Science.gov

Sample records for plasma research experiment

  1. Lab- and space-based researchers discuss plasma experiments

    NASA Astrophysics Data System (ADS)

    Baker, D. N.; Yamada, M.

    Plasma physics provides a common language and set of approaches that tie together all scientists who study the acceleration, transport, and loss processes of the plasma state. Some years ago, researchers from the laboratory and space research communities suggested a workshop to bring together the diverse researchers in the respective fields. A series of workshops on the “Interrelationship between Plasma Experiments in the Laboratory and Space” (IPELS) was established, and the third meeting was held July 24-28, 1995, in the beautiful and historic town of Pitlochry in the Scottish Highlands.The conference reestablished the critical point that plasma physics is an important but surprisingly diversified research discipline. Meetings attendees discussed a number of new approaches to plasma research, including novel diagnostic techniques for use in space, such as active antennas and electric field sounding devices. Detailed discussions covered spacecraft-plasma environment interactions, including vehicle charging and neutral gas release; fundamental aspects of industrial application of dusty plasmas and waves in dusty plasmas; a very distinctive phase transition of coulomb crystals (from solid state to liquid state) in dusty plasmas; and terrella experiments to simulate and study chaotic transport in the ionosphere.

  2. ECR plasma thruster research - Preliminary theory and experiments

    NASA Technical Reports Server (NTRS)

    Sercel, Joel C.; Fitzgerald, Dennis J.

    1989-01-01

    A preliminary theory of the operation of the electron-cyclotron-resonance (ECR) plasma thruster is described along with an outline of recent experiments. This work is presented to communicate the status of an ongoing research effort directed at developing a unified theory to quantitatively describe the operation of the ECR plasma thruster. The theory is presented as a set of nonlinear ordinary differential equations and boundary conditions which describe the plasma density, velocity, and electron temperature. Diagnostic tools developed to measure plasma conditions in the existing research device are described.

  3. Advanced Tokamak Plasmas in the Fusion Ignition Research Experiment

    SciTech Connect

    C.E. Kessel; D. Meade; D.W. Swain; P. Titus; M.A. Ulrickson

    2003-10-13

    The Advanced Tokamak (AT) capability of the Fusion Ignition Research Experiment (FIRE) burning plasma experiment is examined with 0-D systems analysis, equilibrium and ideal-MHD stability, radio-frequency current-drive analysis, and full discharge dynamic simulations. These analyses have identified the required parameters for attractive burning AT plasmas, and indicate that these are feasible within the engineering constraints of the device.

  4. Development of plasma sources for Dipole Research EXperiment (DREX)

    NASA Astrophysics Data System (ADS)

    Xiao, Qingmei; Wang, Zhibin; Peng, E.; Wang, Xiaogang; Xiao, Chijie; Ren, Yang; Ji, Hantao; Mao, Aohua; Li, Liyi

    2017-05-01

    Dipole Research EXperiment (DREX) is a new terrella device as part of the Space Plasma Environment Research Facility (SPERF) for laboratory studies of space physics relevant to the inner magnetospheric plasmas. Adequate plasma sources are very important for DREX to achieve its scientific goals. According to different research requirements, there are two density regimes for DREX. The low density regime will be achieved by an electron cyclotron resonance (ECR) system for the ‘whistler/chorus’ wave investigation, while the high density regime will be achieved by biased cold cathode discharge for the desired ‘Alfvén’ wave study. The parameters of ‘whistler/chorus’ waves and ‘Alfvén’ waves are determined by the scaling law between space and laboratory plasmas in the current device. In this paper, the initial design of these two plasma sources for DREX is described. Focus is placed on the chosen frequency and operation mode of the ECR system which will produce relatively low density ‘artificial radiation belt’ plasmas and the seed electrons, followed by the design of biased cold cathode discharge to generate plasma with high density.

  5. Conceptual Design of Tail-Research EXperiment (T-REX) on Space Plasma Environment Research Facility

    NASA Astrophysics Data System (ADS)

    Xiao, Qingmei; Wang, Xiaogang; E, Peng; Shen, Chao; Wang, Zhibin; Mao, Aohua; Xiao, Chijie; Ding, Weixing; Ji, Hantao; Ren, Yang

    2016-10-01

    Space Environment Simulation Research Infrastructure (SESRI), a scientific project for a major national facility of fundamental researches, has recently been launched at Harbin Institute of Technology (HIT). The Space Plasma Environment Research Facility (SPERF) for simulation of space plasma environment is one of the components of SESRI. It is designed to investigate fundamental issues in space plasma environment, such as energetic particles transportation and the interaction with waves in magnetosphere, magnetic reconnection at magnetopause and magnetotail, etc. Tail-Research Experiment (T-REX) is part of the SPERF for laboratory studies of space physics relevant to tail reconnection and dipolarization process. T-REX is designed to carry out two kinds of experiments: the tail plasmamoid for magnetic reconnection and magnetohydrodynamic waves excited by high speed plasma jet. In this presentation, the scientific goals and experimental plans for T-REX together with the means applied to generate the plasma with desired parameters are reviewed. Two typical scenarios of T-REX with operations of plasma sources and various magnetic configurations to study specific physical processes in space plasmas will also be presented.

  6. Preliminary Pioneer 10 encounter results from the Ames Research Center plasma analyzer experiment

    NASA Technical Reports Server (NTRS)

    Wolfe, J. H.; Collard, H. R.; Mihalov, J. D.; Intriligator, D. S.

    1974-01-01

    Preliminary results from the Ames Research Center plasma analyzer experiment for the Pioneer 10 Jupiter encounter indicate that Jupiter has a detached bow shock and magnetopause similar to the case at Earth but much larger in spatial extent. In contrast to Earth, Jupiter's outer magnetosphere appears to be highly inflated by thermal plasma and therefore highly responsive in size to changes in solar wind dynamic pressure.

