA/cm{sup 2}/W. He{sup 2+} ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He{sup 2+} ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He{sup 2+} ions with the layered-glow DC discharge.

  20. Plasma ignition and steady state simulations of the Linac4 H$^{-}$ ion source

    CERN Document Server

    Mattei, S; Yasumoto, M; Hatayama, A; Lettry, J; Grudiev, A

    2014-01-01

    The RF heating of the plasma in the Linac4 H- ion source has been simulated using an Particle-in-Cell Monte Carlo Collision method (PIC-MCC). This model is applied to investigate the plasma formation starting from an initial low electron density of 1012 m-3 and its stabilization at 1018 m-3. The plasma discharge at low electron density is driven by the capacitive coupling with the electric field generated by the antenna, and as the electron density increases the capacitive electric field is shielded by the plasma and induction drives the plasma heating process. Plasma properties such as e-/ion densities and energies, sheath formation and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.

  1. PROMETHEUS-A: A helicon plasma source for future wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Buttenschoen, Birger; Fahrenkamp, Nils; Grulke, Olaf [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany)

    2015-05-01

    High density plasma sources are of interest for a wide range of applications like plasma-wall interaction studies, plasma thrusters for space propulsion, or future plasma wakefield particle accelerators. In this contribution, we present a high power helicon cell designed for the world's first proton-beam driven plasma wakefield accelerator experiment AWAKE. Using a modular concept with four antennas distributed along a one meter long, five centimeter diameter prototype module providing up to 35 kW of rf power to the plasma, accelerator relevant densities of 6 . 10{sup 20} m{sup -3} are transiently achieved and exceeded. These high density plasmas are characterized for the use with wakefield accelerators, considering density evolution and its reproducibility, plasma profiles and neutral gas inventory.

  2. Advanced Laser and RF Plasma Sources and Diagnostics

    Science.gov (United States)

    2007-06-13

    jacks, fibers, collimators, and breadboards $19,832.71 Interferometry Gunn diode and I-Q mixer $6,775.00 RF Components and Automation High...temperature diagnostics for both our laser window and radiofrequency air plasmas. We have also acquired a tunable 668 nm diode laser, optical filters...diagnostics for both our laser window and radiofrequency air plasmas. We have also acquired a tunable 668 nm diode laser, optical filters, splitters

  3. PLASMOSE - antimicrobial effects of modular atmospheric plasma sources

    OpenAIRE

    Ehlbeck, J; Van Brandenburg, R; von Woedtke, T; Krohmann, U; Stieber, M.; Weltmann, KD

    2008-01-01

    The technological potential of non-thermal plasmas for the antimicrobial treatment of heat sensitive materials is well known and has been documented in a great number of research activities, but the realisation of industrial plasma-based decontamination processes remains a great challenge. One of the reasons for this situation is the fact that an antimicrobial treatment process needs to consider all properties of the product to be treated as well as the requirements of the complete procedure,...

  4. PIC/MCC simulation for magnetized capacitively coupled plasmas driven by combined dc/rf sources

    Science.gov (United States)

    Yang, Shali; Zhang, Ya; Jiang, Wei; Wang, Hongyu; Wang, Shuai

    2016-09-01

    Hybrid dc/rf capacitively coupled plasma (CCP) sources have been popular in substrate etching due to their simplicity in the device structure and better plasma property. In this work, the characteristics of magnetized capacitively coupled plasmas driven by combined dc/rf sources are described by a one-dimensional Particle-in-cell/Monte Carlo collision (PIC/MCC) model. The simulation is using a rf source of 13.56MHz in argon and at a low pressure of 50mTorr. The effects of dc voltage and magnetic field on the plasmas are examined for 200-400V and 0-200Gs. It is found that, to some extent, dc voltage will increase the plasma density, but plasma density drops with increasing dc voltage. The magnetic field will enhance the plasma density significantly, due to the magnetic field will increase the electron life time and decrease the loss to the electrodes. In the bulk plasma, electron temperature is increased with the magnetic field but decreased with the dc voltage. The electron temperature in sheath is higher than in bulk plasma, due to stochastic heating in sheath is greater than Ohmic heating in bulk plasma under low gas pressure. National Natural Science Foundation of China (11405067, 11105057, 11305032, 11275039).

  5. Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

    Science.gov (United States)

    Doo-Hee, Chang; Seung, Ho Jeong; Min, Park; Tae-Seong, Kim; Bong-Ki, Jung; Kwang, Won Lee; Sang Ryul, In

    2016-12-01

    A large-area high-power radio-frequency (RF) driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute (KAERI). The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argon-gas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter, such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the short-and long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region. supported by the Ministry of Science, ICT and Future Planning of the Republic of Korea under the ITER Technology R&D Program, and National R&D Program Through the National Research Foundation of Korea (NRF) Funded by the Ministry of Science, ICT & Future Planning (NRF-2014M1A7A1A03045372)

  6. 75 FR 12988 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and...

    Science.gov (United States)

    2010-03-18

    ... Sources: Asphalt Processing and Asphalt Roofing Manufacturing; Technical Correction AGENCY: Environmental... the asphalt processing and asphalt roofing manufacturing area source category (74 FR 63236). Following... the asphalt processing and asphalt roofing manufacturing area source category on December 2, 2009...

  7. Direct structuring of solids by EUV radiation from a table-top laser produced plasma source

    Science.gov (United States)

    Barkusky, Frank; Bayer, Armin; Peth, Christian; Mann, Klaus

    2009-05-01

    In recent years, technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. Currently, the application of EUV radiation apart from microlithography comes more and more into focus. Main goal of our research is to utilize the unique interaction between soft x-ray radiation and matter for probing, modifying, and structuring solid surfaces. In this contribution we present a setup capable of generating and focusing EUV radiation. It consists of a table-top laser-produced plasma source. In order to obtain a small focal spot resulting in high EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si multilayer coatings is adapted to this source, simultaneously blocking unwanted out-of-band radiation. By demagnified (10x) imaging of the plasma an EUV spot of 5 μm diameter with a maximum energy density of ~0.72 J/cm² is generated (pulse length 8.8 ns). We present first applications of this integrated source and optics system, demonstrating its potential for high-resolution modification and structuring of solid surfaces. As an example, etch rates for PMMA, PC and PTFE depending on EUV fluences were determined, indicating a linear etch behavior for lower energy densities. In order to investigate changes of the chemical composition of PMMA induced by EUV radiation we present FTIR and NEXAFS measurements on irradiated samples. The latter were performed using the laboratory source tuned to the XUV spectral range around the carbon K-edge (λ ~ 4.4 nm) and a flat-field spectrometer. For showing the potential of this setup, first damage tests were performed on grazing incidence gold mirrors. For these thin Gold films, threshold energy densities could be determined, scaling linear with the film thickness.

  8. An Integrated Risk Management Model for Source Water Protection Areas

    Directory of Open Access Journals (Sweden)

    Shang-Lien Lo

    2012-10-01

    Full Text Available Watersheds are recognized as the most effective management unit for the protection of water resources. For surface water supplies that use water from upstream watersheds, evaluating threats to water quality and implementing a watershed management plan are crucial for the maintenance of drinking water safe for humans. The aim of this article is to establish a risk assessment model that provides basic information for identifying critical pollutants and areas at high risk for degraded water quality. In this study, a quantitative risk model that uses hazard quotients for each water quality parameter was combined with a qualitative risk model that uses the relative risk level of potential pollution events in order to characterize the current condition and potential risk of watersheds providing drinking water. In a case study of Taipei Source Water Area in northern Taiwan, total coliforms and total phosphorus were the top two pollutants of concern. Intensive tea-growing and recreational activities around the riparian zone may contribute the greatest pollution to the watershed. Our risk assessment tool may be enhanced by developing, recording, and updating information on pollution sources in the water supply watersheds. Moreover, management authorities could use the resultant information to create watershed risk management plans.

  9. An integrated risk management model for source water protection areas.

    Science.gov (United States)

    Chiueh, Pei-Te; Shang, Wei-Ting; Lo, Shang-Lien

    2012-10-17

    Watersheds are recognized as the most effective management unit for the protection of water resources. For surface water supplies that use water from upstream watersheds, evaluating threats to water quality and implementing a watershed management plan are crucial for the maintenance of drinking water safe for humans. The aim of this article is to establish a risk assessment model that provides basic information for identifying critical pollutants and areas at high risk for degraded water quality. In this study, a quantitative risk model that uses hazard quotients for each water quality parameter was combined with a qualitative risk model that uses the relative risk level of potential pollution events in order to characterize the current condition and potential risk of watersheds providing drinking water. In a case study of Taipei Source Water Area in northern Taiwan, total coliforms and total phosphorus were the top two pollutants of concern. Intensive tea-growing and recreational activities around the riparian zone may contribute the greatest pollution to the watershed. Our risk assessment tool may be enhanced by developing, recording, and updating information on pollution sources in the water supply watersheds. Moreover, management authorities could use the resultant information to create watershed risk management plans.

  10. Droplet-free high-density metal ion source for plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Keiji [Department of Electrical Engineering, College of Engineering, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501 (Japan)]. E-mail: nakamura@solan.chubu.ac.jp; Yoshinaga, Hiroaki [Department of Electrical Engineering, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan); Yukimura, Ken [Department of Electrical Engineering, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan)

    2006-01-15

    This paper reports on plasma parameters and ion composition of droplet-free Zr ion source for plasma immersion ion implantation and deposition (PIII and D). Zirconium (Zr) ions were obtained by ionizing sputtered Zr atoms in inductively-coupled argon discharge. The characteristics of plasma density, plasma potential and electron temperature were typical ones of such a inductive discharge, and the plasma parameters were not significantly influenced by mixing the sputtered Zr atoms into the plasma. Actually, the main ionic component was still Ar{sup +} ions, and the ion density ratio of [Zr{sup +}]/[Ar{sup +}] was as low as {approx}8%. Increase in sputtering rate of the Zr source will be necessary to improve the ion density ratio.

  11. Optimum plasma grid bias for a negative hydrogen ion source operation with Cs

    Energy Technology Data Exchange (ETDEWEB)

    Bacal, Marthe, E-mail: marthe.bacal@lpp.polytechnique.fr [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Sasao, Mamiko [R& D Promotion Organization, Doshisha University, Kamigyoku, Kyoto 602-8580 (Japan); Wada, Motoi [School of Science and Engineering, Doshisha University, Kyotonabe, Kyoto 610-0321 (Japan); McAdams, Roy [CCFE, Culham Science Center, Abingdon, Oxfordshire 0X14 3DB (United Kingdom)

    2016-02-15

    The functions of a biased plasma grid of a negative hydrogen (H{sup −}) ion source for both pure volume and Cs seeded operations are reexamined. Proper control of the plasma grid bias in pure volume sources yields: enhancement of the extracted negative ion current, reduction of the co-extracted electron current, flattening of the spatial distribution of plasma potential across the filter magnetic field, change in recycling from hydrogen atomic/molecular ions to atomic/molecular neutrals, and enhanced concentration of H{sup −} ions near the plasma grid. These functions are maintained in the sources seeded with Cs with additional direct emission of negative ions under positive ion and neutral hydrogen bombardment onto the plasma electrode.

  12. Combustion flame-plasma hybrid reactor systems, and chemical reactant sources

    Science.gov (United States)

    Kong, Peter C

    2013-11-26

    Combustion flame-plasma hybrid reactor systems, chemical reactant sources, and related methods are disclosed. In one embodiment, a combustion flame-plasma hybrid reactor system comprising a reaction chamber, a combustion torch positioned to direct a flame into the reaction chamber, and one or more reactant feed assemblies configured to electrically energize at least one electrically conductive solid reactant structure to form a plasma and feed each electrically conductive solid reactant structure into the plasma to form at least one product is disclosed. In an additional embodiment, a chemical reactant source for a combustion flame-plasma hybrid reactor comprising an elongated electrically conductive reactant structure consisting essentially of at least one chemical reactant is disclosed. In further embodiments, methods of forming a chemical reactant source and methods of chemically converting at least one reactant into at least one product are disclosed.

  13. Diamond-like carbon produced by plasma source ion implantation as a corrosion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Lillard, R.S.; Butt, D.P.; Taylor, T.N.; Walter, K.C.; Nastasi, M.

    1998-03-01

    There currently exists a broad range of applications for which the ability to produce an adherent, hard, wear and, corrosion-resistant coating plays a vital role. These applications include engine components, orthopedic devices, textile manufacturing components, hard disk media, optical coatings, and cutting and machining tools (e.g., punches, taps, scoring dies, and extrusion dies). Ion beam processing can play an important role in all of these technologies. Plasma source ion implantation (PSII) is an emerging technology which has the potential to overcome the limitations of conventional ion implantation by: (1) reducing the time and expense for implanting onto complex shapes and large areas and (2) extending the thickness of the modification zone through ion beam enhanced plasma growth of surface coatings. In PSII, targets are placed directly in a plasma source and then pulse biased to produce a non-line-of-sight process for complex-shaped targets without complex fixturing. If the pulse bias is a relatively high negative potential (20 to 100 kV) ion implantation will result. If however, a low voltage (50--1,200 eV) high duty cycle pulse bias is applied, film deposition from the chamber gas will result, thereby increasing the extent of the surface modification into the 1--10 micron regime. To evaluate the potential for DLC to be used as a corrosion barrier, Electrochemical Impedance Spectroscopy (EIS) and traditional electrochemistry techniques were used to investigate the breakdown mechanism in chloride and nonchloride containing environments. The effect of surface preparation on coating breakdown was also evaluated.

  14. Characterization of an atmospheric pressure air plasma source for polymer surface modification

    Science.gov (United States)

    Yang, Shujun; Tang, Jiansheng

    2013-10-01

    An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU

  15. Shaping the electron beams with submicrosecond pulse duration in sources and electron accelerators with plasma emitters

    CERN Document Server

    Gushenets, V I

    2001-01-01

    One studies the techniques in use to shape submicrosecond electron beams and the physical processes associated with extraction of electrons from plasma in plasma emitters. Plasma emitter base sources and accelerators enable to generate pulse beams with currents varying from tens of amperes up to 10 sup 3 A, with current densities up to several amperes per a square centimeter, with pulse duration constituting hundreds of nanoseconds and with high frequencies of repetition

  16. Injection of auxiliary electrons for increasing the plasma density in highly charged and high intensity ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Odorici, F., E-mail: fabrizio.odorici@bo.infn.it; Malferrari, L.; Montanari, A. [INFN—Bologna, Viale B. Pichat, 6/2, 40127 Bologna (Italy); Rizzoli, R. [INFN—Bologna, Viale B. Pichat, 6/2, 40127 Bologna (Italy); CNR–Istituto per la Microelettronica ed i Microsistemi, Via Gobetti 101, 40129 Bologna (Italy); Mascali, D.; Castro, G.; Celona, L.; Gammino, S.; Neri, L. [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy)

    2016-02-15

    Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to “screen” the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used, as explained by plasma diffusion models.

  17. Injection of auxiliary electrons for increasing the plasma density in highly charged and high intensity ion sources

    Science.gov (United States)

    Odorici, F.; Malferrari, L.; Montanari, A.; Rizzoli, R.; Mascali, D.; Castro, G.; Celona, L.; Gammino, S.; Neri, L.

    2016-02-01

    Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to "screen" the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used, as explained by plasma diffusion models.

  18. Counter-facing plasma focus system as an efficient and long-pulse EUV light source

    Science.gov (United States)

    Kuwabara, H.; Hayashi, K.; Kuroda, Y.; Nose, H.; Hotozuka, K.; Nakajima, M.; Horioka, K.

    2011-04-01

    A plasma focus system composed of a pair of counter-facing coaxial plasma guns is proposed as a long-pulse and efficient EUV light source. A proof-of-concept experiment demonstrated that with an assist of breakdown and outer electrode connections, current sheets evolved into a configuration for stable plasma confinement at the center of the electrode. The current sheets could successively compress and confine the high energy density plasma every half period of the discharge current, enabling highly repetitive light emissions in extreme ultraviolet region with time duration in at least ten microseconds for Xe plasma. Also, we confirmed operations of our system for Li plasma. We estimated the highest EUV energy in Li plasma operation at 93mJ/4π sr per 2% bandwidth per pulse.

  19. Epitaxial aluminum nitride tunnel barriers grown by nitridation with a plasma source

    NARCIS (Netherlands)

    Zijlstra, T.; Lodewijk, C.F.J.; Vercruyssen, N.; Tichelaar, F.D.; Loudkov, D.N.; Klapwijk, T.M.

    2007-01-01

    High critical current-density (10 to 420 kA/cm2) superconductor-insulator-superconductor tunnel junctions with aluminum nitride barriers have been realized using a remote nitrogen plasma from an inductively coupled plasma source operated in a pressure range of 10−3–10−1 mbar. We find a much better r

  20. Plasma diagnostics approach to welding heat source/molten pool interaction

    Energy Technology Data Exchange (ETDEWEB)

    Key, J.F.; McIlwain, M.E.; Isaacson, L.

    1980-01-01

    Plasma diagnostic techniques show that weld fusion zone profile and loss of metal vapors from the molten pool are strongly dependent on both the intensity and distribution of the heat source. These plasma properties, are functions of cathode vertex angle and thermal conductivity of the shielding gas, especially near the anode.

  1. High-density operation of the Proto-MPEX High Intensity Plasma Source

    Science.gov (United States)

    Caughman, J. B. O.; Goulding, R. H.; Biewer, T. M.; Bigelow, T. S.; Campbell, I. H.; Caneses, J.; Diem, S. J.; Martin, E. H.; Parish, C. M.; Rapp, J.; Ray, H. B.; Shaw, G. C.; Showers, M. A.; Donovan, D.; Piotrowicz, P. A.; Martin, D. C.

    2016-10-01

    The Prototype Materials Plasma Experiment (Proto-MPEX) is a linear high-intensity RF plasma source that combines a high-density helicon plasma generator with ion and electron heating sections. It is being used to study the physics of heating over-dense plasmas in a linear configuration with the goal of delivering a plasma heat flux of 10 MW/m2 at a target. The helicon plasma is produced by coupling 13.56 MHz RF power at levels of >100 kW. A 30 kW ion cyclotron antenna has recently been installed, and microwaves at 28 GHz ( 150 kW) are coupled to the electrons in the over-dense helicon plasma via Electron Bernstein Waves (EBW). High plasma densities near the target have been produced in D ( 5 x1019/m3) , and electron temperatures range from 3 to >10 eV, depending on the source parameters. IR camera images of the target plate indicate plasma heat depositions >10 MW/m2 for some operating conditions. Details of the experimental results of the operational domain with respect to Te and ne as well as results from initial plasma material interaction tests will be presented. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC-05-00OR22725.

  2. Characterization of the Inductively Heated Plasma Source IPG6-B

    Science.gov (United States)

    Dropmann, Michael; Laufer, Rene; Herdrich, Georg; Matthews, Lorin; Hyde, Truell

    2014-10-01

    In close collaboration between the Center for Astrophysics, Space Physics and Engineering Research (CASPER) at Baylor University, Texas, and the Institute of Space Systems (IRS) at the University of Stuttgart, Germany, two plasma facilities have been established using the Inductively heated Plasma Generator 6 (IPG6). The facility at Baylor University (IPG6-B) works at a frequency of 13.56 MHz and a maximum power of 15 kW. A vacuum pump of 160 m3/h in combination with a butterfly valve allows pressure control over a wide range. Intended fields of research include basic investigation into thermo-chemistry and plasma radiation, space plasma environments and high heat fluxes e.g. those found in fusion devices or during atmospheric re-entry of spacecraft. After moving the IPG6-B facility to the Baylor Research and Innovation Collaborative (BRIC) it was placed back into operation during the summer of 2014. Initial characterization in the new lab, using a heat flux probe, Pitot probe and cavity calorimeter, has been conducted for Air, Argon and Helium. The results of this characterization are presented.

  3. A solar powered handheld plasma source for microbial decontamination applications

    Science.gov (United States)

    Ni, Y.; Lynch, M. J.; Modic, M.; Whalley, R. D.; Walsh, J. L.

    2016-09-01

    A fully portable atmospheric pressure air plasma system is reported to be suitable for the microbial decontamination of both surfaces and liquids. The device operates in quiescent air, and includes an integrated battery which is charged from a solar cell and weighs less than 750 g, making it highly amenable for a wide variety of applications beyond the laboratory. Using particle imaging velocimetry to visualise air flows around the device, the geometric configuration of the plasma generating electrodes was enhanced to induce a gas flow on the order of 0.5 m s-1 directed towards a sample placed downstream, thus improving the transport of plasma generated reactive species to the sample. The microbial decontamination efficiency of the system was assessed using potable water samples inoculated with common waterborne organisms Escherichia coli and Pseudomonas fluorescens. The reduction in the number of microorganisms was found to be in the range of 2-8 log and was strongly dependent on the plasma generation conditions.

  4. Expansion of a plasma across a transverse magnetic field in a negative hydrogen ion source for fusion

    Science.gov (United States)

    Fantz, Ursel; Schiesko, Loic; Wünderlich, Dirk

    2012-10-01

    Negative ion sources are a key component of the neutral beam injection systems for the international fusion experiment ITER. To achieve the required ion current of 40 A at a tolerable amount of co-extracted electrons (electron to ion ratio below one) the source is separated into a plasma generation region and an expansion chamber equipped with a magnetic filter field (up to 10 mT). The field is needed for: (1) cooling the electrons down and thus minimize the H^- destruction by collisions, (2) to reduce the co-extracted electron current, and (3) to enhance the extraction probability for the surface produced negative ions. The area of the ITER source will be approximately 1m width and 2 m height, the IPP prototype source is a 1/8-size source. The recently installed flexible magnetic filter frame allows for systematic filter field studies (strength, position, polarity). Two Langmuir probes have been used to measure the plasma parameters simultaneously in axial direction. The profiles in the upper and lower part of the expansion chamber show beside the expected electron temperature and density decrease a drop in the plasma potential and a drift depending on the polarity, which vanishes when removing the filter field. The data interpretation is supported by modeling activities.

  5. Nonpoint source pollution loading from an undistributed tropic forest area.

    Science.gov (United States)

    Chang, Chih-Hua; Wen, Ching-Gung; Huang, Chia-Hui; Chang, Shui-Ping; Lee, Chih-Sheng

    2008-11-01

    Water quality and unit nonpoint sources (NPS) pollution load from a forest area were studied in a mountainous watershed in Taiwan. The flow rates were measured with rectangular weirs and samples taken for water quality analysis in both non-rainy and rainy days for 2 years. The subroutine of the Hydrological Simulation Program--FORTRAN was used to simulate runoff for additional 3 years. Total annual loads of various water quality parameters were then estimated by a regression model. Most of the parameter concentrations are higher during the rainy days; their values are typically higher as compared to data from other undisturbed forest areas. Nevertheless, the concentration ratio of dissolved inorganic nitrogen to TN or PO4(3-) -P to TP shows TN or TP no correlations with the flow rates, whereas the concentrations of SS and TP are positively correlated with the flow rate. The fluctuation of annual load from this watershed is significant. For example, six major events of the entire year, for which the total duration is merely 6.4 days, contribute 42% of the annual precipitation and at least 40% of the annual NPS loads. The management for controlling the NPS pollution from this forest watershed is discussed.

  6. Abatement of Perfluorinated Compounds Using Cylindrical Microwave Plasma Source at Low Pressure

    Science.gov (United States)

    Kim, Seong Bong; Park, S.; Park, Y.; Youn, S.; Yoo, S. J.

    2016-10-01

    Microwave plasma source with a cylindrical cavity has been proposed to abate the perfluorinated compounds (PFCs). This plasma source was designed to generate microwave plasma with the cylindrical shape and to be easily installed in existing exhaust line. The microwave frequency is 2.45 GHz and the operating pressure range is 0.1 Torr to 0.3 Torr. The plasma characteristic of the cylindrical microwave plasma source was measured using the optical spectrometer, and tunable diode laser absorption spectroscopy (TDLAS). The destruction and removal efficiency (DRE) of CF4 and CHF3 were measured by a quadrupole mass spectroscopy (QMS) with the various operation conditions. The effect of the addition of the oxygen gas were tested and also the correlation between the plasma parameters and the DRE are presented in this study. This work was supported by R&D Program of ``Plasma Advanced Technology for Agriculture and Food (Plasma Farming)'' through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

  7. Sources of debris flow material in burned areas

    Science.gov (United States)

    Santi, P.M.; deWolfe, V.G.; Higgins, J.D.; Cannon, S.H.; Gartner, J.E.

    2008-01-01

    The vulnerability of recently burned areas to debris flows has been well established. Likewise, it has been shown that many, if not most, post-fire debris flows are initiated by runoff and erosion and grow in size through erosion and scour by the moving debris flow, as opposed to landslide-initiated flows with little growth. To better understand the development and character of these flows, a study has been completed encompassing 46 debris flows in California, Utah, and Colorado, in nine different recently burned areas. For each debris flow, progressive debris production was measured at intervals along the length of the channel, and from these measurements graphs were developed showing cumulative volume of debris as a function of channel length. All 46 debris flows showed significant bulking by scour and erosion, with average yield rates for each channel ranging from 0.3 to 9.9??m3 of debris produced for every meter of channel length, with an overall average value of 2.5??m3/m. Significant increases in yield rate partway down the channel were identified in 87% of the channels, with an average of a three-fold increase in yield rate. Yield rates for short reaches of channels (up to several hundred meters) ranged as high as 22.3??m3/m. Debris was contributed from side channels into the main channels for 54% of the flows, with an average of 23% of the total debris coming from those side channels. Rill erosion was identified for 30% of the flows, with rills contributing between 0.1 and 10.5% of the total debris, with an average of 3%. Debris was deposited as levees in 87% of the flows, with most of the deposition occurring in the lower part of the basin. A median value of 10% of the total debris flow was deposited as levees for these cases, with a range from near zero to nearly 100%. These results show that channel erosion and scour are the dominant sources of debris in burned areas, with yield rates increasing significantly partway down the channel. Side channels are

  8. High power microwave source for a plasma wakefield experiment

    Science.gov (United States)

    Shafir, G.; Shlapakovski, A.; Siman-Tov, M.; Bliokh, Yu.; Leopold, J. G.; Gleizer, S.; Gad, R.; Rostov, V. V.; Krasik, Ya. E.

    2017-01-01

    The results of the generation of a high-power microwave (˜550 MW, 0.5 ns, ˜9.6 GHz) beam and feasibility of wakefield-excitation with this beam in under-dense plasma are presented. The microwave beam is generated by a backward wave oscillator (BWO) operating in the superradiance regime. The BWO is driven by a high-current electron beam (˜250 keV, ˜1.5 kA, ˜5 ns) propagating through a slow-wave structure in a guiding magnetic field of 2.5 T. The microwave beam is focused at the desired location by a dielectric lens. Experimentally obtained parameters of the microwave beam at its waist are used for numerical simulations, the results of which demonstrate the formation of a bubble in the plasma that has almost 100% electron density modulation and longitudinal and transverse electric fields of several kV/cm.

  9. Microstructure and Properties of Plasma Source Nitrided AISI 316 Austenitic Stainless Steel

    Science.gov (United States)

    Li, G. Y.; Lei, M. K.

    2016-11-01

    Plasma source nitriding is a relatively new nitriding technology which can overcome those inherent shortcomings associated with conventional direct current plasma nitriding technology such as the arcing surface damage, the edging effect and the hollow cathode effect. There is considerable study on the properties of nitrided samples for laboratorial scale plasma source nitriding system; however, little information has been reported on the industrial-scale plasma source nitriding system. In this work, AISI 316 austenitic stainless steel samples were nitrided by an industrial-scale plasma source nitriding system at various nitriding temperatures (350, 400, 450 and 500 °C) with a floating potential. A high-nitrogen face-centered-cubic phase (γN) formed on the surface of nitrided sample surface. As the nitriding temperature was increased, the γN phase layer thickness increased, varying from 1.5 μm for the lowest nitriding temperature of 350 °C, to 30 μm for the highest nitriding temperature of 500 °C. The maximum Vickers microhardness of the γN phase layer with a peak nitrogen concentration of 20 at.% is about HV 0.1 N 15.1 GPa at the nitriding temperature of 450 °C. The wear and corrosion experimental results demonstrated that the γN phase was formed on the surface of AISI 316 austenitic stainless steel by plasma source nitriding, which exhibits not only high wear resistance, but also good pitting corrosion resistance.

  10. Plasma characteristics in inductively and capacitively coupled hybrid source using single RF power

    Science.gov (United States)

    Kim, Kwan-Yong; Lee, Moo-Young; Kim, Tae-Woo; Kim, Ju-Ho; Chung, Chin-Wook

    2016-09-01

    Parallel combined inductively coupled plasma (ICP) and capacitively coupled plasma (CCP) using single RF generator was proposed to linear control of the plasma density with RF power. In the case of ICP, linear control of the plasma density is difficult because there is a density jump up due to E to H transition. Although the plasma density of CCP changes linearly with power, the density is lower than that of ICP due to high ion energy loss at the substrate. In our hybrid source, the single RF power generator was connected to electrode and antenna, and the variable capacitor was installed between the antenna and the power generator to control the current flowing through the antenna and the electrode. By adjusting the current ratio between the antenna and the electrode, linear characteristic of plasma density with RF power is achieved.

  11. The Relationship between Plasma Endothelin and Hypoxic- Ischemic Encephalopathy in 70 Tibetan Neonates of Plateau Area

    Institute of Scientific and Technical Information of China (English)

    DEJI Meiduo; ZHAO Rong; ZHAO Min; WU Sulan

    2002-01-01

    Objective To discuss the dynamic changing characteristics of plasma endothelin in Tibetan neonates of plateau area with hypoxic - ischemic encephalopathy. Methods Plasma ET level has been determined for 10 days 72 hours after birth by radioimmunoassay in 70 tibetan neonates with HIE.The control group consisted of 20 healthy neonates. Results During acute stage, plasma ET levels of mild, moderate and severe groups were significantly higher that of control group (P < 0.001 ). During acute stage, plasma ET level was closely related with the severity of HIE. Severer HIE was, higher ET level. Conclusion ET was involved in the regulation of HIE.

  12. Waste Area Grouping 2 Remedial Investigation Phase 1 Seep Task data report: Contaminant source area assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, D.S.

    1996-03-01

    This report presents the findings of the Waste Area Grouping (WAG) 2, Phase 1 Remedial Investigation (RI) Seep Task efforts during 1993 and 1994 at Oak Ridge National Laboratory (ORNL). The results presented here follow results form the first year of sampling, 1992, which are contained in the Phase 1 RI report for WAG 2 (DOE 1995a). The WAG 2 Seep Task efforts focused on contaminants in seeps, tributaries, and main streams within the White Oak Creek (WOC) watershed. This report is designed primarily as a reference for contaminants and a resource for guiding remedial decisions. Additional in-depth assessments of the Seep Task data may provide clearer understandings of contaminant transport from the different source areas in the WOC watershed. WAG 2 consists of WOC and its tributaries downstream of the ORNL main plant area, White Oak Lake, the White Oak Creek Embayment of the Clinch River, and the associated flood plains and subsurface environment. The WOC watershed encompasses ORNL and associated WAGs. WAG 2 acts as an integrator for contaminant releases from the contaminated sites at ORNL and as the conduit transporting contaminants to the Clinch River. The main objectives of the Seep Task were to identify and characterize seeps, tributaries and source areas that are responsible for the contaminant releases to the main streams in WAG 2 and to quantify their input to the total contaminant release from the watershed at White Oak Dam (WOD). Efforts focused on {sup 90}Sr, {sup 3}H, and {sup 137}Cs because these contaminants pose the greatest potential human health risk from water ingestion at WOD. Bimonthly sampling was conducted throughout the WOC watershed beginning in March 1993 and ending in August 1994. Samples were also collected for metals, anions, alkalinity, organics, and other radionuclides.

  13. US-Japan IEC Workshop on Small Plasma and Accelerator Neutron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Miley, George H. [Univ. of Illinois, Champaign, IL (United States). Dept. of Nuclear, Plasma, and Radiological Engineering

    2007-05-25

    This report lays out the agenda for the entire workshop and then lists the abstracts for all 29 presentations. All of these presentations cover small plasma and accelerator neutron sources. A few of the presentations include: Comments about IEC History and Future Directions; Characteristics in Pulse Operation of IEC Device with Confronting Two Plasma Sources; Overview of the University of Wisconsin-Madison IEC Program; Improving IEC Particle Confinement Times Using Multiple Grids; Integral Transport Approach for Molecular Ion Processes in IEC Devices; A Counter Stream Beam D-D Neutron Generator; Low Pressure IECF Operation Using Differentially-Pumped Ion Sources, and more.

  14. High-resolution VUV spectrometer/detector investigations of rare-earth pulsed plasma source (abstract)

    Science.gov (United States)

    Roberts, J. R.; Cromer, C. L.; Bridges, J. M.; Lucatorto, T. B.

    1985-05-01

    A 1.5-m grazing incidence spectrometer with a channel electron multiplier (CEMA) and electronic readout detector has been incorporated with a rare-earth target, pulsed plasma, continuum source. The spectrometer is compact and portable while maintaining high resolution. The CEMA detector consists of a single multichannel plate (MCP) with coned-shaped input pores which are cut at a 15-degree bias to improve efficiency at grazing angles. The source is a rare-earth plasma generated by a 10-J ruby laser producing intense continuum emission for wavelengths from 170 to 5 nm. This system will be used for both stationary and transient high-resolution atomic photoabsorption spectroscopy. The pulsed plasma source itself will be investigated for suitability as a radiometric transfer standard source. Preliminary results obtained with this integrated system will be discussed.

  15. Low temperature plasmas created by photoionization of gases with intense radiation pulses from laser-produced plasma sources

    Science.gov (United States)

    Bartnik, A.; Pisarczyk, T.; Wachulak, P.; Chodukowski, T.; Fok, T.; Wegrzyński, Ł.; Kalinowska, Z.; Fiedorowicz, H.

    2016-12-01

    A comparative study of photoionized plasmas created by soft X-ray (SXR) and extreme ultraviolet (EUV) laser plasma sources was performed. The sources, employing high or low energy laser systems, utilized double-stream Xe/He gas-puff targets irradiated with laser pulses of different parameters. The SXR/EUV beams were used for irradiation of a gas stream, injected into a vacuum chamber synchronously with the radiation pulse. Photoionized plasmas produced this way in Ne gas emitted radiation in the SXR/EUV range. The corresponding spectra were dominated by emission lines originating from singly charged ions. Significant differences between spectra obtained in different experimental conditions concern specific transitions in Ne II ions. Creation of photoionized plasmas by SXR or EUV irradiation resulted in K-shell or L-shell emissions respectively. In case of the low energy system absorption spectra were measured additionally. In case of the high energy system, the electron density measurements were performed by laser interferometry, employing a femtosecond laser system. A maximum electron density reached the value of 2·1018cm-3. For the low energy system, a detection limit was too high for the interferometric measurements, thus only an upper estimation for electron density could be made.

  16. Environmental friendly high efficient light source plasma lamp - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Courret, G.; Calame, L. [Haute Ecole d' ingenierie et de gestion du canton de Vaud, Institut de micro et nano techniques, Yverdon-les-Bains (Switzerland); Meyer, A. [Solaronix SA, Aubonne (Switzerland)

    2007-07-01

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) takes a look at work done on the development of a sulphur-based plasma lamp. In 2007, the capability of a new modulator has been explored. The most important results are discussed. With the production of a 1.2 cm{sup 3} bulb, the way towards the production of a 100 W lamp has been opened. The authors comment that modulation by impulses increases the luminous efficiency in comparison to modulation using a continuous sinusoidal wave. The report deals with the history of the project, the development of the new modulator, the use of rotational effects and the optimisation of the amount of active substances - tellurium and selenium - in the bulb. The electromagnetic coupling system used is described and discussed.

  17. High Power Light Gas Helicon Plasma Source for VASIMR

    Science.gov (United States)

    Squire, Jared P.; Chang-Diaz, Franklin R.; Glover, Timothy W.; Jacobson, Verlin T.; Baity, F. Wally; Carter, Mark D.; Goulding, Richard H.

    2004-01-01

    In the Advanced Space Propulsion Laboratory (ASPL) helicon experiment (VX-10) we have measured a plasma flux to input gas rate ratio near 100% for both helium and deuterium at power levels up to 10 kW. Recent results at Oak Ridge National Laboratory (ORNL) show enhanced efficiency operation with a high power density, over 5 kW in a 5 cm diameter tube. Our helicon is presently 9 cm in diameter and operates up to 10 kW of input power. The data here uses a Boswell double-saddle antenna design with a magnetic cusp just upstream of the antenna. Similar to ORNL, for deuterium at near 10 kW, we find an enhanced performance of operation at magnetic fields above the lower hybrid matching condition.

  18. Accessibility condition of wave propagation and multicharged ion production in electron cyclotron resonance ion source plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yushi, E-mail: kato@eei.eng.osaka-u.ac.jp; Yano, Keisuke; Nishiokada, Takuya; Nagaya, Tomoki; Kimura, Daiju; Kumakura, Sho; Imai, Youta; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    2016-02-15

    A new tandem type source of electron cyclotron resonance (ECR) plasmas has been constructing for producing synthesized ion beams in Osaka University. Magnetic mirror field configuration with octupole magnets can be controlled to various shape of ECR zones, namely, in the 2nd stage plasma to be available by a pair mirror and a supplemental coil. Noteworthy correlations between these magnetic configurations and production of multicharged ions are investigated in detail, as well as their optimum conditions. We have been considering accessibility condition of electromagnetic and electrostatic waves propagating in ECR ion source plasma, and then investigated their correspondence relationships with production of multicharged ions. It has been clarified that there exits efficient configuration of ECR zones for producing multicharged ion beams experimentally, and then has been suggested from detail accessibility conditions on the ECR plasma that new resonance, i.e., upper hybrid resonance, must have occurred.

  19. Study of electron current extraction from a radio frequency plasma cathode designed as a neutralizer for ion source applications

    Energy Technology Data Exchange (ETDEWEB)

    Jahanbakhsh, Sina, E-mail: sinajahanbakhsh@gmail.com; Satir, Mert; Celik, Murat [Department of Mechanical Engineering, Bogazici University, Istanbul 34342 (Turkey)

    2016-02-15

    Plasma cathodes are insert free devices that are developed to be employed as electron sources in electric propulsion and ion source applications as practical alternatives to more commonly used hollow cathodes. Inductively coupled plasma cathodes, or Radio Frequency (RF) plasma cathodes, are introduced in recent years. Because of its compact geometry, and simple and efficient plasma generation, RF plasma source is considered to be suitable for plasma cathode applications. In this study, numerous RF plasma cathodes have been designed and manufactured. Experimental measurements have been conducted to study the effects of geometric and operational parameters. Experimental results of this study show that the plasma generation and electron extraction characteristics of the RF plasma cathode device strongly depend on the geometric parameters such as chamber diameter, chamber length, orifice diameter, orifice length, as well as the operational parameters such as RF power and gas mass flow rate.

  20. Evolution of plasma parameters in a He - N2/Ar magnetic pole enhanced inductive plasma source

    Science.gov (United States)

    Younus, Maria; Rehman, N. U.; Shafiq, M.; Zakaullah, M.; Abrar, M.

    2016-02-01

    A magnetic pole enhanced inductively coupled H e - N2/A r plasma is studied at low pressure, to monitor the effects of helium mixing on plasma parameters like electron number density (ne) , electron temperature (Te) , plasma potential (Vp ) , and electron energy probability functions (EEPFs). An RF compensated Langmuir probe is employed to measure these plasma parameters. It is noted that electron number density increases with increasing RF power and helium concentration in the mixture, while it decreases with increase in filling gas pressure. On the other hand, electron temperature shows an increasing trend with helium concentration in the mixture. At low RF powers and low helium concentration in the mixture, EEPFs show a "bi-Maxwellian" distribution with pressure. While at RF powers greater than 50 W and higher helium concentration in the mixture, EEPFs evolve into "Maxwellian" distribution. The variation of skin depth with RF power and helium concentration in the mixture, and its relation with EEPF are also studied. The effect of helium concentrations on the temperatures of two electron groups ( Tb u l k and Tt a i l ) in the "bi-Maxwellian" EEPFs is also observed. The temperature of low energy electron group ( Tb u l k) shows significant increase with helium addition, while the temperature of tail electrons ( Tt a i l) increases smoothly as compared to ( Tb u l k).

  1. Behavior of moving plasma in solenoidal magnetic field in a laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, S., E-mail: ikeda.s.ae@m.titech.ac.jp [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0108 (Japan); Takahashi, K. [Department of Electrical Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2137 (Japan); Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States); Horioka, K. [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan)

    2016-02-15

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

  2. Behavior of moving plasma in solenoidal magnetic field in a laser ion source

    Science.gov (United States)

    Ikeda, S.; Takahashi, K.; Okamura, M.; Horioka, K.

    2016-02-01

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

  3. High power impulse magnetron sputtering and related discharges: scalable plasma sources for plasma-based ion implantation and deposition

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2009-09-01

    High power impulse magnetron sputtering (HIPIMS) and related self-sputtering techniques are reviewed from a viewpoint of plasma-based ion implantation and deposition (PBII&D). HIPIMS combines the classical, scalable sputtering technology with pulsed power, which is an elegant way of ionizing the sputtered atoms. Related approaches, such as sustained self-sputtering, are also considered. The resulting intense flux of ions to the substrate consists of a mixture of metal and gas ions when using a process gas, or of metal ions only when using `gasless? or pure self-sputtering. In many respects, processing with HIPIMS plasmas is similar to processing with filtered cathodic arc plasmas, though the former is easier to scale to large areas. Both ion implantation and etching (high bias voltage, without deposition) and thin film deposition (low bias, or bias of low duty cycle) have been demonstrated.

  4. Neutral Beam Source and Target Plasma for Development of a Local Electric Field Fluctuation Diagnostic

    Science.gov (United States)

    Bakken, M. R.; Burke, M. G.; Fonck, R. J.; Lewicki, B. T.; Rhodes, A. T.; Winz, G. R.

    2016-10-01

    A new diagnostic measuring local E-> (r , t) fluctuations is being developed for plasma turbulence studies in tokamaks. This is accomplished by measuring fluctuations in the separation of the π components in the Hα motional Stark spectrum. Fluctuations in this separation are expected to be Ẽ / ẼEMSE 10-3EMSE 10-3 . In addition to a high throughput, high speed spectrometer, the project requires a low divergence (Ω 0 .5°) , 80 keV, 2.5 A H0 beam and a target plasma test stand. The beam employs a washer-stack arc ion source to achieve a high species fraction at full energy. Laboratory tests of the ion source demonstrate repeatable plasmas with Te 10 eV and ne 1.6 ×1017 m-3, sufficient for the beam ion optics requirements. Te and ne scalings of the ion source plasma are presented with respect to operational parameters. A novel three-phase resonant converter power supply will provide 6 mA/cm2 of 80 keV H0 at the focal plane for pulse lengths up to 15 ms, with low ripple δV / 80 keV 0.05 % at 280 kHz. Diagnostic development and validation tests will be performed on a magnetized plasma test stand with 0.5 T field. The test chamber will utilize a washer-stack arc source to produce a target plasma comparable to edge tokamak plasmas. A bias-plate with programmable power supply will be used to impose Ẽ within the target plasma. Work supported by US DOE Grant DE-FG02-89ER53296.