  7. Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect

    C.E. Kessel; D. Meade; S.C. Jardin

    2002-01-18

    The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE.

  8. Energetic Particle Physics In Fusion Research In Preparation For Burning Plasma Experiments

    SciTech Connect

    Gorelenkov, Nikolai N

    2013-06-01

    The area of energetic particle (EP) physics of fusion research has been actively and extensively researched in recent decades. The progress achieved in advancing and understanding EP physics has been substantial since the last comprehensive review on this topic by W.W. Heidbrink and G.J. Sadler [1]. That review coincided with the start of deuterium-tritium (DT) experiments on Tokamak Fusion Test reactor (TFTR) and full scale fusion alphas physics studies. Fusion research in recent years has been influenced by EP physics in many ways including the limitations imposed by the "sea" of Alfven eigenmodes (AE) in particular by the toroidicityinduced AEs (TAE) modes and reversed shear Alfven (RSAE). In present paper we attempt a broad review of EP physics progress in tokamaks and spherical tori since the first DT experiments on TFTR and JET (Joint European Torus) including helical/stellarator devices. Introductory discussions on basic ingredients of EP physics, i.e. particle orbits in STs, fundamental diagnostic techniques of EPs and instabilities, wave particle resonances and others are given to help understanding the advanced topics of EP physics. At the end we cover important and interesting physics issues toward the burning plasma experiments such as ITER (International Thermonuclear Experimental Reactor).

  9. Experiments with nonneutral plasmas

    SciTech Connect

    O’Neil, T. M.

    2016-03-25

    Selected experiments with nonneutral plasmas are discussed. These include the laser cooling of a pure ion plasma to a crystalline state, a measurement of the Salpeter enhancement factor for fusion in a strongly correlated plasma and the measurement of thermally excited plasma waves. Also, discussed are experiments that demonstrate Landau damping, trapping and plasma wave echoes in the 2D ExB drift flow of a pure electron plasma, which is isomorphic to the 2D ideal flow (incompressible and inviscid flow) of a neutral fluid.

  10. Plasma contactor research - 1991

    NASA Technical Reports Server (NTRS)

    Buchholtz, Brett; Williams, John D.; Wilbur, Paul J.

    1992-01-01

    A report describing the operating principles of hollow-cathode-based plasma contactors emitting or collecting electrons from an ambient plasma is summarized. Preliminary experiments conducted to determine the noise generated by these plasma contactors in the emission-current return line and in the plasma near it are described. These noise data are measured as current fluctuations in the return line and to the Langmuir probe and then analyzed using a fast Fourier transform technique. The spectral compositions of the data are characterized using power spectral density plots which are examined to identify possible noise source(s) and production mechanism(s). The precautions taken in the construction and calibration of the instrumentation to assure adequate frequency response are described. Experimental results show that line-current noise levels are typically 2 percent of the electron current being emitted or collected. However, noise levels increase to as much as 20 percent of the electron current at a few electron-collection operating conditions. The frequencies associated with most of the noise were harmonics of the 60 Hz input to system power supplies. Plasma noise had characteristics similar in magnitude and frequency to those for the return-line noise, but they contained additional features at frequencies considered to be related to ion-acoustic instabilities. Also discussed is a new probe positioning system built to facilitate future plasma-contractor research.

  11. Plasma Sterilization Experiments

    DTIC Science & Technology

    2008-12-14

    similarity of structure of the top layer ( stratum corneum ) of the artificial skin to that of human skin, because the bacteria were deposited on the...surface prior to treatment in the plasma reactor. The stratum corneum is composed of keratin-rich dead cells surrounded by lipids. This outer layer is...electrical resistance of the stratum corneum relies on the layer being intact. Research using intact skin (Fridman, G. et al. Plasma Chemistry and

  12. Study of energetic particle dynamics in Harbin Dipole eXperiment (HDX) on Space Plasma Environment Research Facility (SPERF)

    NASA Astrophysics Data System (ADS)

    Zhibin, W.; Xiao, Q.; Wang, X.; Xiao, C.; Zheng, J.; E, P.; Ji, H.; Ding, W.; Lu, Q.; Ren, Y.; Mao, A.

    2015-12-01

    Zhibin Wang1, Qingmei Xiao1, Xiaogang Wang1, Chijie Xiao2, Jinxing Zheng3, Peng E1, Hantao Ji1,5, Weixing Ding4, Quaming Lu6, Y. Ren1,5, Aohua Mao11 Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, Harbin, China 150001 2 State Key Lab of Nuclear Physics & Technology, and School of Physics, Peking University, Beijing, China 100871 3ASIPP, Hefei, China, 230031 4University of California at Los Angeles, Los Angeles, CA, 90095 5Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 6University of Science and Technology of China, Hefei, China, 230026 A new terrella device for laboratory studies of space physics relevant to the inner magnetospheric plasmas, Harbin Dipole eXperiment (HDX), is scheduled to be built at Harbin Institute of Technology (HIT), China. HDX is one of two essential parts of Space Plasma Environment Research Facility (SPERF), which is a major national research facility for space physics studies. HDX is designed to provide a laboratory experimental platform to reproduce the earth's magnetospheric structure for investigations on the mechanism of acceleration/loss and wave-particle interaction of energetic particles in radiation belt, and on the influence of magnetic storms on the inner magnetosphere. It can be operated together with Harbin Reconnection eXperiment (HRX), which is another part of SPERF, to study the fundamental processes during interactions between solar wind and Earth's magnetosphere. In this presentation, the scientific goals and experimental plans for HDX, together with the means applied to generate the plasma with desired parameters, including multiple plasma sources and different kinds of coils with specific functions, as well as advanced diagnostics designed to be equipped to the facility for multi-functions, are reviewed. Three typical scenarios of HDX with operations of various coils and plasma sources to study specific physical processes in space plasmas will also be

  13. Space plasma physics research

    NASA Technical Reports Server (NTRS)

    Comfort, Richard H.; Horwitz, James L.

    1993-01-01

    During the course of this grant, work was performed on a variety of topics and there were a number of significant accomplishments. A summary of these accomplishments is included. The topics studied include empirical model data base, data reduction for archiving, semikinetic modeling of low energy plasma in the inner terrestrial magnetosphere and ionosphere, O(+) outflows, equatorial plasma trough, and plasma wave ray-tracing studies. A list of publications and presentations which have resulted from this research is also included.

  14. A new plasma-surface interactions research facility: PISCES-B and first materials erosion experiments on boronized graphite

    SciTech Connect

    Hirooka, Y.; Conn, R.W.; Sketchley, T.; Leung, W.K.; Doerner, R.; Elverum, J.; Gunner, G.; Khandagle, M.; Lehmer, R.; Luong, P.; Ra, Y.; Schmitz, L.; Tynan, G.

    1989-08-01

    A new plasma-surface interactions research facility: PISCES-B has been designed and constructed at University of California, Los Angeles. The entire vacuum chamber is bakable and a base pressure of the order of 10{sup {minus}8} Torr is attainable using two turbo molecular pumps with a total pumping speed of 6000 l/s. The PISCES-B facility can generate continuous plasmas of argon, helium, hydrogen, deuterium and nitrogen. The density of these plasmas ranges from 1 {times} 10{sup {minus}11} to 3 {times} 10{sup {minus}13} cm{sup {minus}3} and the electron temperature ranges from 3 to 51 eV. The plasma bombardment flux to a target surface inserted in the plasma column can be varied from 1 {times} 10{sup 17} to 8 {times} 10{sup 18} ions cm{sup {minus}2} s{sup {minus}1}. Due to the high pumping speed, the neutral pressure of the working gas during plasma generation is controllable in the wide range from 3 {times} 10{sup -5} to 1 {times} 10{sup -3} Torr. These conditions are similar to those seen at the limiter and divertor areas in toroidal fusion devices. Using the PISCES-B facility, first materials erosion experiments have been conducted on 3% boronized graphites and iso-graphites as the reference materials. The chemical sputtering yield due to hydrogen plasma bombardment at 300 eV for 3% boronized graphite has been found to be about 30% smaller than that for iso-graphites at temperatures from room temperature to 900{degree}C. Also, radiation enhanced sublimation due to hydrogen plasma bombardment at 400 eV is found to be suppressed by 20-30% for 3% boronized graphite at temperatures up to 1300{degree}C. No significant surface composition change is observed after hydrogen plasma bombardment to a fluence of the order of 10{sup 22} ions cm{sup {minus}2}. 30 refs., 9 figs., 2 tabs.

  15. Plasma accelerator experiments in Yugoslavia

    NASA Astrophysics Data System (ADS)

    Purić, J.; Astashynski, V. M.; Kuraica, M. M.; Dojčinovié, I. P.

    2002-12-01

    An overview is given of the results obtained in the Plasma Accelerator Experiments in Belgrade, using quasi-stationary high current plasma accelerators constructed within the framework of the Yugoslavia-Belarus Joint Project. So far, the following plasma accelerators have been realized: Magnetoplasma Compressor type (MPC); MPC Yu type; one stage Erosive Plasma Dynamic System (EPDS) and, in final stage of construction two stage Quasi-Stationary High Current Plasma Accelerator (QHPA).

  16. Pioneer 11 encounter - Preliminary results from the Ames Research Center plasma analyzer experiment

    NASA Technical Reports Server (NTRS)

    Mihalov, J. D.; Collard, H. R.; Mckibbin, D. D.; Wolfe, J. H.; Intriligator, D. S.

    1975-01-01

    Pioneer 11 observations of the interaction of Jupiter's magnetosphere with the distant solar wind have confirmed the earlier Pioneer 10 observations of the great size and extreme variability of the outer magnetosphere. The nature of the plasma transitions across Jupiter's bow shock and magnetopause as observed on Pioneer 10 have also been confirmed on Pioneer 11. However, the northward direction of the Pioneer 11 outbound trajectory and the distance of the final magnetopause crossing (80 Jupiter radii) now suggest that Jupiter's magnetosphere is extremely broad with a half-thickness (normal to the ecliptic plane in the noon meridian) which is comparable to or greater than the sunward distance to the nose.

  17. Hard X-ray and Particle Beams Research on 1.7 MA Z-pinch and Laser Plasma Experiments

    NASA Astrophysics Data System (ADS)

    Shrestha, Ishor; Kantsyrev, Victor; Safronova, Alla; Esaulov, Andrey; Nishio, Mineyuki; Shlyaptseva, Veronica; Keim, Steven; Weller, Michael; Stafford, Austin; Petkov, Emil; Schultz, Kimberly; Cooper, Matthew; PPDL Team

    2013-10-01

    Studies of hard x-ray (HXR) emission, electron and ion beam generation in z-pinch and laser plasmas are important for Inertial Confinement Fusion (ICF) and development of HXR sources from K-shell and L-shell radiation. The characteristics of HXR and particle beams produced by implosions of planar wire arrays, nested and single cylindrical wire arrays, and X-pinches were analyzed on 100 ns UNR Zebra generator with current up to 1.7 MA. In addition, the comparison of characteristics of HXR and electron beams on Zebra and 350 fs UNR Leopard laser experiments with foils has been performed. The diagnostics include Faraday cups, HXR diodes, different x-ray spectrometers and imaging systems, and ion mass spectrometer using the technique of Thomson parabola. Future work on HXRs and particle beams in HED plasmas is discussed. This work was supported by the DOE/NNSA Cooperative agreement DE-NA0001984 and in part by DE-FC52-06NA27616. This work was also supported by the Defense Threat Reduction Agency, Basic Research Award # HDTRA1-13-1-0033, to University of Nevada, Reno.