  5. Deposition of dielectric films on silicon using a fore-vacuum plasma electron source.

    Science.gov (United States)

    Zolotukhin, D B; Oks, E M; Tyunkov, A V; Yushkov, Yu G

    2016-06-01

    We describe an experiment on the use of a fore-vacuum-pressure, plasma-cathode, electron beam source with current up to 100 mA and beam energy up to 15 keV for deposition of Mg and Al oxide films on Si substrates in an oxygen atmosphere at a pressure of 10 Pa. The metals (Al and Mg) were evaporated and ionized using the electron beam with the formation of a gas-metal beam-plasma. The plasma was deposited on the surface of Si substrates. The elemental composition of the deposited films was analyzed.

  6. Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source

    CERN Document Server

    Asaji, T; Uchida, T; Minezaki, H; Ishihara, S; Racz, R; Muramatsu, M; Biri, S; Kitagawa, A; Kato, Y; Yoshida, Y

    2015-01-01

    A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.

  7. Tungsten transport and sources control in JET ITER-like wall H-mode plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fedorczak, N., E-mail: nicolas.fedorczak@cea.fr [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Monier-Garbet, P. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Pütterich, T. [MPI für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Brezinsek, S. [Institute of Energy and Climate Research, Forschungszentrum Jlich, Assoc EURATOM-FZJ, Jlich (Germany); Devynck, P.; Dumont, R.; Goniche, M.; Joffrin, E. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Lerche, E. [Association EURATOM-Belgian State, LPP-ERM-KMS, TEC partner, Brussels (Belgium); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Lipschultz, B. [York Plasma Institute, University of York, Heslington, York YO10 5DD (United Kingdom); Luna, E. de la [Laboratorio Nacional de Fusin, Asociacin EURATOM/CIEMAT, 28040 Madrid (Spain); Maddison, G. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Maggi, C. [MPI für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Matthews, G. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Nunes, I. [Istituto de plasmas e fusao nuclear, Lisboa (Portugal); Rimini, F. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Solano, E.R. [Laboratorio Nacional de Fusin, Asociacin EURATOM/CIEMAT, 28040 Madrid (Spain); Tamain, P. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Tsalas, M. [Association EURATOM-Hellenic Republic, NCSR Demokritos 153 10, Attica (Greece); Vries, P. de [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-08-15

    A set of discharges performed with the JET ITER-like wall is investigated with respect to control capabilities on tungsten sources and transport. In attached divertor regimes, increasing fueling by gas puff results in higher divertor recycling ion flux, lower divertor tungsten source, higher ELM frequency and lower core plasma radiation, dominated by tungsten ions. Both pedestal flushing by ELMs and divertor screening (including redeposition) are possibly responsible. For specific scenarios, kicks in plasma vertical position can be employed to increase the ELM frequency, which results in slightly lower core radiation. The application of ion cyclotron radio frequency heating at the very center of the plasma is efficient to increase the core electron temperature gradient and flatten electron density profile, resulting in a significantly lower central tungsten peaking. Beryllium evaporation in the main chamber did not reduce the local divertor tungsten source whereas core radiation was reduced by approximately 50%.

  8. Hard X-ray sources from miniature plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Raspa, V. [Buenos Aires Univ., PLADEMA, CONICET and INFIP (Argentina); Silva, P.; Moreno, J.; Zambra, M.; Soto, L. [Comision Chilena de Energia Nuclear, Santiago (Chile)

    2004-07-01

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, {approx} 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, {approx} 300 ns time to peak current). Hard X-rays are being studied in these devices operating with hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400 J. An effective energy of the order of 90 keV was measured under those conditions. X ray images of different metallic objects also have been obtained. (authors)

  9. Non-thermal atmospheric pressure HF plasma source: generation of nitric oxide and ozone for bio-medical applications

    Science.gov (United States)

    Kühn, S.; Bibinov, N.; Gesche, R.; Awakowicz, P.

    2010-01-01

    A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical NO-detector at variable gas flows. Correlations between plasma parameters and concentrations of the particles in the effluent of the plasma source are discussed. By varying the gas flows, the HF plasma source can be optimized for nitric oxide or ozone production. Maximum concentrations of 2750 ppm and 400 ppm of NO and O3, correspondingly, are generated.

  10. Development of plasma sources for ICRF heating experiment in KMAX mirror device

    Science.gov (United States)

    Sun, Xuan; Liu, Ming; Yi, Hongshen; Lin, Munan; Shi, Peiyun

    2016-10-01

    KMAX, Keda Mirror with AXisymmeticity, is a tandem mirror machine with a length of 10 meters and diameters of 1.2 meters in the central cell and 0.3 meters in the mirror throat. In the past experiments, the plasma was generated by helicon wave launched from the west end. We obtained the blue core mode in argon discharge, however, it cannot provide sufficient plasma for hydrogen discharge, which is at least 1012 cm-3 required for effective ICRF heating. Several attempts have thus been tried or under design to increase the central cell's plasma density: (1) a washer gun with aperture of 1cm has been successfully tested, and a plasma density of 1013 cm-3 was achieved in the west cell near the gun, however, the plasma is only 1011 cm-3 in the central cell possible due to the mirror trapping and/or neutral quenching effect (2) a larger washer gun with aperture of 2.5 cm and a higher power capacitor bank are being assembled in order to generate more plasmas. In addition, how to mitigate the neutrals is under consideration (3) A hot cathode is been designed and will be tested in combination with plasma gun or alone. Preliminary results from those plasma sources will be presented and discussed.

  11. Protection Planning for Rural Centralized Drinking Water Source Areas in Chongqing

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Protection planning is made for rural centralized drinking water source areas according to current situations of rural drinking water and existing problems of centralized drinking water source areas in Chongqing,and in combination with survey,analysis and evaluation of urban-rural drinking water source areas in whole city.There are engineering measures and non-engineering measures,to guarantee drinking water security of rural residents,improve rural ecological environment,realize sustainable use of water resource,and promote sustainable development of society.Engineering measures include conservation and protection of water resource,ecological restoration,isolation,and comprehensive control of pointsource and area-source pollution.Non-engineering measures include construction of monitoring system for drinking water source area,construction of security information system for rural centralized drinking water source area,and construction of emergency mechanism for water pollution accidents in rural water source areas.

  12. Plasma diagnosis as a tool for the determination of the parameters of electron beam evaporation and sources of ionization

    Science.gov (United States)

    Mukherjee, Jaya; Dileep Kumar, V.; Yadav, S. P.; Barnwal, Tripti A.; Dikshit, Biswaranjan

    2016-07-01

    The atomic vapor generated by electron beam heating is partially ionized due to atom-atom collisions (Saha ionization) and electron impact ionization, which depend upon the source temperature and area of evaporation as compared to the area of electron beam bombardment on the target. When electron beam evaporation is carried out by inserting the target inside an insulating liner to reduce conductive heat loss, it is expected that the area of evaporation becomes significantly more than the area of electron beam bombardment on the target, resulting in reduced electron impact ionization. To assess this effect and to quantify the parameters of evaporation, such as temperature and area of evaporation, we have carried out experiments using zirconium, tin and aluminum as a target. By measuring the ion content using a Langmuir probe, in addition to measuring the atomic vapor flux at a specific height, and by combining the experimental data with theoretical expressions, we have established a method for simultaneously inferring the source temperature, evaporation area and ion fraction. This assumes significance because the temperature cannot be reliably measured by an optical pyrometer due to the wavelength dependent source emissivity and reflectivity of thin film mirrors. In addition, it also cannot be inferred from only the atomic flux data at a certain height as the area of evaporation is unknown (it can be much more than the area of electron bombardment, especially when the target is placed in a liner). Finally, the reason for the lower observed electron temperatures of the plasma for all the three cases is found to be the energy loss due to electron impact excitation of the atomic vapor during its expansion from the source.

  13. Atomic processes and equation of state of high Z plasmas for EUV sources and their effects on the spatial and temporal evolution of the plasmas

    Science.gov (United States)

    Sasaki, Akira; Sunahara, Atushi; Furukawa, Hiroyuki; Nishihara, Katsunobu; Nishikawa, Takeshi; Koike, Fumihiro

    2016-03-01

    Laser-produced plasma (LPP) extreme ultraviolet (EUV) light sources have been intensively investigated due to potential application to next-generation semiconductor technology. Current studies focus on the atomic processes and hydrodynamics of plasmas to develop shorter wavelength sources at λ = 6.x nm as well as to improve the conversion efficiency (CE) of λ = 13.5 nm sources. This paper examines the atomic processes of mid-z elements, which are potential candidates for λ = 6.x nm source using n=3-3 transitions. Furthermore, a method to calculate the hydrodynamics of the plasmas in terms of the initial interaction between a relatively weak prepulse laser is presented.

  14. Studies of extreme ultraviolet emission from laser produced plasmas, as sources for next generation lithography

    Science.gov (United States)

    Cummins, Thomas

    The work presented in this thesis is primarily concerned with the optimisation of extreme ultraviolet (EUV) photoemission around 13.5 nm, from laser produced tin (Sn) plasmas. EUV lithography has been identified as the leading next generation technology to take over from the current optical lithography systems, due to its potential of printing smaller feature sizes on integrated circuits. Many of the problems hindering the implementation of EUV lithography for high volume manufacturing have been overcome during the past 20 years of development. However, the lack of source power is a major concern for realising EUV lithography and remains a major roadblock that must be overcome. Therefore in order to optimise and improve the EUV emission from Sn laser plasma sources, many parameters contributing to the make-up of an EUV source are investigated. Chapter 3 presents the results of varying several different experimental parameters on the EUV emission from Sn laser plasmas. Several of the laser parameters including the energy, gas mixture, focusing lens position and angle of incidence are changed, while their effect on the EUV emission is studied. Double laser pulse experiments are also carried out by creating plasma targets for the main laser pulse to interact with. The resulting emission is compared to that of a single laser pulse on solid Sn. Chapter 4 investigates tailoring the CO2 laser pulse duration to improve the efficiency of an EUV source set-up. In doing so a new technique for shortening the time duration of the pulse is described. The direct effects of shortening the CO2 laser pulse duration on the EUV emission from Sn are then studied and shown to improve the efficiency of the source. In Chapter 5 a new plasma target type is studied and compared to the previous dual laser experiments. Laser produced colliding plasma jet targets form a new plasma layer, with densities that can be optimised for re-heating with the main CO2 laser pulse. Chapter 6 will present

  15. Enhancement of H{sup -}/D{sup -} volume production in a double plasma type negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Fukumasa, Osamu; Nishimura, Hideki; Sakiyama, Satoshi [Yamaguchi Univ., Ube (Japan). Faculty of Engineering

    1997-02-01

    H{sup -}/D{sup -} production in a pure volume source has been studied. In our double plasma type negative ion source, both energy and density of fast electrons are well controlled. With the use of this source, the enhancement of H{sup -}/D{sup -} production has been observed. Namely, under the same discharge power, the extracted H{sup -}/D{sup -} current in the double plasma operation is higher than that in the single plasma operation. At the same time, measurements of plasma parameters have been made in the source and the extractor regions for these two cases. (author)

  16. [Spatiotemporal variation of water source supply service in Three Rivers Source Area of China based on InVEST model].

    Science.gov (United States)

    Pan, Tao; Wu, Shao-Hong; Dai, Er-Fu; Liu, Yu-Jie

    2013-01-01

    The Three Rivers Source Area is the largest ecological function region of water source supply and conservation in China. As affected by a variety of driving factors, the ecosystems in this region are seriously degraded, giving definite impacts on the water source supply service. This paper approached the variation patterns of precipitation and runoff coefficient from 1981 to 2010, quantitatively estimated the water source supply of the ecosystems in the region from 1980 to 2005 based on InVEST model, and analyzed the spatiotemporal variation pattern and its causes of the water source supply in different periods. In 1981-2010, the precipitation in the Three Rivers Source Area had a trend of increase after an initial decrease, while the precipitation runoff coefficient presented an obvious decreasing trend, suggesting a reduced capability of runoff water source supply of this region. The potential evapotranspiration had a declining trend, but not obvious, with a rate of -0.226 mm x a(-1). In 1980-2005, the water source supply of the region represented an overall decreasing trend, which was most obvious in the Yellow River Source Area. The spatiotemporal variation of the water source supply in the Three Rivers Source Area was the results of the combined effects of climate and land use change, and the climate factors affected the water source supply mainly through affecting the precipitation and potential evapotranspiration. Climate and land use change induced the ecosystem degradation and underlying surface change, which could be the main driving forces of the declined water source supply in the Three Rivers Source Area.

  17. Narrow bandwidth Thomson photon source development using Laser-Plasma Accelerators

    Science.gov (United States)

    Geddes, C. G. R.; van Tilborg, J.; Tsai, H.-E.; Toth, Cs.; Vay, J.-L.; Lehe, R.; Schroeder, C. B.; Esarey, E.; Rykovanov, S. G.; Grote, D. P.; Friedman, A.; Leemans, W. P.

    2016-10-01

    Compact, high-quality photon sources at MeV energies are being developed based on Laser-Plasma Accelerators (LPAs). An independent scattering laser with controlled pulse shaping in frequency and amplitude can be used together with laser guiding to realize high photon yield and narrow bandwidth. Simulations are presented on production of controllable narrow bandwidth sources using the beam and plasma capabilities of LPAs. Recent experiments and simulations demonstrate controllable LPAs in the energy range appropriate to MeV Thomson sources. Design of experiments and laser capabilities to combine these elements will be presented, towards a compact photon source system. A dedicated facility under construction will be described. Work supported by US DOE NNSA DNN R&D and by Sc. HEP under contract DE-AC02-05CH11231.

  18. Lifetime Calculations on Collector Optics from Laser Plasma Extreme Ultraviolet Sources with Minimum Mass

    Institute of Scientific and Technical Information of China (English)

    WU Tao; WANG Xin-Bing

    2011-01-01

    An ion flux and its kinetic energy spectrum are obtained using a self similar spherically symmetric fluid model of expansion of a collisionless plasma into vacuum. According to the ion flux and energy distribution, the collector optical lifetime is estimated by knowledge of the sputtering yield of conventional Mo/Si multilayer coatings for the CO2 and Nd:YAG pulsed-laser produced plasmas based on the minimum mass tin droplet target without debris mitigation. The results show that the longer wavelength of the CO2 laser produced plasma light source is more suitable for extreme ultraviolet lithography than Nd:YAG laser in respect of fast ion debris induced sputtering damage to the collector mirror.%@@ An ion flux and its kinetic energy spectrum are obtained using a self similar spherically symmetric fluid model of expansion of a collisionless plasma into vacuum.According to the ion flux and energy distribution,the collector optical lifetime is estimated by knowledge of the sputtering yield of conventional Mo/Si multilayer coatings for the CO2 and Nd:YAG pulsed-laser produced plasmas based on the minimum mass tin droplet target without debris mitigation.The results show that the longer wavelength of the CO2 laser produced plasma light source is more suitable for extreme ultraviolet lithography than Nd:YAG laser in respect of fast ion debris induced sputtering damage to the collector mirror.

  19. Atomic Layer Deposition Al2O3 Thin Films in Magnetized Radio Frequency Plasma Source

    Science.gov (United States)

    Li, Xingcun; Chen, Qiang; Sang, Lijun; Yang, Lizhen; Liu, Zhongwei; Wang, Zhenduo

    Self-limiting deposition of aluminum oxide (Al2O3) thin films were accomplished by the plasma-enhanced chemical vapor deposition using trimethyl aluminum (TMA) and O2 as precursor and oxidant, respectively, where argon was kept flowing in whole deposition process as discharge and purge gas. In here we present a novel plasma source for the atomic layer deposition technology, magnetized radio frequency (RF) plasma. Difference from the commercial RF source, magnetic coils were amounted above the RF electrode, and the influence of the magnetic field strength on the deposition rate and morphology are investigated in detail. It concludes that a more than 3 Å/ purging cycle deposition rate and the good quality of ALD Al2O3 were achieved in this plasma source even without extra heating. The ultra-thin films were characterized by including Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectric spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The high deposition rates obtained at ambient temperatures were analyzed after in-situ the diagnostic of plasmas by Langmuir probe.

  20. A Mirror-like ECR Plasma Source for Ionosphere Environment Simulator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A compact mirror-like ECR (electron cyclotron resonance) plasma source for the ionosphere environment simulator was described for the first time in China. The overall sources system was composed of a 200 W 2.45 GHz microwave source, a coaxial 3λo/4 TEM-mode microwave resonance applicator, column and cylindrical Nd-Fe-P magnets, a quartz bell-shaped discharge chamber, a gas inlet system and a plasma-diffusing bore. The preliminary experiment demonstrated that ambi-polar diffusion plasma stream into the simulator (~500 mm long) formed an environment with following parameters: a plasma density ne of 104 cm-3 ~ 106cm-3, an electron temperature Te < 5 eV at a pressure P of 10-1 Pa~10-3 Pa, a plasma uniformity of > 80% over the experimental target with a 160-mm-in-diameter, satisfying primarily the requirement of simulating in a severe ionosphere environment.

  1. Microwave frequency sweep interferometer for plasma density measurements in ECR ion sources: Design and preliminary results

    Science.gov (United States)

    Torrisi, Giuseppe; Mascali, David; Neri, Lorenzo; Leonardi, Ornella; Sorbello, Gino; Celona, Luigi; Castro, Giuseppe; Agnello, Riccardo; Caruso, Antonio; Passarello, Santi; Longhitano, Alberto; Isernia, Tommaso; Gammino, Santo

    2016-02-01

    The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 1011-1013 cm-3 and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called "frequency sweep" method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

  2. Microwave frequency sweep interferometer for plasma density measurements in ECR ion sources: Design and preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, Giuseppe [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University Mediterranea of Reggio Calabria, Reggio Calabria (Italy); Mascali, David; Neri, Lorenzo; Leonardi, Ornella; Celona, Luigi; Castro, Giuseppe; Agnello, Riccardo; Caruso, Antonio; Passarello, Santi; Longhitano, Alberto; Gammino, Santo [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Sorbello, Gino [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University of Catania, Catania, Italy and INFN-LNS, Catania (Italy); Isernia, Tommaso [University Mediterranea of Reggio Calabria, Reggio Calabria (Italy)

    2016-02-15

    The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 10{sup 11}–10{sup 13} cm{sup −3} and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called “frequency sweep” method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

  3. Porcelain-coated antenna for radio-frequency driven plasma source

    Science.gov (United States)

    Leung, Ka-Ngo; Wells, Russell P.; Craven, Glen E.

    1996-01-01

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ion because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile.

  4. Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source

    CERN Document Server

    Pothiraja, Ramasamy; Awakowicz, Peter

    2011-01-01

    Uniform amorphous carbon film is deposited on the inner surface of quartz tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed filamentary plasma source is used for the deposition. Long plasma filaments (~ 140 mm) as a positive discharge are generated inside the tube in argon with methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion that deposited film is amorphous composed of non-hydrogenated sp2 carbon and hydrogenated sp3 carbon. Plasma is characterized using optical emission spectroscopy, voltage-current measurement, microphotography and numerical simulation. On the basis of observed plasma parameters, the kinetics of the film deposition process is discussed.

  5. A Simulator for Producing of High Flux Atomic Oxygen Beam by Using ECR Plasma Source

    Institute of Scientific and Technical Information of China (English)

    Shuwang DUO; Meishuan LI; Yaming ZHANG

    2004-01-01

    In order to study the atomic oxygen corrosion of spacecraft materials in low earth orbit environment, an atomic oxygen simulator was established. In the simulator, a 2.45 GHz microwave source with maximum power of 600 W was launched into the circular cavity to generate ECR (electron cyclotron resonance) plasma. The oxygen ion beam moved onto a negatively biased Mo plate under the condition of symmetry magnetic mirror field confine, then was neutralized and reflected to form oxygen atom beam. The properties of plasma density, electron temperature, plasma space potential and ion incident energy were characterized. The atomic oxygen beam flux was calibrated by measuring the mass loss rate of Kapton during the atomic 5~30 eV and a cross section of φ80 mm could be obtained under the operating pressure of 10-1~10-3 Pa. Such a high flux source can provide accelerated simulation tests of materials and coatings for space applications.

  6. Laser-plasma electron accelerator for all-optical inverse Compton X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, K. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)], E-mail: koyama@nuclear.jp; Yamazaki, A.; Maekawa, A.; Uesaka, M. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan); Hosokai, T. [Tokyo Institute of Technology, 4259 Nagatsuda-cho, Midori-ku, Yokohama 226-8503 (Japan); Miyashita, M. [Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Masuda, S.; Miura, E. [AIST, Tsukuba-central-2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2009-09-01

    Inverse Compton scattering has been gaining attention as a process for the generation of X/{gamma}-ray, since it produces tunable X/{gamma}-ray pulses with a small cone angle of radiation. A table-top tunable Compton X/{gamma}-ray source would be realized by replacing a radio frequency (rf) linac with a laser wakefield accelerator (LWFA), which is one of the advanced accelerators. An empirical scaling law for the LWFA in the self-injection mode showed that the energy gain was inversely proportional to the plasma density. In order to effectively employ the LWFA as a Compton X/{gamma}-ray source, its stability must be improved. For this purpose, we are developing techniques for the injection of initial electrons by a localized wavebreaking at the density ramp of a plasma. The pointing stability and acceleration efficiency of the electron beam were significantly improved by applying an axial magnetic field to the plasma channel.

  7. [Experimental investigation of laser plasma soft X-ray source with gas target].

    Science.gov (United States)

    Ni, Qi-liang; Gong, Yan; Lin, Jing-quan; Chen, Bo; Cao, Jian-lin

    2003-02-01

    This paper describes a debris-free laser plasma soft X-ray source with a gas target, which has high operating frequency and can produce strong soft X-ray radiation. The valve of this light source is drived by a piezoelectrical ceramic whose operating frequency is up to 400 Hz. In comparison with laser plasma soft X-ray sources using metal target, the light source is debris-free. And it has higher operating frequency than gas target soft X-ray sources whose nozzle is controlled by a solenoid valve. A channel electron multiplier (CEM) operating in analog mode is used to detect the soft X-ray generated by the laser plasma source, and the CEM's output is fed to to a charge-sensitive preamplifier for further amplification purpose. Output charges from the CEM are proportional to the amplitude of the preamplifier's output voltage. Spectra of CO2, Xe and Kr at 8-14 nm wavelength which can be used for soft X-ray projection lithography are measured. The spectrum for CO2 consists of separate spectral lines originate mainly from the transitions in Li-like and Be-like ions. The Xe spectrum originating mainly from 4d-5f, 4d-4f, 4d-6p and 4d-5p transitions in multiply charged xenon ions. The spectrum for Kr consists of separate spectral lines and continuous broad spectra originating mainly from the transitions in Cu-, Ni-, Co- and Fe-like ions.

  8. Evolution of plasma parameters in an Ar-N2/He inductive plasma source with magnetic pole enhancement

    Science.gov (United States)

    Maria, Younus; N, U. Rehman; M, Shafiq; M, Naeem; M, Zaka-Ul-Islam; M, Zakaullah

    2017-02-01

    Magnetic pole enhanced inductively coupled plasmas (MaPE-ICPs) are a promising source for plasma-based etching and have a wide range of material processing applications. In the present study Langmuir probe and optical emission spectroscopy were used to monitor the evolution of plasma parameters in a MaPE-ICP Ar-N2/He mixture plasma. Electron density ({n}{{e}}) and temperature ({T}{{e}}), excitation temperature ({T}{{exc}}), plasma potential ({V}{{p}}), skin depth (δ ) and the evolution of the electron energy probability function (EEPF) are reported as a function of radiofrequency (RF) power, pressure and argon concentration in the mixture. It is observed that {n}{{e}} increases while {T}{{e}} decreases with increase in RF power and argon concentration in the mixture. The emission intensity of the argon line at 750.4 nm is also used to monitor the variation of the ‘high-energy tail’ of the EEPF with RF power and gas pressure. The EEPF has a ‘bi-Maxwellian’ distribution at low RF powers and higher pressure in a pure {{{N}}}2 discharge. However, it evolves into a ‘Maxwellian’ distribution at RF powers greater than 70 W for pure {{{N}}}2, and at 50 W for higher argon concentrations in the mixture. The effect of argon concentration on the temperatures of two electron groups in the ‘bi-Maxwellian’ EEPF is examined. The temperature of the low-energy electron group {T}{{L}} shows a decreasing trend with argon addition until the ‘thermalization’ of the two temperatures occurs, while the temperature of high-energy electrons {T}{{H}} decreases continuously.

  9. Finite element analysis of keyhole plasma arc welding based on an adaptive heat source mode

    Institute of Scientific and Technical Information of China (English)

    Hu Qingxian; Wu Chuansong; Zhang Yuming

    2007-01-01

    An adaptive heat source mode is proposed to account for the keyhole effect and the characteristics of volumetric distribution along the direction of the workpiece thickness. Finite element analysis of the temperature field in keyhole plasma arc welding is conducted and the weld geometry is obtained. The predicted results are in agreement with the measured ones.

  10. Study of the general plasma characteristics of a high power multifilament ion source

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberg, K.F.

    1979-09-01

    A general assessment of the steady state and time dependent plasma properties which characterize a high power multifilament ion source is presented. Steady state measurements, obtained via a pulsed electrostatic probe data acquisition system, are described. Fluctuation measurements, obtained via a broadband digital spectral analysis system, are also given.

  11. Laser-Plasma Sources for Soft-X-Ray Projection Lithography

    NARCIS (Netherlands)

    F. Bijkerk,; Shmaenok, L.; Vanhonk, A.; Bastiaensen, R.; Platonov, Y. Y.; Shevelko, A. P.; Mitrofanov, A. V.; Voss, F.; Desor, R.; Frowein, H.; Nikolaus, B.

    1994-01-01

    Results are reported concerning high-repetition-rate excimer lasers with average powers up to 415 W and their usage for generating laser-plasma soft X-ray sources. A conversion efficiency of laser light into monochromatized soft X-ray radiation of 0.7% at 13.5 nm (2% bandwidth) was achieved using an

  12. Detailed beam and plasma measurements on the vessel for extraction and source plasma analyses (VESPA) Penning H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lawrie, S. R., E-mail: scott.lawrie@stfc.ac.uk [STFC ISIS Pulsed Spallation Neutron and Muon Facility, Rutherford Appleton Laboratory, Harwell, Oxford (United Kingdom); John Adams Institute of Accelerator Science, University of Oxford, Oxford (United Kingdom); Faircloth, D. C.; Letchford, A. P.; Whitehead, M. O.; Wood, T. [STFC ISIS Pulsed Spallation Neutron and Muon Facility, Rutherford Appleton Laboratory, Harwell, Oxford (United Kingdom)

    2016-02-15

    A vessel for extraction and source plasma analyses (VESPA) is operational at the Rutherford Appleton Laboratory (RAL). This project supports and guides the overall ion source R&D effort for the ISIS spallation neutron and muon facility at RAL. The VESPA produces 100 mA of pulsed H{sup −} beam, but perveance scans indicate that the source is production-limited at extraction voltages above 12 kV unless the arc current is increased. A high resolution optical monochromator is used to measure plasma properties using argon as a diagnostic gas. The atomic hydrogen temperature increases linearly with arc current, up to 2.8 eV for 50 A; whereas the electron temperature has a slight linear decrease toward 2.2 eV. The gas density is 10{sup 21} m{sup −3}, whilst the electron density is two orders of magnitude lower. Densities follow square root relationships with arc current, with gas density decreasing whilst electron (and hence ion) density increases. Stopping and range of ions in matter calculations prove that operating a high current arc with an argon admixture is extremely difficult because cathode-coated cesium is heavily sputtered by argon.

  13. An experimental study of starting plumes over area sources

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M.J.; Haertel, C.; Fannelop, T.K. [Swiss Federal Institute of Technology, Zuerich (Switzerland). Inst. of Fluid Dynamics

    1999-12-01

    Experiments have been performed to study the dynamics of plumes which develop, if buoyant fluid enters a homogeneous, unstratified environment through a source of finite width. The experiments were conducted in a cubic tank of salt water with 0.8 m side length into which dyes fresh water was released at a constant volume-flow rate through a circular felt at the bottom. The governing non-dimensional parameter of the flow, namely the ratio of inflow velocity to buoyancy velocity, was varied over more than two orders of magnitude in the experiments. The flow is shown to pass through two distinct phases, and a new integral model is presented which describes the flow in the early stage. For later times and at larger distances from the source, the flow is found to be well described by Turner's model for starting plumes from point sources.

  14. Prepulse-induced shock waves in the gas jet target of a laser plasma EUV radiation source

    Science.gov (United States)

    Garbaruk, A. V.; Gritskevich, M. S.; Kalmykov, S. G.; Mozharov, A. M.; Sasin, M. E.

    2017-01-01

    In experiments with a laser-plasma EUV-radiation source, the main IR Nd:YAG laser pulse was preceded by that of a UV KrF excimer laser. Dramatic modulations of EUV plasma emissivity have been observed at long interpulse times, from hundreds of nanoseconds up to microseconds. To discover the nature of these prepulse-produced long-living perturbations of the target, a fluid dynamics numerical simulation of the Xe gas jet has been carried out. The prepulse has been found to generate a quasi-spherical shock wave with a thin dense front layer and a vast rarefied inside area. In the course of time, the front expands and simultaneously drifts downstream along with the gas. Depending on the interpulse time, the IR laser beam either intersects the dense layer or propagates within the rarefied gas cavity whereby the above-mentioned variations in the plasma emission can be explained. The possibilities of making use of the discovered phenomena to enhance the observed EUV plasma brightness are discussed.

  15. Study of Preparation of Large Area Standard Source

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With increasingly widespread application of nuclear technology, many large area contamination detectors are used to measure the contaminated surface by α, β radionuclides in nuclear facilities and isotope production places. To solve the

  16. Plasma source by microwaves: design description; Fuente de plasma por microondas: descripcion de diseno

    Energy Technology Data Exchange (ETDEWEB)

    Camps, E.; Olea, O.; Andrade, R.; Anguiano, G

    1992-03-15

    The design of a device for the formation of a plasma with densities of the order of 10{sup 12} cm{sup -} {sup 3} and low temperatures (T{sub e} {approx} 40 eV) is described. For such purpose it was carried out in the device a microwave discharge (f{sub o} = 2.45 GHz) in a resonator of high Q factor, immersed in a static external magnetic field. The device worked in the regime {omega}{sub ce} {<=} {omega}{sub o}/2 ({omega}{sub ce}- cyclotron frequency of the electrons, ({omega}{sub o} = 2 {pi} f{sub o}) where is possible the excitement of non lineal phenomena of waves transformation. (Author)

  17. Measurements and modeling of the impact of weak magnetic fields on the plasma properties of a planar slot antenna driven plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Jun, E-mail: jun.yoshikawa@tel.com; Susa, Yoshio; Ventzek, Peter L. G. [Tokyo Electron Ltd., Akasaka Biz Tower, 3-1 Akasaka 5-chome, Minato-ku, Tokyo 107-6325 (Japan)

    2015-05-15

    The radial line slot antenna plasma source is a type of surface wave plasma source driven by a planar slot antenna. Microwave power is transmitted through a slot antenna structure and dielectric window to a plasma characterized by a generation zone adjacent to the window and a diffusion zone that contacts a substrate. The diffusion zone is characterized by a very low electron temperature. This renders the source useful for soft etch applications and thin film deposition processes requiring low ion energy. Another property of the diffusion zone is that the plasma density tends to decrease from the axis to the walls under the action of ambipolar diffusion at distances far from where the plasma is generated. A previous simulation study [Yoshikawa and. Ventzek, J. Vac. Sci. Technol. A 31, 031306 (2013)] predicted that the anisotropy in transport parameters due to weak static magnetic fields less than 50 G could be leveraged to manipulate the plasma profile in the radial direction. These simulations motivated experimental tests in which weak magnetic fields were applied to a radial line slot antenna source. Plasma absorption probe measurements of electron density and etch rate showed that the magnetic fields remote from the wafer were able to manipulate both parameters. A summary of these results is presented in this paper. Argon plasma simulation trends are compared with experimental plasma and etch rate measurements. A test of the impact of magnetic fields on charge up damage showed no perceptible negative effect.

  18. Agave Lechuguilla as a Potential Biomass Source in Arid Areas

    Directory of Open Access Journals (Sweden)

    Ahmad Houri

    2016-03-01

    Full Text Available Biomass productivity presents a challenging problem in arid and semi-arid areas.  Despite a large need for energy in the form of solid biomass, liquid fuel or needs for animal feed, these regions remain largely unproductive.  A convenient way to overcome this challenge is to utilize plants with high water-use efficiency.  Agave lechuguilla is an example of a highly productive (3.8 tons ha-1 yr-1 desert plant that holds the potential for producing biomass with minimal water resources.  For this purpose, a global suitability map has been developed showing areas where this plant can be planted, and its productivity was assessed.  A Maxent model was used and was further refined by excluding protected areas and used lands (urban, agriculture, etc...  Productivity assessment provides a good way forward for prioritizing the regional utilization of this plant.   This study provides an initial analysis for the use of arid and semi-arid regions for biomass production.  Results indicate the potential generation of 93.8 million tons per year of dry biomass if the suitable areas were fully utilized.  The analytical method can be readily applied to other potential plant species to optimize the use of certain areas.

  19. Biological stimulation of the Human skin applying health promoting light and plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Awakowicz, P.; Bibinov, N. [Center for Plasma Science and Technology, Ruhr-University, Bochum (Germany); Born, M.; Niemann, U. [Philips Research, Aachen (Germany); Busse, B. [Zell-Kontakt GmbH, Noerten-Hardenberg (Germany); Gesche, R.; Kuehn, S.; Porteanu, H.E. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Berlin (Germany); Helmke, A. [University of Applied Sciences and Arts, Goettingen (Germany); Kaemling, A.; Wandke, D. [CINOGY GmbH, Duderstadt (Germany); Kolb-Bachofen, V.; Liebmann, J. [Institute for Immunobiology, Heinrich-Heine University, Duesseldorf (Germany); Kovacs, R.; Mertens, N.; Scherer, J. [Aurion Anlagentechnik GmbH, Seligenstadt (Germany); Oplaender, C.; Suschek, C. [Clinic for Plastic Surgery, University Clinic, Aachen (Germany); Vioel, W. [Laser-Laboratorium, Goettingen (Germany); University of Applied Sciences and Arts, Goettingen (Germany)

    2009-10-15

    In the frame of BMBF project ''BioLiP'', new physical treatment techniques aiming at medical treatment of the human skin have been developed. The acronym BioLiP stands for ''Desinfektion, Entkeimung und biologische Stimulation der Haut durch gesundheitsfoerdernde Licht- und Plasmaquellen'' (Disinfection, germ reduction and biological stimulation of the human skin by health promoting light and plasma sources). A source applying a low-temperature dielectric barrier discharge plasma (DBD) has been investigated on its effectiveness for skin disinfection and stimulation of biological material. Alternatively an atmospheric plasma source consisting of a microwave resonator combined with a solid state power oscillator has been examined. This concept which allows for a compact and efficient design avoiding external microwave power supply and matching units has been optimized with respect to nitrogen monoxide (NO) production in high yields. In both cases various application possibilities in the medical and biological domain are opened up. Light sources in the visible spectral range have been investigated with respect to the proliferation of human cell types. Intensive highly selective blue light sources based on LED technology can slow down proliferation rates without inducing toxic effects which offers new opportunities for treatments of so-called hyperproliferative skin conditions (e.g. with psoriasis or in wound healing) using UV-free light. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Three-Dimensional Numerical Simulation of Surface-Wave Plasma Source

    Institute of Scientific and Technical Information of China (English)

    LAN Chaohui; CHEN Zhaoquan; LIU Minghai; JIANG Zhonghe; HU Xiwei

    2009-01-01

    A three-dimensional model of a surface-wave plasma(SWP)source is built numerically using the finite-difference time-domain(FDTD)method to investigate the structure of the surface wave propagation along the plasma-dielectric interface and the distributions of electromagnetic fields in the whole system.A good-performance excitation source technique for the waveguide which is pivotal to the simulation is presented.The technique can avoid the dc distortions of magnetic fields caused by the forcing electric wall.An example of simulation is given to confirm the existence of the surface waves.The simulation also shows that the code developed is a useful tool in the computer-aided design of the antenna of the SWP source.

  1. A compact tunable polarized X-ray source based on laser-plasma helical undulators

    CERN Document Server

    Luo, Ji; Zeng, Ming; Vieira, Jorge; Yu, Lu-Le; Weng, Su-Ming; Silva, Luis O; Jaroszynski, Dino A; Sheng, Zheng-Ming; Zhang, Jie

    2016-01-01

    Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because their accelerating gradients are three orders of magnitude larger than traditional accelerators. However, X-ray radiation from such devices still lacks of tunability, especially the intensity and polarization distribution. Here we propose a tunable polarized radiation source from a helical plasma undulator based on plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of $2\\times10^{19} photons/s/mm^{2}/mrad^{2}/0.1%$ bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with the ...

  2. Plasma Outages in Pulsed, High-Power RF Hydrogen Ion Sources

    Science.gov (United States)

    Stockli, Martin; Han, Baoxi; Murray, Syd; Pennisi, Terry; Piller, Chip; Santana, Manuel; Welton, Robert

    2011-04-01

    Pulsed, high-power RF ion sources are needed to produce copious amounts of negative H-ions for high-power accelerators with charge-changing injection schemes. When increasing the RF power, the plasma inductance changes the RF resonance, which drifts away from the low-power resonance. When the RF circuit is tuned to maximize the (pulsed) plasma power, the (off-resonance) power at the beginning of the pulse is reduced. If the induced electric fields fall below the breakdown strength of the hydrogen gas, the plasma fails to develop. This can be avoided with a compromise tune and/or by increasing the inductance of the resonant circuit. However, the breakdown strength of the hydrogen gas increases with time due to the gradual decrease of the electron-rich plasma impurities, which causes plasma outages after weeks of reliable operation. In this paper we discuss the success of different mitigations that were tested and implemented to overcome this fundamental problem of pulsed, high-power RF hydrogen ion sources.

  3. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser ...Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser -plasma,mass-limited, fast electrons, sheath...field Abstract Reduced surface area targets were studied using an ultra-high intensity femtosecond laser in order to determine the effect of electron

  4. L-shell spectroscopic diagnostics of radiation from krypton HED plasma sources

    Science.gov (United States)

    Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Rawat, R. S.; Tan, K. S.; Beiersdorfer, P.; Hell, N.; Brown, G. V.

    2016-11-01

    X-ray spectroscopy is a useful tool for diagnosing plasma sources due to its non-invasive nature. One such source is the dense plasma focus (DPF). Recent interest has developed to demonstrate its potential application as a soft x-ray source. We present the first spectroscopic studies of krypton high energy density plasmas produced on a 3 kJ DPF device in Singapore. In order to diagnose spectral features, and to obtain a more comprehensive understanding of plasma parameters, a new non-local thermodynamic equilibrium L-shell kinetic model for krypton was developed. It has the capability of incorporating hot electrons, with different electron distribution functions, in order to examine the effects that they have on emission spectra. To further substantiate the validity of this model, it is also benchmarked with data gathered from experiments on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory, where data were collected using the high resolution EBIT calorimeter spectrometer.

  5. An Optical Streak Diagnostic for Observing Anode-Cathode Plasmas for Radiographic Source Development

    Energy Technology Data Exchange (ETDEWEB)

    Droemer, Darryl W. [National Security Technologies, LLC; Crain, Marlon D.; Lare, Gregory A. [National Security Technologies, LLC; Bennett, Nichelle L. [National Security Technologies, LLC; Johnston, Mark D. [Sandia National Laboratories

    2013-06-13

    National Security Technologies, LLC, and Sandia National Laboratories are collaborating in the development of pulsed power–driven flash x-ray radiographic sources that utilize high-intensity electron beam diodes. The RITS 6 (Radiographic Integrated Test Stand) accelerator at Sandia is used to drive a self magnetic pinch diode to produce a Bremsstrahlung x-ray source. The high electric fields and current densities associated with these short A-K gap pinch beam diodes present many challenges in diode development. Plasmas generated at both the anode and cathode affect the diode performance, which is manifested in varying spot (source) sizes, total dose output, and impedance profiles. Understanding the nature of these plasmas including closure rates and densities is important in modeling their behavior and providing insight into their mitigation. In this paper we describe a streak camera–based optical diagnostic that is capable of observing and measuring plasma evolution within the A-K gap. By imaging a region of interest onto the input slit of a streak camera, we are able to produce a time-resolved one-dimensional image of the evolving plasma. Typical data are presented.

  6. Pulsed, Inductively Generated, Streaming Plasma Ion Source for Heavy Ion Fusion Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Steven C. Glidden; Howard D Sanders; John B. Greenly; Daniel L. Dongwoo

    2006-04-28

    This report describes a compact, high current density, pulsed ion source, based on electrodeless, inductively driven gas breakdown, developed to meet the requirements on normalized emittance, current density, uniformity and pulse duration for an ion injector in a heavy-ion fusion driver. The plasma source produces >10 μs pulse of Argon plasma with ion current densities >100 mA/cm2 at 30 cm from the source and with strongly axially directed ion energy of about 80 eV, and sub-eV transverse temperature. The source has good reproducibility and spatial uniformity. Control of the current density during the pulse has been demonstrated with a novel modulator coil method which allows attenuation of the ion current density without significantly affecting the beam quality. This project was carried out in two phases. Phase 1 used source configurations adapted from light ion sources to demonstrate the feasibility of the concept. In Phase 2 the performance of the source was enhanced and quantified in greater detail, a modulator for controlling the pulse shape was developed, and experiments were conducted with the ions accelerated to >40 kV.