  18. Plasma contactor research, 1990

    NASA Technical Reports Server (NTRS)

    Williams, John D.; Wilbur, Paul J.

    1991-01-01

    Emissive and Langmuir probes were used to measure plasma potential profiles, plasma densities, electron energy distributions, and plasma noise levels near a hollow cathode-based plasma contactor emitting electrons. The effects of electron emission current (100 to 1500 mA) and contactor flowrate (2 to 10 sccm (Xenon)) on these data are examined. Retarding potential analyzer (RPA) measurements showing that high energy ions generally stream from a contactor along with the electrons being emitted are also presented, and a mechanism by which this occurs is postulated. This mechanism, which involves a high rate of ionization induced between electrons and atoms flowing together from the hollow cathode orifice, results in a region of high positive space charge and high positive potential. Langmuir and RPA probe data suggests that both electrons and ions expand spherically from this potential hill region. In addition to experimental observations, a simple one-dimensional model which describes the electron emission process and predicts the phenomena just mentioned is presented and is shown to agree qualitatively with these observations. Experimental results of the first stage of bilateral cooperation with the Italian Institute of Interplanetary Space Physics (IFSI CNR) are presented. Sharp, well-defined double layers were observed downstream of a contactor collecting electrons from an ambient plasma created in the IFSI Facility. The voltage drop across these double layers was observed to increase with the current drawn from the ambient plasma. This observation, which was not as clear in previous IFSI tests conducted at higher neutral pressures, is in agreement with previous experimental observations made at both Colorado State University and NASA Lewis Research Center. Greater double layer voltage drops, multiple double layers, and higher noise levels in the region near the double layers were also observed when a magnetic field was imposed and oriented perpendicular to the

  19. Laser-Plasma Interaction Experiments and Diagnostics at NRL (Naval Research Laboratory).

    DTIC Science & Technology

    1983-05-11

    Hooker, and S. Knight in Rutherford Laboratory Report RL-82-039 (1982). 38. J. Grun, M.l. Emery, M.J. Herbst, E.A. McLean, S.P. Obenschain, B.H. Ripin...HUNTSVILLE RESEARCH & ENGR. CTR. OICY ATTN ERNEST BAUER 4800 BRADFORD DRIVE OICY ATTN HANS WOLFARD HUNTSVILLE, AL 35807 OICY ATTN JOEL BENGSTON ATTN... BARON OICY ATTN RAY L. LEADABRAND OICY ATTN G. CARPENTER 0ICY ATTN G. PRICE OICY ATTN J. PETERSON OICY ATTN R. HAKE, JR. OICY ATTN V. GONZALES OICY

  20. Plasma electron analysis: Voyager plasma science experiment

    NASA Technical Reports Server (NTRS)

    Sittler, E. C., Jr.

    1983-01-01

    The Plasma Science Experiment (PLS) on the Voyager spacecraft provide data on the plasma ions and electrons in the interplanetary medium and the magnetospheres of the giant planets Jupiter and Saturn. A description of the analysis used to obtain electron parameters (density, temperature, etc.) from the plasma science experiment PLS electron measurements which cover the energy range from 10 eV to 5950 eV is presented. The electron sensor (D cup) and its transmission characteristics are described. A derivation of the fundamental analytical expression of the reduced distribution function F(e) is given. The electron distribution function F(e), used in the moment integrations, can be derived from F(e). Positive ions produce a correction current (ion feedthrough) to the measured electron current, which can be important to the measurements of the suprathermal electron component. In the case of Saturn, this correction current, which can either add to or subtract from the measured electron current, is less than 20% of the measured signal at all times. Comments about the corrections introduced by spacecraft charging to the Saturn encounter data, which can be important in regions of high density and shadow when the spacecraft can become negatively charged are introduced.

  1. Experimental Plasma Research project summaries

    SciTech Connect

    1980-09-01

    This report contains descriptions of the activities supported by the Experimental Plasma Research Branch of APP. The individual project summaries were prepared by the principal investigators and include objectives and milestones for each project. The projects are arranged in six research categories: Plasma Properties; Plasma Heating; Plasma Diagnostics; Atomic, Molecular and Nuclear Physics; Advanced Superconducting Materials; and the Fusion Plasma Research Facility (FPRF). Each category is introduced with a statement of objectives and recent progress and followed by descriptions of individual projects. An overall budget summary is provided at the beginning of the report.

  2. A SPHERICAL PLASMA DYNAMO EXPERIMENT

    SciTech Connect

    Spence, E. J.; Reuter, K.; Forest, C. B.

    2009-07-20

    We propose a plasma experiment to be used to investigate fundamental properties of astrophysical dynamos. The highly conducting, fast-flowing plasma will allow experimenters to explore systems with magnetic Reynolds numbers an order of magnitude larger than those accessible with liquid-metal experiments. The plasma is confined using a ring-cusp strategy and subject to a toroidal differentially rotating outer boundary condition. As proof of principle, we present magnetohydrodynamic simulations of the proposed experiment. When a von Karman-type boundary condition is specified, and the magnetic Reynolds number is large enough, dynamo action is observed. At different values of the magnetic Prandtl and Reynolds numbers the simulations demonstrate either laminar or turbulent dynamo action.

  3. Plasma-materials interactions and edge-plasma physics research

    SciTech Connect

    Hirooka, Y.

    1991-12-01

    This report discusses the: Pisces Program; Pisces Facilities; Pisces Experiments: Materials and Surface Physics; Pisces Experiments: Edge Plasma Physics; and, Theoretical Analysis: Edge Plasma Behavior.