  7. High current multicharged metal ion source using high power gyrotron heating of vacuum arc plasma.

    Science.gov (United States)

    Vodopyanov, A V; Golubev, S V; Khizhnyak, V I; Mansfeld, D A; Nikolaev, A G; Oks, E M; Savkin, K P; Vizir, A V; Yushkov, G Yu

    2008-02-01

    A high current, multi charged, metal ion source using electron heating of vacuum arc plasma by high power gyrotron radiation has been developed. The plasma is confined in a simple mirror trap with peak magnetic field in the plug up to 2.5 T, mirror ratio of 3-5, and length variable from 15 to 20 cm. Plasma formed by a cathodic vacuum arc is injected into the trap either (i) axially using a compact vacuum arc plasma gun located on axis outside the mirror trap region or (ii) radially using four plasma guns surrounding the trap at midplane. Microwave heating of the mirror-confined, vacuum arc plasma is accomplished by gyrotron microwave radiation of frequency 75 GHz, power up to 200 kW, and pulse duration up to 150 micros, leading to additional stripping of metal ions by electron impact. Pulsed beams of platinum ions with charge state up to 10+, a mean charge state over 6+, and total (all charge states) beam current of a few hundred milliamperes have been formed.

  8. Comparison of different plasma chambers in microwave ion source for the intense neutron tube

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations between microwave absorption efficiency and plasma chamber structure and thickness of the microwave introduction window are studied. The microwave absorption efficiency reaches to 100% when plasma chamber is 100mm long and the window thickness is 30mm. The microwave absorption efficiency as a function of pressure is also presented.

  9. Bright X-ray source from a laser-driven micro-plasma-waveguide

    CERN Document Server

    Yi, Longqing

    2016-01-01

    Bright tunable x-ray sources have a number of applications in basic science, medicine and industry. The most powerful sources are synchrotrons, where relativistic electrons are circling in giant storage rings. In parallel, compact laser-plasma x-ray sources are being developed. Owing to the rapid progress in laser technology, very high-contrast femtosecond laser pulses of relativistic intensities become available. These pulses allow for interaction with micro-structured solid-density plasma without destroying the structure by parasitic pre-pulses. The high-contrast laser pulses as well as the manufacturing of materials at micro- and nano-scales open a new realm of possibilities for laser interaction with photonic materials at the relativistic intensities. Here we demonstrate, via numerical simulations, that when coupling with a readily available 1.8 Joule laser, a micro-plasma-waveguide (MPW) may serve as a novel compact x-ray source. Electrons are extracted from the walls by the laser field and form a dense ...

  10. Attenuation and source properties at the Coso Geothermal area, California

    Science.gov (United States)

    Hough, S.E.; Lees, J.M.; Monastero, F.

    1999-01-01

    We use a multiple-empirical Green's function method to determine source properties of small (M -0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa. P- and S-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous EGF studies of M 2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path Q estimates for P and S waves are determined using the multiple-empirical Green's function (MEGF) method of Hough (1997), whereby spectra from clusters of colocated events at a given station are inverted for a single attenuation parameter, ??, with source parameters constrained from EGF analysis. The ?? estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual ?? estimates are expected. The variability in ?? estimates determined here therefore suggests real lateral variability in Q structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred ?? value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in Q structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central low

  11. Influence of ion species ratio on grid-enhanced plasma source ion implantation

    Institute of Scientific and Technical Information of China (English)

    Wang Jiu-Li; Zhang Gu-Ling; Liu Yuan-Fu; Wang You-Nian; Liu Chi-Zi; Yang Si-Ze

    2004-01-01

    @@ Grid-enhanced plasma source ion implantation (GEPSII) is a newly proposed technique to modify the inner-surface properties of a cylindrical bore. In this paper, a two-ion fluid model describing nitrogen molecular ions N2+ and atomic ions N+ is used to investigate the ion sheath dynamics between the grid electrode and the inner surface of a cylindrical bore during the GEPSII process, which is an extension of our previous calculations in which only N2+ was considered.Calculations are concentrated on the results of ion dose and impact energy on the target for different ion species ratios in the core plasma. The calculated results show that more atomic ions N+ in the core plasma can raise the ion impact energy and reduce the ion dose on the target.

  12. Conformal doping of topographic silicon structures using a radial line slot antenna plasma source

    Science.gov (United States)

    Ueda, Hirokazu; Ventzek, Peter L. G.; Oka, Masahiro; Horigome, Masahiro; Kobayashi, Yuuki; Sugimoto, Yasuhiro; Nozawa, Toshihisa; Kawakami, Satoru

    2014-06-01

    Fin extension doping for 10 nm front end of line technology requires ultra-shallow high dose conformal doping. In this paper, we demonstrate a new radial line slot antenna plasma source based doping process that meets these requirements. Critical to reaching true conformality while maintaining fin integrity is that the ion energy be low and controllable, while the dose absorption is self-limited. The saturated dopant later is rendered conformal by concurrent amorphization and dopant containing capping layer deposition followed by stabilization anneal. Dopant segregation assists in driving dopants from the capping layer into the sub silicon surface. Very high resolution transmission electron microscopy-Energy Dispersive X-ray spectroscopy, used to prove true conformality, was achieved. We demonstrate these results using an n-type arsenic based plasma doping process on 10 to 40 nm high aspect ratio fins structures. The results are discussed in terms of the different types of clusters that form during the plasma doping process.

  13. Unstable plasma characteristics in mirror field electron cyclotron resonance microwave ion source

    Indian Academy of Sciences (India)

    S K Angra; Parshant Kumar; R R Dongaonkar; R P Bajpai

    2000-05-01

    Electron cyclotron plasma reactor are prone to instabilities in specific input power [3–7] region (150–450 watts). In this region power absorption by gas molecules in the cavity is very poor and enhanced input power gets reflected substantially without increasing ion density. There are abrupt changes in plasma characteristics when input power was decreased from maximum to minimum, it was observed that reflected power changed from < 2% to ∼ 50%. Minimum two jumps in reflected power were noticed in this specific power region and these appear to be highly sensitive to three stub tuner position in the waveguide for this particular input power zone. Unstable plasma region of this source is found to be dependent upon the magnetic field strength. Some changes in reflected power are also noticed with pressure, flow and bias and they are random in nature.

  14. 2$\\pi$ proportional counting chamber for large-area-coated $\\beta$ sources

    Indian Academy of Sciences (India)

    DESAI SHRADDHA S

    2016-06-01

    Detection system for measuring absolute emission rate from large-area-coated $\\beta$ sources has been indigenously developed. The system consists of a multiwire-based proportional counter with gas flow and a source mounted within the sensitive volume of the detector. Design of the counter enables efficient counting of emissions in $2\\pi$ solid angle.A provision is made for change ofthe source and immediate measurement of source activity. These sources are used to calibrate the efficiency of contamination monitors at radiological facilities. Sensitive area of the detector covers 165◦ solid angle nearing $2\\pi$ of emission from the source of size $100 \\times 150$ mm. Performance of the chamber is tested using collimated $^{55}$Fe X-ray source and $^{90}$Sr / $^{90}$Y coated $\\beta$ sources of various activities. The activity measurement system is established as a national primary standard for calibration of coated $\\beta$ sources at Radiological Laboratory at BARC. Design and performanceof the chamber are presented.

  15. Multi-Modality Pulsed AC Source for Medical Applications of Non-Equilibrium Plasmas

    Science.gov (United States)

    Friedrichs, Daniel; Gilbert, James

    2014-10-01

    A burgeoning field has developed around the use of non-equilibrium (``cold'') plasmas for various medical applications, including wound treatment, surface sterilization, non-thermal hemostasis, and selective cell destruction. Proposed devices typically utilize pulsed DC power sources, which have no other therapeutic utility, and may encounter significant regulatory restrictions regarding their safety for use in patient care. Additionally, dedicated capital equipment is difficult for healthcare facilities to justify. In this work, we have demonstrated for the first time the generation of non-equilibrium plasma using pulsed AC output from a specially-designed electrosurgical generator. The ability to power novel non-equilibrium plasma devices from a piece of equipment already ubiquitous in operating theatres should significantly reduce the barriers to adoption of plasma devices. We demonstrate the ability of a prototype device, coupled to this source, to reduce bacterial growth in vitro. Such a system could allow a single surgical instrument to provide both non-thermal sterilization and thermal tissue dissection.

  16. SiC detectors for radiation sources characterization and fast plasma diagnostic

    Science.gov (United States)

    Cannavò, A.; Torrisi, L.

    2016-09-01

    Semiconductor detectors based on SiC have been investigated to characterize the radiations (photons and particles) emitted from different sources, such as radioactive sources, electron guns, X-ray tubes and laser-generated plasmas. Detectors show high response velocity, low leakage current, high energy gap and high radiation hardness. Their high detection efficiency permits to use the detectors in spectroscopic mode and in time-of-flight (TOF) approach, generally employed to monitor low and high radiation fluxes, respectively. Using the laser start signal, they permit to study the properties of the generated plasma in vacuum by measuring accurately the particle velocity and energy using pulsed lasers at low and high intensities. Possible applications will be reported and discussed.

  17. Modeling and measuring the transport and scattering of energetic debris in an extreme ultraviolet plasma source

    Science.gov (United States)

    Sporre, John R.; Elg, Daniel T.; Kalathiparambil, Kishor K.; Ruzic, David N.

    2016-01-01

    A theoretical model for describing the propagation and scattering of energetic species in an extreme ultraviolet (EUV) light lithography source is presented. An EUV light emitting XTREME XTS 13-35 Z-pinch plasma source is modeled with a focus on the effect of chamber pressure and buffer gas mass on energetic ion and neutral debris transport. The interactions of the energetic debris species, which is generated by the EUV light emitting plasma, with the buffer gas and chamber walls are considered as scattering events in the model, and the trajectories of the individual atomic species involved are traced using a Monte Carlo algorithm. This study aims to establish the means by which debris is transported to the intermediate focus with the intent to verify the various mitigation techniques currently employed to increase EUV lithography efficiency. The modeling is compared with an experimental investigation.

  18. Deposition and sputtering yields on EUV collector mirror from Laser Plasma Extreme Ultraviolet Sources

    Energy Technology Data Exchange (ETDEWEB)

    Wu Tao [Wuhan National Laboratory for Optoelectronics, School of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Rao Zhiming [Depart of Computer Science, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi (China); Wang Shifang, E-mail: flatime@163.com [School of Physics and Electric Information, Hubei University of Education 1 Nanhuan Road, Wuhan East High-Tech. Zone, Wuhan 430205, Hubei (China)

    2011-02-01

    Based on the self-similar solution of gas dynamic equations, spherical expansion of the highly ionized plasma with limited mass into a vacuum is investigated for the droplet target laser-produced plasma extreme ultraviolet (LPP-EUV) sources. Using partially numerical and partially analytical technology, the velocity, the temperature and the density profiles in the plume versus ionization degree, adiabatic index and initial conditions are presented. Furthermore, the spatial thickness variations of the deposited substrate witness and ion sputtering yields for Ru, Mo, and Si under Sn ion bombardment are theoretically calculated, which can be useful to enable LPP-EUV sources suppliers to estimate collector lifetime and improve debris mitigation systems.

  19. Extreme Ultraviolet Light Emission from Z-Pinch Discharge Plasma Source

    Science.gov (United States)

    Watanabe, Masato; Song, Inho; Sakamoto, Toshiro; Kobayashi, Yasunori; Okino, Akitoshi; Mohanty, Smruti R.; Horioka, Kazuhiko; Hotta, Eiki

    2006-01-01

    A capillary Z-pinch discharge light source for EUV lithography has been developed. Our device is equipped with a water-cooled ceramic capillary and electrodes, and a solid state pulsed power generator. A stacked static induction thyristors are used as switching elements, which enable high repetition rate operation of pulsed power supply. A magnetic switch is connected in series, which not only assists the semiconductor switch but also provides a preionization current. In the present study, EUV radiation emitted from pinching plasma in a xenon-filled capillary was quantitatively measured using an in-band calorimeter. Time-integrated in-band source image was also observed using a pinhole camera system. Furthermore, new electrode system using plasma jet has been developed.

  20. Inductively driven surface-plasma negative ion source for N-NBI use (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Belchenko, Yu., E-mail: belchenko@inp.nsk.su; Abdrashitov, G.; Deichuli, P.; Ivanov, A.; Gorbovsky, A.; Kondakov, A.; Sanin, A.; Sotnikov, O.; Shikhovtsev, I. [Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2016-02-15

    The long-pulse surface-plasma source prototype is developed at Budker Institute of Nuclear Physics for negative-ion based neutral beam injector use. The essential source features are (1) an active temperature control of the ion-optical system electrodes by circulation of hot thermal fluid through the channels, drilled in the electrode bodies, (2) the concaved transverse magnetic field in the extraction and acceleration gaps, preventing the electrons trapping and avalanching, and (3) the directed cesium deposition via distribution tubes adjacent to the plasma grid periphery. The long term effect of cesium was obtained just with the single cesium deposition. The high voltage strength of ion-optical system electrodes was improved with actively heated electrodes. A stable H{sup −} beam with a current ∼1 A and energy 90 keV was routinely extracted and accelerated.

  1. Chromospheric Nanoflares as a Source of Coronal Plasma: II. Repeating Nanoflares

    CERN Document Server

    Bradshaw, Stephen J

    2016-01-01

    The million degree plasma of the solar corona must be supplied by the underlying layers of the atmosphere. The mechanism and location of energy release, and the precise source of coronal plasma, remain unresolved. In earlier work we pursued the idea that warm plasma is supplied to the corona via direct heating of the chromosphere by nanoflares, contrary to the prevailing belief that the corona is heated in-situ and the chromosphere is subsequently energized and ablated by thermal conduction. We found that single (low-frequency) chromospheric nanoflares could not explain the observed intensities, Doppler-shifts, and red/blue asymmetries in Fe XII and XIV emission lines. In the present work we follow up on another suggestion that the corona could be powered by chromospheric nanoflares that repeat on a timescale substantially shorter than the cooling/draining timescale. That is, a single magnetic strand is re-supplied with coronal plasma before the existing plasma has time to cool and drain. We perform a series ...

  2. Effect of Wall Material on H– Production in a Plasma Sputter-Type Ion Source

    Directory of Open Access Journals (Sweden)

    Y. D. M. Ponce

    2004-12-01

    Full Text Available The effect of wall material on negative hydrogen ion (H– production was investigated in a multicusp plasma sputter-type ion source (PSTIS. Steady-state cesium-seeded hydrogen plasma was generated by a tungsten filament, while H– was produced through surface production using a molybdenum sputter target. Plasma parameters and H– yields were determined from Langmuir probe and Faraday cup measurements, respectively. At an input hydrogen pressure of 1.2 mTorr and optimum plasma discharge parameters Vd = –90 V and Id = –2.25 A, the plasma parameters ne was highest and T–e was lowest as determined from Langmuir probe measurements. At these conditions, aluminum generates the highest ion current density of 0.01697 mA/cm2, which is 64% more than the 0.01085 mA/cm2 that stainless steel produces. The yield of copper, meanwhile, falls between the two materials at 0.01164 mA/cm2. The beam is maximum at Vt = –125 V. Focusing is achieved at VL = –70 V for stainless steel, Vt = –60 V for aluminum, and Vt = –50 V for copper. The results demonstrate that proper selection of wall material can greatly enhance the H– production of the PSTIS.

  3. Key area identification of pollution sources of drinking water sources in rural areas%村镇饮用水源地污染关键区识别

    Institute of Scientific and Technical Information of China (English)

    程公德; 殷国玺; 谢崇宝; 张国华; 杨洁

    2014-01-01

    In the upstream of water sources, many pollutants are output from key pollution areas of water sources, and thus identifying key pollution areas of water sources is a key to protection and pollution control of rural drinking water source. In this paper, a method to directly identify key pollution areas was proposed and applied to investigate the pollution situation of rural drinking water sources in Anjishan reservoir area in 2011. Residential areas, farmlands, mines, and other land use types were identified as the pollution sources based on image classification techniques of remote sensing. Hydrology analysis tools for ArcGIS software were used to determine catchment of Anjishan basin. Batch Sub watershed Delineation tool combined with the distribution of the main pollution sources was used to divide Anjishan basin into 19 sub watershed, and land use areas for each sub watershed were summarized. In rural areas, Anjishan reservoir area was mainly affected by pollutants from non-point sources. So, farmland, aquaculture sewage, mines and rural life were considered as main pollution sources of this area. For these sources, COD (chemical oxygen demand), NH3-N (ammonia nitrogen), TN (total nitrogen) and TP (total phosphorus) were the main pollution factors. Source strength coefficient of each factor for each source was obtained from national reports and amended with survey data. Exceeds bid index method was adopted to calculate the weights of pollution factors based on their contributions rates, and degree of pollution was also calculated based on the weights. The pollution degree of water source for each sub watershed was calculated through degree of pollution of each pollution source and its corresponding land use area. The pollution degree of each sub watershed was converted to pollution concentration based on annual rainfall. Environmental quality standards for surface water in China are often used to assess the condition of water sources. In the standard, Class III

  4. A study on vacuum aspects of electron cyclotron resonance ion source plasma

    Science.gov (United States)

    Ghosh, S.; Taki, G. S.; Mallick, C.; Bhandari, R. K.

    2008-05-01

    The electron cyclotron resonance (ECR) ion source is special type hot plasma machine where the high temperature electrons co-exist with multiply charge state ions and neutrals. A few years ago 6.4 GHz. ECR ion source (VEC-ECR) was developed indigenously at VECC. This multiply charged ion source is being used continuously to inject heavy ion beams into the cyclotron. Vacuum plays the major role in ECR ion source. The water cooled plasma chamber is made from an oxygen free high conductivity copper billet to meet the suitable surface condition for vacuum purpose. The entire volume of the ion source is pumped by two 900 1/s special type oil diffusion pumps to achieve 5×10-8 Torr. Usually main plasma chamber is pumped by the plasma itself. Moreover a few 1/s additional pumping speed is provided through extraction hole and pumping slot on the extraction electrode. A study has been carried out to understand the role of vacuum on the multiply charged heavy ion production process. Considering the ion production and loss criteria, it is seen that for getting Ar18+ better vacuum is essential for lower frequency operation. So, an ECR ion source can give better charge state current output operating at higher frequency and stronger confining magnetic field under a specific vacuum condition. The low pressure condition is essential to minimize charge exchange loss due to recombination of multiply charged ions with the neutral atoms. A fixed ratio of neutral to electron density must be maintained for optimizing a particular charge state in the steady state condition. As the electron density is proportional to square of the injected microwave frequency (nevpropf2) a particular operating pressure is essential for a specific charge state. From the study, it has been obtained that the production of Ar18+ ions needs a pressure ~ 9.6×10-8 Torr for 6.4 GHz. ECR ion source. It is also obtained that an ECR ion source, works at a particular vacuum level, can give better charge state

  5. Operational and theoretical temperature considerations in a Penning surface plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Faircloth, D. C., E-mail: dan.faircloth@stfc.ac.uk; Lawrie, S. R. [ISIS Neutron and Muon Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, OX11 0QX (United Kingdom); Pereira Da Costa, H. [CERN, Geneva (Switzerland); Dudnikov, V. [Muons Inc. United States of America (United States)

    2015-04-08

    A fully detailed 3D thermal model of the ISIS Penning surface plasma source is developed in ANSYS. The proportion of discharge power applied to the anode and cathode is varied until the simulation matches the operational temperature observations. The range of possible thermal contact resistances are modelled, which gives an estimation that between 67% and 85% of the discharge power goes to the cathode. Transient models show the electrode surface temperature rise during the discharge pulse for a range of duty cycles. The implications of these measurements are discussed and a mechanism for governing cesium coverage proposed. The requirements for the design of a high current long pulse source are stated.

  6. A Detailed Study of Debris Flow Source Areas in the Northern Colorado Front Range.

    Science.gov (United States)

    Arana-Morales, A.; Baum, R. L.; Godt, J.

    2014-12-01

    Nearly continuous, heavy rainfall occurred during 9-13 September 2013 causing flooding and widespread landslides and debris flows in the northern Colorado Front Range. Whereas many recent studies have identified erosion as the most common process leading to debris flows in the mountains of Colorado, nearly all of the debris flows mapped in this event began as small, shallow landslides. We mapped the boundaries of 415 September 2013 debris flows in the Eldorado Springs and Boulder 7.5-minute quadrangles using 0.5-m-resolution satellite imagery. We characterized the landslide source areas of six debris flows in the field as part of an effort to identify what factors controlled their locations. Four were on a dip slope in sedimentary rocks in the Pinebrook Hills area, near Boulder, and the other two were in granitic rocks near Gross Reservoir. Although we observed no obvious geomorphic differences between the source areas and surrounding non-landslide areas, we noted several characteristics that the source areas all had in common. Slopes of the source areas ranged from 28° to 35° and most occurred on planar or slightly concave slopes that were vegetated with grass, small shrubs, and sparse trees. The source areas were shallow, irregularly shaped, and elongated downslope: widths ranged from 4 to 9 m, lengths from 6 to 40 m and depths ranged from 0.7 to 1.2 m. Colluvium was the source material for all of the debris flows and bedrock was exposed in the basal surface of all of the source areas. We observed no evidence for concentrated surface runoff upslope from the sources. Local curvature and roughness of bedrock and surface topography, and depth distribution and heterogeneity of the colluvium appear to have controlled the specific locations of these shallow debris-flow source areas. The observed distribution and characteristics of the source areas help guide ongoing efforts to model initiation of the debris flows.

  7. Penning plasma based simultaneous light emission source of visible and VUV lights

    Science.gov (United States)

    Vyas, G. L.; Prakash, R.; Pal, U. N.; Manchanda, R.; Halder, N.

    2016-06-01

    In this paper, a laboratory-based penning plasma discharge source is reported which has been developed in two anode configurations and is able to produce visible and VUV lights simultaneously. The developed source has simultaneous diagnostics facility using Langmuir probe and optical emission spectroscopy. The two anode configurations, namely, double ring and rectangular configurations, have been studied and compared for optimum use of the geometry for efficient light emissions and recording. The plasma is produced using helium gas and admixture of three noble gases including helium, neon, and argon. The source is capable to produce eight spectral lines for pure helium in the VUV range from 20 to 60 nm and total 24 spectral lines covering the wavelength range 20-106 nm for the admixture of gases. The large range of VUV lines is generated from gaseous admixture rather from the sputtered materials. The recorded spectrum shows that the plasma light radiations in both visible and VUV range are larger in double ring configuration than that of the rectangular configurations at the same discharge operating conditions. To clearly understand the difference, the imaging of the discharge using ICCD camera and particle-in-cell simulation using VORPAL have also been carried out. The effect of ion diffusion, metastable collision with the anode wall and the nonlinear effects are correlated to explain the results.

  8. Negative ion beam formation using thermal contact ionization type plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Fukuura, Yoshiyuki; Murakami, Kazutugu; Masuoka, Toshio; Katsumata, Itsuo [Osaka City Univ. (Japan). Faculty of Engineering

    1997-02-01

    The small ion sources utilizing thermal ionization have been already developed, and at present, in order to increase ion yield, that being developed to the cylindrical plasma prototype having the inner surface of a Re foil cylinder as the ionization surface, and stably functioning at 3,000 K has been developed, and by using this plasma source, the research on the formation of various ions has been carried out. At present, the research on the formation of Li negative ion beam is carried out. The separation of negative ions from electrons is performed with the locally limited magnetic field using a small iron core electromagnet placed behind the electrostatic accelerating lens system. So for, the formation of about 2 {mu}A at maximum of negative ions was confirmed. It was decided to identify the kinds of ions by time of flight (TOF) process, and the various improvements for this purpose were carried out. The experimental setup, the structure of the plasma source, the circuits for TOF measurement and so on are explained. The experimental results are reported. The problems are the possibility of the formation of alkali metals, the resolution of the time axis of the TOF system and so on. (K.I.)

  9. SOLAR TO AC POWER SOURCE FOR REMOTE AREAS USING SEIG

    Directory of Open Access Journals (Sweden)

    MEHMET AKBABA

    2012-02-01

    Full Text Available Photovoltaic generators (PVG are increasingly used to provide electricity in remote areas. However, in many applications the DC generated electricity by a PVG need to be converted to AC. Traditionally DC to AC inverters have been widely used for this purpose. In this paper, a different system is proposed in which a self excited induction generator (SEIG driven by a permanent magnet DC motor (DCM and powered from a PVG through a maximum power point tracker (MPPT are used. A step-up chopper is utilized as an MPPT unit. The proposed system is modelled in time domain, and a detailed transient and steady-state analysis are presented. The main reason behind analyzing the system in the time domain is because of the fact that for unknown speeds, the methods developed for steady-state analysis of SEIGs can not be applied. The presented work shows that the full available power of the PVG can be harnessed by selecting suitable values for the duty cycle and the frequency of the step up chopper and the excitation capacitor of the SEIG. It is also shown that with such a combination power utilization efficiency of more than 83% can be achieved.

  10. Plasma kinetics, tissue distribution, and cerebrocortical sources of reverse triiodothyronine in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Obregon, M.J.; Larsen, P.R.; Silva, J.E.

    1985-06-01

    Studies in vitro have shown that rT3 is a potent and competitive inhibitor of T4 5'-deiodination (5'D). Recent studies in vivo have shown that cerebrocortical (Cx) T4 5'D-type II (5'D-II) activity (propylthiouracil (PTU) insensitive pathway), is reduced by T4 and rT3, the latter being more potent than T3 in Cx 5'D-II suppression. Some other reports had described rT3 production in rat brain as a very active pathway of thyroid hormone metabolism. To examine the possibility that rT3 plays a physiological role in regulating Cx 5'D-II, we have explored rT3 plasma kinetics, plasma to tissue exchange, and uptake by tissues in the rat, as well as the metabolic routes of degradation and the sources of rT3 in cerebral cortex (Cx). Plasma and tissue levels were assessed with tracer (/sup 125/I)rT3. Two main compartments were defined by plasma disappearance curves in euthyroid rats (K/sub 1/ = -6.2 h-1 and K/sub 2/ = -0.75 h-1). In Cx of euthyroid rats, (/sup 125/I)rT3 peaked 10 min after iv injection, tissue to plasma ratio being 0.016 +/- 0.004 (SE). In thyroidectomized rats, plasma and tissue (/sup 125/I)rT3 concentrations were higher than in euthyroid rats, except for the Cx that did not change. PTU caused further increases in all the tissues studied, except for the Cx and the pituitaries of thyroidectomized rats. From the effect of blocking 5'D-I with PTU or reducing its activity by making the animals hypothyroid, we concluded that 5'D-I accounts for most of the rT3 clearance from plasma. In contrast, in Cx and pituitary the levels of rT3 seem largely affected by 5'D-II activity. Since the latter results suggest that plasma rT3 does not play a major role in determining rT3 levels in these tissues, we explored the sources of rT3 in Cx using (/sup 125/I)T4. The (/sup 125/I)rT3 (T4) to (/sup 125/I)T4 ratio remained constant at 0.03 from 1 up to 5 h after injection of (/sup 125/I)T4.

  11. Application of Characteristics of Seismogenic Structures in the Determination of Parameter of Potential Seismic Source Areas

    Institute of Scientific and Technical Information of China (English)

    Zhou Bengang

    2005-01-01

    The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does not only have the intension that "this area has the possibility for destructive earthquakes to occur in the future" but also means that earthquakes of high magnitude interval have the characteristics of similar recurrence. When determining the seismic activity parameters of a statistical unit, some active tectonic blocks in the unit may have different background earthquakes. In order to better reflect the heterogeneity in space of seismic activities, it is necessary to divide the potential seismic source areas into three orders.By analyzing the recurrence characteristics of earthquakes of high magnitude interval in the potential source area and calculating the occurrence probability of earthquakes of high magnitude interval in the potential seismic source area in the time window for prediction, the average annual occurrence rate of earthquakes can be obtained by the method of probability equivalent conversion in the time window for prediction. This would be helpful for considering the recurrence characteristics of strong earthquakes in potential source areas within the framework of seismic risk analysis of China. Besides, the insufficient frequency of characteristic earthquakes of the next high magnitude interval in the potential source area and the heterogeneity of strong earthquakes on seismogenic structures are analyzed to see their application in seismic risk analysis.

  12. Satellite based Observations of Saharan Dust Source Areas - Comparison and Variability

    Science.gov (United States)

    Schepanski, K.; Tegen, I.; Macke, A.

    2012-04-01

    Satellite remote sensing products such as Meteosat Second Generation (MSG) Infra Red (IR) dust index and Ozone Monitoring Instrument (OMI) Aerosol Index (AI) are commonly used to infer dust source areas. We compare two different methods for dust source identification, (1) a "back-tacking" method applied to 4 years of 15-minute MSG IR dust index, and (2) a "frequency" method applied to daily OMI AI and daily MODIS DeepBlue Aerosol Optical Thickness (AOT) data for the same time period. Using the "back-tracking" method, dust source areas are inferred by tracking individual dust plumes back to their place of origin, allowed by the high temporal resolution of the MSG images. OMI AI and MODIS Deep Blue AOT products are available on daily resolution only, which disables for back-tracking of individual dust plumes. Thus, dust source areas are retrieved by relating the frequencies of occurrence of high dust loadings to source areas. The spatial distribution of inferred dust source areas from the two methods shows significant differences. The MSG back-tracking method highlights frequent dust emission from sources within complex terrain, while frequencies of high OMI AI values emphasise topographic basins as important dust source areas. Dust source areas retrieved from DeepBlue AOTs are generally placed further south towards the Sahel region. This study shows that the temporal resolution of satellite dust products is a key issue in retrieving dust source areas. Both, the spatial distribution of dust sources and their annual cycle strongly depend on the acquisition time related to the start of dust emission.

  13. A Proposal for a Novel H- Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization

    Science.gov (United States)

    Tarvainen, O.; Kurennoy, S.

    2009-03-01

    A design for a novel H- ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE111 eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H- ion beam is further "self-extracted" through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H- ion current, beam emittance and duty factor of the novel source are estimated.

  14. Laser-driven electron beamlines generated by coupling laser-plasma sources with conventional transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Antici, P. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati, Via E. Fermi, 40, 00044 Frascati (Italy); SAPIENZA, University of Rome, Dip. SBAI, Via A. Scarpa 14, 00161 Rome (Italy); INFN - Sezione di Roma, c/o Dipartimento di Fisica - SAPIENZA, University of Rome, P.le Aldo Moro, 2 - 00185 Rome (Italy); Bacci, A.; Chiadroni, E.; Ferrario, M.; Rossi, A. R. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati, Via E. Fermi, 40, 00044 Frascati (Italy); Benedetti, C. [University of Bologna and INFN - Bologna (Italy); Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L. [SAPIENZA, University of Rome, Dip. SBAI, Via A. Scarpa 14, 00161 Rome (Italy); INFN - Sezione di Roma, c/o Dipartimento di Fisica - SAPIENZA, University of Rome, P.le Aldo Moro, 2 - 00185 Rome (Italy); Serafini, L. [INFN-Milan and Department of Physics, University of Milan, Via Celoria 16, 20133 Milan (Italy)

    2012-08-15

    Laser-driven electron beamlines are receiving increasing interest from the particle accelerator community. In particular, the high initial energy, low emittance, and high beam current of the plasma based electron source potentially allow generating much more compact and bright particle accelerators than what conventional accelerator technology can achieve. Using laser-generated particles as injectors for generating beamlines could significantly reduce the size and cost of accelerator facilities. Unfortunately, several features of laser-based particle beams need still to be improved before considering them for particle beamlines and thus enable the use of plasma-driven accelerators for the multiple applications of traditional accelerators. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both a versatile electron source and a controllable beam. In this paper, we perform start-to-end simulations to generate laser-driven beamlines using conventional accelerator codes and methodologies. Starting with laser-generated electrons that can be obtained with established multi-hundred TW laser systems, we compare different options to capture and transport the beams. This is performed with the aim of providing beamlines suitable for potential applications, such as free electron lasers. In our approach, we have analyzed which parameters are critical at the source and from there evaluated different ways to overcome these issues using conventional accelerator elements and methods. We show that electron driven beamlines are potentially feasible, but exploiting their full potential requires extensive improvement of the source parameters or innovative technological devices for their transport and capture.

  15. Laser-driven electron beamlines generated by coupling laser-plasma sources with conventional transport systems

    Science.gov (United States)

    Antici, P.; Bacci, A.; Benedetti, C.; Chiadroni, E.; Ferrario, M.; Rossi, A. R.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Serafini, L.

    2012-08-01

    Laser-driven electron beamlines are receiving increasing interest from the particle accelerator community. In particular, the high initial energy, low emittance, and high beam current of the plasma based electron source potentially allow generating much more compact and bright particle accelerators than what conventional accelerator technology can achieve. Using laser-generated particles as injectors for generating beamlines could significantly reduce the size and cost of accelerator facilities. Unfortunately, several features of laser-based particle beams need still to be improved before considering them for particle beamlines and thus enable the use of plasma-driven accelerators for the multiple applications of traditional accelerators. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both a versatile electron source and a controllable beam. In this paper, we perform start-to-end simulations to generate laser-driven beamlines using conventional accelerator codes and methodologies. Starting with laser-generated electrons that can be obtained with established multi-hundred TW laser systems, we compare different options to capture and transport the beams. This is performed with the aim of providing beamlines suitable for potential applications, such as free electron lasers. In our approach, we have analyzed which parameters are critical at the source and from there evaluated different ways to overcome these issues using conventional accelerator elements and methods. We show that electron driven beamlines are potentially feasible, but exploiting their full potential requires extensive improvement of the source parameters or innovative technological devices for their transport and capture.

  16. What are the Sources of Solar Energetic Particles? Element Abundances and Source Plasma Temperatures

    CERN Document Server

    Reames, Donald V

    2015-01-01

    We have spent 50 years in heated discussion over which populations of solar energetic particles (SEPs) are accelerated at flares and which by shock waves driven out from the Sun by coronal mass ejections (CMEs). The association of the large "gradual" SEP events with shock acceleration is supported by the extensive spatial distribution of SEPs and by the delayed acceleration of the particles. The relative abundances of the elements in these gradual events are a measure of those in the ambient solar corona, differing from those in the photosphere by a widely-observed function of the first ionization potential (FIP) of the elements. SEP events we call "impulsive", the traditional "3He-rich" events with enhanced heavy-element abundances, are associated with type III radio bursts, flares, and narrow CMEs; they selectively populate flux tubes that thread a localized source, and they are fit to new particle-in-cell models of magnetic reconnection on open field lines as found in solar jets. These models help explain ...

  17. Debris-free laser plasma sources for EUVL based on gas jets

    Energy Technology Data Exchange (ETDEWEB)

    Kubiak, G.D.; O`Connell, D.; Krenz, K.D.

    1996-03-01

    EUV sources for EUVL must not only be bright for throughput, they must also be debris-free to increase condenser longevity. Many schemes to achieve bright, clean sources for EUVL have been studied, including mass-limited targets, cryogenic targets, electric discharges, and electron-beam pumped vapor. Several of these sources show promise, with varying degrees of brightness, debris reduction, and system complexity. We have studied pulsed gas jets, which we find to be relatively simple, debris-free sources when used under appropriate conditions. Under transverse, 1.06 {mu}m irradiation of the jet at incident laser intensities in the range of 10{sup 11}-10{sup 12} Watts/cm{sup 2}, the conversion efficiency into 2{pi} steradians is in the range of 0.3-0.4%, or approximately half the value exhibited by solid Au or W targets under similar conditions. Source sizes in the range of 350 {mu}m x 400 {mu}m can be achieved, as shown in Fig. 2, depending sensitively on both laser and gas jet parameters. One issue that must be overcome in the use of gas jet targets is the requirement that the laser-irradiated plasma be located as far from the jet nozzle as possible to avoid debris generation while maintaining adequate EUV conversion. We will describe conditions under which these criteria are met. Measurements of the reflectance lifetimes of multilayer-coated mirrors placed near the plasma source under these conditions will also be presented. The potential for scaling such sources up to meet the requirements of a commercial EUVL system will be discussed.

  18. Influences of guide-tube and bluff-body on advanced atmospheric pressure plasma source for single-crystalline polymer nanoparticle synthesis at low temperature

    Science.gov (United States)

    Kim, Dong Ha; Park, Choon-Sang; Kim, Won Hyun; Shin, Bhum Jae; Hong, Jung Goo; Park, Tae Seon; Seo, Jeong Hyun; Tae, Heung-Sik

    2017-02-01

    The use of a guide-tube and bluff-body with an advanced atmospheric pressure plasma source is investigated for the low-temperature synthesis of single-crystalline high-density plasma polymerized pyrrole (pPPy) nano-materials on glass and flexible substrates. Three process parameters, including the position of the bluff-body, Ar gas flow rate, and remoteness of the substrate from the intense and broadened plasma, are varied and examined in detail. Plus, for an in-depth understanding of the flow structure development with the guide-tube and bluff-body, various numerical simulations are also conducted using the same geometric conditions as the experiments. As a result, depending on both the position of the bluff-body and the Ar gas flow rate, an intense and broadened plasma as a glow-like discharge was produced in a large area. The production of the glow-like discharge played a significant role in increasing the plasma energy required for full cracking of the monomers in the nucleation region. Furthermore, a remote growth condition was another critical process parameter for minimizing the etching and thermal damage during the plasma polymerization, resulting in single- and poly-crystalline pPPy nanoparticles at a low temperature with the proposed atmospheric pressure plasma jet device.

  19. Experimental investigation of laser-produced-plasma EUV source based on liquid target

    Institute of Scientific and Technical Information of China (English)

    QI Li-hong; NI Qi-liang; CHEN Bo

    2005-01-01

    A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target LPP source had EUV emission at 11~20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.

  20. Modeling laser produced plasmas with smoothed particle hydrodynamics for next generation advanced light sources

    Science.gov (United States)

    Holladay, Robert; Griffith, Alec; Murillo, Michael S.

    2016-10-01

    A computational model has been developed to study the evolution of a plasma generated by next-generation advanced light sources such as SLAC's LCLS and LANL's proposed MaRIE. Smoothed Particle Hydrodynamics (SPH) is used to model the plasma evolution because of the ease with which it handles the open boundary conditions and large deformations associated with these experiments. Our work extends the basic SPH method by utilizing a two-fluid model of an electron-ion plasma that also incorporates time dependent ionization and recombination by allowing the SPH fluid particles to have an evolving mass based on the mean ionization state of the plasma. Additionally, inter-species heating, thermal conduction, and electric fields are also accounted for. The effects of various initial conditions and model parameters will be presented, with the goal of using this framework to develop a model that can be used in the design and interpretation of future experiments. This work was supported by the Los Alamos National Laboratory Computational Physics Workshop.

  1. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source.

    Science.gov (United States)

    Wyndham, E S; Favre, M; Valdivia, M P; Valenzuela, J C; Chuaqui, H; Bhuyan, H

    2010-09-01

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  2. Initial evaluation and comparison of plasma damage to atomic layer carbon materials using conventional and low T{sub e} plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Jagtiani, Ashish V.; Miyazoe, Hiroyuki; Chang, Josephine; Farmer, Damon B.; Engel, Michael; Neumayer, Deborah; Han, Shu-Jen; Engelmann, Sebastian U., E-mail: suengelm@us.ibm.com; Joseph, Eric A. [IBM, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Boris, David R.; Hernández, Sandra C.; Walton, Scott G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lock, Evgeniya H. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2016-01-15

    The ability to achieve atomic layer precision is the utmost goal in the implementation of atomic layer etch technology. Carbon-based materials such as carbon nanotubes (CNTs) and graphene are single atomic layers of carbon with unique properties and, as such, represent the ultimate candidates to study the ability to process with atomic layer precision and assess impact of plasma damage to atomic layer materials. In this work, the authors use these materials to evaluate the atomic layer processing capabilities of electron beam generated plasmas. First, the authors evaluate damage to semiconducting CNTs when exposed to beam-generated plasmas and compare these results against the results using typical plasma used in semiconductor processing. The authors find that the beam generated plasma resulted in significantly lower current degradation in comparison to typical plasmas. Next, the authors evaluated the use of electron beam generated plasmas to process graphene-based devices by functionalizing graphene with fluorine, nitrogen, or oxygen to facilitate atomic layer deposition (ALD). The authors found that all adsorbed species resulted in successful ALD with varying impact on the transconductance of the graphene. Furthermore, the authors compare the ability of both beam generated plasma as well as a conventional low ion energy inductively coupled plasma (ICP) to remove silicon nitride (SiN) deposited on top of the graphene films. Our results indicate that, while both systems can remove SiN, an increase in the D/G ratio from 0.08 for unprocessed graphene to 0.22 to 0.26 for the beam generated plasma, while the ICP yielded values from 0.52 to 1.78. Generally, while some plasma-induced damage was seen for both plasma sources, a much wider process window as well as far less damage to CNTs and graphene was observed when using electron beam generated plasmas.

  3. Discharge-produced plasma extreme ultraviolet (EUV) source and ultra high vacuum chamber for studying EUV-induced processes

    CERN Document Server

    Dolgov, A; Abrikosov, A; Snegirev, E; Krivtsun, V M; Lee, C J; Bijkerk, F

    2014-01-01

    An experimental setup that directly reproduces Extreme UV-lithography relevant conditions for detailed component exposure tests is described. The EUV setup includes a pulsed plasma radiation source, operating at 13.5 nm; a debris mitigation system; collection and filtering optics; and an UHV experimental chamber, equipped with optical and plasma diagnostics. The first results, identifying the physical parameters and evolution of EUV-induced plasmas are presented. Finally, the applicability and accuracy of the in situ diagnostics is briefly discussed.

  4. Matching a (sub)nanosecond pulse source to a corona plasma reactor

    Science.gov (United States)

    Huiskamp, T.; Beckers, F. J. C. M.; Hoeben, W. F. L. M.; van Heesch, E. J. M.; Pemen, A. J. M.

    2016-10-01

    In this paper we investigate the energy transfer from the pulses of a (sub)nanosecond pulse source to the plasma in a corona-plasma reactor. This energy transfer (or ‘matching’) should be as high as possible. We studied the effect of multiple parameters on matching, such as the reactor configuration, the pulse duration and amplitude and the energy density. The pulse reflection on the reactor interface has a significant influence on matching, and should be as low as possible to transfer the most energy into the reactor. We developed a multiple-wire inner conductor for the reactor which decreases the vacuum impedance of the reactor to decrease the pulse reflection on the reactor interface while maintaining a high electric field on the wire. The results were very encouraging and showed an energy transfer efficiency of over 90 percent. The matching results further show that there is only a small effect on the matching between different wire diameters. In addition, a long reactor and a long pulse result in the best matching due to the more intense plasma that is generated in these conditions. Finally, even without the multiple-wire reactor, we are able to achieve a very good matching (over 80 percent) between our pulse source and the reactor.

  5. AmBe Radiological Source Replacement Using Dense Plasma Focus Z-Pinch

    Science.gov (United States)

    Shaw, Brian; Povilus, Alexander; Chapman, Steven; Podpaly, Yuri; Cooper, Christopher; Higginson, Drew; Link, Anthony; Schmidt, Andrea

    2016-10-01

    A dense plasma focus (DPF) is a compact plasma gun that produces high energy ion beams up to several MeV through strong potential gradients formed from m=0 plasma instabilities. These ion beams can be used to replace radiological sources for a variety of applications. Americium-beryllium (AmBe) neutron sources are commonly used for oil well logging. An optimized DPF produces high energy helium ion beams of 2+ MeV which can interact with a beryllium target to produce neutrons. The alpha-Be interaction produces a neutron energy spectrum similar to the neutrons produced by the AmBe reaction. To demonstrate this concept experimentally a 2 kJ DPF is used to produce a beam of alpha particles which interacts with a beryllium target. We report on the improvements made to the DPF platform using He gas and the observation of 3.0 ×104 peak neutrons generated per shot. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. The Project PLASMONX for Plasma Acceleration Experiments and a Thomson X-Ray Source at SPARC

    CERN Document Server

    Serafini, Luca; Alessandria, Franco; Bacci, Alberto; Baldeschi, Walter; Barbini, Alessandro; Bellaveglia, Marco; Bertolucci, Sergio; Biagini, Maria; Boni, Roberto; Bonifacio, Rodolfo; Boscolo, Ilario; Boscolo, Manuela; Bottigli, Ubaldo; Broggi, Francesco; Castellano, Michele; Cecchetti, Carlo A; Cialdi, Simone; Clozza, Alberto; De Martinis, Carlo; Di Pirro, Giampiero; Drago, Alessandro; Esposito, Adolfo; Ferrario, Massimo; Ficcadenti, L; Filippetto, Daniele; Fusco, Valeria; Galimberti, Marco; Gallo, Alessandro; Gatti, Giancarlo; Ghigo, Andrea; Giove, Dario; Giulietti, Antonio; Giulietti, Danilo; Gizzi, Leonida A; Golosio, Bruno; Guiducci, Susanna; Incurvati, Maurizio; Köster, Petra; Labate, Luca; Ligi, Carlo; Marcellini, Fabio; Maroli, Cesare; Mauri, Marco; Migliorati, Mauro; Mostacci, Andrea; Oliva, Pier N; Palumbo, Luigi; Pellegrino, Luigi; Petrillo, Vittoria; Piovella, Nicola; Poggiu, Angela; Pozzoli, Roberto; Preger, Miro; Ricci, Ruggero; Rome, Massimiliano; Rossi, Antonella; Sanelli, Claudio; Serio, Mario; Sgamma, Francesco; Spataro, Bruno; Stecchi, Alessandro; Stella, Angelo; Stumbo, Simone; Tazzioli, Franco; Tommasini, Paolo; Vaccarezza, Cristina; Vescovi, Mario; Vicario, Carlo

    2005-01-01

    We present the status of the activity on the project PLASMONX, which foresees the installation of a multi-TW Ti:Sa laser system at the CNR-ILIL laboratory to conduct plasma acceleration experiments and the construction of an additional beam line at SPARC to develop a Thomson X-ray source at INFN-LNF. After pursuing self-injection experiments at ILIL, when the electron beam at SPARC will be available the SPARC laser system will be upgraded to TW power level in order to conduct either external injection plasma acceleration experiments and ultra-bright X-ray pulse generation with the Thomson source. Results of numerical simulations modeling the interaction of the SPARC electron beam and the counter-propagating laser beam are presented with detailed discussion of the monochromatic X-ray beam spectra generated by Compton backscattering: X-ray energies are tunable in the range 20 to 1000 keV, with pulse duration from 30 fs to 20 ps. Preliminary simulations of plasma acceleration with self-injection are illustrated,...

  7. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    CERN Document Server

    Tanaka, T; Shinohara, M; Takagi, T

    2002-01-01

    Application of pulsed high negative voltage (approx 10 mu s pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N sub 2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N sub 2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron mic...

  8. Développement d'une source EUV plasma laser pour la micro-lithographie

    Science.gov (United States)

    Segers, M.; Bougeard, M.; Caprin, E.; Ceccotti, T.; Chichmanian, F.; Descamps, D.; Haltebourg, P.; Hergott, J.-F.; Hulin, S.; Normand, D.; Schmidt, M.; Sublemontier, O.

    2003-06-01

    Le Groupe des Applications Plasma (GAP) du CEA à Saclay participe au projet national PREUVE du Réseau Micro- et Nano-Technologies. Ce projet a été lancé fin 1999 pour réunir et développer les compétences en France sur la lithographie dans l'extrême ultraviolet (LEUV). Au sein de PREUVE, notre objectif a été le développement d'une source plasma laser dans I'EUV autour de 13nm afin de contribuer à la réalisation d'un premier banc d'essai pour la lithographie (BEL) en Europe. Afin de réaliser cette source, nous utilisons un plasma émetteur qui est produit par l'interaction d'un laser de type Nd :YAG sur un jet de gouttelettes de xénon. A la fin du projet PREUVE, cette source satisfait les principales spécifications et répond en particulier aux besoins en flux de photons EUV pour réaliser des tests d'insolation EUV avec le banc d'essai. Suite à ces résultats prometteurs, nous démarrons actuellement un projet industriel EXULITE avec nos partenaires du CEA, d'Alcatel et de Thalès sur le développement d'une source EUV de puissance pour des machines de lithographie de production. Ce projet se terminera en 2005.

  9. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy.

    Science.gov (United States)

    Miaja-Avila, L; O'Neil, G C; Uhlig, J; Cromer, C L; Dowell, M L; Jimenez, R; Hoover, A S; Silverman, K L; Ullom, J N

    2015-03-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼10(6) photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10(7) laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  10. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  11. Elk and Deer Study, Material Disposal Area G, Technical Area 54: Source document

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Ferenbaugh; P. R. Fresquez; M. H. Ebinger; G. J. Gonzales; P. A. Jordan

    1999-09-01

    As nuclear research has become more prevalent, environmental contamination from the disposal of radioactive waste has become a prominent issue. At Los Alamos National Laboratory (LANL) in northern New Mexico, radioactive contamination from disposal operations has raised some very specific concerns. Material Disposal Area G (Area G) is the primary low-level radioactive waste disposal site at LANL and occupies an area adjacent to land belonging to the Native American community of the Pueblo of San Ildefonso. Analyses of soil and vegetation collected from the perimeter of Area G have shown concentrations of radionuclides greater than background concentrations established for northern New Mexico. As a result, Pueblo residents had become concerned that contaminants from Area G could enter tribal lands through various ecological pathways. The residents specifically questioned the safety of consuming meat from elk and deer that forage near Area G and then migrate onto tribal lands. Consequently, this study addresses the uptake of {sup 3}H, {sup 90}Sr, {sup tot}U, {sup 238}Pu, {sup 239}Pu, {sup 241}Am, and {sup 137}Cs by elk (Cervus elaphus) and deer (Odocoileus hemionus) that forage around the perimeter of Area G and the associated doses to the animals and to humans who consume these animals. Radionuclide uptake by and internal dose to animals was estimated using equations modified from National Council on Radiological Protection Report 76. The Residual Radiation computer code was used to estimate the external dose to animals and the dose to humans consuming meat. Soil and water concentrations from the perimeter of Area G and from background regions in northern New Mexico were averaged over 4 years (1993--1996) and used as input data for the models. Concentration estimates generated by the model correspond to the concentration range measured in actual tissue samples from elk and deer collected at LANL. The highest dose estimates for both animals (0.028 mrad/d) and humans

  12. Impacts of DEM uncertainties on critical source areas identification for non-point source pollution control based on SWAT model

    Science.gov (United States)

    Xu, Fei; Dong, Guangxia; Wang, Qingrui; Liu, Lumeng; Yu, Wenwen; Men, Cong; Liu, Ruimin

    2016-09-01

    The impacts of different digital elevation model (DEM) resolutions, sources and resampling techniques on nutrient simulations using the Soil and Water Assessment Tool (SWAT) model have not been well studied. The objective of this study was to evaluate the sensitivities of DEM resolutions (from 30 m to 1000 m), sources (ASTER GDEM2, SRTM and Topo-DEM) and resampling techniques (nearest neighbor, bilinear interpolation, cubic convolution and majority) to identification of non-point source (NPS) critical source area (CSA) based on nutrient loads using the SWAT model. The Xiangxi River, one of the main tributaries of Three Gorges Reservoir in China, was selected as the study area. The following findings were obtained: (1) Elevation and slope extracted from the DEMs were more sensitive to DEM resolution changes. Compared with the results of the 30 m DEM, 1000 m DEM underestimated the elevation and slope by 104 m and 41.57°, respectively; (2) The numbers of subwatersheds and hydrologic response units (HRUs) were considerably influenced by DEM resolutions, but the total nitrogen (TN) and total phosphorus (TP) loads of each subwatershed showed higher correlations with different DEM sources; (3) DEM resolutions and sources had larger effects on CSAs identifications, while TN and TP CSAs showed different response to DEM uncertainties. TN CSAs were more sensitive to resolution changes, exhibiting six distribution patterns at all DEM resolutions. TP CSAs were sensitive to source and resampling technique changes, exhibiting three distribution patterns for DEM sources and two distribution patterns for DEM resampling techniques. DEM resolutions and sources are the two most sensitive SWAT model DEM parameters that must be considered when nutrient CSAs are identified.

  13. Large diameter permanent-magnets-expanded plasma source for spontaneous generation of low-energy ion beam.

    Science.gov (United States)

    Takahashi, Kazunori; Suzuki, Tatsuya; Ando, Akira

    2014-02-01

    Diameter of a permanent-magnets-expanded, radiofrequency (rf) plasma source is enlarged up to ∼13 cm for an application to a space propulsion device and tested with being attached to a diffusion chamber. The source is operated at 13.56 MHz 300 W rf power in low-pressure (40 mPa) argon. Measurement of ion energy distribution functions downstream of the source exit shows generation of a supersonic ion beam of about 20 eV. The detailed radial measurements demonstrate that the diameter and energy of the ion beam corresponds to the source tube diameter and the potential difference between the source and downstream plasmas, and that the radial profile of the beam flux is similar to the plasma density profile in the source cavity.

  14. ELM simulation experiments on Pilot-PSI using simultaneous high flux plasma and transient heat/particle source

    NARCIS (Netherlands)

    De Temmerman, G.; Zielinski, J. J.; van Diepen, S.; Marot, L.; Price, M.

    2011-01-01

    A new experimental setup has been developed for edge localized mode (ELM) simulation experiments with relevant steady-state plasma conditions and transient heat/particle source. The setup is based on the Pilot-PSI linear plasma device and allows the superimposition of a transient heat/particle pulse

  15. Recent performance of and plasma outage studies with the SNS H- source

    Science.gov (United States)

    Stockli, M. P.; Han, B.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R.

    2016-02-01

    Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ˜55-kW 2-MHz plasma pulses reflecting ˜90% of the continuous ˜300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H2 gas also increased the H- beam current to ˜55 mA and increased the RFQ transmission by ˜7% (relative).

  16. A versatile, pulsed anion source utilizing plasma-entrainment: Characterization and applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yu-Ju; Lehman, Julia H.; Lineberger, W. Carl, E-mail: wcl@jila.colorado.edu [JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309 (United States)

    2015-01-28

    A novel pulsed anion source has been developed, using plasma entrainment into a supersonic expansion. A pulsed discharge source perpendicular to the main gas expansion greatly reduces unwanted “heating” of the main expansion, a major setback in many pulsed anion sources in use today. The design principles and construction information are described and several examples demonstrate the range of applicability of this anion source. Large OH{sup −}(Ar){sub n} clusters can be generated, with over 40 Ar solvating OH{sup −}. The solvation energy of OH{sup −}(Ar){sub n}, where n = 1-3, 7, 12, and 18, is derived from photoelectron spectroscopy and shows that by n = 12-18, each Ar is bound by about 10 meV. In addition, cis– and trans– HOCO{sup −} are generated through rational anion synthesis (OH{sup −} + CO + M → HOCO{sup −} + M) and the photoelectron spectra compared with previous results. These results, along with several further proof-of-principle experiments on solvation and transient anion synthesis, demonstrate the ability of this source to efficiently produce cold anions. With modifications to two standard General Valve assemblies and very little maintenance, this anion source provides a versatile and straightforward addition to a wide array of experiments.

  17. A versatile, pulsed anion source utilizing plasma-entrainment: Characterization and applications

    Science.gov (United States)

    Lu, Yu-Ju; Lehman, Julia H.; Lineberger, W. Carl

    2015-01-01

    A novel pulsed anion source has been developed, using plasma entrainment into a supersonic expansion. A pulsed discharge source perpendicular to the main gas expansion greatly reduces unwanted "heating" of the main expansion, a major setback in many pulsed anion sources in use today. The design principles and construction information are described and several examples demonstrate the range of applicability of this anion source. Large OH-(Ar)n clusters can be generated, with over 40 Ar solvating OH-. The solvation energy of OH-(Ar)n, where n = 1-3, 7, 12, and 18, is derived from photoelectron spectroscopy and shows that by n = 12-18, each Ar is bound by about 10 meV. In addition, cis- and trans- HOCO- are generated through rational anion synthesis (OH- + CO + M → HOCO- + M) and the photoelectron spectra compared with previous results. These results, along with several further proof-of-principle experiments on solvation and transient anion synthesis, demonstrate the ability of this source to efficiently produce cold anions. With modifications to two standard General Valve assemblies and very little maintenance, this anion source provides a versatile and straightforward addition to a wide array of experiments.

  18. Fluorination of edges and central areas of monolayer graphene by SF6 and CHF3 plasma treatments.

    Science.gov (United States)

    Chen, Minjiang; Qiu, Caiyu; Zhou, Haiqing; Yang, Huaichao; Yu, Fang; Sun, Lianfeng

    2013-02-01

    In this work, we report the fluorination of edges and central areas of monolayer graphene by SF6 and CHF3 plasma treatments. After fluorination by SF6 plasma, G and 2D peaks of Raman spectroscopy for the edges have upshifts, which are much bigger than the upshifts for central areas of monolayer graphene. For the intensity ratio of I(2D)/I(G), it becomes smaller after SF6 plasma treatments and magnitude of change is similar for the edges and that of the central areas. These observations indicate that the fluorination by SF6 plasma treatments can induce p-doping to graphene, which is more significant for the edges comparing to the central areas. Moreover, the ratio of I(D)/I(G) becomes larger both for the edges and the central areas. For CHF3 plasma treatments, although similar results can be obtained, the p-doping to graphene is less and more defects are introduced comparing to SF6 plasma treatment. Therefore, for fluorination of monolayer graphene, SF6 plasma is better than CHF3 plasma.

  19. Laser-plasma EUV source dedicated for surface processing of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Bartnik, A., E-mail: abartnik@wat.edu.pl [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Szczurek, M.; Wachulak, P.W. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland)

    2011-08-11

    In this work, a 10 Hz laser-plasma extreme ultraviolet (EUV) source built for surface processing of polymers is presented. The source is based on a double-stream gas puff target created in a vacuum chamber synchronously with the pumping laser pulse. The target is formed by pulsed injection of Kr, Xe or a KrXe gas mixture into a hollow stream of helium. The EUV radiation is focused using a grazing incidence gold-plated ellipsoidal collector. Spectrum of the reflected radiation consists of a narrow feature with intensity maximum at 10-11 nm wavelength and a long-wavelength spectral tail up to 70 nm. The exact spectral distribution depends on a gas applied for plasma creation. To avoid strong absorption of the EUV radiation in a residual gas present in the chamber during the source operation a two step differential pumping system was employed. The system allows for polymer processing under relatively high vacuum conditions (10{sup -5} mbar) or in a reactive gas atmosphere. Polymer samples can be irradiated in a focal plane of the EUV collector or at some distance downstream the focal plane. This way fluence of the EUV beam at the polymer surface can be regulated.

  20. Vacuum arc with a distributed cathode spot as a plasma source for plasma separation of spent nuclear fuel and radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Amirov, R. Kh., E-mail: ravus46@yandex.ru; Vorona, N. A.; Gavrikov, A. V.; Lizyakin, G. D.; Polishchuk, V. P.; Samoilov, I. S.; Smirnov, V. P.; Usmanov, R. A.; Yartsev, I. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    Results from experimental studies of a vacuum arc with a distributed cathode spot on the heated cathode are presented. Such an arc can be used as a plasma source for plasma separation of spent nuclear fuel and radioactive waste. The experiments were performed with a gadolinium cathode, the properties of which are similar to those of an uranium arc cathode. The heat flux from the plasma to the cathode (and its volt equivalent) at discharge voltages of 4-15 V and discharge currents of 44-81 A, the radial distribution of the emission intensity of gadolinium atoms and singly charged ions in the arc channel at a voltage of 4.3 V, and the plasma electron temperature behind the anode were measured. The average charge of plasma ions at arc voltages of 3.5-8 V and a discharge current of 52 A and the average rate of gadolinium evaporation in the discharge were also determined.

  1. Plasma Selenium Measurements in Subjects from Areas with Contrasting Gastric Cancer Risks in Colombia

    Science.gov (United States)

    Camargo, Maria Constanza; Burk, Raymond F.; Bravo, Luis E.; Piazuelo, Maria B.; Hill, Kristina E.; Fontham, Elizabeth T.; Motley, Amy K.; Yepez, Maria C.; Mora, Yolanda; Schneider, Barbara G.; Correa, Pelayo

    2008-01-01

    Background An inverse association between selenium status and incidence of different neoplasias including gastric cancer has been reported. This pilot study aimed to determine and compare selenium status in two Colombian populations with different gastric cancer risks: a high-risk area in the volcanic region of the Andes Mountains and a low-risk area on the Pacific coast. Methods Eighty nine adult males were recruited in the outpatient clinics of two public hospitals (44 and 45 from high- and low-risk areas, respectively) and provided a blood sample. Seventy one (79.8%) participants underwent upper gastrointestinal endoscopy. Plasma selenium was assayed using a fluorometric method, selenoprotein-P by ELISA, and glutathione peroxidase activity by a spectrophometric method. Histological diagnosis and Helicobacter pylori infection were evaluated in gastric biopsy samples. Unpaired samples t-test and linear regression analyses were used for statistical analyses. Results Although none of the subjects in either of the two geographic areas was selenium deficient, the level of plasma selenium was significantly lower in men from the high-risk area compared with those from the low-risk area. Levels of selenoprotein-P and glutathione peroxidase activity were similar between groups after adjustment for confounders. Selenium measurements were not associated with histopathological diagnosis. Conclusions The high incidence of gastric cancer in the Andean region of Colombia is unlikely to be explained by selenium deficiency. We cannot exclude, however, that suboptimal selenium levels may exist in the gastric mucosa of subjects in the high-risk area. Therefore, the benefit of selenium supplementation in gastric cancer prevention cannot be dismissed. PMID:18375257

  2. Thermo-mechanical design of the Plasma Driver Plate for the MITICA ion source

    Energy Technology Data Exchange (ETDEWEB)

    Pavei, Mauro, E-mail: mauro.pavei@igi.cnr.it [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy); Palma, Mauro Dalla; Marcuzzi, Diego [Consorzio RFX, EURATOM-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy)

    2010-12-15

    In the framework of the activities for the development of the Neutral Beam Injector (NBI) for ITER, the detailed design of the Radio-Frequency (RF) negative ion source has been carried out. One of the most heated components of the RF source is the rear vertical plate, named Plasma Driver Plate (PDP), where the Back-Streaming positive Ions (BSI+) generated from stripping losses in the accelerator and back scattered on the plasma source impinge on. The heat loads that result are huge and concentrated, with first estimate of the power densities up to 60 MW/m{sup 2}. The breakdowns that occur into the accelerator cause such heat loads to act cyclically, so that the PDP is thermo-mechanically fatigue loaded. Moreover, the surface of the PDP facing the plasma is functionally required to be temperature controlled and to be molybdenum or tungsten coated. The thermo-hydraulic design of the plate has been carried out considering active cooling with ultra-pure water. Different heat sink materials, hydraulic circuit layout and manufacturing processes have been considered. The heat exhaust has been optimized by changing the channels geometry, the path of the heat flux in the heat sink, the thickness of the plate and maximizing the Heat Transfer Coefficient. Such optimization has been carried out by utilizing 3D Finite Element (FE) models. Afterwards all the suitable mechanical (aging, structural monotonic and cyclic) verifications have been carried out post-processing the results of the thermo-mechanical 3D FE analyses in accordance to specific procedures for nuclear components exposed to high temperature. The effect of sputtering phenomenon due to the high energy BSI+ impinging on the plate has been considered and combined with fatigue damage for the mechanical verification of the PDP. Alternative solutions having molybdenum (or tungsten coatings) facing the plasma, aiming to reduce the sputtering rate and the consequent plasma pollution, have been evaluated and related 3D FE

  3. Pollution sources identification of polycyclic aromatic hydrocarbons of soils in Tianjin area, China

    Energy Technology Data Exchange (ETDEWEB)

    Ye, B.X.; Zhang, Z.H.; Mao, T. [University of Petroleum, Beijing (China). Faculty of Natural Resources & Information Technology

    2006-07-15

    A total of 188 surface soil samples were collected from different types of utilization soils in Tianjin area. Factor analysis and scatter point surface tension spine function interpolation were used to analyze types and spatial distributions of PAH sources of surface soils in Tianjin area. The results showed that most pollution sources were mixed sources including coal burning and petroleum spill. Mixed sources occupied 56.12%, 58.96%, 46.45% and 59.50% in farmland of wastewater irrigation, common farmland, wild land and city green-belt, respectively. Other pollution sources such as vehicle emission, biogenic conversion, wood burning and natural gas combustion were also significant. The spatial distributions of pollution sources were closely related to geographic location, geographic condition and living habit of indigenes.

  4. Source segregation of food waste in office areas: Factors affecting waste generation rates and quality

    DEFF Research Database (Denmark)

    Edjabou, Vincent Maklawe Essonanawe; Boldrin, Alessio; Scheutz, Charlotte

    2015-01-01

    Existing legislation mandates that the amount of waste being recycled should be increased. Among others, in its Resource Strategy Plan, the Danish Government decided that at least 60% of food waste generated by the service sector, including in office areas, should be source-sorted and collected...... separately by 2018. To assess the achievability of these targets, source-sorted food waste and residual waste from office areas was collected and weighed on a daily basis during 133 working days. Waste composition analyses were conducted every week to investigate the efficiency of the source-sorting campaign...... and the purity of the source-sorted food waste. The moisture content of source-sorted food waste and residual waste fractions, and potential methane production from source-sorted food waste, was also investigated.Food waste generation equated to 23. ±. 5. kg/employee/year, of which 20. ±. 5. kg...

  5. 76 FR 13514 - National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources

    Science.gov (United States)

    2011-03-14

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION... Manufacturing Area Sources AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is issuing this final rule to stay the requirement for certain affected sources to comply with the title...

  6. Catalytic action of β source on x-ray emission from plasma focus

    Science.gov (United States)

    Ahmad, S.; Sadiq, Mehboob; Hussain, S.; Shafiq, M.; Zakaullah, M.; Waheed, A.

    2006-01-01

    The influence of preionization around the insulator sleeve by a mesh-type β source (Ni6328) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4π geometry is measured as a function of argon and hydrogen gas filling pressures with and without β source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the β source. With argon, the CuKα emission is estimated to be 27.14 J with an efficiency of 0.7% for β source and 21.5 J with an efficiency of 0.55% without β source. The maximum x-ray yield in 4π geometry is found to be about 68.90 J with an efficiency of 1.8% for β source and 54.58 J with an efficiency of 1.4% without β source. With hydrogen, CuKα emission is 11.82 J with an efficiency of 0.32% for β source and 10.07 J with an efficiency of 0.27% without β source. The maximum x-ray yield in 4π geometry is found to be 30.20 J with an efficiency of 0.77% for β source and 25.58 J with an efficiency of 0.6% without β source. The x-ray emission with Pb insert at the anode tip without β source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4π geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without β source.

  7. Simulation methods of ion sheath dynamics in plasma source ion implantation

    Institute of Scientific and Technical Information of China (English)

    WANG Jiuli; ZHANG Guling; WANG Younian; LIU Yuanfu; LIU Chizi; YANG Size

    2004-01-01

    Progress of the theoretical studies on the ion sheath dynamics in plasma source ion implantation (PSII) is reviewed in this paper. Several models for simulating the ion sheath dynamics in PSII are provided. The main problem of nonuniform ion implantation on the target in PSII is discussed by analyzing some calculated results. In addition, based on the relative researches in our laboratory, some calculated results of the ion sheath dynamics in PSII for inner surface modification of a cylindrical bore are presented. Finally, new ideas and tendency for future researches on ion sheath dynamics in PSII are proposed.

  8. Interaction of plasmas in laser ion source with double laser system

    Energy Technology Data Exchange (ETDEWEB)

    Fuwa, Y., E-mail: yasuhiro.fuwa@riken.jp [Graduate School of Science, Kyoto University, Kyoto (Japan); Riken, Wako, Saitama (Japan); Ikeda, S. [Riken, Wako, Saitama (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Tokyo (Japan); Kumaki, M. [Riken, Wako, Saitama (Japan); Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo (Japan); Sekine, M. [Riken, Wako, Saitama (Japan); Department of Nuclear Engineering, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Cinquegrani, D. [Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Romanelli, M. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850 (United States); Kanesue, T.; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Iwashita, Y. [Institute for Chemical Research, Kyoto University, Uji, Kyoto (Japan)

    2014-02-15

    Multiple laser shots could be used to elongate an ion beam pulse width or to intensify beam current from laser ion sources. In order to confirm the feasibility of the multiple shot scheme, we investigated the properties of plasmas produced by double laser shots. We found that when the interval of the laser shots is shorter than 10 μs, the ion current profile had a prominent peak, which is not observed in single laser experiments. The height of this peak was up to five times larger than that of single laser experiment.

  9. Compact Cryogenic Source of Periodic Hydrogen and Argon Droplet Beams for Intense Laser-Plasma Generation

    CERN Document Server

    Fraga, R A Costa; Kühnel, M; Hochhaus, D C; Schottelius, A; Polz, J; Kaluza, M C; Neumayer, P; Grisenti, R E

    2011-01-01

    We present a cryogenic source of periodic streams of micrometer-sized hydrogen (H2) and argon (Ar) droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art low-repetition rate high-power lasers, in which a precise synchronization between the laser pulses and the droplets is mandatory. We demonstrate this explicitly by irradiating Ar droplets with pulses from a Petawatt laser.

  10. Compact cryogenic source of periodic hydrogen and argon droplet beams for relativistic laser-plasma generation

    Energy Technology Data Exchange (ETDEWEB)

    Fraga, R. A. Costa; Kalinin, A.; Kuehnel, M.; Schottelius, A. [Institut fuer Kernphysik, J. W. Goethe-Universitaet, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Hochhaus, D. C.; Neumayer, P. [EMMI Extreme Matter Institute and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany); FIAS Frankfurt Institute for Advanced Studies, J. W. Goethe-Universitaet, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Polz, J. [Institut fuer Optik und Quantenelektronik, Max-Wien-Platz 1, 07743 Jena (Germany); Kaluza, M. C. [Institut fuer Optik und Quantenelektronik, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Froebelstieg 3, 07743 Jena (Germany); Grisenti, R. E. [Institut fuer Kernphysik, J. W. Goethe-Universitaet, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, 64291 Darmstadt (Germany)

    2012-02-15

    We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art high-power lasers in which a precise synchronization between the laser pulses and the droplets is mandatory. We show this by irradiating argon droplets with multi-terawatt pulses.

  11. Diagnosis of Hydrogen Plasma in a Miniature Penning Ion Source by Double Probes

    Institute of Scientific and Technical Information of China (English)

    JIN Dazhi; YANG Zhonghai; XIAO Kunxiang; DAI Jingyi

    2009-01-01

    Parameters of hydrogen plasma in a miniature Penning discharge ion source,including the electron temperature and the electron density,were measured by using double probes.The results indicate that the electron density increases and the electron temperature decreases with the increase in gas pressure and the discharge current.The electron temperature is about 5~9 eV and the electron density is 6.0x1013~1.2×1014 m-3 while the discharge current is in a range of 50~12μA.

  12. Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, T., E-mail: shibat@post.j-parc.jp; Ueno, A.; Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Naito, F. [J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Nishida, K.; Mochizuki, S.; Hatayama, A. [Keio University, Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Mattei, S.; Lettry, J. [European Organization for Nuclear Research (CERN), 1211 Geneva 23 (Switzerland)

    2016-02-15

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30–120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

  13. The European large area ISO survey - III. 90-mu m extragalactic source counts

    DEFF Research Database (Denmark)

    Efstathiou, A.; Oliver, S.; Rowan-Robinson, M.

    2000-01-01

    We present results and source counts at 90 mum extracted from the preliminary analysis of the European Large Area ISO Survey (ELAIS). The survey covered about 12 deg(2) of the sky in four main areas and was carried out with the ISOPHOT instrument onboard the Infrared Space Observatory (ISO...

  14. Investigation of the dynamics of the Z-pinch imploding plasma for a laser-assisted discharge-produced Sn plasma EUV source

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Q; Yamada, J; Kishi, N; Watanabe, M; Okino, A; Horioka, K; Hotta, E, E-mail: zhu.q.ab@m.titech.ac.jp [Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta 4259 J2-35, Midori-ku, Yokohama 226-8502 (Japan)

    2011-04-13

    Dynamics of the imploding plasma and its relations to the 13.5 nm EUV emissions have been experimentally investigated for a laser-assisted Sn based discharge-produced plasma EUV source. The behaviours and two-dimensional electron density distributions of the EUV-emitting plasma were obtained using the time-resolved shadowgraph and Nomarski interferometric techniques. Observation of the plasma piston in the prepinch phase justified the validity of the zero-dimensional thin-shell model, from which the ion charge state of the prepinch plasma in the cathode region was estimated. The sausage (m = 0) instability that usually enhances the EUV emission was observed, with the radial electron density distribution that displays a concave shape at the crest of the plasma and a bell shape at the neck; the maximum of the electron density is located at one peak of the concave distribution at the crest instead of the neck. Intense EUV emission was produced by the Z-pinch plasma with the electron density (2.0-3.0) x 10{sup 18} cm{sup -3}. Moreover, the shock waves generated in the anode region can also produce in-band EUV emission with the intensity of 30% of that from the Z-pinch plasma.

  15. Tunable room temperature terahertz sources based on two dimensional plasma instability in GaN HEMTs

    Science.gov (United States)

    El Fatimy, A.; Suemitsu, T.; Otsuji, T.; Dyakonova, N.; Knap, W.; Meziani, Y. M.; Vandenbrouk, S.; Madjour, K.; Théron, D.; Gaquiere, Ch; Prystawko, P.; Skierbiszewski, C.

    2009-11-01

    In this work, we report on room temperature terahertz radiation from sub-micron size GaN/AlGaN based high electron mobility transistors (HEMTs). They could successfully replace the standard Fourier Transform spectrometer source and were investigated with a standard Si-bolometer as a detector. The relatively broad (~1THz) emission line was observed. The maxima were found to be tunable by the gate voltage between 0.75 and 2.1 THz. The observed emission was interpreted as due to the current driven plasma waves instability in the two-dimensional electron gas. The emitted power from a single device reached 150 nW, showing possible application of these transistors as compact sources for terahertz spectroscopy and imaging.

  16. Tunable room temperature terahertz sources based on two dimensional plasma instability in GaN HEMTs

    Energy Technology Data Exchange (ETDEWEB)

    Fatimy, A El; Suemitsu, T; Otsuji, T; Knap, W [Research Institute of Electrical Communication (RIEC), Tohoku University, 2-1-1 Katahira, Aoba-Ku, 980-8577, Sendai (Japan); Dyakonova, N [Groupe d' Etude des Semiconducteurs, UMR CNRS 5650, Universite Montpellier 2, 34095 Montpellier (France); Meziani, Y M [Dpto. de Fisica Aplicada, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain); Vandenbrouk, S; Madjour, K; Theron, D; Gaquiere, Ch [Institut d' Electronique et de Microelectronique du Nord, UMR CNRS 8520, 59655 Villeneuve d' Acsq (France); Prystawko, P; Skierbiszewski, C, E-mail: a.elfatimy@riec.tohoku.ac.j, E-mail: ElFatimyA@cardiff.ac.u [Institutes of High Pressure Physics, PAS, Unipress, Sokolowska 29/37, 01-142 Warsaw (Poland)

    2009-11-15

    In this work, we report on room temperature terahertz radiation from sub-micron size GaN/AlGaN based high electron mobility transistors (HEMTs). They could successfully replace the standard Fourier Transform spectrometer source and were investigated with a standard Si-bolometer as a detector. The relatively broad ({approx}1THz) emission line was observed. The maxima were found to be tunable by the gate voltage between 0.75 and 2.1 THz. The observed emission was interpreted as due to the current driven plasma waves instability in the two-dimensional electron gas. The emitted power from a single device reached 150 nW, showing possible application of these transistors as compact sources for terahertz spectroscopy and imaging.

  17. MIT modular x-ray source systems for the study of plasma diagnostics

    Science.gov (United States)

    Coleman, J. W.; Wenzel, K. W.; Petrasso, R. D.; Lo, D. H.; Li, C. K.; Lierzer, J. R.; Wei, T.

    1992-10-01

    Two new x-ray source systems are now on line at our facility. Each provides an e-beam to 25 kV. Targets are interchangeable between machines, and four x-ray detectors may be used simultaneously with a target. The gridded e-gun of the RACEHORSE system gives a 0.5-1.0-cm pulsable spot on target. The nongridded e-gun of the SCORPION system provides a 0.3-mm or smaller dc microspot on target. RACEHORSE is being used to study and characterize type-II diamond photoconductors for use in diagnosing plasmas, while SCORPION is being used to develop a slitless spectrograph using photographic film. Source design details and some RACEHORSE results are presented.

  18. Feasibility analysis of a Plasma Focus neutron source for BNCT treatment of transplanted human liver

    Science.gov (United States)

    Benzi, V.; Mezzetti, F.; Rocchi, F.; Sumini, M.

    2004-01-01

    Boron Neutron Capture Therapy preliminary treatments on transplanted human liver have been recently conducted at Pavia University. The need of high fluences of thermal neutrons imposed the use of the available thermal channel of a TRIGA reactor properly modified for this application. We analyse the possibility of using the Plasma Focus (PF) machine as a pulsed neutron source for this medical application instead of a nuclear reactor. Thermalization of the fast (2.45 MeV for D-D reactions) neutrons produced by the PF is gained with a paraffin or polyethylene moderator which contains both the neutron source and the irradiation chamber. The design parameters of a PF optimized for such an application are discussed, as well as other considerations on the advantages that this machine can bring to this kind of cancer therapy.

  19. Concept of a laser-plasma based electron source for sub-10 fs electron diffraction

    CERN Document Server

    Faure, J; Beaurepaire, B; Gallé, G; Vernier, A; Lifschitz, A

    2015-01-01

    We propose a new concept of an electron source for ultrafast electron diffraction with sub-10~fs temporal resolution. Electrons are generated in a laser-plasma accelerator, able to deliver femtosecond electron bunches at 5 MeV energy with kHz repetition rate. The possibility of producing this electron source is demonstrated using Particle-In-Cell simulations. We then use particle tracking simulations to show that this electron beam can be transported and manipulated in a realistic beamline, in order to reach parameters suitable for electron diffraction. The beamline consists of realistic static magnetic optics and introduces no temporal jitter. We demonstrate numerically that electron bunches with 5~fs duration and containing 1.5~fC per bunch can be produced, with a transverse coherence length exceeding 2~nm, as required for electron diffraction.

  20. Temperature of the Source Plasma in Gradual Solar Energetic Particle Events

    CERN Document Server

    Reames, Donald V

    2015-01-01

    Scattering, during interplanetary transport in large, "gradual" solar energetic-particle (SEP) events, can cause element abundance enhancements or suppressions that depend upon the mass-to-charge ratio A/Q of the ions as an increasing power law early in events and a decreasing power law of the residual ions later. Since the Q values for the ions depend upon the source plasma temperature T, best fits to the power-law dependence of enhancements vs. A/Q provide a fundamentally new method to determine the most probable value of T for these events. We find that fits to the times of increasing and decreasing powers give similar values of T, most commonly (69%) in the range of 0.8-1.6 MK, consistent with the acceleration of ambient coronal plasma by shock waves driven out from the Sun by coronal mass ejections (CMEs). However, 24% of the SEP events studied showed plasma of 2.5-3.2 MK, typical of that previously determined for the smaller impulsive SEP events; these particles may be reaccelerated preferentially by qu...

  1. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    Science.gov (United States)

    Adjei, Daniel; Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk; Vyšín, Luděk; Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M.; Pina, Ladislav; Davídková, Marie; Juha, Libor

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray "water window" spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280-540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 103 photons/μm2/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms' sensitivity to pulsed radiation in the "water window", where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET - Linear Energy Transfer) and dose-rate effects in radiobiology.

  2. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    Energy Technology Data Exchange (ETDEWEB)

    Adjei, Daniel, E-mail: nana.adjeidan@gmail.com [Institute of Optoelectronics, Military University of Technology, 2, Kaliskiego Str., 00-908 Warsaw (Poland); Radiation Protection Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk [Institute of Optoelectronics, Military University of Technology, 2, Kaliskiego Str., 00-908 Warsaw (Poland); Vyšín, Luděk [Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Faculty of Nuclear Sciences and Engineering Physics, Czech Technical University in Prague, Břehová 7, 115 19 Prague 1 (Czech Republic); Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M. [Institute of Nuclear Physics, Polish Academy of Sciences, 152, Radzikowskiego Str., 31-342 Cracow (Poland); Pina, Ladislav [Faculty of Nuclear Sciences and Engineering Physics, Czech Technical University in Prague, Břehová 7, 115 19 Prague 1 (Czech Republic); Davídková, Marie [Institute of Nuclear Physics, Czech Academy of Sciences, Řež (Czech Republic); Juha, Libor [Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray “water window” spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280–540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 10{sup 3} photons/μm{sup 2}/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms’ sensitivity to pulsed radiation in the “water window”, where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET – Linear Energy Transfer) and dose-rate effects in radiobiology.

  3. Afterglow of a microwave microstrip plasma as an ion source for mass spectrometry

    Science.gov (United States)

    Pfeuffer, Kevin P.; White, Allen; Broekaert, José A. C.; Hieftje, Gary M.

    2015-01-01

    A microwave-induced plasma that was previously used for optical emission spectrometry has been repurposed as an afterglow ion source for mass spectrometry. This compact microwave discharge, termed the microstrip plasma (MSP), is operated at 20-50 W and 2.45 GHz in helium at a flow of 300 mL/min. The primary background ions present in the afterglow are ionized and protonated water clusters. An exponential dilution chamber was used to introduce volatile organic compounds into the MSP afterglow and yielded limits of detection in the 40 ppb to 7 ppm range (v/v). A hydride-generation system was also utilized for detection of volatile hydride-forming elements (arsenic, antimony, tin) in the afterglow and produced limits of detection in the 10-100 ppb range in solution. The MSP afterglow was found capable of desorption and ionization of analyte species directly from a solid substrate, suggesting its use as an ion source for ambient desorption/ionization mass spectrometry.

  4. Effect of Dietary Inulin Source on Piglet Performance, Immunoglobulin Concentration, and Plasma Lipid Profile

    Directory of Open Access Journals (Sweden)

    Grela Eugeniusz R.

    2014-10-01

    Full Text Available The aim of the study was to evaluate the effect of an inulin source (aqueous or aqueous-alcoholic extract, dried chicory root, or dried Jerusalem artichoke tubers on piglet performance, plasma lipid profile, and immunoglobulin concentration. The study was conducted on 534 piglets (44 litters allocated to five nutritional groups: group I (control - fed basal diet, groups II and III receiving basal diet supplemented with 2% of inulin (aqueous and aqueous-alcoholic extract respectively, and groups IV and V -4% additive of dried artichoke or dried chicory respectively. During the trial, piglets’ body weight, feed intake, diarrhoea incidence, and mortality were controlled. Blood samples were collected twice from six animals of each group. In blood plasma, indices of lipid profile and concentrations of IgA, IgG and IgM were measured. The addition of inulin, regardless of its form (extracts or dried plants, significantly improved the rearing indices. In piglets of groups III, IV and V a significant improvement of daily weight gains and feed efficiency was noted. Inulin showed hypolipidemic activity (lowered total cholesterol level and stimulated piglet immune system manifested by elevated IgA and IgG concentrations. Irrespective of the inulin source, a lower mortality rate resulting from the improvement of animal health was noted in all experimental groups.

  5. Progress in Development of Dense Plasma Focus Pinch for AmBe Radiological Source Replacement

    Science.gov (United States)

    Falabella, Steve; Povilus, Alex; Schmidt, Andrea; Ellsworth, Jennifer; Link, Anthony; Sears, Jason; Higginson, Drew; Jiang, Sheng

    2015-11-01

    A dense plasma focus (DPF) is a compact plasma gun accelerator that can produce intense, high energy ion beams (multiple MeV). These ion beams could be used to replace radiological sources for a variety of applications. Using a 2kJ DPF with a helium gas fill, alpha particles are accelerated into a beryllium target in order to generate a neutron spectrum similar to an AmBe source. We report on initial observations of neutron yields for this system and efforts to optimize and improve repeatability of pinch performance. In particular, incorporating results from newly-developed kinetic LSP simulations, we demonstrated higher neutron yields by adjusting the geometry of the anode electrode. In addition, we present preliminary measurements for energy distributions of ions accelerated by the pinch. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work supported by US DOE/NA-22 Office of Non-proliferation Research and Development.

  6. First beam measurements on the vessel for extraction and source plasma analyses (VESPA) at the Rutherford Appleton Laboratory (RAL)

    Energy Technology Data Exchange (ETDEWEB)

    Lawrie, Scott R., E-mail: scott.lawrie@stfc.ac.uk [ISIS Neutron and Muon Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, OX11 0QX (United Kingdom); John Adams Institute for Accelerator Science, Department of Physics, University of Oxford (United Kingdom); Faircloth, Daniel C.; Letchford, Alan P.; Perkins, Mike; Whitehead, Mark O.; Wood, Trevor [ISIS Neutron and Muon Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, OX11 0QX (United Kingdom)

    2015-04-08

    In order to facilitate the testing of advanced H{sup −} ion sources for the ISIS and Front End Test Stand (FETS) facilities at the Rutherford Appleton Laboratory (RAL), a Vessel for Extraction and Source Plasma Analyses (VESPA) has been constructed. This will perform the first detailed plasma measurements on the ISIS Penning-type H{sup −} ion source using emission spectroscopic techniques. In addition, the 30-year-old extraction optics are re-designed from the ground up in order to fully transport the beam. Using multiple beam and plasma diagnostics devices, the ultimate aim is improve H{sup −} production efficiency and subsequent transport for either long-term ISIS user operations or high power FETS requirements. The VESPA will also accommodate and test a new scaled-up Penning H{sup −} source design. This paper details the VESPA design, construction and commissioning, as well as initial beam and spectroscopy results.