  4. Plasma Wakefield Experiments at FACET

    SciTech Connect

    Hogan, M.J.; England, R.J.; Frederico, J.; Hast, C.; Li, S.Z.; Litos, M.; Walz, D.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; Muggli, P.; Pinkerton, S.; Shi, Y.; /Southern California U.

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to {approx}20{micro}m long and focused to {approx}10{micro}m wide. The intense fields of the FACET bunches will be used to field ionize neutral lithium or cesium vapor produced in a heat pipe oven. Previous experiments at the SLAC FFTB facility demonstrated 50GeV/m gradients in an 85cm field ionized lithium plasma where the interaction distance was limited by head erosion. Simulations indicate the lower ionization potential of cesium will decrease the rate of head erosion and increase single stage performance. The initial experimental program will compare the performance of lithium and cesium plasma sources with single and double bunches. Later experiments will investigate improved performance with a pre-ionized cesium plasma. The status of the experiments and expected performance are reviewed. The FACET Facility is being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The facility will begin commissioning in summer 2011 and conduct an experimental program over the coming five years to study electron and positron beam driven plasma acceleration with strong wake loading in the non-linear regime. The FACET experiments aim to demonstrate high-gradient acceleration of electron and positron beams with high efficiency and negligible emittance growth.

  5. A rotating directional probe for the measurements of fast ion losses and plasma rotation at Tokamak Experiment for Technology Oriented Research.

    PubMed

    Rack, M; Liang, Y; Jaegers, H; Assmann, J; Satheeswaran, G; Xu, Y; Pearson, J; Yang, Y; Denner, P; Zeng, L

    2013-08-01

    This work discusses a new directional probe designed for measurements of fast ion losses and the plasma rotation with a high angular resolution in magnetically confined plasmas. Directional and especially Mach probes are commonly used diagnostics for plasma flow measurements, and their applicability for the fast ion losses detection has been demonstrated. A limitation of static Mach probes is their low angular resolution. At the Tokamak Experiment for Technology Oriented Research, the angular resolution is strongly restricted by the finite number of available measurement channels. In a dynamic plasma, where instabilities can lead to local changes of the field line pitch-angle, plasma flow, or fast ion losses, a low angular resolution makes a precise data analysis difficult and reduces the quality of the measured data. The new probe design, the rotating directional probe, combines the features of early directional probes and Mach probes. It consists of two radially aligned arrays of nine Langmuir probe pins with each array facing opposite directions. During the measurement the probe head rotates along its axis to measure the ion saturation current from all directions. As a result, the rotating directional probe simultaneously provides an angular dependent plasma flow and fast ion losses measurement at different radial positions. Based on the angular dependent data, a precise determination of the current density is made. In addition, the simultaneous measurement of the ion saturation current at different radial positions allows for resolving radially varying field line pitch-angles and identifying the radial dynamic of processes like fast ion losses.

  6. Space plasma contractor research, 1988

    NASA Technical Reports Server (NTRS)

    Williams, John D.; Wilbur, Paul J.

    1989-01-01

    Results of experiments conducted on hollow cathode-based plasma contractors are reported. Specific tests in which attempts were made to vary plasma conditions in the simulated ionospheric plasma are described. Experimental results showing the effects of contractor flowrate and ion collecting surface size on contactor performance and contactor plasma plume geometry are presented. In addition to this work, one-dimensional solutions to spherical and cylindircal space-charge limited double-sheath problems are developed. A technique is proposed that can be used to apply these solutions to the problem of current flow through elongated double-sheaths that separate two cold plasmas. Two conference papers which describe the essential features of the plasma contacting process and present data that should facilitate calibration of comprehensive numerical models of the plasma contacting process are also included.

  7. Plasma theory and simulation research

    SciTech Connect

    Birdsall, C.K.

    1989-01-01

    Our research group uses both theory and simulation as tools in order to increase the understanding of instabilities, heating, diffusion, transport and other phenomena in plasmas. We also work on the improvement of simulation, both theoretically and practically. Our focus has been more and more on the plasma edge (the sheath''), interactions with boundaries, leading to simulations of whole devices (someday a numerical tokamak).

  8. Experiments on TFTR supershot plasmas

    SciTech Connect

    Strachan, J.D.; Bell, M.; Janos, A.; Kaye, S.; Kilpatrick, S.; Manos, D.; Mansfield, D.; Mueller, D.; Owens, K; Timberlake, J.; Pitcher, C.S.; Snipes, J.

    1992-05-01

    Improvements to the TFTR limiter have extended the threshold for carbon blooms (an uncontrolled massive influx of carbon) to greater than 32 MW for 1 sec so that blooms seldom occur in present TFTR Supershot experiments. As a result of the progression from strong blooms to modest blooms to no blooms, improvements in confinement could be correlated with the occurrence of a carbon bloom in the plasma which immediately preceded the supershot. It is speculated that the carbon influx during a carbon bloom results in a limiter surface which has a slightly reduced self=sputtering yield for subsequent discharge. The influence on the supershot plasma seems similar to phenomena obtained by conditioning with lithium pellets.

  9. Plasma and magnetospheric research

    NASA Astrophysics Data System (ADS)

    Comfort, R. H.; Horwitz, J. L.

    1985-10-01

    Several programs and variations have been developed to determine statistical means of different plasma parameters when binned in different variables. These parameters include temperature, densities and spacecraft potentials for any of the ion species, as well as ratios of these variables for any other ion species to the corresponding variable for H(+). The variables for binning include L, radial distance, and geomagnetic latitude; and separate statistics are automatically run for local morning and local evening data. These programs all run from output files from the plasma parameter thin sheath analysis program. A variant program also bins for magnetic activity, using either Kp or Dst, which requires an additional magnetic activity input file. These programs can be run either interactively or in batch mode, using file listings generated by a DIRECTORY command. In addition to printed output, these programs generate output files which can be used to plot the results. Programs to plot these averaged data are under development.