  7. A two-stream plasma electron microwave source for high-power millimeter wave generation, phase 1

    Science.gov (United States)

    Guest, Gareth E.; Dandl, Raphael A.

    1989-03-01

    A novel high power millimeter/microwave source is proposed in which one or more pairs of interpenetrating streams of electrons, flowing through a background plasma in a static magnetic field are used to generate a hot-electron plasma that is confined in a mirror-like magnetic field. Energy stored in the anisotropic, hot-electron plasma is then used to amplify pulses of unstable plasma waves to large amplitude by selective deactivation of mechanisms that stabilize the hot-electron plasma during the energy accumulation phase when the density of hot electrons is rapidly increased through the beam-plasma interaction. The Phase 1 program has yielded a design for an experimental arrangement capable of verifying the key aspects of this novel source concept, as well as a theoretical framework for interpreting the empirical Phase 2 results produced by the experimental device and extrapolating those results to evaluate the suitability of the proposed source to meet the requirements of various high power microwave and millimeter wave defense and industrial applications. The experiments will be carried out in a timely and cost-effective way by employing the AMPHED (a CW magetic mirror) experimental facility at Applied Microwave Plasma Concepts (AMPC).

  8. Neutron generator for BNCT based on high current ECR ion source with gyrotron plasma heating.

    Science.gov (United States)

    Skalyga, V; Izotov, I; Golubev, S; Razin, S; Sidorov, A; Maslennikova, A; Volovecky, A; Kalvas, T; Koivisto, H; Tarvainen, O

    2015-12-01

    BNCT development nowadays is constrained by a progress in neutron sources design. Creation of a cheap and compact intense neutron source would significantly simplify trial treatments avoiding use of expensive and complicated nuclear reactors and accelerators. D-D or D-T neutron generator is one of alternative types of such sources for. A so-called high current quasi-gasdynamic ECR ion source with plasma heating by millimeter wave gyrotron radiation is suggested to be used in a scheme of D-D neutron generator in the present work. Ion source of that type was developed in the Institute of Applied Physics of Russian Academy of Sciences (Nizhny Novgorod, Russia). It can produce deuteron ion beams with current density up to 700-800 mA/cm(2). Generation of the neutron flux with density at the level of 7-8·10(10) s(-1) cm(-2) at the target surface could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV. Estimations show that it is enough for formation of epithermal neutron flux with density higher than 10(9) s(-1) cm(-2) suitable for BNCT. Important advantage of described approach is absence of Tritium in the scheme. First experiments performed in pulsed regime with 300 mA, 45 kV deuteron beam directed to D2O target demonstrated 10(9) s(-1) neutron flux. This value corresponds to theoretical estimations and proofs prospects of neutron generator development based on high current quasi-gasdynamic ECR ion source.

  9. Kilohertz sources of hard x rays and fast ions with femtosecond laser plasmas

    Science.gov (United States)

    Thoss, A.; Richardson, M.; Korn, G.; Faubel, M.; Stiel, H.; Vogt, U.; Elsaesser, T.

    2003-01-01

    We demonstrate a new, stable, kilohertz femtosecond laser plasma source of hard-x-ray continuum and Kα emission that uses a microscopic liquid jet target that is continuous and debris free. Plasmas produced by ultrashort (50-fs) intense laser pulses from a fine (10-30-μm diameter) liquid Ga jet emit bright 9.3- and 10.3-keV Kα and Kβ lines superimposed on a multikilovolt bremmstrahlung continuum. Kilohertz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high-intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot to shot and debris free. Our target provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We show the hard-x-ray spectrum described above. The source was generated by a 50-fs-duration, 1-kHz, 2-W, high-intensity Ti:sapphire laser. Using the same technology, we also generate forward-going sub-mega-electron-volt (sub-MeV) protons from a 10-μm liquid water target at 1-kHz repetition rates. Kilohertz sources of high-energy ions will find many applications in time-resolved particle interaction studies and will lead to efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors in both the forward and the backward directions up to energies of ~500 keV. As the intensity of compact high-repetition-rate lasers sources increases, we can expect improvements in the energy, conversion efficiency, and directionality to occur. The effect of these developments is discussed. As compact, high-repetition-rate femtosecond laser technology reaches focused intensities of ~1019 W/cm2, many new applications of high-repetition-rate hard-x-ray and MeV ion sources will become practical.

  10. Analysis on Physical Characteristics of Rural Solid Waste in Dongjiang River Source Area, China

    Directory of Open Access Journals (Sweden)

    WANG Tao

    2014-06-01

    Full Text Available Dongjiang river is the source of drinking water of Guangdong Province and Hongkong, and the source area includes three counties in Ganzhou city of Jiangxi Province: Xunwu, Anyuan and Dingnan. Three typical villages were chosen in Dongjiang river source area to investigate the producing quantity and physical characteristics of rural solid waste. Results of investigation showed that the dominant ingredient in rural solid waste in Dongjiang river source area was kitchen waste, taking over 60%, followed by dust, reaching 12%, while other components took less than 10%. The per-capita producing quantity of solid waste of county-level village was 0.2~0.47 kg·d -1 and averaged by 0.36 kg·d -1, while that of town-level village was 0.18~0.35 kg· d -1, averaged by 0.29 kg· d -1 and that of hamlet was 0.07~0.33 kg· d -1, averaged by 0.17 kg· d -1. Water content in rural mixed solid waste of investigated area was significantly linear with percentage of kitchen waste in the mixed waste(R 2 =0.626, P=0.019. The average calorie wasaround 2 329 kJ·kg -1, which indicated that the rural solid waste in Dongjiang river source area was not suitable for incineration disposal directly.

  11. 40 CFR Table 1 to Subpart Ddddddd... - Applicability of General Provisions to Prepared Feeds Manufacturing Area Sources

    Science.gov (United States)

    2010-07-01

    ... Prepared Feeds Manufacturing Area Sources 1 Table 1 to Subpart DDDDDDD of Part 63 Protection of Environment... Pollutants for Area Sources: Prepared Feeds Manufacturing Pt. 63, Subpt. DDDDDDD, Table 1 Table 1 to Subpart DDDDDDD of Part 63—Applicability of General Provisions to Prepared Feeds Manufacturing Area Sources...

  12. Plasma properties of a new-type surface wave-sustained plasma source under the conditions of depositing DLC films

    Science.gov (United States)

    Xu, Junqi; Kousaka, Hiroyuki; Umehara, Noritsugu; Diao, Dongfeng

    2006-01-01

    Surface wave-sustained plasma (SWP) is one of the low-pressure, high- density plasma. Applying this technique, diamond-like carbon (DLC) films with excellent characteristics can be prepared by physical vapor deposition (PVD) method. However, the films' application is restricted in some degree, because it is difficult to control the film properties. In this paper, SWP was excited along a conductive rod at a frequency of 2.45 GHz without magnetic fields around the chamber wall. The fundamental theories of plasma diagnostic were presented and plasma properties were studied with a Langmuir probe under the conditions of depositing DLC films by PVD method with a graphite target. Plasma density, electron temperature, plasma potential and target current were measured at difference technique parameters such as gas pressure, microwave power, and so on. As a result, it was proved that plasma properties are greatly affected by microwave power, target voltage and argon gas pressure in chamber. The gas mass flow rate had almost no effect on plasma characters. At the same time, the results indicated that electron density is up to 10 11-10 12cm -3 even at the low pressure of 1 Pa.

  13. Analysis of the relationship between landslides size distribution and earthquake source area

    Science.gov (United States)

    Valagussa, Andrea; Crosta, Giovanni B.; Frattini, Paolo; Xu, Chong

    2014-05-01

    The spatial distribution of earthquake induced landslides around the seismogenetic source has been analysed to better understand the triggering of landslides in seismic areas and to forecast the maximum distance at which an earthquake, with a certain magnitude, can induce landslides (e.g Keefer, 1984). However, when applying such approaches to old earthquakes (e.g 1929 Buller and 1968 Iningahua earthquakes New Zealand; Parker, 2013; 1976 Friuli earthquake, Italy) one should be concerned about the undersampling of smaller landslides which can be cancelled by erosion and landscape evolution. For this reason, it is important to characterize carefully the relationship between landslide area and number with distance from the source, but also the size distribution of landslides as a function of distance from the source. In this paper, we analyse the 2008 Wenchuan earthquake landslide inventory (Xu et al, 2013). The earthquake triggered more than 197,000 landslides of different type, including rock avalanches, rockfalls, translational and rotational slides, lateral spreads and derbies flows. First, we calculated the landslide intensity (number of landslides per unit area) and spatial density (landslide area per unit area) as a function of distance from the source area of the earthquake. Then, we developed magnitude frequency curves (MFC) for different distances from the source area. Comparing these curves, we can describe the relation between the distance and the frequency density of landslide in seismic area. Keefer D K (1984) Landslides caused by earthquakes. Geological Society of America Bulletin, 95(4), 406-421. Parker R N, (2013) Hillslope memory and spatial and temporal distributions of earthquake-induced landslides, Durham theses, Durham University. Xu, C., Xu, X., Yao, X., & Dai, F. (2013). Three (nearly) complete inventories of landslides triggered by the May 12, 2008 Wenchuan Mw 7.9 earthquake of China and their spatial distribution statistical analysis

  14. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    Science.gov (United States)

    Fan Zhu; Rodriguez Gonzalez, David; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  15. Carbon dioxide sources and oilfields in a nine-state area of the southwest United States

    Energy Technology Data Exchange (ETDEWEB)

    Finney, R.E.; Heath, L.J.

    1977-04-01

    Data on the prospective available CO/sub 2/ in a nine-state area of the Southwest were collected from scattered sources and compiled to make the information readily available to operators who may be interested in using CO/sub 2/ techniques for enhanced oilfield recoveries. Maps of the oilfields in the area studied are provided so that location of supply source can be related to possible point of use. The best potential sources of CO/sub 2/ are flue gas from electric generating plants, flue gas from cement plants, output from ammonia plants and natural gas reservoirs. The CO/sub 2/ sources are listed by states and include the operator's name, location name, county, and average available amounts of CO/sub 2/.

  16. A GIS Based Variable Source Area Model for Large-scale Basin Hydrology

    Directory of Open Access Journals (Sweden)

    Rajesh Vijaykumar Kherde

    2014-05-01

    Full Text Available A geographic information system-based rainfall runoff model that simulate variable source area runoff using topographic features of the basin is presented. The model simulate the flow processes on daily time step basis and has four non linear stores viz. Interception store, soil moisture store, channel store and ground water store. Source area fraction is modelled as a function of antecedent soil moisture, net rainfall and pore capacity raised to the power of areal average topographic index (. Source area fraction is used in conjuction with topographic index to develop linear relations for runoff, Infiltration and interflow. An exponential relation is developed for lower zone evapotranspiration and non-linear exponential relations to model macropore flow and base flow are proposed.

  17. Use of rare earth oxides as tracers to identify sediment source areas for agricultural hillslopes

    OpenAIRE

    2010-01-01

    Understanding sediment sources is essential to enable more effective targeting of in-field mitigation approaches to reduce diffuse pollution from agricultural land. In this paper we report on the application of rare earth element oxides to arable soils at hillslope scale in order to determine sediment source areas and their relative importance, using a non-intrusive method of surface spraying. Runoff, sediments and rare earth elements lost from four arable hillslope lengths at a site in the U...

  18. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  19. Spectral Measurements of Cyg X-3: A Thermal Source Embedded in Hot Plasma within a Cold Shell

    Indian Academy of Sciences (India)

    R. K. Manchanda

    2002-09-01

    The attempts at unified model fitting to explain the spectral variations in Cyg X-3 suggest equally probable fits with a combination of an absorbed blackbody and a separately absorbed power law with an exponential cut-off or a composite of absorbed free-free emission with a power law hard X-ray component apart from the iron emission line. These seemingly ordinary but ad hoc mixtures of simple X-ray emission mechanisms have a profound implication about the geometry of the X-ray source. While the first set suggests a black-hole nature of the compact object, the second combination is consistent with a neutron star binary picture. The spectral variability at hard X-ray energies above 30 keV can provide crucial input for the unified picture. In this paper, we present spectral observations of Cyg X-3, made in our on-going survey of galactic and extragalactic X-ray sources in the 20–200 keV energy region, using Large Area Scintillation counter Experiment. The data show a clear power-law photon spectrum of the form $\\frac{{\\rm d}N}{{\\rm d}E}$ ∼ -2.8 in the 20 to 130 keVenergy range. Acomparison with earlier data suggests that the total number of X-ray photons in the entire 2–500 keV energy band is conserved at all time for a given luminosity level irrespective of the state. We propose that this behaviour can be explained by a simple geometry in which a thermal X-ray source is embedded in a hot plasma formed by winds from the accretion disk within a cold shell. The high/soft and low/hard X-ray states of the source are simply the manifestation of the extent of the surrounding scattering medium in which the seed photons are Comptonized and hot plasma can be maintained by either the X-ray driven winds or the magneto-centrifugal winds.

  20. Ion Behavior and Gas Mixing in electron cyclotron resonance plasmas as sources of highly charged ions (concept

    OpenAIRE

    Melin, G.; Drentje, A. G.; Girard, A; Hitz, D.

    1999-01-01

    Abstract: An ECR ion source is basically an ECR heated plasma confinement machine, with hot electrons and cold ions. The main parameters of the ion population have been analyzed, including temperature, losses, and confinement time. The "gas mixing" effect has been studied in this context. An expression is derived for determining the ion temperature from the values of all extracted ion currents. One aim is to study the ion temperature behavior in argon plasmas without and with mixing different...

  1. Low-pressure hydrogen discharge maintenance in a large-size plasma source with localized high radio-frequency power deposition

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, D.; Shivarova, A., E-mail: ashiva@phys.uni-sofia.bg; Paunska, Ts. [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria); Tarnev, Kh. [Department of Applied Physics, Technical University-Sofia, BG-1000 Sofia (Bulgaria)

    2015-03-15

    The development of the two-dimensional fluid-plasma model of a low-pressure hydrogen discharge, presented in the study, is regarding description of the plasma maintenance in a discharge vessel with the configuration of the SPIDER source. The SPIDER source, planned for the neutral-beam-injection plasma-heating system of ITER, is with localized high RF power deposition to its eight drivers (cylindrical-coil inductive discharges) and a large-area second chamber, common for all the drivers. The continuity equations for the charged particles (electrons and the three types of positive ions) and for the neutral species (atoms and molecules), their momentum equations, the energy balance equations for electrons, atoms and molecules and the Poisson equations are involved in the discharge description. In addition to the local processes in the plasma volume, the surface processes of particle reflection and conversion on the walls as well as for a heat exchange with the walls are included in the model. The analysis of the results stresses on the role of the fluxes (particle and energy fluxes) in the formation of the discharge structure. The conclusion is that the discharge behavior is completely obeyed to non-locality. The latter is displayed by: (i) maximum values of plasma parameters (charged particle densities and temperatures of the neutral species) outside the region of the RF power deposition, (ii) shifted maxima of the electron density and temperature, of the plasma potential and of the electron production, (iii) an electron flux, with a vortex structure, strongly exceeding the total ion flux which gives evidence of a discharge regime of non-ambipolarity and (iv) a spatial distribution of the densities of the neutral species resulting from their fluxes.

  2. Laser-plasma sourced, temperature dependent, VUV spectrophotometer using dispersive analysis

    Science.gov (United States)

    French, R. H.

    1990-04-01

    We have developed a vacuum ultraviolet spectrophotometer with wide energy and temperature range coverage, utilizing a laser-plasma light source (LPLS), CO2-laser sample heating and time-resolved dispersive analysis. Reflection and transmission spectra can be taken from 1.7 to 40eV (31-700nm) on samples at 15-1800K with a time resolution of 20-400ns. These capabilities permit the study of the temperature dependence of the electronic structure, encompassing the effects of thermal lattice expansion and electron-phonon interaction, and changes in the electronic structure associated with equilibrium and metastable phase transitions and stress relaxation. The LPLS utilizes a samarium laser-plasma created by a Q-switched Nd:YAG laser (500mJ/pulse) to produce high brightness, stable, continuum radiation. The spectrophotometer is of a single beam design using calibrated iridium reference mirrors. White light is imaged off the sample in to the entrance slit of a l-m polychromator. The resolution is 0.1 to 0.3nm. The dispersed light is incident on a focal plane phosphor, fiber-optic-coupled to an image-intensified reticon detector. For spectroscopy between 300 and 1800K, the samples are heated in situ with a 150 Watt CO2 laser. The signal to noise ratio in the VUV, for samples at 1800 K, is excellent. From 300 K to 15 K samples are cooled using a He cryostat.

  3. Laser-produced plasma He-alpha source for pulse radiography

    Institute of Scientific and Technical Information of China (English)

    Ruirong Wang; Weimin Chen; Chusheng Mao; Jiaqin Dong; Sizu Fu

    2009-01-01

    Through the use of time and space integrated kiloelectronvolt (keV) spectroscopy, we investigate the thermal emission of plasma, which produces strong line emission from the titanium K shell (He-α at 4.7 keV and H-α at 4.9 keV), created by laser. In order to optimize the conversion efficiency enhancement on titanium foils, the experiment is conducted under a variety of laser-driven intensity conditions. The X-ray emission intensity at 4.7 keV is measured and compared with prediction. The experimental result demonstrates that the solid Ti target laser-produced plasma (LPP) source has X-ray emission at 4.7 keV, which are all generated from electronic transitions in Ti ions at pulse width of 2.1 ns or 30 ps, the crudely evaluated He-α X-ray intensity appears to slightly increase with laser intensity enhancement, and the pre-pulse effect increases the conversion efficiency of the He-α X-ray. In addition, a 90-μm-thick Ti foil as a filter is used to transmit He-α X-ray at near 4.7 keV, creating a quasi-monochromatic transmission and greatly reducing thc lower- and higher-energy background.

  4. Radiography using a dense plasma focus device as a source of pulsed X-rays

    Science.gov (United States)

    Herrera, Julio; Castillo, Fermín; Gamboa, Isabel; Rangel, José

    2007-11-01

    Soft and hard X-ray emissions have been studied in the FN-II, which is a small dense plasma focus machine (5 kJ), operating at the Instituto de Ciencias Nucleares, UNAM, using aluminum filtered pin-hole cameras. Their angular distribution has been measured using TLD-200 dosimeters [1]. Their temporal evolution has been observed by means of a PIN diode, and scinltillators coupled to photomultipliers outside the discharge chamber. The X rays source can be concentrated by placing a needle on the end of the electrode. X-rays crossing across a 300 micron aluminum window, through the axis of the machine, can be used to obtain high contrast radiographs, with an average dose of 0.4 mGy per shot. In contrast, the average dose with a hollow cathode is 0.2 mGy per shot. This work is partially supported by grant IN105705 de la DGAPA-UNAM. [1] F. Castillo, J.J.E. Herrera, J. Rangel, I. Gamboa, G. Espinosa y J.I. Golzarri ``Angular Distribution of fusion products and X-rays emitted by a small dense plasma focus machine'' Journal of Applied Physics 101 013303-1-7 (2007).

  5. Intense positron beam as a source for production of electron-positron plasma

    Science.gov (United States)

    Stoneking, M. R.; Horn-Stanja, J.; Stenson, E. V.; Pedersen, T. Sunn; Saitoh, H.; Hergenhahn, U.; Niemann, H.; Paschkowski, N.; Hugenschmidt, C.; Piochacz, C.

    2016-10-01

    We aim to produce magnetically confined, short Debye length electron-positron plasma and test predicted properties for such systems. A first challenge is obtaining large numbers of positrons; a table-top experiment (system size 5 cm) with a temperature less than 5 eV requires about 1010 positrons to have more than 10 Debye lengths in the system. The NEPOMUC facility at the FRM II research reactor in Germany is one of the world's most intense positron sources. We report on characterization (using a retarding field energy analyzer with magnetic field gradient) of the NEPOMUC beam as delivered to the open beam port at various beam energies and in both the re-moderated and primary beam configurations in order to design optimal trapping (and accumulation) schemes for production of electron-positron plasma. The intensity of the re-moderated (primary) beam is in the range 2 -3 x 107 /s (1 - 5 x 108 /s). The re-moderated beam is currently the most promising for direct injection and confinement experiments; it has a parallel energy spread of 15 - 35% and the transverse energy spread is 6 - 15% of the parallel energy. We report on the implications for injection and trapping in a dipole magnetic field as well as plans for beam development, in situ re-moderation, and accumulation. We also report results demonstrating a difference in phosphor luminescent response to low energy positrons versus electrons.

  6. Simulation of the Partially Ionized Reacting Plasma Flow in a Negative Hydrogen Ion Source

    Science.gov (United States)

    Gatsonis, Nikolaos; Averkin, Sergey; Olson, Lynn

    2012-10-01

    A High Pressure Discharge Negative Ion Source (HPDNIS) operating on hydrogen is been under investigation. The Negative Ion Production (NIP) section of the HPDNIS attaches to the 10-100 Torr RF-discharge chamber with a micronozzle and ends with a grid that extracts the negative ion beam. The partially ionized and reacting plasma flow in the NIP section is simulated using an unstructured three-dimensional Direct Simulation Monte Carlo (U3DSMC) code. The NIP section contains a low-pressure plasma that includes H2, vibrationally-rotationally excited H2^*, negative hydrogen atoms H^-, and electrons. Primary reactions in the NIP section are dissociate attachment, H2^*+e->H^0+H^-and electron collisional detachment, e+H^-->H+2e. The U3DSMC computational domain includes the entrance to the NIP nozzle and the extraction grid at the exit. The flow parameters at the entrance are based on conditions in the RF-discharge chamber and are implemented in U3DSMC using a Kinetic-Moment subsonic boundary conditions method. The rotational and vibrational degrees of freedom in U3DSMC are implemented using the Larsen-Borgnakke model. Chemical reactions are implemented in U3DSMC using the Quantum-Kinetic model. Simulations cover the regime of operation of the HPDNIS and examine the flow characteristics inside the NIP section.

  7. Low Energy Plasma Focus as an Intense X-ray Source for Radiography

    Institute of Scientific and Technical Information of China (English)

    S. Hussain; M. Zakaullah; Shujaat Ali; A. Waheed

    2004-01-01

    Study on X-ray emission from a low energy (1.8 k J) plasma focus device powered by a 9 μF capacitor bank, charged at 20 kV and giving peak discharge current of about 175 kA by using a lead-inserted copper-tapered anode is reported. The X-ray yield in different energy windows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry is found to be (27.3±1.1) J and corresponding wall plug efficiency for X-ray generation is 1.52 ±0.06%. X-ray emission, presumably due to bombarding activity of electrons in current sheath at the anode tip was dominant, which is confirmed by the pinhole images. The feasibility of the device as an intense X-ray source for radiography is demonstrated.

  8. Low-Energy Plasma Focus Device as an Electron Beam Source

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Khan

    2014-01-01

    Full Text Available A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line radiations were registered upon usage as targets. The maximum electron beam charge and density were estimated to be 0.31 μC and 13.5×1016/m3, respectively. The average energy of the electron beam was 500 keV. The high flux of the electron beam can be potentially applicable in material sciences.

  9. A desktop extreme ultraviolet microscope based on a compact laser-plasma light source

    Science.gov (United States)

    Wachulak, P. W.; Torrisi, A.; Bartnik, A.; Węgrzyński, Ł.; Fok, T.; Fiedorowicz, H.

    2017-01-01

    A compact, desktop size microscope, based on laser-plasma source and equipped with reflective condenser and diffractive Fresnel zone plate objective, operating in the extreme ultraviolet (EUV) region at the wavelength of 13.8 nm, was developed. The microscope is capable of capturing magnified images of objects with 95-nm full-pitch spatial resolution (48 nm 25-75% KE) and exposure time as low as a few seconds, combining reasonable acquisition conditions with stand-alone desktop footprint. Such EUV microscope can be regarded as a complementary imaging tool to already existing, well-established ones. Details about the microscope, characterization, resolution estimation and real sample images are presented and discussed.

  10. Low-Energy Plasma Focus Device as an Electron Beam Source

    Science.gov (United States)

    Seong Ling, Yap; Naresh Kumar, Nitturi; Lian Kuang, Lim; Chiow San, Wong

    2014-01-01

    A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line radiations were registered upon usage as targets. The maximum electron beam charge and density were estimated to be 0.31 μC and 13.5 × 1016/m3, respectively. The average energy of the electron beam was 500 keV. The high flux of the electron beam can be potentially applicable in material sciences. PMID:25544952

  11. Environmental friendly high efficient light source. Plasma lamp. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Courret, G.

    2006-07-01

    This annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of a high-efficiency source of light based on the light emission of a plasma. The report presents a review of work done in 2006, including thermodynamics and assessment of the efficiency of the magnetron, tests with small bulbs, study of the standing wave ratio (microwave fluxes) and the development of a new coupling system to allow ignition in very small bulbs. Also, knowledge on the fillings of the bulb and induced effects of the modulator were gained. The development of a second generation of modulator to obtain higher efficiency at lower power is noted.

  12. Calibration Of A KrF Laser-Plasma Source For X-Ray Microscopy Applications

    Science.gov (United States)

    Turcu, I. C. E.; O'Neill, F.; Zammit, U.; Al-Hadithi, Y.; Eason, R. W.; Rogayski, A. M.; Hills, C. P. B.; Michette, A. G.

    1988-02-01

    Plasma X-ray sources for biological microscopy in the water-window have been produced by focusing tige 200 3, 50 ns Sprit q KrF laser onto carbon targets at irradiance between 2.2 x 10" W/cm4 and 3.7 x 10i3W/cm. Absolute measurements of X-ray production have been made using a calibrated, vacuum X-ray diode detector. A peak conversion efficiency . 10% is measured from KrF laseri)Tight tcto wate-window X-rays at 280 eV < hv < 530 eV for a target irradiance . 1 x x 10 W/cm'. Some measurements with gold and tungsten targets give conversion efficiencies 2$25% at a similar laser irradiance.

  13. Helicon Discharge with Selectable Nitrogen Reactive Species Production as a Plasma Source for III-group Nitrides Growth by MBE

    Science.gov (United States)

    Biloiu, Costel; Doss, Forest; Scime, Earl

    2004-11-01

    Plasma assisted molecular beam epitaxy (PAMBE) of III-N materials is a potential alternative to MOCVD for fabrication of high quality wide band gap semiconductor devices. In the helicon plasma source, it may be possible to control the population of specific reactive nitrogen species by modification of the electron energy distribution function through the resonant wave-particle interaction arising from electrons traveling at same velocity as the helicon wave phase velocity. We report preliminary results on control of reactive nitrogen species performed in a steady state, high density, helicon plasma source CHEWIE (Compact HElicon Waves and Instabilities Experiment). The helicon vacuum chamber is a 12 cm long, Pyrex tube, 6 cm in diameter, connected to a stainless steel diffusion chamber. RF power of up to 1.0 kW over a frequency range of 3-28 MHz is used to create the steady state plasma. A 7 cm long, half wave, m = +1, helical antenna couples the rf energy into the plasma. A single solenoidal magnetic field coil surrounds the source and is capable of generating axial magnetic fields up to 600 G. Optical emission spectroscopy investigations show that under certain conditions, the decay from the long lived A^3Σ_u^+ state dominates the emission spectrum of the plasma.

  14. Online tuning of impedance matching circuit for long pulse inductively coupled plasma source operation--an alternate approach.

    Science.gov (United States)

    Sudhir, Dass; Bandyopadhyay, M; Kraus, W; Gahlaut, A; Bansal, G; Chakraborty, A

    2014-01-01

    Impedance matching circuit between radio frequency (RF) generator and the plasma load, placed between them, determines the RF power transfer from RF generator to the plasma load. The impedance of plasma load depends on the plasma parameters through skin depth and plasma conductivity or resistivity. Therefore, for long pulse operation of inductively coupled plasmas, particularly for high power (∼100 kW or more) where plasma load condition may vary due to different reasons (e.g., pressure, power, and thermal), online tuning of impedance matching circuit is necessary through feedback. In fusion grade ion source operation, such online methodology through feedback is not present but offline remote tuning by adjusting the matching circuit capacitors and tuning the driving frequency of the RF generator between the ion source operation pulses is envisaged. The present model is an approach for remote impedance tuning methodology for long pulse operation and corresponding online impedance matching algorithm based on RF coil antenna current measurement or coil antenna calorimetric measurement may be useful in this regard.

  15. Characteristics of silicon nitride deposited by VHF (162 MHz)-plasma enhanced chemical vapor deposition using a multi-tile push-pull plasma source

    Science.gov (United States)

    Kim, Ki Seok; Sirse, Nishant; Kim, Ki Hyun; Rogers Ellingboe, Albert; Kim, Kyong Nam; Yeom, Geun Young

    2016-10-01

    To prevent moisture and oxygen permeation into flexible organic electronic devices formed on substrates, the deposition of an inorganic diffusion barrier material such as SiN x is important for thin film encapsulation. In this study, by a very high frequency (162 MHz) plasma-enhanced chemical vapor deposition (VHF-PECVD) using a multi-tile push-pull plasma source, SiN x layers were deposited with a gas mixture of NH3/SiH4 with/without N2 and the characteristics of the plasma and the deposited SiN x film as the thin film barrier were investigated. Compared to a lower frequency (60 MHz) plasma, the VHF (162 MHz) multi-tile push-pull plasma showed a lower electron temperature, a higher vibrational temperature, and higher N2 dissociation for an N2 plasma. When a SiN x layer was deposited with a mixture of NH3/SiH4 with N2 at a low temperature of 100 °C, a stoichiometric amorphous Si3N4 layer with very low Si-H bonding could be deposited. The 300 nm thick SiN x film exhibited a low water vapor transmission rate of 1.18  ×  10-4 g (m2 · d)-1, in addition to an optical transmittance of higher than 90%.

  16. Study of the feasibility of distributed cathodic arc as a plasma source for development of the technology for plasma separation of SNF and radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Amirov, R. Kh.; Vorona, N. A.; Gavrikov, A. V.; Liziakin, G. D.; Polistchook, V. P.; Samoylov, I. S.; Smirnov, V. P.; Usmanov, R. A., E-mail: ravus46@yandex.ru; Yartsev, I. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-12-15

    One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics.

  17. Simplification of the Plasma Load of Negative-Pulse-Bias Source Used in Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    Dong QI; Ninghui WANG; Guoqiang LIN; Zhenfeng DING

    2003-01-01

    Based on the voltage and current fluctuating phenomenon in the arc plasma load under the negative-pulse-bias, usingthe plasma physics theory and analysis of computer simulation expatiates that the nature of plasma load in vacuumarc plasma is a capacitance

  18. kHz femtosecond laser-plasma hard X-ray and fast ion source

    Science.gov (United States)

    Thoss, A.; Korn, G.; Richardson, M. C.; Faubel, M.; Stiel, H.; Voigt, U.; Siders, C. W.; Elsaesser, T.

    2002-04-01

    We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and Kα emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, Kα and Kβ lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ~500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

  19. Which meteorological conditions produce worst-case odors from area sources?

    Science.gov (United States)

    Sattler, Melanie; Devanathan, Sapna

    2007-11-01

    Two competing meteorological factors influence atmospheric concentrations of pollutants from open liquid area sources such as wastewater treatment plant units: temperature and stability. High temperatures in summer produce greater emissions from liquid area sources because of increased compound volatility; however, these emissions tend to disperse more readily because of frequent occurrence of unstable conditions. An opposite scenario occurs in winter, with lesser emissions due to lower temperatures, but also frequently less dispersion, due to stable atmospheric conditions. The primary objective of this modeling study was thus to determine whether higher atmospheric concentrations from open liquid area sources occur more frequently in summer, when emissions are greater but so is dispersion, or in winter, when emissions are lesser but so is dispersion. The study utilized a rectangular clarifier emitting hydrogen sulfide as a sample open liquid area source. Dispersion modeling runs were conducted using ISCST3 and AERMOD, encompassing 5 yr of hourly meteorological data divided by season. Emission rates were varied hourly on the basis of a curve-fit developed from previously collected field data. Model output for each season was used to determine (1) maximum 2-min average concentrations, (2) the number of odor events (2-min average concentrations greater than odor detection thresholds), and (3) areas of impact. On the basis of these 3 types of output, it was found that the worst-case odors were associated with summer, considering impacts of meteorology upon both emissions and dispersion. Not accounting for the impact of meteorology on emissions (using a constant worst-case emission rate) caused concentrations to be overpredicted compared with a variable emission rate case. The highest concentrations occurred during stability classes D, E, and F, as anticipated. A comparison of ISCST3 and AERMOD found that for the area source modeled, ISCST3 predicted higher

  20. Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

    2014-03-15

    A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

  1. Electron energy distributions and electron impact source functions in Ar/N{sub 2} inductively coupled plasmas using pulsed power

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Michael D., E-mail: mdlogue@umich.edu; Kushner, Mark J., E-mail: mjkush@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)

    2015-01-28

    In plasma materials processing, such as plasma etching, control of the time-averaged electron energy distributions (EEDs) in the plasma allows for control of the time-averaged electron impact source functions of reactive species in the plasma and their fluxes to surfaces. One potential method for refining the control of EEDs is through the use of pulsed power. Inductively coupled plasmas (ICPs) are attractive for using pulsed power in this manner because the EEDs are dominantly controlled by the ICP power as opposed to the bias power applied to the substrate. In this paper, we discuss results from a computational investigation of EEDs and electron impact source functions in low pressure (5–50 mTorr) ICPs sustained in Ar/N{sub 2} for various duty cycles. We find there is an ability to control EEDs, and thus source functions, by pulsing the ICP power, with the greatest variability of the EEDs located within the skin depth of the electromagnetic field. The transit time of hot electrons produced in the skin depth at the onset of pulse power produces a delay in the response of the EEDs as a function of distance from the coils. The choice of ICP pressure has a large impact on the dynamics of the EEDs, whereas duty cycle has a small influence on time-averaged EEDs and source functions.

  2. Limited sampling strategy for determining metformin area under the plasma concentration-time curve

    DEFF Research Database (Denmark)

    Santoro, Ana Beatriz; Stage, Tore Bjerregaard; Struchiner, Claudio José;

    2016-01-01

    and experimental conditions (r(2) = 0.976). The LSS model reproduced previously reported results for effects of polymorphisms in OCT2 and MATE1 genes on AUC(0,24 h) and renal clearance of metformin. CONCLUSIONS: The two point LSS algorithm may be used to assess the systemic exposure to metformin under diverse......AIM: The aim was to develop and validate limited sampling strategy (LSS) models to predict the area under the plasma concentration-time curve (AUC) for metformin. METHODS: Metformin plasma concentrations (n = 627) at 0-24 h after a single 500 mg dose were used for LSS development, based on all.......9-7.7%. The accuracy of the two point LSS model was verified in study cohorts of individuals receiving single 500 or 1000 mg (r(2) = -0.933-0.934) or seven 1000 mg daily doses (r(2) = 0.918), as well as using data from 16 published studies covering a wide range of metformin doses, demographics, clinical...

  3. Investigation on the Plasma-Induced Emission Properties of Large Area Carbon Nanotube Array Cathodes with Different Morphologies

    Directory of Open Access Journals (Sweden)

    Liu Liang

    2011-01-01

    Full Text Available Abstract Large area well-aligned carbon nanotube (CNT arrays with different morphologies were synthesized by using a chemical vapor deposition. The plasma-induced emission properties of CNT array cathodes with different morphologies were investigated. The ratio of CNT height to CNT-to-CNT distance has considerable effects on their plasma-induced emission properties. As the ratio increases, emission currents of CNT array cathodes decrease due to screening effects. Under the pulse electric field of about 6 V/μm, high-intensity electron beams of 170–180 A/cm2 were emitted from the surface plasma. The production mechanism of the high-intensity electron beams emitted from the CNT arrays was plasma-induced emission. Moreover, the distribution of the electron beams was in situ characterized by the light emission from the surface plasma.

  4. Elements of plasma technology

    CERN Document Server

    Wong, Chiow San

    2016-01-01

    This book presents some fundamental aspects of plasma technology that are important for beginners interested to start research in the area of plasma technology . These include the properties of plasma, methods of plasma generation and basic plasma diagnostic techniques. It also discusses several low cost plasma devices, including pulsed plasma sources such as plasma focus, pulsed capillary discharge, vacuum spark and exploding wire; as well as low temperature plasmas such as glow discharge and dielectric barrier discharge which the authors believe may have potential applications in industry. The treatments are experimental rather than theoretical, although some theoretical background is provided where appropriate. The principles of operation of these devices are also reviewed and discussed.

  5. Determination of fluoride source in ground water using petrographic studies in Dashtestan area, south of Iran

    Science.gov (United States)

    Battaleb-Looie, Sedigheh; Moore, Farid, ,, Dr.

    2010-05-01

    The groundwater occurs in Dashtestan area, contains a high level of fluoride. Since groundwater is vastly used for drinking and irrigation purposes, the local residents are at high risk of fluoride toxicity, as already evidenced by the occurrence of dental Fluorosis in many residents. 35 surface and groundwater samples were collected in September, 2009. The results show that in 23 samples the fluoride concentration is above the permissible level (1.5ppm). Petrographic study of lithological units in the catchment area indicates that mica minerals are the most probable source of fluoride content in the study area.

  6. Material sources of escaped gases from Tianchi volcanic geothermal area, Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    上官志冠; 郑雅琴; 董继川

    1997-01-01

    On the basis of the chemical components and stable isotopic compositions of escaped gases from the Tianchi volcanic geothermal area, the material sources of these gases are discussed, presenting that they are mainly derived from the residual mantle-derived magma in the crust; Changbai geothermal area may be directly interlinked with the eruption canal in history; there is a stable reservoir of the geothermal water and the deep-seated gases under the Changbai geothermal area, with water temperature of the reservoir being about (166±9)℃.

  7. Development and evaluation of a lightweight sensor system for emission sampling from open area sources

    Science.gov (United States)

    A new sensor system for mobile and aerial emission sampling was developed for open area sources, such as open burning. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, and black carbon, samplers for particulate matter with ...

  8. Development and evaluation of a lightweight sensor system for aerial emission sampling from open area sources

    Science.gov (United States)

    A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

  9. Standardization of flux chambers and wind tunnels for area source emission measurements at animal feeding operations

    Science.gov (United States)

    Researchers and practitioners have used many varied designs of wind tunnels and flux chambers to measure the flux of volatile organic compounds, odor, and ammonia from area sources at animal feeding operations. The measured fluxes are used to estimate emission factors or compare treatments. We sho...

  10. 77 FR 59931 - Single Source Program Expansion Supplement Award to Area Health Education Centers (AHEC) Program...

    Science.gov (United States)

    2012-10-01

    ... HUMAN SERVICES Health Resources and Services Administration Single Source Program Expansion Supplement... Guam School of Nursing. SUMMARY: The Health Resources and Services Administration (HRSA)'s Bureau of... University of Guam School of Nursing, an Area Health Education Center (AHEC) Program grantee, to...

  11. Use of rare earth oxides as tracers to identify sediment source areas for agricultural hillslopes

    Directory of Open Access Journals (Sweden)

    C. Deasy

    2010-11-01

    Full Text Available Understanding sediment sources is essential to enable more effective targeting of in-field mitigation approaches to reduce diffuse pollution from agricultural land. In this paper we report on the application of rare earth element oxides to arable soils at hillslope scale in order to determine sediment source areas and their relative importance, using a non-intrusive method of surface spraying. Runoff, sediments and rare earth elements lost from four arable hillslope lengths at a site in the UK with clay soils were monitored from three rainfall events after tracer application. Measured erosion rates were low, reflecting the typical event conditions occurring at the site, and less than 1% of the applied REO tracers were recovered, which is consistent with the results of comparable studies. Tracer recovery at the base of the hillslope was able to indicate the relative importance of different hillslope sediment source areas, which were found to be consistent between events. The principal source of eroded sediments was the upslope area, implying that the wheel tracks were principally conduits for sediment transport, and not highly active sites of erosion. Mitigation treatments for sediment losses from arable hillslopes should therefore focus on methodologies for trapping mobile sediments within wheel track areas through increasing surface roughness or reducing the connectivity of sediment transport processes.

  12. Use of rare earth oxides as tracers to identify sediment source areas for agricultural hillslopes

    Directory of Open Access Journals (Sweden)

    C. Deasy

    2010-07-01

    Full Text Available Understanding sediment sources is essential to enable more effective targeting of in-field mitigation approaches to reduce diffuse pollution from agricultural land. In this paper we report on the application of rare earth element oxides to arable soils at hillslope scale in order to determine sediment source areas and their relative importance, using a non-intrusive method of surface spraying. Runoff, sediments and rare earth elements lost from four arable hillslope lengths at a site in the UK with clay soils were monitored from three rainfall events after tracer application. Measured erosion rates were low, reflecting the typical event conditions occurring at the site, and less than 1% of the applied REO tracers were recovered, which is consistent with the results of comparable studies. Tracer recovery at the base of the hillslope was able to indicate the relative importance of different hillslope sediment source areas, which were found to be consistent between events. The principal source of eroded sediments was the upslope area, implying that the wheel tracks were principally conduits for sediment transport, and not highly active sites of erosion. Mitigation treatments for sediment losses from arable hillslopes should therefore focus on methodologies for trapping mobile sediments within wheel track areas through increasing surface roughness or reducing the connectivity of sediment transport processes.

  13. Use of rare earth oxides as tracers to identify sediment source areas for agricultural hillslopes

    Science.gov (United States)

    Deasy, C.; Quinton, J. N.

    2010-11-01

    Understanding sediment sources is essential to enable more effective targeting of in-field mitigation approaches to reduce diffuse pollution from agricultural land. In this paper we report on the application of rare earth element oxides to arable soils at hillslope scale in order to determine sediment source areas and their relative importance, using a non-intrusive method of surface spraying. Runoff, sediments and rare earth elements lost from four arable hillslope lengths at a site in the UK with clay soils were monitored from three rainfall events after tracer application. Measured erosion rates were low, reflecting the typical event conditions occurring at the site, and less than 1% of the applied REO tracers were recovered, which is consistent with the results of comparable studies. Tracer recovery at the base of the hillslope was able to indicate the relative importance of different hillslope sediment source areas, which were found to be consistent between events. The principal source of eroded sediments was the upslope area, implying that the wheel tracks were principally conduits for sediment transport, and not highly active sites of erosion. Mitigation treatments for sediment losses from arable hillslopes should therefore focus on methodologies for trapping mobile sediments within wheel track areas through increasing surface roughness or reducing the connectivity of sediment transport processes.

  14. Geochemistry of Eagle Ford group source rocks and oils from the first shot field area, Texas

    Science.gov (United States)

    Edman, Janell D.; Pitman, Janet K.; Hammes, Ursula

    2010-01-01

    Total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance analyses performed on Eagle Ford Group core and cuttings samples from the First Shot field area, Texas demonstrate these samples have sufficient quantity, quality, and maturity of organic matter to have generated oil. Furthermore, gas chromatography and biomarker analyses performed on Eagle Ford Group oils and source rock extracts as well as weight percent sulfur analyses on the oils indicate the source rock facies for most of the oils are fairly similar. Specifically, these source rock facies vary in lithology from shales to marls, contain elevated levels of sulfur, and were deposited in a marine environment under anoxic conditions. It is these First Shot Eagle Ford source facies that have generated the oils in the First Shot Field. However, in contrast to the generally similar source rock facies and organic matter, maturity varies from early oil window to late oil window in the study area, and these maturity variations have a pronounced effect on both the source rock and oil characteristics. Finally, most of the oils appear to have been generated locally and have not experienced long distance migration. 

  15. Cryobehavior of the plasma membrane in protoplasts isolated from cold-acclimated Arabidopsis leaves is related to surface area regulation.

    Science.gov (United States)

    Yamazaki, Tomokazu; Kawamura, Yukio; Uemura, Matsuo

    2008-06-01

    Extracellular freezing in plants results in dehydration and mechanical stresses upon the plasma membrane. Plants that acquire enhanced freezing tolerance after cold acclimation can withstand these two physical stresses. To understand the tolerance to freeze-induced physical stresses, the cryobehavior of the plasma membrane was observed using protoplasts isolated from cold-acclimated Arabidopsis thaliana leaves with the combination of a lipophilic fluorescent dye FM 1-43 and cryomicroscopy. We found that many vesicular structures appeared in the cytoplasmic region near the plasma membrane just after extracellular freezing occurred. These structures, referred to as freeze-induced vesicular structures (FIVs), then developed horizontally near the plasma membrane during freezing. There was a strong correlation between the increase in individual FIV size and the decrease in the surface area of the protoplasts during freezing. Some FIVs fused with their neighbors as the temperature decreased. Occasionally, FIVs fused with the plasma membrane, which may be necessary to relax the stress upon the plasma membrane during freezing. Vesicular structures resembling FIVs were also induced when protoplasts were mechanically pressed between a coverslip and slide glass. Fewer FIVs formed when protoplasts were subjected to hyperosmotic solution, suggesting that FIV formation is associated with mechanical stress rather than dehydration. Collectively, these results suggest that cold-acclimated plant cells may balance membrane tension in the plasma membrane by regulating the surface area. This enables plant cells to withstand the direct mechanical stress imposed by extracellular freezing.

  16. Contamination characteristics and possible sources of PM10 and PM2.5 in different functional areas of Shanghai, China

    Science.gov (United States)

    Wang, Jun; Hu, Zimei; Chen, Yuanyuan; Chen, Zhenlou; Xu, Shiyuan

    2013-04-01

    From July 2009 through September 2010, PM10 and PM2.5 were collected at two different functional areas in Shanghai (Baoshan district, an industrial area, and Putuo district, a mixed-use area of residential, commercial, and educational compounds). In our analysis, 15 elements were determined using a 710-ES Inductively Coupled Plasma-Emission Spectrometer (ICP-AES). The contents of PM2.5, PM10, and metal elements at the two different sites were comparatively analyzed. The results show that the mean annual concentrations of PM10 and PM2.5 (149.22 μg m-3 and 103.07 μg m-3, respectively) in Baoshan district were significantly higher than those in Putuo district (97.44 μg m-3 and 62.25 μg m-3 respectively). The concentrations of PM10 and PM2.5 were both greatest in winter and lowest in summer, with the two different sites exhibiting the same seasonal variation. It was found that the proportions of 15 metal elements in PM10 and PM2.5 in Baoshan district were 20.49% and 20.56%, respectively, while the proportions in Putuo district were higher (25.98% and 25.93%, respectively). In addition, the proportions of eight heavy metals in PM10 and PM2.5 were 5.50% and 3.07%, respectively, for Baoshan district, while these proportions in Putuo district were 3.18% and 2.77%, respectively, indicating that heavy metal pollution is more pronounced in Baoshan district. Compared with cities in developed countries, the total levels of PM10, PM2.5 and heavy metals in Shanghai were slightly higher. Scanning electron microscopy (SEM) and principal component analysis (PCA) suggested that the possible sources of PM10 in Baoshan district were ground level fugitive dust, traffic sources, and industrial activities, whereas PM2.5 mainly originated from industrial activities, coal combustion, and traffic sources. The sources are same for PM10 and PM2.5 in Putuo region, which originate from traffic sources and ground level fugitive dust.

  17. [Classification of Priority Area for Soil Environmental Protection Around Water Sources: Method Proposed and Case Demonstration].

    Science.gov (United States)

    Li, Lei; Wang, Tie-yu; Wang, Xiaojun; Xiao, Rong-bo; Li, Qi-feng; Peng, Chi; Han, Cun-liang

    2016-04-15

    Based on comprehensive consideration of soil environmental quality, pollution status of river, environmental vulnerability and the stress of pollution sources, a technical method was established for classification of priority area of soil environmental protection around the river-style water sources. Shunde channel as an important drinking water sources of Foshan City, Guangdong province, was studied as a case, of which the classification evaluation system was set up. In detail, several evaluation factors were selected according to the local conditions of nature, society and economy, including the pollution degree of heavy metals in soil and sediment, soil characteristics, groundwater sensitivity, vegetation coverage, the type and location of pollution sources. Data information was mainly obtained by means of field survey, sampling analysis, and remote sensing interpretation. Afterwards, Analytical Hierarchy Process (AHP) was adopted to decide the weight of each factor. The basic spatial data layers were set up respectively and overlaid based on the weighted summation assessment model in Geographical Information System (GIS), resulting in a classification map of soil environmental protection level in priority area of Shunde channel. Accordingly, the area was classified to three levels named as polluted zone, risky zone and safe zone, which respectively accounted for 6.37%, 60.90% and 32.73% of the whole study area. Polluted zone and risky zone were mainly distributed in Lecong, Longjiang and Leliu towns, with pollutants mainly resulted from the long-term development of aquaculture and the industries containing furniture, plastic constructional materials and textile and clothing. In accordance with the main pollution sources of soil, targeted and differentiated strategies were put forward. The newly established evaluation method could be referenced for the protection and sustainable utilization of soil environment around the water sources.

  18. Ion source research and development at University of Jyväskylä: Studies of different plasma processes and towards the higher beam intensities

    Energy Technology Data Exchange (ETDEWEB)

    Koivisto, H., E-mail: hannu.koivisto@phys.jyu.fi; Kalvas, T.; Tarvainen, O.; Komppula, J.; Laulainen, J.; Kronholm, R.; Ranttila, K.; Tuunanen, J. [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Thuillier, T. [LPSC, CNRS/IN2P3, Université Grenoble-Alpes1, 53 Rue des Martyrs, 38026 Grenoble Cedex (France); Xie, D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720 (United States); Machicoane, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-02-15

    Several ion source related research and development projects are in progress at the Department of Physics, University of Jyväskylä (JYFL). The work can be divided into investigation of the ion source plasma and development of ion sources, ion beams, and diagnostics. The investigation covers the Electron Cyclotron Resonance Ion Source (ECRIS) plasma instabilities, vacuum ultraviolet (VUV) and visible light emission, photon induced electron emission, and the development of plasma diagnostics. The ion source development covers the work performed for radiofrequency-driven negative ion source, RADIS, beam line upgrade of the JYFL 14 GHz ECRIS, and the development of a new room-temperature-magnet 18 GHz ECRIS, HIISI.

  19. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

    Science.gov (United States)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The transfer line enables the unstable isotopes generated by the 238U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

  20. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams.

    Science.gov (United States)

    Manzolaro, M; Meneghetti, G; Andrighetto, A; Vivian, G

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The transfer line enables the unstable isotopes generated by the (238)U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

  1. Stable droplet generator for a high brightness laser produced plasma extreme ultraviolet source

    Science.gov (United States)

    Vinokhodov, A.; Krivokorytov, M.; Sidelnikov, Yu.; Krivtsun, V.; Medvedev, V.; Bushuev, V.; Koshelev, K.; Glushkov, D.; Ellwi, S.

    2016-10-01

    We present the results of the low-melting liquid metal droplets generation based on excited Rayleigh jet breakup. We discuss on the operation of the industrial and in-house designed and manufactured dispensing devices for the droplets generation. Droplet diameter can be varied in the range of 30-90 μm. The working frequency of the droplets, velocity, and the operating temperature were in the ranges of 20-150 kHz, 4-15 m/s, and up to 250 °C, respectively. The standard deviations for the droplet center of mass position both their diameter σ < 1 μm at the distance of 45 mm from the nozzle. Stable operation in the long-term (over 1.5 h) was demonstrated for a wide range of the droplet parameters: diameters, frequencies, and velocities. Physical factors affecting the stability of the generator operation have been identified. The technique for droplet synchronization, allowing using the droplet as a target for laser produced plasma, has been created; in particular, the generator has been successfully used in a high brightness extreme ultraviolet (EUV) light source. The operation with frequency up to 8 kHz was demonstrated as a result of the experimental simulation, which can provide an average brightness of the EUV source up to ˜1.2 kW/mm2 sr.

  2. Use of rare earth oxide tracers to determine source areas for sediment eroded from arable hillslopes

    Science.gov (United States)

    Deasy, C.; Quinton, J. N.

    2009-04-01

    Soil erosion from arable hillslopes has both on-site and off-site effects. On-site, erosion and redistribution of sediment can lead to the loss of productive field area and a reduction in organic matter and nutrient content in topsoil. Off-site, the transport and deposition of eroded sediment in downstream waters is associated with turbidity, sedimentation and reduced water quality, as sediments are associated with the transport of nutrients, particularly phosphorus (P) and nitrogen (N), heavy metals and pesticides. Arable land is a major source for these sediments, with studies in the UK estimating the cultivated fields may be responsible for up to 80% of particulate P in rivers. Previous studies at Loddington in Leicestershire, UK have demonstrated that most of the P and much of the N eroded from hillslope is in particulate form, transported in association with sediment suspended in runoff. Results also suggest that tramlines are the principal pathway for erosion from arable fields containing combinable crops. As tramlines are regularly spaced over the whole field, they potentially act as conduits for runoff, sediment and sediment-associated nutrients to be lost from the hillslope. However, it is not yet clear where the source areas are for sediment eroded via this pathway. To understand the movement of sediment on arable hillslopes, a hillslope-scale tracer experiment was undertaken in one year at the same site. The aims of this study were (1) to develop an application method for rare earth oxide tracers suitable for using on a hillslope scale to assess sediment movement over a number of storm events, (2) to determine the erosion rates of different contributing hillslope areas, (3) to determine the relative contributions of sediment eroded from each of these areas in order to assess the importance of different hillslope source areas for soil erosion. Different rare earth oxide tracers were applied in solution using a knapsack sprayer to four areas of the

  3. Identifying hydrologically sensitive areas using LiDAR DEMs to mitigate critical source areas of diffuse pollution: development and application

    Science.gov (United States)

    Thomas, Ian; Jordan, Phil; Mellander, Per-Erik; Fenton, Owen; Shine, Oliver; hUallacháin, Daire Ó.; Creamer, Rachel; McDonald, Noeleen; Dunlop, Paul; Murphy, Paul

    2016-04-01

    Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants such as phosphorus (P). A new GIS-based HSA Index is presented that identifies HSAs at the sub-field scale. It uses a soil topographic index (STI) and accounts for the hydrological disconnection of overland flow via topographic impediment from flow sinks such as hedgerows and depressions. High resolution (0.25-2 m) LiDAR Digital Elevation Models (DEMs) are utilised to capture these microtopographic controls on flow pathways and hydrological connectivity. The HSA Index was applied to four agricultural catchments (~7.5-12 km2) with contrasting topography and soil types. Catchment HSA sizes were estimated using high resolution rainfall-quickflow measurements during saturated winter storm events in 2009-2014, and mapped using the HSA Index. HSA sizes ranged from 1.6-3.4% of the catchment area during median storm events and 2.9-8.5% during upper quartile events depending on whether well or poorly drained soils dominated, which validated HSA Index value distributions. Total flow sink volume capacities ranged from 8,298-59,584 m3 and caused 8.5-24.2% of overland-flow-generating-areas and 16.8-33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified 'delivery points' along surface runoff pathways where transported pollutants such as P are delivered to the open drainage network. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips (RBS) reduced costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5 years respectively, which included LiDAR DEM acquisition costs. Considering that HSAs are often the dominant P CSA factor in agricultural catchments and can override

  4. 40 CFR Table 1 to Subpart Gggggg... - Applicability of General Provisions to Primary Zinc Production Area Sources

    Science.gov (United States)

    2010-07-01

    ... Primary Zinc Production Area Sources 1 Table 1 to Subpart GGGGGG of Part 63 Protection of Environment... AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Primary Nonferrous Metals Area Sources-Zinc, Cadmium, and Beryllium Pt. 63, Subpt....

  5. Effect of basic physical parameters to control plasma meniscus and beam halo formation in negative ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K. [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan); Okuda, S.; Nishioka, S.; Hatayama, A. [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2013-09-14

    Our previous study shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources: the negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. In this article, the detail physics of the plasma meniscus and beam halo formation is investigated with two-dimensional particle-in-cell simulation. It is shown that the basic physical parameters such as the H{sup −} extraction voltage and the effective electron confinement time significantly affect the formation of the plasma meniscus and the resultant beam halo since the penetration of electric field for negative ion extraction depends on these physical parameters. Especially, the electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of electron diffusion across the magnetic field. The plasma meniscus penetrates deeply into the source plasma region when the effective electron confinement time is short. In this case, the curvature of the plasma meniscus becomes large, and consequently the fraction of the beam halo increases.

  6. Development of a low-energy and high-current pulsed neutral beam injector with a washer-gun plasma source for high-beta plasma experiments.

    Science.gov (United States)

    Ii, Toru; Gi, Keii; Umezawa, Toshiyuki; Asai, Tomohiko; Inomoto, Michiaki; Ono, Yasushi

    2012-08-01

    We have developed a novel and economical neutral-beam injection system by employing a washer-gun plasma source. It provides a low-cost and maintenance-free ion beam, thus eliminating the need for the filaments and water-cooling systems employed conventionally. In our primary experiments, the washer gun produced a source plasma with an electron temperature of approximately 5 eV and an electron density of 5 × 10(17) m(-3), i.e., conditions suitable for ion-beam extraction. The dependence of the extracted beam current on the acceleration voltage is consistent with space-charge current limitation, because the observed current density is almost proportional to the 3/2 power of the acceleration voltage below approximately 8 kV. By optimizing plasma formation, we successfully achieved beam extraction of up to 40 A at 15 kV and a pulse length in excess of 0.25 ms. Its low-voltage and high-current pulsed-beam properties enable us to apply this high-power neutral beam injection into a high-beta compact torus plasma characterized by a low magnetic field.

  7. A Guillemin type E pulse forming network as the driver for a pulsed, high density plasma source.

    Science.gov (United States)

    Rathod, Priyavandna J; Anitha, V P; Sholapurwala, Z H; Saxena, Y C

    2014-06-01

    A Guillemin type E pulse forming network (PFN) has been designed, developed, and tested for its application in generating high density (~1 × 10(18) m(-3)) plasmas. In the present study, plasma thus generated is utilized to investigate the interaction of high power microwaves (HPMs) with plasma in an experimental architecture known as SYMPLE (System for Microwave PLasma Experiment). Plasma discharges of ~100 μs (max) duration are to be produced, by delivering energy of 5 kJ stored in a PFN to the plasma source, a washer gun. The output of the PFN, in terms of its rise time, flat top and amplitude, needs to be tailored, depending on the experimental requirements. An ignitron (NL8900) trigger generator (ITG) is developed in-house to control the PFN discharge through the gun. This ITG is also to be used in a circuit that synchronizes the HPM and plasma shots, to ensure that HPM-plasma interaction takes place during a temporal regime where appropriate parametric conditions are satisfied. Hence it is necessary to retain the jitter within ±2.5 μs. Further, requirement on plasma quiescence (~10%) necessitates maintaining the ripple within 5%. The developmental work of the PFN, keeping in view the above criteria and the test results, is presented in this paper. The parameters of the PFN have been analytically approximated and verified with PSPICE simulation. The test results presented include rise time ~5-8 μs, flat top variable in the range 20-100 μs, ripple within ~1.5%, and jitter within ±2.5 μs, producing quiescent (plasma discharge meeting the experimental requirements.

  8. Sub-Auroral Ion Drifts as a Source of Mid-Latitude Plasma Density Irregularities

    Science.gov (United States)

    Sotnikov, V.; Kim, T.; Mishin, E.; Paraschiv, I.; Rose, D.

    Ionospheric irregularities cause scintillations of electromagnetic signals that can severely affect navigation and transionospheric communication, in particular during space storms. At midlatitudes, such space weather events are caused mainly by subauroral electric field structures (SAID/SAPS) [1, 2]. SAID/SAPS -related shear flows and plasma density troughs point to interchange and Kelvin-Helmholtz type instabilities as a possible source of plasma irregularities. A model of nonlinear development of these instabilities based on the two-fluid hydrodynamic description with inclusion of finite Larmor radius effects will be presented. A numerical code in C language to solve the derived nonlinear equations for analysis of interchange and flow velocity shear instabilities in the ionosphere was developed. This code was used to analyze competition between interchange and Kelvin Helmholtz instabilities in the equatorial region [3]. The high-resolution simulations with continuous density and velocity profiles will be driven by the ambient conditions corresponding to the in situ Defence Military Satellite Program (DMSP) satellite low-resolution data [2] during UHF/GPS L-band subauroral scintillation events. [1] Mishin, E. (2013), Interaction of substorm injections with the subauroral geospace: 1. Multispacecraft observations of SAID, J. Geophys. Res. Space Phys., 118, 5782-5796, doi:10.1002/jgra.50548. [2] Mishin, E., and N. Blaunstein (2008), Irregularities within subauroral polarization stream-related troughs and GPS radio interference at midlatitudes. In: T. Fuller-Rowell et al. (eds), AGU Geophysical Monograph 181, MidLatitude Ionospheric Dynamics and Disturbances, pp. 291-295, doi:10.1029/181GM26, Washington, DC, USA. [3] V. Sotnikov, T. Kim, E. Mishin, T. Genoni, D. Rose, I. Paraschiv, Development of a Flow Velocity Shear Instability in the Presence of Finite Larmor Radius Effects, AGU Fall Meeting, San Francisco, 15 - 19 December, 2014.

  9. Chemical mass balance source apportionment of PM 10 in an industrialized urban area of Northern Greece

    Science.gov (United States)

    Samara, C.; Kouimtzis, Th; Tsitouridou, R.; Kanias, G.; Simeonov, V.

    Ambient PM 10 were sampled at three sites in an industrialized urban area of Northern Greece during June 1997-June 1998 and analyzed for 17 chemical elements, 5 water-soluble ions and 13 polycyclic aromatic hydrocarbons. In addition, chemical source profiles consisting of the same particulate components were obtained for a number of industrial activities (cement, fertilizer and asphalt production, quarry operations, metal electroplating, metal welding and tempering, steel manufacture, lead and bronze smelters, metal scrap incineration), residential oil burning, non-catalyst and catalyst-equipped passenger cars, diesel fuelled taxis and buses, as well as for geological fugitive sources (paved road dust and soil from open lands). Ambient and source data were used in a chemical mass balance (CMB) receptor model for source identification and apportionment. Results of CMB modeling showed that major source of ambient PM 10 at all three sites was diesel vehicle exhaust. Significant contribution from industrial oil burning was also evidenced at the site located closest to the industrial area.

  10. The effects of added hydrogen on a helium atmospheric-pressure plasma jet ambient desorption/ionization source.

    Science.gov (United States)

    Wright, Jonathan P; Heywood, Matthew S; Thurston, Glen K; Farnsworth, Paul B

    2013-03-01

    We present mass spectrometric data demonstrating the effect that hydrogen has on a helium-based dielectric-barrier discharge (DBD) atmospheric-pressure plasma jet used as an ambient desorption/ionization (ADI) source. The addition of 0.9 % hydrogen to the helium support gas in a 35-W plasma jet increased signals for a range of test analytes, with enhancement factors of up to 68, without proportional increases in background levels. The changes in signal levels result from a combination of changes in the desorption kinetics from the surface and increased ion production in the gas phase. The enhancement in ADI-MS performance despite the quenching of key plasma species reported in earlier studies suggests that ionization with a H2/He plasma jet is the result of an alternate mechanism involving the direct generation of ionized hydrogen.

  11. Size Matters: What Are the Characteristic Source Areas for Urban Planning Strategies?

    Science.gov (United States)

    Fan, Chao; Myint, Soe W.; Wang, Chenghao

    2016-01-01

    Urban environmental measurements and observational statistics should reflect the properties generated over an adjacent area of adequate length where homogeneity is usually assumed. The determination of this characteristic source area that gives sufficient representation of the horizontal coverage of a sensing instrument or the fetch of transported quantities is of critical importance to guide the design and implementation of urban landscape planning strategies. In this study, we aim to unify two different methods for estimating source areas, viz. the statistical correlation method commonly used by geographers for landscape fragmentation and the mechanistic footprint model by meteorologists for atmospheric measurements. Good agreement was found in the intercomparison of the estimate of source areas by the two methods, based on 2-m air temperature measurement collected using a network of weather stations. The results can be extended to shed new lights on urban planning strategies, such as the use of urban vegetation for heat mitigation. In general, a sizable patch of landscape is required in order to play an effective role in regulating the local environment, proportional to the height at which stakeholders’ interest is mainly concerned. PMID:27832111

  12. Study of plasma meniscus formation and beam halo in negative ion source using the 3D3VPIC model

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, S.; Goto, I.; Hatayama, A. [Graduate school of Science and Technology, Keio University, Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Miyamoto, K. [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan); Fukano, A. [Tokyo Metropolitan Collage of Industrial Technology, Higashioi, Shinagawa, Tokyo 140-0011 (Japan)

    2015-04-08

    In this paper, the effect of the electron confinement time on the plasma meniscus and the fraction of the beam halo is investigated by 3D3V-PIC (three dimension in real space and three dimension in velocity space) (Particle in Cell) simulation in the extraction region of negative ion source. The electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of diffusion across the magnetic field. Our 3D3V-PIC results support the previous result by 2D3V-PIC results i.e., it is confirmed that the penetration of the plasma meniscus becomes deep into the source plasma region when the effective confinement time is short.

  13. Self-consistent three-dimensional modeling and simulation of large-scale rectangular surface-wave plasma source

    Institute of Scientific and Technical Information of China (English)

    Lan Chao-Hui; Lan Chao-Zhen; Hu Xi-Wei; Chen Zhao-Quan; Liu Ming-Hai

    2009-01-01

    A self-consistent and three-dimensional (3D) model of argon discharge in a large-scale rectangular surface-wave plasma (SWP) source is presented in this paper, which is based on the finite-difference time-domain (FDTD) approximation to Maxwell's equations self-consistently coupled with a fluid model for plasma evolution. The discharge characteristics at an input microwave power of 1200 W and a filling gas pressure of 50 Pa in the SWP source are analyzed. The simulation shows the time evolution of deposited power density at different stages, and the 3D distributions of electron density and temperature in the chamber at steady state. In addition, the results show that there is a peak of plasma density approximately at a vertical distance of 3 cm from the quartz window.

  14. X-ray spectroscopy of warm and hot electron components in the CAPRICE source plasma at EIS testbench at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, D., E-mail: davidmascali@lns.infn.it; Celona, L.; Castro, G.; Torrisi, G.; Neri, L.; Gammino, S.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Maimone, F.; Maeder, J.; Tinschert, K.; Spaedtke, K. P.; Rossbach, J.; Lang, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Romano, F. P. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); Musumarra, A.; Altana, C.; Caliri, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, via S. Sofia 64, 95123 Catania (Italy)

    2014-02-15

    An experimental campaign aiming to detect X radiation emitted by the plasma of the CAPRICE source – operating at GSI, Darmstadt – has been carried out. Two different detectors (a SDD – Silicon Drift Detector and a HpGe – hyper-pure Germanium detector) have been used to characterize the warm (2–30 keV) and hot (30–500 keV) electrons in the plasma, collecting the emission intensity and the energy spectra for different pumping wave frequencies and then correlating them with the CSD of the extracted beam measured by means of a bending magnet. A plasma emissivity model has been used to extract the plasma density along the cone of sight of the SDD and HpGe detectors, which have been placed beyond specific collimators developed on purpose. Results show that the tuning of the pumping frequency considerably modifies the plasma density especially in the warm electron population domain, which is the component responsible for ionization processes: a strong variation of the plasma density near axis region has been detected. Potential correlations with the charge state distribution in the plasma are explored.

  15. Experimental and theoretical determination of the efficiency of a sub-atmospheric flowing high power cascaded arc hydrogen plasma source

    NARCIS (Netherlands)

    Vijvers, W. A. J.; D.C. Schram,; Shumack, A. E.; Cardozo, N. J. L.; Rapp, J.; van Rooij, G. J.

    2010-01-01

    Cascaded arc plasma sources with channel diameters between 4 and 8mm were experimentally investigated at discharge currents up to 900A and hydrogen (H-2) flow rates up to 10 slm. Pressure measurements at the arc exit showed that the heavy particle temperature in the discharge channel was about 0.8 e

  16. Ion Behavior and Gas Mixing in electron cyclotron resonance plasmas as sources of highly charged ions (concept

    NARCIS (Netherlands)

    Melin, G.; Drentje, A. G.; Girard, A.; Hitz, D.

    1999-01-01

    Abstract: An ECR ion source is basically an ECR heated plasma confinement machine, with hot electrons and cold ions. The main parameters of the ion population have been analyzed, including temperature, losses, and confinement time. The "gas mixing" effect has been studied in this context. An express

  17. REFINING THE ASSOCIATIONS OF THE FERMI LARGE AREA TELESCOPE SOURCE CATALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F. [Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino (Italy); D’Abrusco, R.; Paggi, A.; Smith, Howard A. [Harvard-Smithsonian Astrophysical Observatory, Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Landoni, M. [INAF-Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, I-23807 Merate (Italy); Masetti, N. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Giroletti, M. [INAF Istituto di Radioastronomia, via Gobetti 101, I-40129, Bologna (Italy); Otí-Floranes, H.; Jiménez-Bailón, E. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 877, Ensenada, 22800 Baja California, México (Mexico); Chavushyan, V.; Patiño-Álvarez, V. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51-216, 72000 Puebla, México (Mexico); Digel, S. W. [SLAC National Accelerator Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Tosti, G. [Dipartimento di Fisica, Università degli Studi di Perugia, I-06123 Perugia (Italy)

    2015-03-15

    The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) was released in 2010 February and the Fermi-LAT 2-Year Source Catalog (2FGL) appeared in 2012 April, based on data from 24 months of operation. Since they were released, many follow up observations of unidentified γ-ray sources have been performed and new procedures for associating γ-ray sources with potential counterparts at other wavelengths have been developed. Here we review and characterize all of the associations as published in the 1FGL and 2FGL catalogs on the basis of multifrequency archival observations. In particular, we located 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition we present new spectroscopic observations of eight γ-ray blazar candidates. Based on our investigations, we introduce a new counterpart category of “candidate associations” and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. We compare the 1FGL-assigned counterparts with those listed in 2FGL to determine which unassociated sources became associated in later releases of the Fermi catalogs. We also search for potential counterparts to all of the remaining unassociated Fermi sources. Finally, we prepare a refined and merged list of all of the associations of 1FGL plus 2FGL that includes 2219 unique Fermi objects. This is the most comprehensive and systematic study of all the associations collected for the γ-ray sources available to date. We conclude that 80% of the Fermi sources have at least one known plausible γ-ray emitter within their positional uncertainty regions.

  18. Particle sources with high-intensity lasers: a tool for plasma diagnostics and an innovative source for applications; Sources de particules avec des lasers de haute intensite: un outil pour les diagnostics plasma et une source innovante pour les applications

    Energy Technology Data Exchange (ETDEWEB)

    Fritzler, S

    2003-09-15

    This work is an experimental study on particle generation with high-intensity lasers. This document is divided into 4 parts, whereas the first is dedicated to theoretical basics of particle generation and acceleration mechanisms during relativistic laser plasma interactions, the 3 other parts cover experimental studies on neutron, electron as well as proton generation. In the first part basic laser and plasma characteristics will be introduced as well as physical processes of interest during the interaction of a relativistic high-intensity laser with an underdense / overdense plasma. In the second part we introduce methodological basics of neutron generation by D(d,n)He{sup 3} reactions since this can reveal information about ion kinetics and possible ion heating mechanisms in plasmas. Subsequently the set-up for this experiment, pursued in the underdense regime, will be described in detail. The experimental results will be discussed for the gas jet interaction as well as for the beam target model since it was deduced that plasma ions are heated during the interaction to fusion temperatures of about 1 keV. The third part describes the generation of an electron beam with an energy up to 200 MeV in a new regime termed 'forced laser Wakefield'. Here, the presented experimental results were for the first time fully explained and even extended by the numerical modelling of this interaction in terms of energy, yield, angular divergence, emittance as well as bunch length of this electron beam. In the last part we present a 10 MeV proton beam generation using foil targets and a 10 Hz laser. Again the kinematic simulation of this experiment is in agreement with the experimental results by means of yield and angular divergence.

  19. Influence of dielectric materials on uniformity of large-area capacitively coupled plasmas for N2/Ar discharges

    Science.gov (United States)

    Liang, Ying-Shuang; Zhang, Yu-Ru; Wang, You-Nian

    2016-10-01

    The effect of the dielectric ring on the plasma radial uniformity is numerically investigated in the practical 450-mm capacitively coupled plasma reactor by a two-dimensional self-consistent fluid model. The simulations were performed for N2/Ar discharges at the pressure of 300 Pa, and the frequency of 13.56 MHz. In the practical plasma treatment process, the wafer is always surrounded by a dielectric ring, which is less studied. In this paper, the plasma characteristics are systematically investigated by changing the properties of the dielectric ring, i.e., the relative permittivity, the thickness and the length. The results indicate that the plasma parameters strongly depend on the properties of the dielectric ring. As the ratio of the thickness to the relative permittivity of the dielectric ring increases, the electric field at the wafer edge becomes weaker due to the stronger surface charging effect. This gives rise to the lower ion density, flux and N atom density at the wafer edge. Thus the homogeneous plasma density is obtained by selecting optimal dielectric ring relative permittivity and thickness. In addition, we also find that the length of the dielectric ring should be as short as possible to avoid the discontinuity of the dielectric materials, and thus obtain the large area uniform plasma. Project supported by the National Natural Science Foundation of China (Grant Nos. 11335004 and 11405019) and the Important National Science and Technology Specific Project of China (Grant No. 2011ZX02403-001).

  20. Overview of Space Station attached payloads in the areas of solar physics, solar terrestrial physics, and plasma processes

    Science.gov (United States)

    Roberts, W. T.; Kropp, J.; Taylor, W. W. L.

    1986-01-01

    This paper outlines the currently planned utilization of the Space Station to perform investigations in solar physics, solar terrestrial physics, and plasma physics. The investigations and instrumentation planned for the Solar Terrestrial Observatory (STO) and its associated Space Station accommodation requirements are discussed as well as the planned placement of the STO instruments and typical operational scenarios. In the area of plasma physics, some preliminary plans for scientific investigations and for the accommodation of a plasma physics facility attached to the Space Station are outlined. These preliminary experiment concepts use the space environment around the Space Station as an unconfined plasma laboratory. In solar physics, the initial instrument complement and associated accommodation requirements of the Advanced Solar Observatory are described. The planned evolutionary development of this observatory is outlined, making use of the Space Station capabilities for servicing and instrument reconfiguration.

  1. Application of carbon isotope for discriminating sources of soil CO2 in karst area, Guizhou

    Institute of Scientific and Technical Information of China (English)

    黎廷宇; 王世杰

    2001-01-01

    Using carbon isotope of soil CO2 this paper discussed the sources of soil CO2 in karst area, Guizhou Province, China. Oxidation-decomposition of organic matter, respiration of plant root and activity of microbe are thought to be the major sources of soil CO2. However, in karst area, the contribution of dissolution of underlying carbonate rock to soil CO2 should be considered as in acidic environment. Atmospheric CO2 is the major composition of soil CO2 in surface layer of soil profiles and its proportion in soil CO2 decreases with increase of soil depth. CO2 produced by dissolution of carbonate rock contributes 34%-46% to soil CO2 below the depth of 10cm in the studied soil profiles covered by grass.

  2. V.U.V. plasma spectroscopy diagnostic of electron cyclotron resonance multicharged ion sources; Diagnostic de plasmas crees dans des sources d'ions multicharges a resonance cyclotronique electronique par spectroscopie V.U.V

    Energy Technology Data Exchange (ETDEWEB)

    Berreby, R

    1997-12-15

    To characterize the multicharged ions within the plasma of an E.C.R. ion source, the V.U.V. spectroscopy is used as a non invasive diagnostic of excited matter. In E.C.R.I. S. (electron cyclotron resonance ion source) electrons are heated and magnetically confined within the mirror machine to overcome the successive ionization potentials of the desired elements. As the electrons bounce inside the magnetic configuration in their gyration movement, they interact with the microwaves injected into the source at the resonance frequency. To enhance the performances in high charge states and extracted currents delivered by E.C.R.I.S., the fundamental parameters of the plasma created in these machines must be known. The goal of spectroscopic diagnostics in the V.U.V. range installed on the sources is to determine electron density and temperature on one hand, and the ionic densities and confinement time on the other hand. We used microchannel plates as detector on a 3 meter grazing incidence spectrometer equipped with a 600 lines/mm holographic grating. The calibration of the whole grating with detector was performed by two different methods. These are the branching ratio and charge exchange methods. Identification of lines emitted by a plasma, which gather the whole charge states of ions is necessary to make an exhaustive study of the plasma state. And finally, the determination of plasma parameters like electron density and temperature and ion densities and confinement times that uses theoretical models were the aim of this work. (author)

  3. Development of a Protocol and a Screening Tool for Selection of DNAPL Source Area Remediation

    Science.gov (United States)

    2012-02-01

    and Sale T. ZVI-clay soil mixing treats DNAPL source 13 2.2 Newsletter area at 35-foot depth Technology News and Trends, February 2006. http://www...Type Hood D and Tmvnsend G. ERH pilot project removes 48 tons of PCA 27 2.2 Newsletter DNAPL within six months. Technology News and Trends...Dupin, H. J., and McCarty, P. L. 2000, Impact of Colony Morphologies and Disinfection on Biological Clogging in Porous Media, Environmental Science

  4. An Analysis of the Development of Renewable Energy Sources in the Western Minority Areas

    Institute of Scientific and Technical Information of China (English)

    Deng Yanfei; Liu Mingyang

    2016-01-01

    The biggest challenge for China’s energy is sustainability of the environment. Espe-cially in recent years, global warming, frequent natural disasters, and the serious reduction of the natural resources and energy are gravely affecting normal production and mankind’s existence. Burn-ing large amounts of fossil fuel produces green-house gases and polluted soot. The development and utilization of renewable energy is extremely ur-gent. In other words, renewable energy sources must grow briskly. Under the guidance of the na-tional policy of the“13 th Five Year Plan”, the de-velopment and utilization of renewable energy sources in the Western Minority Areas must be strengthened based on local conditions, by paying attention to relevant personnel training, and en-couraging innovation and entrepreneurship so that the development of local renewable energy sources can reach a new level.

  5. Source apportionment for urban PM10 and PM2.5 in the Beijing area

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; GUO JingHua; SUN YeLe; YUAN Hui; ZHUANG GuoShun; ZHUANG YaHui; HAO ZhengPing

    2007-01-01

    Airborne particulate matter (PM2.5 and PM10) samples were collected at the Beijing Normal University sampling site in the urban area of Beijing, China in dry and wet seasons during 2001―2004. Concentrations of 23 elements and 14 ions in particulate samples were determined by ICP-AES and IC, respectively. Source apportionment results derived from both Positive Matrix Factorization (PMF) and Chemical Mass Balance (CMB) models indicate that the major contributors of PM2.5 and PM10 in Beijing are: soil dust, fossil fuel combustion, vehicle exhausts, secondary particulate, biomass burning and some industrial sources. We have identified both regional common sources, such as vehicular emissions, particulate of secondary origin and biomass burning, as well as country-specific problems, such as sand storms and soil dust that should be addressed for effective air quality control.

  6. FreeSASA: An open source C library for solvent accessible surface area calculations.

    Science.gov (United States)

    Mitternacht, Simon

    2016-01-01

    Calculating solvent accessible surface areas (SASA) is a run-of-the-mill calculation in structural biology. Although there are many programs available for this calculation, there are no free-standing, open-source tools designed for easy tool-chain integration. FreeSASA is an open source C library for SASA calculations that provides both command-line and Python interfaces in addition to its C API. The library implements both Lee and Richards' and Shrake and Rupley's approximations, and is highly configurable to allow the user to control molecular parameters, accuracy and output granularity. It only depends on standard C libraries and should therefore be easy to compile and install on any platform. The library is well-documented, stable and efficient. The command-line interface can easily replace closed source legacy programs, with comparable or better accuracy and speed, and with some added functionality.

  7. Research Progress on the Problem of Fluid, Heat and Energy Distribution near the Earthquake Source Area

    Institute of Scientific and Technical Information of China (English)

    Yan Rui; Jiang Changsheng; Shao Zhigang; Zhou Longquan; Li Yingchun

    2011-01-01

    As the basic problems in seismology, fluid, heat and energy distribution near earthquake sources during earthquake generation have been the leading subjects of concern to seismologists. Currently, more and more research shows fluid around earthquake source areas, which plays an important role in the process of earthquake preparation and generation. However, there is considerable controversy over the source of fluid in the deep crust. As for the problem of heat around earthquake source areas, different models have been proposed to explain the stress heat flow paradox. Among them, the dynamic weakening model has been thought to be the key to solving the heat flow paradox issue. After large earthquakes, energy distribution is directly related to friction heat. It is of timely and important practical significance to immediately implement deep drilling in-site surveying to gain understanding of fluid, friction heat and energy distribution during earthquake generation. The latest international progress in fluid, heat and energy distribution research has been reviewed in this paper which will bring important inspiration for the understanding of earthquake preparation and occurrence.

  8. Water Quality Assessment of Various Sources in Rural Areas in the Lowveld Region of Swaziland

    Directory of Open Access Journals (Sweden)

    Amos Olutola Fadiran

    2012-03-01

    Full Text Available This study assesses water quality levels of sources used by rural communities in the lowveld region of Swaziland. The water quality assessments are based on household perceptions about water quality and laboratory water quality analyses which were carried out on selected water quality parameters. A total of 180 household heads were interviewed and in addition water samples from 13 locations were analysed. The parameters considered were physical factors including pH, colour, taste and odour. Results of pH tests indicated that 23.1% of the water sources were acidic, 7.7% were neutral and 69.2% were alkaline. Water collected from the unprotected wells tested acidic, had a pH of 5.96, implying that it is corrosive and might present health risks to humans and livestock. Sources with highly alkaline water were the borehole, spring, hot spring standpipes, and rivers. Survey findings show that colour, taste, smell and turbidity are the quality parameters mostly used by rural households to determine water suitability for domestic use. Most ground water sources were found to have saline water due to low ground water recharge in the area. Water quality remains a sustainable development challenge in the rural areas of Swaziland.

  9. Source Apportionment of PM10 by Positive Matrix Factorization in Urban Area of Mumbai, India

    Directory of Open Access Journals (Sweden)

    Indrani Gupta

    2012-01-01

    Full Text Available Particulate Matter (PM10 has been one of the main air pollutants exceeding the ambient standards in most of the major cities in India. During last few years, receptor models such as Chemical Mass Balance, Positive Matrix Factorization (PMF, PCA–APCS and UNMIX have been used to provide solutions to the source identification and contributions which are accepted for developing effective and efficient air quality management plans. Each site poses different complexities while resolving PM10 contributions. This paper reports the variability of four sites within Mumbai city using PMF. Industrial area of Mahul showed sources such as residual oil combustion and paved road dust (27%, traffic (20%, coal fired boiler (17%, nitrate (15%. Residential area of Khar showed sources such as residual oil combustion and construction (25%, motor vehicles (23%, marine aerosol and nitrate (19%, paved road dust (18% compared to construction and natural dust (27%, motor vehicles and smelting work (25%, nitrate (16% and biomass burning and paved road dust (15% in Dharavi, a low income slum residential area. The major contributors of PM10 at Colaba were marine aerosol, wood burning and ammonium sulphate (24%, motor vehicles and smelting work (22%, Natural soil (19%, nitrate and oil burning (18%.

  10. Contamination source review for Building E6891, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    The US Army Aberdeen Proving Ground (APG) commissioned Argonne National Laboratory (ANL) to conduct a contamination source review to identify and define areas of toxic or hazardous contaminants and to assess the physical condition and accessibility of various APG buildings. This report provides the results of the contamination source review for Building E6891. The information obtained from this review may be used to assist the US Army in planning for the future use or disposition of the buildings. The contamination source review consisted of the following tasks: historical records search, physical inspection, photographic documentation, geophysical investigation, and collection of air samples. This building is part of the Lauderick Creek Concrete Slab Test Site, located in the Lauderick Creek Area in the Edgewood Area. Many of the APG facilities constructed between 1917 and the 1960s are no longer used because of obsolescence and their poor state of repair. Because many of these buildings were used for research, development, testing, and/or pilot-scale production of chemical warfare agents and other military substances the potential exists` for portions of the buildings to be contaminated with these substances, their degradation products, and other laboratory or industrial chemicals. These buildings and associated structures or appurtenances may contribute to environmental concerns at APG.