  10. Nonequilibrium Plasma Research

    DTIC Science & Technology

    2010-05-01

    Unfiltered Image Sequences of the Plasma Jet and CDBD Emission Acquired with a 5 ns Gated ICCD Camera. (b) Normalized Intensity from Displacement Current...measurements. A 15-ns-rise-time high-voltage stacked MOSFET switch was used to apply 6 kV to the electrodes for pulse durations of 250 ns at a 100- Hz...streamers were recorded using an intensified CCD camera. The camera gate was set to 20 ns and delayed with respect to the overvoltage peak by 20-ns

  11. A Physics Exploratory Experiment on Plasma Liner Formation

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Knapp, Charles E.; Kirkpatrick, Ronald C.; Siemon, Richard E.; Turchi, Peter

    2002-01-01

    Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to do in order to explore the dynamics of merging plasma jets to form a plasma liner as a first step in establishing an experimental database for plasma-jets driven magnetized target fusion (PJETS-MTF). Using past experience in fusion energy research as a model, we envisage a four-phase program to advance the art of PJETS-MTF to fusion breakeven Q is approximately 1). The experiment (PLX (Plasma Liner Physics Exploratory Experiment)) described in this paper serves as Phase I of this four-phase program. The logic underlying the selection of the experimental parameters is presented. The experiment consists of using twelve plasma guns arranged in a circle, launching plasma jets towards the center of a vacuum chamber. The velocity of the plasma jets chosen is 200 km/s, and each jet is to carry a mass of 0.2 mg - 0.4 mg. A candidate plasma accelerator for launching these jets consists of a coaxial plasma gun of the Marshall type.

  12. Research in plasma physics

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Three aspects of barium ion cloud dynamics are discussed. First, the effect of the ratio of ion cloud conductivity to background ionospheric conductivity on the motion of barium ion clouds is investigated and compared with observations of barium ion clouds. This study led to the suggestion that the conjugate ionosphere participates in the dynamics of barium ion clouds. Second, analytic work on the deformation of ion clouds is presented. Third, a linearized stability theory was extended to include the effect of the finite extent of an ion cloud, as well as the effect of the ratio of ion cloud to ionospheric conductivities. The stability properties of a plasma with contra-streaming ion beams parallel to a magnetic field are investigated. The results are interpreted in terms of parameters appropriate for collisionless shock waves. It is found that this particular instability can be operative only if the up-stream Alfven Mach number exceeds 5.5.

  13. Space plasma research

    NASA Technical Reports Server (NTRS)

    Comfort, R. H.; Horwitz, J. L.

    1986-01-01

    Four basic areas were covered: development of analysis techniques and software and numerical simulations; data analysis and interpretation; spacecraft sheath studies; and laboratory studies. The important details were documented in terms of either appropriate software documentation or publication in referred publication, conference proceeding and technical reports. The major accomplishments are summarized, followed by a chronological listing of the publications and presentations which resulted from the research.

  14. [Plasma properties research: Task 3

    SciTech Connect

    Not Available

    1992-12-31

    The principal research activities of the Magneto-Fluid Dynamics Division relate to magnetic fusion plasma physics. In addition, there is a modest amount of work in closely related areas, including space plasma physics, fluid dynamics, and dynamical systems. Members of the Magneto-Fluid Dynamics Division maintain close contacts with fusion researchers in the US and abroad. Some of the work of the Division is clearly directed towards ITER and TPX, while other problems relate to the broader development of fusion plasma physics and to the support of other issues arising in the many experimental programs. Topics of some note in the last year that are discussed in this report are: Application of sophisticated statistical techniques to tokamak data reduction, including time series analysis of TFTR fluctuation data and spline analysis of profile data. Continuing development of edge plasma and divertor modelling, including initial ergodic divertor studies. Analysis of energetic fusion products losses from TFTR plasmas. Examination of anomalous transport in dynamical systems induced by chaotic-like Hamiltonian motion. Numerical simulation of the development of singular MHD equilibria. Exploration of the validity of moment expansions of kinetic equations for weakly collisional systems. Studies of RF- and ripple-induced helium ash removal. Ballooning mode studies in fluids and rotating stars. Studies in dynamical systems, including explosive instabilities, development of chaos, and motion of collisionless particles in a domain with overlapping islands.

  15. [Plasma properties research: Task 3

    SciTech Connect

    Not Available

    1992-01-01

    The principal research activities of the Magneto-Fluid Dynamics Division relate to magnetic fusion plasma physics. In addition, there is a modest amount of work in closely related areas, including space plasma physics, fluid dynamics, and dynamical systems. Members of the Magneto-Fluid Dynamics Division maintain close contacts with fusion researchers in the US and abroad. Some of the work of the Division is clearly directed towards ITER and TPX, while other problems relate to the broader development of fusion plasma physics and to the support of other issues arising in the many experimental programs. Topics of some note in the last year that are discussed in this report are: Application of sophisticated statistical techniques to tokamak data reduction, including time series analysis of TFTR fluctuation data and spline analysis of profile data. Continuing development of edge plasma and divertor modelling, including initial ergodic divertor studies. Analysis of energetic fusion products losses from TFTR plasmas. Examination of anomalous transport in dynamical systems induced by chaotic-like Hamiltonian motion. Numerical simulation of the development of singular MHD equilibria. Exploration of the validity of moment expansions of kinetic equations for weakly collisional systems. Studies of RF- and ripple-induced helium ash removal. Ballooning mode studies in fluids and rotating stars. Studies in dynamical systems, including explosive instabilities, development of chaos, and motion of collisionless particles in a domain with overlapping islands.