  11. Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

    Directory of Open Access Journals (Sweden)

    Ganhua Lu

    2006-01-01

    Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

  12. Effect of dietary protein sources on production performance, egg quality, and plasma parameters of laying hens

    Science.gov (United States)

    Wang, Xiaocui; Zhang, Haijun; Wang, Hao; Wang, Jing; Wu, Shugeng; Qi, Guanghai

    2017-01-01

    Objective This study was conducted to evaluate the effects of dietary protein sources (soybean meal, SBM; low-gossypol cottonseed meal, LCSM; double-zero rapeseed meal, DRM) on laying performance, egg quality, and plasma parameters of laying hens. Methods A total of 432 32-wk-old laying hens were randomly divided into 6 treatments with 6 replicates of 12 birds each. The birds were fed diets containing SBM, LCSM100, or DRM100 individually or in combination with an equal amount of crude protein (CP) (LCSM50, DRM50, and LCSM50-DRM50). The experimental diets, which were isocaloric (metabolizable energy, 11.11 MJ/kg) and isonitrogenous (CP, 16.5%), had similar digestible amino acid profile. The feeding trial lasted 12 weeks. Results The daily egg mass was decreased in the LCSM100 and LCSM50-DRM50 groups (p0.05) and showed increased yolk color at the end of the trial (p0.05). Conclusion Together, our results suggest that the LCSM100 or DRM100 diets may produce the adverse effects on laying performance and egg quality after feeding for 8 more weeks. The 100.0 g/kg LCSM diet or the148.7 g/kg DRM diet has no adverse effects on laying performance and egg quality. PMID:27608634

  13. Preparation of plastic and biopolymer multilayer films by plasma source ion implantation.

    Science.gov (United States)

    Shin, Gye Hwa; Lee, Yeon Hee; Lee, Jin Sil; Kim, Young Soo; Choi, Won Seok; Park, Hyun Jin

    2002-07-31

    The plasma source ion implantation (PSII) technique was used to improve the adhesion between linear low-density polyethylene (LLDPE) and biopolymer. LLDPE was treated with the PSII using O(2) or CF(4) gas to modify its surface. After modification, chitosan or corn zein was used for coating on LLDPE. Wettability of the LLDPE surface was evaluated with a contact angle meter by the sessile drop method. X-ray photoelectron spectroscopy (XPS) was used to analyze the LLDPE surface. Before and after treatment, in the case of LLDPE treated with O(2) PSII, oxygen-containing functional groups were formed on the implanted surface. In the CF(4) PSII treated LLDPE, it was observed that the fluorine concentration on the surface of LLDPE remarkably increased and hydrophobic groups were formed by chemical reaction. Bilayer films coated with chitosan or corn zein showed 10 times lower oxygen permeability. Tensile strength of multilayer films was decreased a little compared with that of LLDPE. The plastic and biopolymer multilayer films have potential for food packaging application because of their O(2) gas barrier property and easy recyclability of the multilayer film.

  14. Low-Energy Plasma Focus as a Tailored X-Ray Source

    Science.gov (United States)

    Zakaullah, M.; Alamgir, K.; Shafiq, M.; Sharif, M.; Waheed, A.; Murtaza, G.

    2000-06-01

    A low-energy (2.3 kJ) plasma focus energized by a single 32-μF capacitor charged at 12 kV with filling gases hydrogen, neon, and argon is investigated as an X-ray source. Experiments are conducted with a copper and an aluminum anode. Specifically, attention is given to tailoring the radiation in different windows, e.g., 1.2-1.3 keV, 1.3-1.5 keV, 2.5-5 keV, and Cu-Kα line radiation. The highest X-ray emission is observed with neon filling and the copper anode in the 1.2-1.3 keV window, which we speculate to be generated due to recombination of hydrogenlike neon ions with a few eV to a few 10s of eV electrons. The wall-plug efficiency of the device is found to be 4%. The other significant emission occurs with hydrogen filling, which exhibits wall-plug efficiency of 1.7% for overall X-ray emission and 0.35% for Cu-Kα line radiation. The emission is dominated by the interaction of electrons in the current sheath with the anode tip. The emission with the aluminum anode and hydrogen filling is up to 10 J, which corresponds to wall-plug efficiency of 0.4%. The X-ray emission with argon filling is less significant.

  15. Bone marrow plasma cells are a primary source of serum HIV-1-specific antibodies in chronically infected individuals.

    Science.gov (United States)

    Montezuma-Rusca, Jairo M; Moir, Susan; Kardava, Lela; Buckner, Clarisa M; Louie, Aaron; Kim, Leo J Y; Santich, Brian H; Wang, Wei; Fankuchen, Olivia R; Diaz, Gabriella; Daub, Janine R; Rosenzweig, Sergio D; Chun, Tae-Wook; Li, Yuxing; Braylan, Raul C; Calvo, Katherine R; Fauci, Anthony S

    2015-03-15

    Several potent and broadly neutralizing Abs to HIV-1 have been isolated recently from peripheral blood B cells of infected individuals, based on prescreening of Ab activity in the serum. However, little is known regarding the cells that make the Abs that circulate in the blood. Accordingly, we investigated the most likely source, the bone marrow, of chronically HIV-1-infected individuals who were not receiving antiretroviral therapy. Increased frequencies of plasma cells, as well as B cell precursors, namely preB-I and preB-II, and decreased frequencies of mature B cells were observed in bone marrow aspirates of these individuals compared with HIV-negative counterparts. Increased frequencies of bone marrow plasma cells are consistent with known hallmarks of HIV-1 infection, namely hypergammaglobulinemia and increased frequencies of peripheral blood plasmablasts. Levels of HIV-1 envelope (Env)-binding and HIV-1-neutralizing Abs were measured in serum, and corresponding frequencies of Ab-secreting or Env-binding cells were measured in the blood (plasmablasts and memory B cells) and in the bone marrow (plasma cells). A strong correlation was observed between serum HIV-1-specific Abs and Env-specific bone marrow-derived plasma cells, but not circulating plasmablasts or memory B cells. These findings demonstrate that, despite HIV-1-induced phenotypic and functional B cell dysregulation in the peripheral blood and secondary lymphoid tissues, bone marrow plasma cells remain a primary source for circulating HIV-1-specific Abs in HIV-1-infected individuals.

  16. Work function measurements during plasma exposition at conditions relevant in negative ion sources for the ITER neutral beam injection.

    Science.gov (United States)

    Gutser, R; Wimmer, C; Fantz, U

    2011-02-01

    Cesium seeded sources for surface generated negative hydrogen ions are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER. The stability and delivered current density depend highly on the work function during vacuum and plasma phases of the ion source. One of the most important quantities that affect the source performance is the work function. A modified photocurrent method was developed to measure the temporal behavior of the work function during and after cesium evaporation. The investigation of cesium exposed Mo and MoLa samples under ITER negative hydrogen ion based neutral beam injection relevant surface and plasma conditions showed the influence of impurities which result in a fast degradation when the plasma exposure or the cesium flux onto the sample is stopped. A minimum work function close to that of bulk cesium was obtained under the influence of the plasma exposition, while a significantly higher work function was observed under ITER-like vacuum conditions.

  17. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

    Science.gov (United States)

    Chaplin, Vernon H; Bellan, Paul M

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  18. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi; Neri, Lorenzo; Gammino, Santo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Biri, Sándor; Rácz, Richárd; Pálinkás, József [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/c, H-4026 Debrecen (Hungary); Caliri, Claudia [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università degli Studi di Catania, Dip.to di Fisica e Astronomia, via Santa Sofia 64, 95123 Catania (Italy); Romano, Francesco Paolo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy); Torrisi, Giuseppe [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, DIIES, Via Graziella, I-89100 Reggio Calabria (Italy)

    2016-02-15

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed “on-line” during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.

  19. Refining the associations of the Fermi Large Area Telescope Source Catalogs

    CERN Document Server

    Massaro, F; Landoni, M; Paggi, A; Masetti, N; Giroletti, M; Otí-Floranes, H; Chavushyan, V; Jiménez-Bailón, E; Patiño-Álvarez, V; Digel, S W; Smith, Howard A; Tosti, G

    2015-01-01

    The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) was released in February 2010 and the Fermi-LAT 2-Year Source Catalog (2FGL) appeared in April 2012, based on data from 24 months of operation. Since their releases, many follow up observations of unidentified gamma-ray sources (UGSs) were performed and new procedures to associate gamma-ray sources with potential counterparts at other wavelengths were developed. Here we review and characterize all the associations as published in the 1FGL and 2FGL catalog on the basis of multifrequency archival observations. In particular we located 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition we present new spectroscopic observations of 8 gamma-ray blazar candidates. Based on our investigations, we introduce a new counterpart category of "candidate associations" and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. We compare the 1FGL-assigned coun...

  20. Penumbral imaging and numerical evaluation of large area source neutron imaging system

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The fusion neutron penumbral imaging system Monte Carlo model was established. The transfer functions of the two discrete units in the neutron source were obtained in two situations:Imaging in geometrical near-optical and real situation. The spatial resolutions of the imaging system in two situations were evaluated and compared. The penumbral images of four units in the source were obtained by means of 2-dimensional (2D) convolution and Monte Carlo simulation. The penumbral images were reconstructed with the same method of filter. The same results were confirmed. The encoding essence of penumbral imaging was revealed. With MCNP(Monte Carlo N-particle) simulation,the neutron penumbral images of the large area source (200 μm×200 μm) on scintillation fiber array were obtained. The improved Wiener filter method was used to reconstruct the penumbral image and the source image was obtained. The results agree with the preset neutron source image. The feasibility of the neutron imaging system was verified.

  1. Penumbral imaging and numerical evaluation of large area source neutron imaging system

    Institute of Scientific and Technical Information of China (English)

    WU YueLei; HU HuaSi; ZHANG BoPing; LI LinBo; CHEN Da; SHAN Qing; ZHU Jie

    2009-01-01

    The fusion neutron penumbral imaging system Monte Carlo model was established. The transfer func-tions of the two discrete units in the neutron source were obtained in two situations: Imaging in geo-metrical near-optical and real situation. The spatial resolutions of the imaging system in two situations were evaluated and compared. The penumbral images of four units in the source were obtained by means of 2-dimensional (2D) convolution and Monte Carlo simulation. The penumbral images were reconstructed with the same method of filter. The same results were confirmed. The encoding essence of penumbral imaging was revealed. With MCNP(Monte Carlo N-particle) simulation, the neutron pen-umbral images of the large area source (200 μm×200 μm) on scintillation fiber array were obtained. The improved Wiener filter method was used to reconstruct the penumbral image and the source image was obtained. The results agree with the preset neutron source image. The feasibility of the neutron imaging system was verified.

  2. Low pressure arc discharges with hollow cathodes and their using in plasma generators and charged particle sources

    CERN Document Server

    Vintizenko, L G; Koval, N N; Tolkachev, V S; Lopatin, I V; Shchanin, P M

    2001-01-01

    Paper presents the results of investigation into arc discharges with a hollow cathode generating 10 sup 1 sup 0 -10 sup 1 sup 2 concentration gas-discharge plasma in essential (approx 1 m sup 3) volumes at low (10 sup - sup 2 -1 Pa) pressures and up to 200 A discharge currents. One studied design of discharge systems with heated and cold cathodes their peculiar features, presented the parameters of plasma generators and of charged particle sources based on arc discharges and discussed, as well, the problems of more rational application of those systems in the processes for surface modification of solids

  3. Pulsed ion sheath dynamics in a cylindrical bore for inner surface grid-enhanced plasma source ion implantation

    CERN Document Server

    Wang Jiu Li; Fan Song Hua; Yang Wu Bao; Yang Size

    2002-01-01

    Based on authors' recently proposed grid-enhanced plasma source ion implantation (GEPSII) technique for inner surface modification of materials with cylindrical geometry, the authors present the corresponding theoretical studies of the temporal evolution of the plasma ion sheath between the grid electrode and the target in a cylindrical bore. Typical results such as the ion sheath evolution, time-dependent ion density and time-integrated ion energy distribution at the target are calculated by solving Poisson's equation coupled with fluid equations for collisionless ions and Boltzmann assumption for electrons using finite difference methods. The calculated results can further verify the feasibility and superiority of this new technique

  4. Intense, Narrow-band THz Emission from a Current Source Immersed in Cut-off of Plasma-like Media

    Science.gov (United States)

    Hur, Min Sup; Ersfeld, Bernhard; Noble, Adam; Suk, Hyyong; Jaroszynski, Dino

    2016-10-01

    Recently we found an interesting behavior of the electromagnetic radiation emerging from cut-off condition of a plasma-like medium, when it is driven by a current source. Differently from conventional total reflection of the incident wave at the cut-off, we found a spatially diffusing and temporally growing electromagnetic field from the current source. Direct result of such diffusion-growth is the selectively enhanced emission (SEE) at the cut-off frequency from a generally broadband current oscillation. We demonstrate examples demonstrating the SEE. One is the two-color-driven THz emission from field ionization of the gas slab located in a tapered waveguide. The emission propagating through the waveguide exhibits a significantly enhanced spectral density at the cut-off frequency. The other example is the THz emission from a magnetized plasma driven by two colliding ultra-short laser pulses. Since a very narrow-band emission can be selectively enhanced from a broadband radiation source, the SEE concept can be used for conversion of a general broadband THz source to a narrow-band one by locating it in a meta-structure such as the waveguide or a plasma-like medium. We discuss other possible systems to which SEE can be applied.

  5. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    Science.gov (United States)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2

  6. Water Residence Times and Runoff Sources Across an Urbanizing Gradient (Croton Water Supply Area, New York)

    Science.gov (United States)

    Vitvar, T.; Burns, D. A.; Duncan, J. M.; Hassett, J. M.; McDonnell, J. J.

    2002-12-01

    Water residence times and nutrient budgets were measured in 3 small watersheds in the Croton water supply area, NY. The watersheds (less than 1km 2) have different levels of urbanization (natural, semi-developed and fully developed), different mechanisms of runoff generation (quick flow on impervious surfaces and slow flow through the subsurface) and different watershed landscape characteristics (wet zones, hillslopes). Throughfall, stream water, soil water and groundwater in the saturated zone were sampled bi-weekly during a period of up to 2 years and analyzed for major chemical constituents, oxygen-18 content, and nitrogen species. Mean residence times of the stream water of about 30 weeks were estimated using Oxygen-18 and Helium-3/Tritium isotopes for all 3 watersheds. There was no significant difference in mean residence times among the three study watersheds, despite their different levels of urbanization. However, residence times from a few weeks up to ca 2 years vary within the watersheds, depending on the local runoff sources and their geographical conditions (riparian and hillslope topography, aquifer type). The runoff sources were quantified for selected streamwater and groundwater sampling sites using the end member mixing analysis technique (EMMA). The mixing analysis shows the impact of the runoff sources on runoff generation in the selected watersheds, i.e. it shows how big is the impact of urbanization on the runoff generation and how big is the natural control. These results may be useful in watershed management and planning of further urbanization in the Croton water supply area.

  7. Variation in low food access areas due to data source inaccuracies.

    Science.gov (United States)

    Ma, Xiaoguang; Battersby, Sarah E; Bell, Bethany A; Hibbert, James D; Barnes, Timothy L; Liese, Angela D

    2013-12-01

    Several spatial measures of community food access identifying so called "food deserts" have been developed based on geospatial information and commercially-available, secondary data listings of food retail outlets. It is not known how data inaccuracies influence the designation of Census tracts as areas of low access. This study replicated the U.S. Department of Agriculture Economic Research Service (USDA ERS) food desert measure and the Centers for Disease Control and Prevention (CDC) non-healthier food retail tract measure in two secondary data sources (InfoUSA and Dun & Bradstreet) and reference data from an eight-county field census covering169 Census tracts in South Carolina. For the USDA ERS food deserts measure accuracy statistics for secondary data sources were 94% concordance, 50-65% sensitivity, and 60-64% positive predictive value (PPV). Based on the CDC non-healthier food retail tracts both secondary data demonstrated 88-91% concordance, 80-86% sensitivity and 78-82% PPV. While inaccuracies in secondary data sources used to identify low food access areas may be acceptable for large-scale surveillance, verification with field work is advisable for local community efforts aimed at identifying and improving food access.

  8. Fluid regime in the source and preparation area of an earthquake

    Science.gov (United States)

    Kissin, I. G.

    2016-09-01

    Peculiarities of the fluid regime in the source and in the area of preparation of an earthquake which accommodates the evolution of the precursors are considered. The qualitative characteristics and the conditions of migration of the fluids, as well as their influence on the disjunctive deformations of the crust are discussed. During the development of the earthquake source, the fluid regime in this area depends on the redistribution of the fluids and their inflow from the outside. The fluid inflow and the increase in the fluid pressure are mainly due to the filtering from the subvertical permeable faults and the metamorphic dehydration of the rocks in the walls of the main fault. The fluids may also be supplied to the source from the near-surface horizons, and most of the induced earthquakes are associated with this process. These earthquakes can be considered as large-scale natural experiments which can shed light on the contribution of fluids in this phenomenon. A particular role in the mechanism of natural seismicity is played by the inflow of high-pressure fluids through the faults from the deep zones of the section.

  9. Signatures of the source for the Emeishan flood basalts in the Ertan area: Pb isotope evidence

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Emeishan flood basalts can be divided into high-Ti (HT) basalt (Ti/Y>500) and low-Ti (LT) basalt (Ti/Y<500). Sr, Nd isotopic characteristics of the lavas indicate that the LT- and the HT-type magmas originated from distinct mantle sources and parental magmas. The LT-type magma was derived from a shallower lithospheric mantle, whereas the HT-type magma was derived from a deeper mantle source that may be possibly a mantle plume. However, few studies on the Emeishan flood basalts involved their Pb isotopes, especially the Ertan basalts. In this paper, the authors investigated basalt samples from the Ertan area in terms of Pb isotopes, in order to constrain the source of the Emeishan flood basalts. The ratios of 206Pb/204Pb (18.31-18.41), 207Pb/204Pb (15.55-15.56) and 208Pb/204Pb (38.81-38.94) are significantly higher than those of the depleted mantle, just lying between EM I and EM II. This indicates that the Emeishan HT basalts (in the Ertan area) are the result of mixing of EMI end-member and EMII end-member.

  10. Airborne Quercus pollen in SW Spain: Identifying favourable conditions for atmospheric transport and potential source areas.

    Science.gov (United States)

    Maya-Manzano, José María; Fernández-Rodríguez, Santiago; Smith, Matt; Tormo-Molina, Rafael; Reynolds, Andrew M; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela; Sadyś, Magdalena

    2016-11-15

    The pollen grains of Quercus spp. (oak trees) are allergenic. This study investigates airborne Quercus pollen in SW Spain with the aim identifying favourable conditions for atmospheric transport and potential sources areas. Two types of Quercus distribution maps were produced. Airborne Quercus pollen concentrations were measured at three sites located in the Extremadura region (SW Spain) for 3 consecutive years. The seasonal occurrence of Quercus pollen in the air was investigated, as well as days with pollen concentrations ≥80Pm(-3). The distance that Quercus pollen can be transported in appreciable numbers was calculated using clusters of back trajectories representing the air mass movement above the source areas (oak woodlands), and by using a state-of-the-art dispersion model. The two main potential sources of Quercus airborne pollen captured in SW Spain are Q. ilex subsp. ballota and Q. suber. The minimum distances between aerobiological stations and Quercus woodlands have been estimated as: 40km (Plasencia), 66km (Don Benito), 62km (Zafra) from the context of this study. Daily mean Quercus pollen concentration can exceed 1,700Pm(-3), levels reached not less than 24 days in a single year. High Quercus pollen concentration were mostly associated with moderate wind speed events (6-10ms(-1)), whereas that a high wind speed (16-20ms(-1)) seems to be associated with low concentrations.

  11. Food sources of the Manila clam Ruditapes philippinarum in intertidal areas: evidence from stable isotope analysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liqiang; YAN Xiwu; YANG Feng

    2013-01-01

    Based on stable isotope analysis,we characterized the dietary regime of the Manila clam Ruditapesphilippinarum inhabiting intertidal areas along the Liaodong Peninsula,Northern China.Samples,including particulate organic matter (POM; n=30),benthic microalgae (BMI; n=30) and R.philippinarum (n=60),were collected from six sampling sites displaying the same ecological conditions.Of the two primary food sources,POM was more depleted in δ13C (-20.61‰ to-22.89‰) than BMI was (-13.90‰ to-16.66‰).With respect to 15N,BMI was more enriched (2.90‰ to 4.07‰) than POM was (4.13‰ to 5.12‰).The δ13C values of R.philippinarum ranged from-18.78‰ to-19.35‰ and the δ15N values from 7.96‰ to 8.63‰,which were intermediate between the POM and BMI values.In a two-source isotope mixing model,we estimated the relative contributions of POM and BMI to the diet of R.philippinarum to be 74.2% and 25.8%,respectively.We conclude that R.philippinarum feeds mainly on POM,and BMI is also an important supplemental food source in intertidal areas.

  12. First results with a surface conversion H ion source based on helicon wave mode-driven plasma discharge

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie A [Los Alamos National Laboratory; Geros, Ernest [Los Alamos National Laboratory; Rouleau, Gary [Los Alamos National Laboratory; Zaugg, Thomas J [Los Alamos National Laboratory

    2008-01-01

    The currently employed converter-type negative ion source at Los Alamos Neutron Science Center (LANSCE) is based on cesium enhanced surface production of H{sup -} ion beams in a filament-driven discharge. The extracted H{sup -} beam current is limited by the achievable plasma density, which depends primarily on the electron emission current from the filaments. The emission current can be increased by increasing the filament temperature but, unfortunately, this leads not only to shorter filament lifetime but also to an increase in metal evaporation from the filament, which degrades the performance of the H{sup -} conversion surface. In order to overcome these limitations we have designed and tested a prototype of a surface conversion H{sup -} ion source, based on excitation of helicon plasma wave mode with an external antenna. The source has been operated with and without cesium injection. An H{sup -} beam current of over 12 mA has been transported through the low energy beam transport of the LANSCE ion source test stand. The results of these experiments and the effects of different source parameters on the extracted beam current are presented. The limitations of the source prototype are discussed and future improvements are proposed based on the experimental observations.

  13. Levels, Composition and Sources of PM in the Mexico City Metropolitan Area During the MILAGRO Campaign

    Science.gov (United States)

    Querol, X.; Pey, J.; Minguillon, M. C.; Perez, N.; Alastuey, A.; Moreno, T.; Bernabe, R.; Blanco, S.; Cardenas, B.

    2007-05-01

    Particle air pollution in urban agglomerations comes mostly from anthropogenic sources, mainly traffic, industrial processes, energy production, domestic and residential emissions, construction, but also a minor contribution from natural sources may be expected (bioaerosols, soil dust, marine aerosol). Once emitted into the atmosphere, this complex mixture of pollutants may be transformed as a function of the ambient conditions and the interaction among the different PM components, and also between PM components and gaseous pollutants. This system is especially complex in mega-cities due to the large emission volumes of PM components and gaseous precursors, the high variability and broad distribution of emission sources, and the possible long range transport of the polluted air masses. Speciation studies help to identify major sources of PM components with the end objective of applying plans and programs for PM pollution abatement. In this framework, concentration levels and compositions of particulate matter (PM2.5, PM10 and TSP) have been measured simultaneously at two sites in the Mexico City Metropolitan Area (T0 and CENICA) and at one site 50 km away from Mexico City (T1) during the MILAGRO campaign (1st to 31st March 2006). Spatial and time (day and night) variations have been analysed. Coarse fraction levels were higher at T1 than at CENICA and T0, contrary to what was expected. This was due to the important soil re-suspension at T1, contributing significantly to the crustal load. Moreover, crustal levels were higher during daytime than during nights at all sites, while some secondary compounds (sulphate and ammonium) presented an opposite trend. Regarding trace elements, levels of Pb, Zn and Cd were higher at T0 than at CENICA and T1, probably due to traffic contribution. Arsenic levels did not show a clear pattern, being alternatively higher at CENICA and T0. Two intense episodes of Hg particulate have been recorded, more noticeable at T1 than at the urban

  14. 40 CFR Table 1 to Subpart Ccccccc... - Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Applicability of General Provisions to Paints and Allied Products Manufacturing Area Sources 1 Table 1 to Subpart CCCCCCC of Part 63 Protection... Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing Pt. 63, Subpt....

  15. 40 CFR Table 1 to Subpart Zzzzzz... - Applicability of General Provisions to Aluminum, Copper, and Other Nonferrous Foundries Area Sources

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Applicability of General Provisions to Aluminum, Copper, and Other Nonferrous Foundries Area Sources 1 Table 1 to Subpart ZZZZZZ of Part 63... Standards for Hazardous Air Pollutants: Area Source Standards for Aluminum, Copper, and Other...

  16. 40 CFR Table 2-to Subpart Xxxxxx... - Applicability of General Provisions to Metal Fabrication or Finishing Area Sources

    Science.gov (United States)

    2010-07-01

    ... Finishing Area Sources Instructions for Table 2—As required in § 63.11523, “General Provisions Requirements... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Applicability of General Provisions to Metal Fabrication or Finishing Area Sources 2 Table 2-to Subpart XXXXXX of Part 63 Protection...

  17. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Science.gov (United States)

    2010-07-01

    ... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of Environment... Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas? The requirements for new source review for the 8-hour ozone standard are located in § 51.165 of this part....

  18. Laser-plasma accelerator and femtosecond photon sources-based ultrafast radiation chemistry and biophysics

    Science.gov (United States)

    Gauduel, Y. A.

    2017-02-01

    The initial distribution of energy deposition triggered by the interaction of ionizing radiations (far UV and X rays, electron, proton and accelerated ions) with molecular targets or integrated biological systems is often decisive for the spatio-temporal behavior of radiation effects that take place on several orders of magnitude. This contribution deals with an interdisciplinary approach that concerns cutting-edge advances on primary radiation events, considering the potentialities of innovating strategies based on ultrafast laser science, from femtosecond photon sources to laser-driven relativistic particles acceleration. Recent advances of powerful TW laser sources (~ 1019 Wcm‑2) and laser-plasma interactions providing ultrashort relativistic particle beams in the energy domain 2.5–150 MeV open exciting opportunities for the development of high-energy radiation femtochemistry (HERF). Early radiation damages being dependent on the survival probability of secondary electrons and radial distribution of short-lived radicals inside ionization clusters, a thorough knowledge of these processes involves the real-time probing of primary events in the temporal range 10‑14–10‑11 s. In the framework of a closed synergy between low-energy radiation femtochemistry (LERF) and the emerging domain of HERF, the paper focuses on early phenomena that occur in the prethermal regime of low-energy secondary electrons, considering very short-lived quantum effects in aqueous environments. A high dose-rate delivered by femtosecond electron beam (~ 1011–1013 Gy s‑1) can be used to investigate early radiation processes in native ionization tracks, down to 10‑12 s and 10‑9 m. We explain how this breakthrough favours the innovating development of real-time nanodosimetry in biologically relevant environments and open new perspectives for spatio-temporal radiation biophysics. The emerging domain of HERF would provide guidance for understanding the specific bioeffects of

  19. Primary sources and toxicity of PAHs in Milwaukee-area streambed sediment

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Lutz, Michelle A.; Ingersoll, Christopher G.; Dorman, Rebecca A.; Magruder, Christopher; Magruder, Matthew

    2016-01-01

    High concentrations of polycyclic aromatic hydrocarbons (PAHs) in streams can be a significant stressor to aquatic organisms. To understand the likely sources and toxicity of PAHs in Milwaukee-area streams, streambed sediment samples from 40 sites and parking lot dust samples from 6 sites were analyzed for 38 parent PAHs and 25 alkylated PAHs. Diagnostic ratios, profile correlations, principal components analysis, source-receptor modeling, and mass fractions analysis were used to identify potential PAH sources to streambed sediment samples, and land-use analysis was used to relate streambed sediment PAH concentrations to different urban-related land uses. On the basis of this multiple lines-of-evidence approach, coal-tar pavement sealant was indicated as the primary source of PAHs in a majority of streambed sediment samples, contributing an estimated 77% of total PAHs to samples, on average. Comparison to the Probable Effect Concentrations and (or) the Equilibrium Partitioning Sediment Benchmark indicates that 78% of stream sediment samples are likely to cause adverse effects to benthic organisms. Laboratory toxicity tests on a 16-sample subset of the streambed sites using the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) measured significant reductions in one or more biological endpoints, including survival, in 75% of samples, with H. azteca more responsive than C. dilutus.

  20. Ion beam extraction from a matrix ECR plasma source by discrete ion-focusing effect

    DEFF Research Database (Denmark)

    Stamate, Eugen; Draghici, Mihai

    2010-01-01

    Positive or negative ion beams extracted from plasma are used in a large variety of surface functionalization techniques such as implantation, etching, surface activation, passivation or oxidation. Of particular importance is the surface treatment of materials sensitive to direct plasma exposure ...

  1. Numerical simulation of the coal combustion process initiated by a plasma source

    Science.gov (United States)

    Askarova, A. S.; Messerle, V. E.; Ustimenko, A. B.; Bolegenova, S. A.; Maksimov, V. Yu.

    2014-12-01

    Numerical experiments on the torch combustion of the coal dust prepared by a plasma-thermochemical treatment for combustion have been done using the method of three-dimensional simulation. It is shown that the plasma preparation of coal for combustion enables one to optimize the process, improve the conditions for inflammation and combustion and minimize the emissions of harmful substances.

  2. Characterization of an atmospheric double arc argon-nitrogen plasma source

    Science.gov (United States)

    Tu, X.; Chéron, B. G.; Yan, J. H.; Yu, L.; Cen, K. F.

    2008-05-01

    In the framework of studies devoted to hazardous waste destruction, an original dc double anode plasma torch has been designed and tested, which produces an elongated, weak fluctuation and reproducible plasma jet at atmospheric pressure. The arc instabilities and dynamic behavior of the double arc argon-nitrogen plasma jet are investigated through the oscillations of electrical signals by combined means of fast Fourier transform and Wigner distribution. In our experiment, the restrike mode is identified as the typical fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra and Wigner distributions exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which reveals that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the undulation of the power supply and both arc roots motion on the anode channels. In addition, the microscopic properties of the plasma jet inside and outside the arc chamber are investigated by means of optical emission spectroscopy, which yields excitation, electronic, rotational, and vibrational temperatures, as well as the electron number density. The results allow us to examine the validity criteria of a local thermodynamic equilibrium (LTE) state in the plasma arc. The measured electron densities are in good agreement with those calculated from the LTE model, which indicates that the atmospheric double arc argon-nitrogen plasma in the core region is close to the LTE state under our experimental conditions.

  3. Tethys and Dione as sources of outward-flowing plasma in Saturn's magnetosphere.

    Science.gov (United States)

    Burch, J L; Goldstein, J; Lewis, W S; Young, D T; Coates, A J; Dougherty, M K; André, N

    2007-06-14

    Rotating at over twice the angular speed of Earth, Saturn imposes a rapid spin on its magnetosphere. As a result, cold, dense plasma is believed to be flung outward from the inner magnetosphere by centrifugal force and replaced by hotter, more tenuous plasma from the outer magnetosphere. The centrifugal interchange of plasmas in rotating magnetospheres was predicted many years ago and was conclusively demonstrated by observations in Jupiter's magnetosphere, which--like that of Saturn (but unlike that of Earth)--is rotationally dominated. Recent observations in Saturn's magnetosphere have revealed narrow injections of hot, tenuous plasma believed to be the inward-moving portion of the centrifugal interchange cycle. Here we report observations of the distribution of the angle between the electron velocity vector and the magnetic field vector ('pitch angle') obtained in the cold, dense plasma adjacent to these inward injection regions. The observed pitch-angle distributions are indicative of outward plasma flow and consistent with centrifugal interchange in Saturn's magnetosphere. Further, we conclude that the observed double-peaked ('butterfly') pitch-angle distributions result from the transport of plasma from regions near the orbits of Dione and Tethys, supporting the idea of distinct plasma tori associated with these moons.

  4. Estimating methane emissions from biological and fossil-fuel sources in the San Francisco Bay Area

    Science.gov (United States)

    Jeong, Seongeun; Cui, Xinguang; Blake, Donald R.; Miller, Ben; Montzka, Stephen A.; Andrews, Arlyn; Guha, Abhinav; Martien, Philip; Bambha, Ray P.; LaFranchi, Brian; Michelsen, Hope A.; Clements, Craig B.; Glaize, Pierre; Fischer, Marc L.

    2017-01-01

    We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September - December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166-289 Gg CH4/yr (at 95% confidence), 1.3-2.3 times higher than a recent inventory with much of the underestimation from landfill. Including the VOCs, 82 ± 27% of total posterior median CH4 emissions are biological and 17 ± 3% fossil fuel, where landfill and natural gas dominate the biological and fossil-fuel CH4 of prior emissions, respectively.

  5. Residual Characters and Sources of Organochlorine Pesticides in Soils of Tianjin Area, China

    Directory of Open Access Journals (Sweden)

    WANG Ying

    2016-09-01

    Full Text Available The spatial distribution characteristics and the sources of organochlorine pesticides(OCPs were studied according to the field sampling and quantitative analysis of OCPs of soils in 188 points with 6 land-use types and 2 irrigation types from Tianjin area. This article investigated the residual levels, spatial and profile distribution of the isomers of hexachloro -cyclohexane soprocide(HCHs and dichlorodiphenyl trichloroethane (DDTs firstly, and then made the comparison with the residues in the past. The results showed that the con-tents of HCHs and DDTs in the soil of Tianjin reached to class A of the national standard. The distribution characteristics of HCHs in soils from Tianjin indicated that the inner suburban district and the coastal region were the most polluted areas, downtown took the second place, and outer suburban district was the least polluted. The distribution characteristics of DDTs showed that the inner suburban district and the downtown were the most polluted area, outer suburban district took the second place, and the coastal region was the least polluted. In different land-use types, there was the highest OCPs residues in urban green area. And there was no significant differences of OCPs residues between irrigation area and sewage irrigation area. The results of profile analysis indicated that the total amount of OCPs was mainly found in the 0~30 cm of farming layer. Based on the comparison of the residues of HCHs with that of DDTs, the degradation rate of DDTs was higher than that of HCHs, and abnormal residual levels were found in some areas of Tianjin.

  6. Simulations on the influence of the spatial distribution of source electrons on the plasma in a cusped-field thruster

    Science.gov (United States)

    Brandt, Tim; Trottenberg, Thomas; Groll, Rodion; Jansen, Frank; Hey, Franz Georg; Johann, Ulrich; Kersten, Holger; Braxmaier, Claus

    2015-06-01

    We present results from simulations on the influence of source electrons on the plasma properties in a magnetic cusps environment. Our simulations are based on the VSim/Vorpal particle-in-cell plasma simulation package. Magnetic cusps are a typical feature of High Efficiency Multistage Plasma Thrusters (HEMPTs). This research is part of an effort to downscale a HEMPT to thrust levels in the μN and sub- μN regime. The aim is to fulfill the requirements of upcoming formation flight satellites and probes. Those missions demand very precise attitude control. In order to get the necessary insight, the plasma of a section of the HEMPT discharge chamber is simulated with idealized boundary conditions. The results for such a section at two different distributions of source electrons are shown. A significant increase of the overall ion number is recognized for one of the distributions. Comparisons with published similar simulations are made. Factors that should be important for improvements of this thruster type are highlighted.

  7. Compact ring-based X-ray source with on-orbit and on-energy laser-plasma injection

    CERN Document Server

    Turner, Marlene; Edelen, Auralee; Gerity, James; Lajoie, Andrew; Lawler, Gerard; Lishilin, Osip; Moon, Kookjin; Sahai, Aakash Ajit; Seryi, Andrei; Shih, Kai; Zerbe, Brandon

    2016-01-01

    We report here the results of a one week long investigation into the conceptual design of an X-ray source based on a compact ring with on-orbit and on-energy laser-plasma accelerator. We performed these studies during the June 2016 USPAS class "Physics of Accelerators, Lasers, and Plasma..." applying the art of inventiveness TRIZ. We describe three versions of the light source with the constraints of the electron beam with energy $1\\,\\rm{GeV}$ or $3\\,\\rm{GeV}$ and a magnetic lattice design being normal conducting (only for the $1\\,\\rm{GeV}$ beam) or superconducting (for either beam). The electron beam recirculates in the ring, to increase the effective photon flux. We describe the design choices, present relevant parameters, and describe insights into such machines.

  8. A model for dispersion from area sources in convective turbulence. [for air pollution

    Science.gov (United States)

    Crane, G.; Panofsky, H. A.; Zeman, O.

    1977-01-01

    Four independent estimates of the vertical distribution of the eddy coefficient for dispersion of a passive contaminant from an extensive area source in a convective layer have been presented. The estimates were based on the following methods: (1) a second-order closure prediction, (2) field data of pollutant concentrations over Los Angeles, (3) lab measurements of particle dispersion, and (4) assumption of equality between momentum and mass transfer coefficients in the free convective limit. It is suggested that K-values estimated both from second-order closure theory and from Los Angeles measurements are systematically underestimated.

  9. Source area and seasonal Sr-87/Sr-86 variations in rivers of the Amazon basin

    OpenAIRE

    R. V. Santos; Sondag, Francis; Cochonneau, Gérard; Lagane, C.; Brunet, P.; Hattingh, K.; Chaves, J. G. S.

    2015-01-01

    We report the results of a detailed study of dissolved Sr isotopes in the Solimoes and Beni-Madeira Rivers of the Amazon basin. This study developed data collected over 8years indicating large spatial and temporal variations in dissolved Sr isotopes among the rivers of the Amazon basin. The large Sr-87/Sr-86 variations were found to be correlated with the geology of the source areas of the suspended sediments. The Beni-Madeira River displays a high average Sr-87/Sr-86 ratio and large Sr-87/Sr...

  10. Water quality in the Cambridge, Massachusetts, drinking-water source area, 2005-8

    Science.gov (United States)

    Smith, Kirk P.; Waldron, Marcus C.

    2015-01-01

    During 2005-8, the U.S. Geological Survey, in cooperation with the Cambridge, Massachusetts, Water Department, measured concentrations of sodium and chloride, plant nutrients, commonly used pesticides, and caffeine in base-flow and stormwater samples collected from 11 tributaries in the Cambridge drinking-water source area. These data were used to characterize current water-quality conditions, to establish a baseline for future comparisons, and to describe trends in surface-water quality. The data also were used to assess the effects of watershed characteristics on surface-water quality and to inform future watershed management.

  11. Distribution and sources of polycyclic aromatic hydrocarbons in main aquacultural areas in Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    MASKAOUI Khalid; HU Zhong; ZHOU Junliang; HAN Yali

    2007-01-01

    The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogenic sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.

  12. Numerical simulation of electromagnetic fields and impedance of CERN LINAC4 H- source taking into account the effect of the plasma

    Science.gov (United States)

    Grudiev, A.; Lettry, J.; Mattei, S.; Paoluzzi, M.; Scrivens, R.

    2014-02-01

    Numerical simulation of the CERN LINAC4 H- source 2 MHz RF system has been performed taking into account a realistic geometry from 3D Computer Aided Design model using commercial FEM high frequency simulation code. The effect of the plasma has been added to the model by the approximation of a homogenous electrically conducting medium. Electric and magnetic fields, RF power losses, and impedance of the circuit have been calculated for different values of the plasma conductivity. Three different regimes have been found depending on the plasma conductivity: (1) Zero or low plasma conductivity results in RF electric field induced by the RF antenna being mainly capacitive and has axial direction; (2) Intermediate conductivity results in the expulsion of capacitive electric field from plasma and the RF power coupling, which is increasing linearly with the plasma conductivity, is mainly dominated by the inductive azimuthal electric field; (3) High conductivity results in the shielding of both the electric and magnetic fields from plasma due to the skin effect, which reduces RF power coupling to plasma. From these simulations and measurements of the RF power coupling on the CERN source, a value of the plasma conductivity has been derived. It agrees well with an analytical estimate calculated from the measured plasma parameters. In addition, the simulated and measured impedances with and without plasma show very good agreement as well demonstrating validity of the plasma model used in the RF simulations.

  13. Numerical simulation of electromagnetic fields and impedance of CERN LINAC4 H(-) source taking into account the effect of the plasma.

    Science.gov (United States)

    Grudiev, A; Lettry, J; Mattei, S; Paoluzzi, M; Scrivens, R

    2014-02-01

    Numerical simulation of the CERN LINAC4 H(-) source 2 MHz RF system has been performed taking into account a realistic geometry from 3D Computer Aided Design model using commercial FEM high frequency simulation code. The effect of the plasma has been added to the model by the approximation of a homogenous electrically conducting medium. Electric and magnetic fields, RF power losses, and impedance of the circuit have been calculated for different values of the plasma conductivity. Three different regimes have been found depending on the plasma conductivity: (1) Zero or low plasma conductivity results in RF electric field induced by the RF antenna being mainly capacitive and has axial direction; (2) Intermediate conductivity results in the expulsion of capacitive electric field from plasma and the RF power coupling, which is increasing linearly with the plasma conductivity, is mainly dominated by the inductive azimuthal electric field; (3) High conductivity results in the shielding of both the electric and magnetic fields from plasma due to the skin effect, which reduces RF power coupling to plasma. From these simulations and measurements of the RF power coupling on the CERN source, a value of the plasma conductivity has been derived. It agrees well with an analytical estimate calculated from the measured plasma parameters. In addition, the simulated and measured impedances with and without plasma show very good agreement as well demonstrating validity of the plasma model used in the RF simulations.

  14. Gas-discharge sources with charged particle emission from the plasma of glow discharge with a hollow cathode

    CERN Document Server

    Semenov, A P

    2001-01-01

    One studied properties of a magnetron discharge with a cold hollow and uncooled rod cathodes. One demonstrated the dominant effect of thermoelectron emission of a rod cathode heated in a discharge on characteristics of discharge and on emission properties of a gas-discharge plasma and the possibility pf a smooth transition of glow discharge to diffusion mode of arc discharge combustion. Paper describes sources of ions and electrons with improved physical and generalized design and engineering parameters. One shows the promise of the electrode structure of a hollow cathode magnetron discharge to be used as a source, in particular, of the atomic hydrogen and of atom flow of a working rod cathode

  15. Ion angular distribution in plasma of vacuum arc ion source with composite cathode and elevated gas pressure.

    Science.gov (United States)

    Nikolaev, A G; Savkin, K P; Yushkov, G Yu; Oks, E M

    2014-02-01

    The Metal Vapor Vacuum Arc (MEVVA) ion sources are capable of generating ion beams of almost all metals of the periodic table. For this kind of ion source, a combination of gas feeding with magnetic field allows the simultaneous generation of both metal and gaseous ions. That makes the MEVVA ion source an excellent instrument for science and application. This work presents results of investigation for ion angular distributions in vacuum arc plasma of Mevva-V.Ru ion source for composite cathodes and for elevated gas pressure. It was shown that for all the cathode materials, singly charged ions have wider angular distribution than multiply charged ions. Increasing the working gas pressure leads to a significant change in the angular distribution of gaseous ions, while with the distribution of metal ions gas remains practically unchanged. The reasons for such different influences are discussed.

  16. Development of Laser-Produced Tin Plasma-Based EUV Light Source Technology for HVM EUV Lithography

    Directory of Open Access Journals (Sweden)

    Junichi Fujimoto

    2012-01-01

    Full Text Available Since 2002, we have been developing a carbon dioxide (CO2 laser-produced tin (Sn plasma (LPP extreme ultraviolet (EUV light source, which is the most promising solution because of the 13.5 nm wavelength high power (>200 W light source for high volume manufacturing. EUV lithography is used for its high efficiency, power scalability, and spatial freedom around plasma. We believe that the LPP scheme is the most feasible candidate for the EUV light source for industrial use. We have several engineering data from our test tools, which include 93% Sn ionization rate, 98% Sn debris mitigation by a magnetic field, and 68% CO2 laser energy absorption rate. The way of dispersion of Sn by prepulse laser is key to improve conversion efficiency (CE. We focus on prepulsed laser pulsed duration. When we have optimized pulse duration from nanosecond to picosecond, we have obtained maximum 4.7% CE (CO2 laser to EUV; our previous data was 3.8% at 2 mJ EUV pulse energy. Based on these data we are developing our first light source as our product: “GL200E.” The latest data and the overview of EUV light source for the industrial EUV lithography are reviewed in this paper.

  17. Plasma radiation sources. Quasi-adiabatic theory and numerical modeling in the electro-diffusive approximation

    Science.gov (United States)

    Guillory, J. U.; Terry, R. E.

    1984-07-01

    This report describes work done under DNA Contract 001-79-C-0189 from February 1982 to June 1983, and some more recent work. Part 1 includes treatments of a simple zero-D implosion code, analytic but very approximate scaling laws for radiation, and a discussion of preliminary work on nonlinear field penetration of plasma. Part 2 contains a discussion of electrodiffusive 1D modeling of annular plasma implosions. The thermoelectrical field, its role in field penetrations, the nonlocal constraints required in field diffusion (and some arising from field diffusion), flux limits and the acceleration process for annular plasmas are discussed.

  18. Ion shell distributions as free energy source for plasma waves on auroral field lines mapping to plasma sheet boundary layer

    Directory of Open Access Journals (Sweden)

    A. Olsson

    2004-06-01

    Full Text Available Ion shell distributions are hollow spherical shells in velocity space that can be formed by many processes and occur in several regions of geospace. They are interesting because they have free energy that can, in principle, be transmitted to ions and electrons. Recently, a technique has been developed to estimate the original free energy available in shell distributions from in-situ data, where some of the energy has already been lost (or consumed. We report a systematic survey of three years of data from the Polar satellite. We present an estimate of the free energy available from ion shell distributions on auroral field lines sampled by the Polar satellite below 6 RE geocentric radius. At these altitudes the type of ion shells that we are especially interested in is most common on auroral field lines close to the polar cap (i.e. field lines mapping to the plasma sheet boundary layer, PSBL. Our analysis shows that ion shell distributions that have lost some of their free energy are commonly found not only in the PSBL, but also on auroral field lines mapping to the boundary plasma sheet (BPS, especially in the evening sector auroral field lines. We suggest that the PSBL ion shell distributions are formed during the so-called Velocity Dispersed Ion Signatures (VDIS events. Furthermore, we find that the partly consumed shells often occur in association with enhanced wave activity and middle-energy electron anisotropies. The maximum downward ion energy flux associated with a shell distribution is often 10mWm-2 and sometimes exceeds 40mWm-2 when mapped to the ionosphere and thus may be enough to power many auroral processes. Earlier simulation studies have shown that ion shell distributions can excite ion Bernstein waves which, in turn, energise electrons in the parallel direction. It is possible that ion shell distributions are the link between the X-line and the auroral wave activity and electron

  19. Spatial distribution of the electrical potential and ion concentration in the downstream area of atmospheric pressure remote plasma

    Directory of Open Access Journals (Sweden)

    M. V. Mishin

    2014-10-01

    Full Text Available This paper presents the results from an experimental study of the ion flux characteristics behind the remote plasma zone in a vertical tube reaction chamber for atmospheric pressure plasma enhanced chemical vapor deposition. Capacitively coupled radio frequency plasma was generated in pure He and gas mixtures: He–Ar, He–O2, He–TEOS. We previously used the reaction system He–TEOS for the synthesis of self-assembled structures of silicon dioxide nanoparticles. It is likely that the electrical parameters of the area, where nanoparticles have been transported from the synthesis zone to the substrate, play a significant role in the self-organization processes both in the vapor phase and on the substrate surface. The results from the spatial distribution of the electrical potential and ion concentration in the discharge downstream area measured by means of the external probe of original design and the special data processing method are demonstrated in this work. Positive and negatives ions with maximum concentrations of 106–107 cm−3 have been found at 10–80 mm distance behind the plasma zone. On the basis of the revealed distributions for different gas mixtures, the physical model of the observed phenomena is proposed. The model illustrates the capability of the virtual ion emitter formation behind the discharge gap and the presence of an extremum of the electrical potential at the distance of approximately 10−2–10−1 mm from the grounded electrode.

  20. Estimation of the Threshold Friction Velocities over Various Dust Storm Source Areas in Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHU Hao; ZHANG Hongsheng

    2010-01-01

    The emission of dust particles into the atmosphere is governed by the aerodynamic and resistant factors, which are quantified by the friction velocity u. and the threshold friction velocity u*t, respectively. The threshold friction velocity u*t influences the vertical dust flux and dust transport. Based on the micro-meteorological data obtained in the springs of 2004 and 2006 over Hunshandake desert area, Loess Plateau, and Gobi desert area, the relationship between dust concentration and friction velocity for the dust events that occurred over Hunshandake desert area was investigated, and the threshold friction velocities over the three different dust source areas were estimated. The results show that the value of dust concentration is low during the pre-emission stage of a dust storm event, and the rapid increase of friction velocity provides favor-able dynamic conditions for dust emission. During the dust emission stage, the dust concentration increases sharply due to mechanical and thermal turbulent mixing. At the calm-down stage, the dust concentration drops nearly linearly with the decreasing friction velocity, on account of the gravitational deposition of larger dust particles. When the dust concentration is higher than 200 μgm-3, it is considered as a dust emission process. According to the criteria, the values of threshold friction velocity over Hunshandake desert area and Gobi region are 0.6 and 0.45 m s-1, respectively. The threshold friction velocity over Loess Plateau depends on the wind direction, due to the complex terrain and inhomogeneous surface. The northwest wind shows the effects of the Mu Us desert in the northwest. The corresponding u*t is 0.35 m s-1. The south wind exhibits the characteristics of the Loess hilly dunes in the south, and the u*t is 0.7 m s-1. The large roughness length of the Loess hilly dunes and the large inter-particle cohesion for the clay soil texture increases the local friction velocity. Different threshold friction

  1. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

    2009-03-15

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  2. Investigation of sources of atmospheric aerosol at a hot spot area in Dhaka, Bangladesh.

    Science.gov (United States)

    Begum, Bilkis A; Biswas, Swapan K; Kim, Eugene; Hopke, Philip K; Khaliquzzaman, Mohammed

    2005-02-01

    Samples of fine and coarse fractions of airborne particulate matter were collected at the Farm Gate area in Dhaka from July 2001 to March 2002. Dhaka is a hot spot area with very high pollutant concentrations because of the proximity of major roadways. The samples were collected using a "Gent" stacked filter unit in two fractions of 0- to 2.2-microm and 2.2- to 10-microm sizes. The samples were analyzed for elemental concentrations by particle-induced X-ray excitation (PIXE) and for black carbon by reflectivity methods, respectively. The data were analyzed by positive matrix factorization (PMF) to identify the possible sources of atmospheric aerosols in this area. Six sources were found for both the coarse and fine PM fractions. The data sets were also analyzed by an expanded model to explore additional sources. Seven and six factors were obtained for coarse and fine PM fractions, respectively, in these analyses. The identified sources are motor vehicle, soil dust, emissions from construction activities, sea salt, biomass burning/brick kiln, resuspended/fugitive Pb, and two-stroke engines. From the expanded modeling, approximately 50% of the total PM2.2 mass can be attributed to motor vehicles, including two-stroke engine vehicle in this hot spot in Dhaka, whereas the PMF modeling indicates that 45% of the total PM2.2 mass is from motor vehicles. The PMF2 and expanded models could resolve approximately 4% and 3% of the total PM2.2 mass as resuspended/fugitive Pb, respectively. Although, Pb has been eliminated from gasoline in Bangladesh since July 1999, there still may be substantial amounts of accumulated lead in the dust near roadways as well as fugitive Pb emissions from battery reclaimation and other industries. Soil dust is the largest component of the coarse particle fraction (PM2.2-10) accounting for approximately 71% of the total PM2.2-10 mass in the expanded model, whereas from the PMF modeling, the dust (undifferentiated) contribution is approximately 49%.

  3. Evaluation of the source area of rooftop scalar measurements in London, UK using wind tunnel and modelling approaches.

    Science.gov (United States)

    Brocklehurst, Aidan; Boon, Alex; Barlow, Janet; Hayden, Paul; Robins, Alan

    2014-05-01

    The source area of an instrument is an estimate of the area of ground over which the measurement is generated. Quantification of the source area of a measurement site provides crucial context for analysis and interpretation of the data. A range of computational models exists to calculate the source area of an instrument, but these are usually based on assumptions which do not hold for instruments positioned very close to the surface, particularly those surrounded by heterogeneous terrain i.e. urban areas. Although positioning instrumentation at higher elevation (i.e. on masts) is ideal in urban areas, this can be costly in terms of installation and maintenance costs and logistically difficult to position instruments in the ideal geographical location. Therefore, in many studies, experimentalists turn to rooftops to position instrumentation. Experimental validations of source area models for these situations are very limited. In this study, a controlled tracer gas experiment was conducted in a wind tunnel based on a 1:200 scale model of a measurement site used in previous experimental work in central London. The detector was set at the location of the rooftop site as the tracer was released at a range of locations within the surrounding streets and rooftops. Concentration measurements are presented for a range of wind angles, with the spread of concentration measurements indicative of the source area distribution. Clear evidence of wind channeling by streets is seen with the shape of the source area strongly influenced by buildings upwind of the measurement point. The results of the wind tunnel study are compared to scalar concentration source areas generated by modelling approaches based on meteorological data from the central London experimental site and used in the interpretation of continuous carbon dioxide (CO2) concentration data. Initial conclusions will be drawn as to how to apply scalar concentration source area models to rooftop measurement sites and

  4. Contamination source review for Building E2370, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    O`Reilly, D.P.; Glennon, M.A.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    The US Army Aberdeen Proving Ground (APG) commissioned Argonne National Laboratory (ANL) to conduct a contamination source review to identify and define areas of toxic or hazardous contaminants and to assess the physical condition and accessibility of APG buildings. The information obtained from this review may be used to assist the US Army in planning for the future use or disposition of the buildings. The contamination source review consisted of the following tasks: historical records search, physical inspection, photographic documentation, and geophysical investigation. This report provides the results of the contamination source review for Building E2370. Many of the APG facilities constructed between 1917 and the 1960s are no longer used because of obsolescence and their poor state of repair. Because many of these buildings were used for research, development, testing, and/or pilot-scale production of chemical warfare agents and other military substances, the potential exists for portions of the buildings to be contaminated with these substances, their degradation products, and other laboratory or industrial chemicals. These buildings and associated structures or appurtenances may contribute to environmental concerns at APG.

  5. Laser-driven x-ray and neutron source development for industrial applications of plasma accelerators

    Science.gov (United States)

    Brenner, C. M.; Mirfayzi, S. R.; Rusby, D. R.; Armstrong, C.; Alejo, A.; Wilson, L. A.; Clarke, R.; Ahmed, H.; Butler, N. M. H.; Haddock, D.; Higginson, A.; McClymont, A.; Murphy, C.; Notley, M.; Oliver, P.; Allott, R.; Hernandez-Gomez, C.; Kar, S.; McKenna, P.; Neely, D.

    2016-01-01

    Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal operation of high power laser-solid interactions for neutron and x-ray beam generation. Measurements and Monte Carlo radiation transport simulations show that neutron yield is increased by a factor ~2 when a 1 mm copper foil is placed behind a 2 mm lithium foil, compared to using a 2 cm block of lithium only. We explore x-ray generation with a 10 picosecond drive pulse in order to tailor the spectral content for radiography with medium density alloy metals. The impact of using  >1 ps pulse duration on laser-accelerated electron beam generation and transport is discussed alongside the optimisation of subsequent bremsstrahlung emission in thin, high atomic number target foils. X-ray spectra are deconvolved from spectrometer measurements and simulation data generated using the GEANT4 Monte Carlo code. We also demonstrate the unique capability of laser-driven x-rays in being able to deliver single pulse high spatial resolution projection imaging of thick metallic objects. Active detector radiographic imaging of industrially relevant sample objects with a 10 ps drive pulse is presented for the first time, demonstrating that features of 200 μm size are resolved when projected at high magnification.

  6. The role of plasma/neutral source and loss processes in shaping the giant planet magnetospheres

    Science.gov (United States)

    Delamere, P. A.

    2014-12-01

    The giant planet magnetospheres are filled with neutral and ionized gases originating from satellites orbiting deep within the magnetosphere. The complex chemical and physical pathways for the flow of mass and energy in this partially ionized plasma environment is critical for understanding magnetospheric dynamics. The flow of mass at Jupiter and Saturn begins, primarily, with neutral gases emanating from Io (~1000 kg/s) and Enceladus (~200 kg/s). In addition to ionization losses, the neutral gases are absorbed by the planet, its rings, or escape at high speeds from the magnetosphere via charge exchange reactions. The net result is a centrifugally confined torus of plasma that is transported radially outward, distorting the magnetic field into a magnetodisc configuration. Ultimately the plasma is lost to the solar wind. A critical parameter for shaping the magnetodisc and determining its dynamics is the radial plasma mass transport rate (~500 kg/s and ~50 kg/s for Jupiter and Saturn respectively). Given the plasma transport rates, several simple properties of the giant magnetodiscs can be estimated including the physical scale of the magnetosphere, the magnetic flux transport, and the magnitude of azimuthal magnetic field bendback. We will discuss transport-related magnetic flux conservation and the mystery of plasma heating—two critical issues for shaping the giant planet magnetospheres.

  7. Observationally-constrained carbonaceous aerosol source estimates for the Pearl River Delta area of China

    Science.gov (United States)

    Li, N.; Fu, T.-M.; Cao, J. J.; Zheng, J. Y.; He, Q. Y.; Long, X.; Zhao, Z. Z.; Cao, N. Y.; Fu, J. S.; Lam, Y. F.

    2015-11-01

    We simulated elemental carbon (EC) and organic carbon (OC) aerosols over the Pearl River Delta (PRD) area of China and compared the results to seasonal surface measurements, with the aim of quantifying carbonaceous aerosol sources from a "top-down" perspective. Our regional model was driven by current-best estimates of PRD EC (39.5 Gg C yr-1) and OC (32.8 Gg C yr-1) emissions and included updated secondary organic aerosol formation pathways. The simulated annual mean EC and OC concentrations were 4.0 and 7.7 μg C m-3, respectively, lower than the observed annual mean EC and OC concentrations (4.5 and 13.1 μg C m-3, respectively). We used multiple regression to match the simulated EC against seasonal mean observations. The resulting top-down estimate for EC emission in the PRD area was 52.9 ± 8.0 Gg C yr-1. We estimated the OC emission in the PRD area to be 60.2 ± 10.3 Gg C yr-1, based on the top-down EC emission estimate and the primary OC / EC ratios derived from bottom-up statistics. Using these top-down emission estimates, the simulated average annual mean EC and OC concentrations were improved to 4.4 and 9.5 μg C m-3, respectively, closer to the observations. Secondary sources accounted for 42 % of annual mean surface OC in our top-down simulations, with biogenic VOCs being the most important precursors.

  8. A scrutiny of heterogeneity at the TCE Source Area BioREmediation (SABRE) test site

    Science.gov (United States)

    Rivett, M.; Wealthall, G. P.; Mcmillan, L. A.; Zeeb, P.

    2015-12-01

    A scrutiny of heterogeneity at the UK's Source Area BioREmediation (SABRE) test site is presented to better understand how spatial heterogeneity in subsurface properties and process occurrence may constrain performance of enhanced in-situ bioremediation (EISB). The industrial site contained a 25 to 45 year old trichloroethene (TCE) dense non-aqueous phase liquid (DNAPL) that was exceptionally well monitored via a network of multilevel samplers and high resolution core sampling. Moreover, monitoring was conducted within a 3-sided sheet-pile cell that allowed a controlled streamtube of flow to be drawn through the source zone by an extraction well. We primarily focus on the longitudinal transect of monitoring along the length of the cell that provides a 200 groundwater point sample slice along the streamtube of flow through the DNAPL source zone. TCE dechlorination is shown to be significant throughout the cell domain, but spatially heterogeneous in occurrence and progress of dechlorination to lesser chlorinated ethenes - it is this heterogeneity in dechlorination that we primarily scrutinise. We illustrate the diagnostic use of the relative occurrence of TCE parent and daughter compounds to confirm: dechlorination in close proximity to DNAPL and enhanced during the bioremediation; persistent layers of DNAPL into which gradients of dechlorination products are evident; fast flowpaths through the source zone where dechlorination is less evident; and, the importance of underpinning flow regime understanding on EISB performance. Still, even with such spatial detail, there remains uncertainty over the dataset interpretation. These includes poor closure of mass balance along the cell length for the multilevel sampler based monitoring and points to needs to still understand lateral flows (even in the constrained cell), even greater spatial resolution of point monitoring and potentially, not easily proven, ethene degradation loss.

  9. APPROACH TO CONSTRUCTING 3D VIRTUAL SCENE OF IRRIGATION AREA USING MULTI-SOURCE DATA

    Directory of Open Access Journals (Sweden)

    S. Cheng

    2015-10-01

    Full Text Available For an irrigation area that is often complicated by various 3D artificial ground features and natural environment, disadvantages of traditional 2D GIS in spatial data representation, management, query, analysis and visualization is becoming more and more evident. Building a more realistic 3D virtual scene is thus especially urgent for irrigation area managers and decision makers, so that they can carry out various irrigational operations lively and intuitively. Based on previous researchers' achievements, a simple, practical and cost-effective approach was proposed in this study, by adopting3D geographic information system (3D GIS, remote sensing (RS technology. Based on multi-source data such as Google Earth (GE high-resolution remote sensing image, ASTER G-DEM, hydrological facility maps and so on, 3D terrain model and ground feature models were created interactively. Both of the models were then rendered with texture data and integrated under ArcGIS platform. A vivid, realistic 3D virtual scene of irrigation area that has a good visual effect and possesses primary GIS functions about data query and analysis was constructed.Yet, there is still a long way to go for establishing a true 3D GIS for the irrigation are: issues of this study were deeply discussed and future research direction was pointed out in the end of the paper.

  10. Carbon storages in plantation ecosystems in sand source areas of north Beijing, China.

    Directory of Open Access Journals (Sweden)

    Xiuping Liu

    Full Text Available Afforestation is a mitigation option to reduce the increased atmospheric carbon dioxide levels as well as the predicted high possibility of climate change. In this paper, vegetation survey data, statistical database, National Forest Resource Inventory database, and allometric equations were used to estimate carbon density (carbon mass per hectare and carbon storage, and identify the size and spatial distribution of forest carbon sinks in plantation ecosystems in sand source areas of north Beijing, China. From 2001 to the end of 2010, the forest areas increased more than 2.3 million ha, and total carbon storage in forest ecosystems was 173.02 Tg C, of which 82.80 percent was contained in soil in the top 0-100 cm layer. Younger forests have a large potential for enhancing carbon sequestration in terrestrial ecosystems than older ones. Regarding future afforestation efforts, it will be more effective to increase forest area and vegetation carbon density through selection of appropriate tree species and stand structure according to local climate and soil conditions, and application of proper forest management including land-shaping, artificial tending and fencing plantations. It would be also important to protect the organic carbon in surface soils during forest management.

  11. Mineralogical analysis of attic dust samples for contamination source identification in an industrial area, Ajka, Hungary

    Science.gov (United States)

    Völgyesi, Péter; Jordan, Gyozo; Gosar, Mateja; Szabó, Csaba; Miler, Miloš; Kónya, Péter; Bartha, András

    2013-04-01

    The post-war centrally directed economy forced massive heavy industry in Hungary, producing huge amount of wastes and pollution. Long-term airborne emissions from mining, coal-fired power plants and alumina industry have left the legacy of widely distributed contamination around industrial areas and nearby settlements in the Ajka region. Recent research suggests that significant amount of airborne pollutants, deposited in the urban environment, can be efficiently studied by attic dust analysis. The sampling strategy followed a grid-based stratified random sampling design and 30 samples were collected in 27 houses (at least 30 years old) in a 8x8 grid of the 64 km2 project area. In order to determine the pollution potential of attic dust samples, geochemical and mineralogical analyses were performed. The main aim of the mineralogical analyses was to study the phase composition of the dust particles and to identify potential anthropogenic sources. The total concentrations of the toxic elements (As, Pb, Cd, Cu, Ni and Zn) were measured with ICP-OES and mercury content was analyzed with atomic absorption spectrometry. Phase analyses of the samples were carried out by the means of scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-Ray diffraction (XRD) methods. Laser particle size analyzer was used to measure the grain size of attic dust particles. Results showed that the studied attic dust in the Ajka urban area was contaminated mostly by Hg, Pb and Zn with contents ranging between 0.1-2 ppm, 42.5-881 ppm and 90.2-954 ppm, respectively. However, the study of extreme data values (statistical outliers) has shown that at certain points airborne dust can be extremely contaminated also with Cd (0.4-11.7 ppm). The size of the attic dust particles varied between 0.2 and 113 µm. Based on the SEM/EDS and XRD analysis, the most frequently identified mineralogical phases were quartz, calcite, gypsum and Fe- and Al-bearing phases. Fe

  12. Blazing trails: Microquasars as head-tail sources and the seeding of magnetized plasma into the ISM

    CERN Document Server

    Heinz, S; Sunyaev, R A; Fender, R P

    2008-01-01

    We discuss the dynamics of microquasar jets in the interstellar medium, with specific focus on the effects of the X-ray binaries' space velocity with respect to the local Galactic standard of rest. We argue that, during late stages in the evolution of large scale radio nebulae around microquasars, the ram pressure of the interstellar medium due to the microquasar's space velocity becomes important and that microquasars with high velocities form the Galactic equivalent of extragalactic head-tail sources, i.e., that they leave behind trails of stripped radio plasma. Because of their higher space velocities, low-mass X-ray binaries are more likely to leave trails than high-mass X-ray binaries. We show that the volume of radio plasma released by microquasars over the history of the Galaxy is comparable to the disk volume and argue that a fraction of a few percent of the radio plasma left behind by the X-ray binary is likely mixed with the neutral phases of the ISM before the plasma is removed from the disk by buo...

  13. Two-dimensional temperature distribution inside a hemispherical bowl-shaped target for plasma source ion implantation

    Institute of Scientific and Technical Information of China (English)

    刘成森; 王艳辉; 王德真

    2005-01-01

    One important parameter for the plasma source ion implantation (PSII) process is the target temperature obtained during the surface modification. Because the power input to the target being implanted can be large, its temperature is quite high. The target temperature prediction is useful, whether the high temperature is required in the experiment.In addition, there is likely to be temperature variation across the target surface, which can lead to locally different surface properties. In this paper, we have presented a model to predict and explain the temperature distribution on a hemispherical bowl-shaped vessel during plasma source ion implantation. A two-dimensional fluid model to derive both the ion flux to the target and the energy imparted to the substrate by the ions in the plasma sheath simulation is employed. The calculated energy input and radiative heat loss are used to predict the temperature rise and variation inside the sample in the thermal model. The shape factor of the target for radiation is taken into account in the radiative energy loss. The influence of the pulse duration and the pulsing frequency on the temperature distribution is investigated in detail. Our work shows that at high pulsing frequencies the temperature of the bowl will no longer rise with the increase of the pulsing frequency.

  14. Plasma lipid levels of rats fed a diet containing pork fat as a source of lipids after splenic surgery.

    Science.gov (United States)

    Dinis, Ana Paula Gonçalves; Marques, Ruy Garcia; Simões, Fernanda Correia; Diestel, Cristina Fajardo; Caetano, Carlos Eduardo Rodrigues; Secchin, Dióscuro José Ferreira; Neto, José Firmino Nogueira; Portela, Margareth Crisóstomo

    2009-06-01

    Experimental studies have suggested an important role of the spleen in lipid metabolism, although with controversial results. Our purpose was to analyze the effect of a nutritionally balanced (NB) diet and a diet containing pork fat (PF) as source of lipids on the lipid profile of rats submitted to splenic surgery. Sixty adult male Wistar rats were divided into six groups of 10 animals each: 1 sham-operated, NB diet; 2 sham-operated, PF diet; 3 total splenectomy (TS), NB diet; 4 TS, PF diet; 5 TS followed by splenic autotransplantation (SA), NB diet; and 6 SA, PF diet. Blood samples were collected at the beginning (D0) and after 12 weeks of the experiment (D + 12) for plasma lipid determination. Morphologic regeneration of splenic tissues was observed, with no differences between groups 5 and 6. When D + 12 plasma lipid levels were compared to D0 levels there were no differences in groups 1, 3, and 5, while in groups 2, 4, and 6 total cholesterol (TC), low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triacylglycerols (TAG) increased, and high density lipoprotein (HDL) decreased. At D + 12, groups 2, 4, and 6 had lower HDL than group 3. In conclusion, regardless of the surgical procedure applied to the spleen, an NB diet maintained plasma lipid levels while a diet with PF as source of lipids changed the animals' lipid profile.

  15. Integral equation for electrostatic waves generated by a point source in a spatially homogeneous magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Podesta, John J. [Space Science Institute, Boulder, Colorado 80301 (United States)

    2012-08-15

    The electric field generated by a time varying point charge in a three-dimensional, unbounded, spatially homogeneous plasma with a uniform background magnetic field and a uniform (static) flow velocity is studied in the electrostatic approximation which is often valid in the near field. For plasmas characterized by Maxwell distribution functions with isotropic temperatures, the linearized Vlasov-Poisson equations may be formulated in terms of an equivalent integral equation in the time domain. The kernel of the integral equation has a relatively simple mathematical form consisting of elementary functions such as exponential and trigonometric functions (sines and cosines), and contains no infinite sums of Bessel functions. Consequently, the integral equation is amenable to numerical solutions and may be useful for the study of the impulse response of magnetized plasmas and, more generally, the response to arbitrary waveforms.

  16. A CCD area detector for X-ray diffraction under high pressure for rotating anode source

    Indian Academy of Sciences (India)

    Amar Sinha; Alka B Garg; V Vijayakumar; B K Godwal; S K Sikka

    2000-04-01

    Details of a two-dimensional X-ray area detector developed using a charge coupled device, a image intensifier and a fibre optic taper are given. The detector system is especially optimized for angle dispersive X-ray diffraction set up using rotating anode generator as X-ray source. The performance of this detector was tested by successfully carrying out powder X-ray diffraction measurements on various materials such as intermetallics AuIn2, AuGa2, high material Pd and low scatterer adamantane (C10H16) at ambient conditions. Its utility for quick detection of phase transitions at high pressures with diamond anvil cell is demonstrated by reproducing the known pressure induced structural transitions in RbI, KI and a new structural phase transition in AuGa2 above 10 GPa. Various softwares have also been developed to analyze data from this detector.

  17. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete.

  18. Quality of source water and drinking water in urban areas of Myanmar.

    Science.gov (United States)

    Sakai, Hiroshi; Kataoka, Yatsuka; Fukushi, Kensuke

    2013-01-01

    Myanmar is one of the least developed countries in the world, and very little information is available regarding the nation's water quality. This report gives an overview of the current situation in the country, presenting the results of various water-quality assessments in urban areas of Myanmar. River, dam, lake, and well water sources were examined and found to be of generally good quality. Both As and F(-) were present in relatively high concentrations and must be removed before deep wells are used. Heterotrophic plate counts in drinking water were highest in public pots, followed by nonpiped tap water, piped tap water, and bottled water. Measures need to be taken to improve low-quality water in pots and nonpiped tap waters.

  19. The 2016 Al-Mishraq sulphur plant fire: source and risk area estimation

    CERN Document Server

    Björnham, Oscar; von Schoenberg, Pontus; Waleij, Annica; Liljedahl, Birgitta; Brännström, Niklas

    2016-01-01

    On October 20:th 2016, Daesh (Islamic State) set fire to the sulphur production site Al-Mishraq as the battle of Mosul became more intense. A huge plume of toxic sulphur dioxide and hydrogen sulphide caused comprising casualties. The intensity of the release was reaching levels of minor volcanic eruptions which was observed by several satellites. By investigation of the measurement data from the MetOp-A, MetOp-B, Aura, and Meteosat-10 satellites we have estimated the time-dependent source term for sulphur dioxide which in total amounted to 271 kton released into the atmosphere during six days. The long-range dispersion model PELLO was utilized to simulate the atmospheric transport over the Middle East. The ground-level concentrations predicted by the simulation were validated against observation from the Turkey National Air Quality Monitoring Network. Finally, the simulation data provided an estimate of the risk area using a probit analysis.

  20. Ion-acoustic double layers in the presence of plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, H.; Ashour-Abdalla, M.

    1981-11-01

    Steady-state plasma turbulence and formation of negative potential spikes and double layers in the presence of ion acoustic instabilities have been studied by means of one-dimensional particle simulations in which velocities of a small fraction of electrons are replaced by the initial drifting Maxwellian at a constant rate. A steady state is found where negative potential spikes appear randomly in space and time giving rise to an anomalous resistivity much greater than previously found. Comparisons of the simulation results with laboratory and space plasmas are discussed.

  1. Source processes of industrially-induced earthquakes at the Geysers geothermal area, California

    Science.gov (United States)

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1999-01-01

    Microearthquake activity at The Geysers geothermal area, California, mirrors the steam production rate, suggesting that the earthquakes are industrially induced. A 15-station network of digital, three-component seismic stations was operated for one month in 1991, and 3,900 earthquakes were recorded. Highly-accurate moment tensors were derived for 30 of the best recorded earthquakes by tracing rays through tomographically derived 3-D VP and VP / VS structures, and inverting P-and S-wave polarities and amplitude ratios. The orientations of the P-and T-axes are very scattered, suggesting that there is no strong, systematic deviatoric stress field in the reservoir, which could explain why the earthquakes are not large. Most of the events had significant non-double-couple (non-DC) components in their source mechanisms with volumetric components up to ???30% of the total moment. Explosive and implosive sources were observed in approximately equal numbers, and must be caused by cavity creation (or expansion) and collapse. It is likely that there is a causal relationship between these processes and fluid reinjection and steam withdrawal. Compensated linear vector dipole (CLVD) components were up to 100% of the deviatoric component. Combinations of opening cracks and shear faults cannot explain all the observations, and rapid fluid flow may also be involved. The pattern of non-DC failure at The Geysers contrasts with that of the Hengill-Grensdalur area in Iceland, a largely unexploited water-dominated field in an extensional stress regime. These differences are poorly understood but may be linked to the contrasting regional stress regimes and the industrial exploitation at The Geysers.

  2. Source-rock evaluation of the Dakhla Formation black shale in Gebel Duwi, Quseir area, Egypt

    Science.gov (United States)

    El Kammar, M. M.

    2015-04-01

    A relatively thick Upper Cretaceous-Lower Tertiary sedimentary succession is exposed in Gebel Duwi, Red Sea area, through an almost horizontal tunnel cutting the NE dipping strata from Quseir to Thebes formations. The black shale belonging to Dakhla Formation represents a real potential for future energy resource for Egypt. Dakhla Formation consists mainly of organic-rich calcareous shale to argillaceous limestone that can be considered as a good to excellent source rock potential. The total organic carbon (TOC) content ranges from 2.04% to 12.08%, and the Hydrogen Index (HI) values range from 382 to 1024 mg HC/g TOC. Samples of the Dakhla Formation contain mostly kerogen of types I and II that prone oil and oil-gas, indicating marine organic matter derived mainly from algae and phytoplankton organisms and proposing typical oil source kerogen. The average of the potential index (PI) value is 0.02 mg HC/g rock, which indicates the beginning of a considerable amount of oil generation from the Dakhla Formation. The Tmax values range from 427 to 435 °C. Based on the Tmax data and PI values, the studied black shale samples are immature to early mature for hydrocarbon generation in the Duwi area. The data reduction suggests four main factors covering about 91% of the total variances. The average of the calorific value (459 kcal/kg) indicates unworkable efficiency of such black shale for direct combustion use in power stations. However, selective operation of specific horizons having the highest calorific values may provide viable resources.

  3. Final Air Toxics Standards for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources Fact Sheet

    Science.gov (United States)

    This page contains a December 2007 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources

  4. Metals and Rare Earth Elements in polar aerosol as specific markers of natural and anthropogenic aerosol sources areas and atmospheric transport processes

    Science.gov (United States)

    Giardi, Fabio; Becagli, Silvia; Caiazzo, Laura; Cappelletti, David; Grotti, Marco; Malandrino, Mery; Salzano, Roberto; Severi, Mirko; Traversi, Rita; Udisti, Roberto

    2016-04-01

    Metals and Rare Earth Elements (REEs) in the aerosol have conservative properties from the formation to the deposition and can be useful to identify and quantify their natural and anthropic sources and to study the atmospheric transport processes. In spite of their importance relatively little is known about metals and especially REEs in the Artic atmosphere due to their low concentration in such environment. The present work reports the first attempt to determine and interpret the behaviour of metals and REEs in polar aerosol at high temporal resolution. Daily PM10 samples of arctic atmospheric particulate were collected on Teflon filters, during six spring-summer campaigns, since 2010, in the laboratory of Gruvebadet in Ny Ålesund (78°56' N, 11°56' E, Svalbard Islands, Norway). Chemical analyses were carried out through Inductively Coupled Plasma Mass Spectrometer provided with a desolvation nebulizer inlet system, allowing to reduce isobaric interferences and thus to quantify trace and ultra-trace metals in very low concentration in the Arctic aerosol samples. The results are useful in order to study sources areas, transport processes and depositional effects of natural and anthropic atmospheric particulate reaching the Arctic from southern industrialized areas; moreover, the observed seasonal trends give information about the different impact of natural and anthropic emissions driven by phenomena such as the Arctic Haze and the melting of the snow. In particular Rare Earth Elements (often in the ppt range) can be considered as soil's fingerprints of the particulate source areas and their determination, together with air-mass backtrajectory analysis, allow to identify dust source areas for the arctic mineral aerosol.

  5. Morphological effects on the plasma-induced emission properties of large area ZnO nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Liao Qingliang; Qi Junjie; Yang Ya; Huang Yunhua; Zhang Yue; Zhang Zheng [Department of Materials Physics, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing 100083 (China); Xia Liansheng, E-mail: yuezhang@ustb.edu.c [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2009-11-07

    Large area well-aligned ZnO nanorod arrays with different morphologies were fabricated by hydrothermal methods. The plasma-induced emission properties of ZnO nanorod arrays with different morphologies under a pulsed electric field were investigated. When the aspect ratios of nanorods increased, the emission currents of arrays were enhanced remarkably. As for the synthesized high density ZnO nanorod arrays, the emission currents of the nanorod arrays decreased with the increase in the nanorod densities owing to the screening effect. The plasma-induced emission properties of the ZnO nanorod arrays were improved by controlling the array morphologies. Under the pulsed electric field of 7-8 V {mu}m{sup -1}, the highest emission current density of the ZnO nanorod arrays reached 91.16 A cm{sup -2}. Moreover, the surface plasmas on the ZnO nanorod arrays with different morphologies were always distributed uniformly. The results of this study provide a design strategy for ZnO nanorod arrays, which are used as plasma-flashover cathode emitters.

  6. Continuous plasma outflows from the edge of a solar active region as a possible source of solar wind.

    Science.gov (United States)

    Sakao, Taro; Kano, Ryouhei; Narukage, Noriyuki; Kotoku, Jun'ichi; Bando, Takamasa; Deluca, Edward E; Lundquist, Loraine L; Tsuneta, Saku; Harra, Louise K; Katsukawa, Yukio; Kubo, Masahito; Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo, Masumi; Bookbinder, Jay A; Golub, Leon; Korreck, Kelly E; Su, Yingna; Shibasaki, Kiyoto; Shimizu, Toshifumi; Nakatani, Ichiro

    2007-12-07

    The Sun continuously expels a huge amount of ionized material into interplanetary space as the solar wind. Despite its influence on the heliospheric environment, the origin of the solar wind has yet to be well identified. In this paper, we report Hinode X-ray Telescope observations of a solar active region. At the edge of the active region, located adjacent to a coronal hole, a pattern of continuous outflow of soft-x-ray-emitting plasmas was identified emanating along apparently open magnetic field lines and into the upper corona. Estimates of temperature and density for the outflowing plasmas suggest a mass loss rate that amounts to approximately 1/4 of the total mass loss rate of the solar wind. These outflows may be indicative of one of the solar wind sources at the Sun.

  7. R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    S.-H. Kim, M.T. Crofford, M. Doleans, J.D. Mammosser, J. Saunders

    2011-03-01

    The SNS SCL is reliably operating at 0.93 GeV output energy with an energy reserve of 10MeV with high availability. Most of the cavities exhibit field emission, which directly or indirectly (through heating of end groups) limits the gradients achievable in the high beta cavities in normal operation with the beam. One of the field emission sources would be surface contaminations during surface processing for which mild surface cleaning, if any, will help in reducing field emission. An R&D effort is in progress to develop in-situ surface processing for the cryomodules in the tunnel without disassembly. As the first attempt, in-situ plasma processing has been applied to the CM12 in the SNS SRF facility after the repair work with a promising result. This paper will report the R&D status of plasma processing in the SNS.

  8. Using FLUKA to Study Concrete Square Shield Performance in Attenuation of Neutron Radiation Produced by APF Plasma Focus Neutron Source

    Science.gov (United States)

    Nemati, M. J.; Habibi, M.; Amrollahi, R.

    2013-04-01

    In 2010, representatives from the Nuclear Engineering and physics Department of Amirkabir University of Technology (AUT) requested development of a project with the objective of determining the performance of a concrete shield for their Plasma Focus as neutron source. The project team in Laboratory of Nuclear Engineering and physics department of Amirkabir University of Technology choose some shape of shield to study on their performance with Monte Carlo code. In the present work, the capability of Monte Carlo code FLUKA will be explored to model the APF Plasma Focus, and investigating the neutron fluence on the square concrete shield in each region of problem. The physical models embedded in FLUKA are mentioned, as well as examples of benchmarking against future experimental data. As a result of this study suitable thickness of concrete for shielding APF will be considered.

  9. Contamination source review for Building E1489, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Billmark, K.A.; Hayes, D.C.; Draugelis, A.K. [and others

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review of Building E1489 at the Aberdeen Proving Ground (APG) in Maryland. This report may be used to assist the U.S. Army-in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, and geophysical investigation. The field investigations were performed in 1994-1995. Building E1489 located in J-Field on the Gunpowder Peninsula in APG`s Edgewood Area housed a power generator that supplied electricity to a nearby observation tower. Building E1489 and the generator were abandoned in 1974, demolished by APG personnel and removed from real estate records. A physical inspection and photographic documentation of Building E1489 were completed by ANL staff during November 1994. In 1994, ANL staff conducted geophysical surveys in the immediate vicinity of Building E1489 by using several nonintrusive methods. Survey results suggest the presence of some underground objects near Building E1489, but they do not provide conclusive evidence of the source of geophysical anomalies observed during the survey. No air monitoring was conducted at the site, and no information on underground storage tanks associated with Building E1489 was available.

  10. Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands).

    Science.gov (United States)

    Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia

    2011-01-01

    The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees (Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs (Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea

  11. Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands)

    Science.gov (United States)

    Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia

    2011-01-01

    The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees ( Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs ( Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea

  12. [Water environmental capacity calculation model for the rivers in drinking water source conservation area].

    Science.gov (United States)

    Chen, Ding-jiang; Lü, Jun; Shen, Ye-na; Jin, Shu-quan; Shi, Yi-ming

    2008-09-01

    Based on the one-dimension model for water environmental capacity (WEC) in river, a new model for the WEC estimation in river-reservoir system was developed in drinking water source conservation area (DWSCA). In the new model, the concept was introduced that the water quality target of the rivers in DWSCA was determined by the water quality demand of reservoir for drinking water source. It implied that the WEC of the reservoir could be used as the water quality control target at the reach-end of the upstream rivers in DWSCA so that the problems for WEC estimation might be avoided that the differences of the standards for a water quality control target between in river and in reservoir, such as the criterions differences for total phosphorus (TP)/total nitrogen (TN) between in reservoir and in river according to the National Surface Water Quality Standard of China (GB 3838-2002), and the difference of designed hydrology conditions for WEC estimation between in reservoir and in river. The new model described the quantitative relationship between the WEC of drinking water source and of the river, and it factually expressed the continuity and interplay of these low water areas. As a case study, WEC for the rivers in DWSCA of Laohutan reservoir located in southeast China was estimated using the new model. Results indicated that the WEC for TN and TP was 65.05 t x a(-1) and 5.05 t x a(-1) in the rivers of the DWSCA, respectively. According to the WEC of Laohutan reservoir and current TN and TP quantity that entered into the rivers, about 33.86 t x a(-1) of current TN quantity should be reduced in the DWSCA, while there was 2.23 t x a(-1) of residual WEC of TP in the rivers. The modeling method was also widely applicable for the continuous water bodies with different water quality targets, especially for the situation of higher water quality control target in downstream water body than that in upstream.

  13. Contamination source review for Building E3162, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G.A.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review for Building E3162 at the Aberdeen Proving Ground (APG) in Maryland. The report may be used to assist the US Army in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, geophysical investigation, and collection of air samples. The field investigations were performed by ANL during 1994 and 1995. Building E3162 (APG designation) is part of the Medical Research Laboratories Building E3160 Complex. This research laboratory complex is located west of Kings Creek, east of the airfield and Ricketts Point Road, and south of Kings Creek Road in the Edgewood Area of APG. The original structures in the E3160 Complex were constructed during World War 2. The complex was originally used as a medical research laboratory. Much of the research involved wound assessment involving chemical warfare agents. Building E3162 was used as a holding and study area for animals involved in non-agent burns. The building was constructed in 1952, placed on inactive status in 1983, and remains unoccupied. Analytical results from these air samples revealed no distinguishable difference in hydrocarbon and chlorinated solvent levels between the two background samples and the sample taken inside Building E3162.

  14. Low Hydrogen Content Silicon Nitride Films Deposited at Room Temperature with an ECR Plasma Source

    NARCIS (Netherlands)

    Isai, Gratiela I.; Holleman, Jisk; Wallinga, Hans; Woerlee, Pierre H.

    2004-01-01

    Silicon nitride layers with very low hydrogen content (less than 1 atomic percent) were deposited at near room temperature, from N2 and SiH4, with a multipolar electron cyclotron resonance plasma. The influences of pressure and nitrogen flow rate on physical and electrical properties were studied in