  16. Research briefing on contemporary problems in plasma science

    NASA Technical Reports Server (NTRS)

    1991-01-01

    An overview is presented of the broad perspective of all plasma science. Detailed discussions are given of scientific opportunities in various subdisciplines of plasma science. The first subdiscipline to be discussed is the area where the contemporary applications of plasma science are the most widespread, low temperature plasma science. Opportunities for new research and technology development that have emerged as byproducts of research in magnetic and inertial fusion are then highlighted. Then follows a discussion of new opportunities in ultrafast plasma science opened up by recent developments in laser and particle beam technology. Next, research that uses smaller scale facilities is discussed, first discussing non-neutral plasmas, and then the area of basic plasma experiments. Discussions of analytic theory and computational plasma physics and of space and astrophysical plasma physics are then presented.

  17. Electrodynamic plasma motor/generator experiment

    NASA Technical Reports Server (NTRS)

    Mccoy, James E.

    1987-01-01

    The Plasma Motor/Generator Proof of Function (PMG/POF) experiment, a low-cost payload for flight aboard the Shuttle Orbiter using the Hitchhiker G carrier, is discussed. The primary objective of this experiment is to verify that hollow cathode plasma sources can couple electric currents from either end of a long wire moving through the space plasma in LEO into and through that plasma to produce a PMG circuit. The support structure and the electrical components of the experiment are described. The experimental operation is discussed, including the calibration, experimental measurements, and follow-on missions.

  18. Using the Tritium Plasma Experiment to evaluate ITER PFC safety

    SciTech Connect

    Longhurst, G.R.; Anderl, R.A.; Bartlit, J.R.; Causey, R.A.; Haines, J.R.

    1993-07-01

    The Tritium Plasma Experiment was assembled at Sandia National Laboratories, Livermore to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 {times} 10{sup 19} ions/cm{sup 2} {center_dot} s and a plasma temperature of about 15 eV using a plasma that includes tritium. With the closure of the Tritium Research Laboratory at Livermore, the experiment was moved to the Tritium Systems Test Assembly facility at Los Alamos National Laboratory. An experimental program has been initiated there using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. A considerable lack of data exists in these areas for many of the materials, especially beryllium, being considered for use in ITER. Not only will basic material behavior with respect to safety issues in the divertor environment be examined, but innovative techniques for optimizing performance with respect to tritium safety by material modification and process control will be investigated. Supplementary experiments will be carried out at the Idaho National Engineering Laboratory and Sandia National Laboratory to expand and clarify results obtained on the Tritium Plasma Experiment.

  19. Collisionless Plasma Astrophysics Simulation Experiments using Lasers

    SciTech Connect

    Woolsey, N. C.; Ash, A. D.; Courtois, C.; Gregory, C. D.; Hall, I. M.; Howe, J.; Dendy, R. O.

    2006-04-07

    Laboratory experiment is an attractive method of exploring the plasma physics that may occur in solar and astrophysical shocks. An experiment enables repeated and detailed measurements of a plasma as the input conditions are adjusted. To form a scaled experiment of an astrophysical shock a plasma physics model of the shock is required, and the important dimensionless parameters identified and reproduced in the laboratory. A laboratory simulation of a young supernova remnant is described. The experiment uses the interaction of two millimetre-sized counter-streaming laser-produced plasmas placed in a strong transverse magnetic field to achieve this scaling. The collision-free dynamics of the two plasmas and their interaction are studied with and without the magnetic field through spatially and temporally resolved optical measurements. Laboratory astroplasma physics experiments using high-energy, high-power laser technology enables us to reproduce in the laboratory the conditions of temperature and pressure that are met in extreme stellar environments.

  20. Lithium plasma emitter for collisionless magnetized plasma experiment.

    PubMed

    Kawamori, Eiichirou; Lee, Jyun-Yi; Huang, Yi-Jue; Syugu, Wun-Jheng; Song, Sung-Xuang; Hsieh, Tung-Yuan; Cheng, C Z

    2011-09-01

    This paper presents a newly developed lithium plasma emitter, which can provide quiescent and low-temperature collisionless conditions for magnetized plasma experiments. This plasma emitter generates thermal emissions of lithium ions and electrons to produce a lithium plasma. Lithium type beta-eucryptite and lanthanum-hexaboride (LaB(6)) powders were mixed and directly heated with a tungsten heater to synthesize ion and electron emissions. As a result, a plasma with a diameter of ~15 cm was obtained in a magnetic mirror configuration. The typical range of electron density was 10(12)-10(13) m(-3) and that of electron temperature was 0.1-0.8 eV with the emitter operation temperature of about 1500 K. The amplitude fluctuations for the plasma density were lower than 1%. © 2011 American Institute of Physics

  1. How can laboratory plasma experiments contribute to space and &astrophysics?

    NASA Astrophysics Data System (ADS)

    Yamada, M.

    Plasma physics plays key role in a wide range of phenomena in the universe, from laboratory plasmas to the magnetosphere, the solar corona, and to the tenuous interstellar and intergalactic gas. Despite the huge difference in physical scales, there are striking similarities in plasma behavior of laboratory and space plasmas. Similar plasma physics problems have been investigated independently by both laboratory plasma physicists and astrophysicists. Since 1991, cross fertilization has been increased among laboratory plasma physicists and space physicists through meeting such as IPELS [Interrelationship between Plasma Experiments in the Laboratory and Space] meeting. The advances in laboratory plasma physics, along with the recent surge of astronomical data from satellites, make this moment ripe for research collaboration to further advance plasma physics and to obtain new understanding of key space and astrophysical phenomena. The recent NRC review of astronomy and astrophysics notes the benefit that can accrue from stronger connection to plasma physics. The present talk discusses how laboratory plasma studies can contribute to the fundamental understandings of the space and astrophysical phenomena by covering common key physics topics such as magnetic reconnection, dynamos, angular momentum transport, ion heating, and magnetic self-organization. In particular, it has recently been recognized that "physics -issue- dedicated" laboratory experiments can contribute significantly to the understanding of the fundamental physics for space-astrophysical phenomena since they can create fundamental physics processes in controlled manner and provide well-correlated plasma parameters at multiple plasma locations simultaneously. Such dedicated experiments not only can bring about better understanding of the fundamental physics processes but also can lead to findings of new physics principles as well as new ideas for fusion plasma confinement. Several dedicated experiments have

  2. Hot ion plasma heating experiments in SUMMA

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Posta, S. J.; Snyder, A.; Englert, G. W.

    1974-01-01

    Initial results are presented for the hot-ion plasma heating experiments conducted in the new SUMMA (superconducting magnetic mirror apparatus) at NASA Lewis Research Center. A discharge is formed by applying a radially inward dc electric field between cylindrical anodes and hallow cathodes located at the peak of the mirrors. Data were obtained at midplane magnetic field strengths from 1.0 to 3.5 tesla. Charge-exchange neutral particle energy analyzer data were reduced to ion temperatures using a plasma model that included a Maxwellian energy distribution superimposed on an azimuthal drift, finite ion orbits, and radial variations in density and electric field. The best ion temperatures in a helium plasma were 5 keV and in hydrogen the H2(+) and H(+) ions were 1.2 keV and 1 keV respectively. Optical spectroscopy line broadening measurements yielded ion temperatures about 50 percent higher than the charge-exchange neutral particle analyzer results. Spectroscopically obtained electron temperature ranged from 3 to 30 eV. Ion temperature was found to scale roughly linearly with the ratio of power input-to-magnetic field strength, P/B.

  3. Magnetized laboratory plasma jets: experiment and simulation.

    PubMed

    Schrafel, Peter; Bell, Kate; Greenly, John; Seyler, Charles; Kusse, Bruce

    2015-01-01

    Experiments involving radial foils on a 1 MA, 100 ns current driver can be used to study the ablation of thin foils and liners, produce extreme conditions relevant to laboratory astrophysics, and aid in computational code validation. This research focuses on the initial ablation phase of a 20 μm Al foil (8111 alloy), in a radial configuration, driven by Cornell University's COBRA pulsed power generator. In these experiments ablated surface plasma (ASP) on the top side of the foil and a strongly collimated axial plasma jet are observed developing midway through the current rise. With experimental and computational results this work gives a detailed description of the role of the ASP in the formation of the plasma jet with and without an applied axial magnetic field. This ∼1 T field is applied by a Helmholtz-coil pair driven by a slow, 150 μs current pulse and penetrates the load hardware before arrival of the COBRA pulse. Several effects of the applied magnetic field are observed: (1) without the field extreme-ultraviolet emission from the ASP shows considerable azimuthal asymmetry while with the field the ASP develops azimuthal motion that reduces this asymmetry, (2) this azimuthal motion slows the development of the jet when the field is applied, and (3) with the magnetic field the jet becomes less collimated and has a density minimum (hollowing) on the axis. PERSEUS, an XMHD code, has qualitatively and quantitatively reproduced all these experimental observations. The differences between this XMHD and an MHD code without a Hall current and inertial effects are discussed. In addition the PERSEUS results describe effects we were not able to resolve experimentally and suggest a line of future experiments with better diagnostics.

  4. PlasmaLab/EkoPlasma - The Future of Complex Plasma Research in Space

    NASA Astrophysics Data System (ADS)

    Knapek, Christina; Fortov, Vladimir; Huber, Peter; Mohr, Daniel; Konopka, Uwe; Lipaev, Andrey; Molotkov, Vladimir; Petrov, Oleg; Zähringer, Erich; Thomas, Hubertus

    2016-07-01

    The PlasmaLab project, a Russian-German cooperation, has the aim to develop a future laboratory for the investigation of complex plasmas under microgravity conditions on the International Space Station (ISS). Within the project, a new plasma chamber, the Zyflex chamber, has been developed and is now being prepared to be launched to the ISS in 2020 as a laboratory setup with the name EkoPlasma (Experiment komplex Plasma). The Zyflex chamber is a large, cylindrical plasma chamber with parallel, rf-driven electrodes and a flexible inner geometry. It is designed to extend the accessible experimental parameter range and to allow an independent control of the plasma parameters, therefore increasing the experimental possibilities and expected knowledge gain significantly. Further, a 3D optical diagnostic will allow for the study of particle dynamics in 3D realtime. Possible future research topics include e.g. phase transitions, the dynamics of liquids, phase separation, or turbulence. The experimental setup will be presented, as well as some preliminary results of experiments on earth and in parabolic flights to visualize the possibilities of this new laboratory. This work and some of the authors are funded by DLR/BMWi (FKZ 50WM1441).

  5. Meter scale plasma source for plasma wakefield experiments

    SciTech Connect

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

    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.

  6. E-157: A Plasma Wakefield Acceleration Experiment

    SciTech Connect

    Muggli, Patrick

    2000-10-20

    The E-157 plasma wakefield experiment addresses issues relevant to a meter long plasma accelerator module. In particular, a 1.4 m long plasma source has been developed for the experiment. The transverse dynamics of the beam in the plasma is studied: multiple betatron oscillations of the beam envelope, flipping of the beam tail, stability against the hose instability, emission of synchrotron radiation by the beam in the plasma. The bending of the 28.5 GeV beam at the plasma/vapor interface is observed for the first time. The longitudinal dynamics of the beam, i.e. the energy loss and gain by the electrons in the wake, is strongly affected by the oscillation of the beam tail instability.

  7. Statistical Physics Experiments Using Dusty Plasmas

    NASA Astrophysics Data System (ADS)

    Goree, John

    2016-10-01

    Compared to other areas of physics research, Statistical Physics is heavily dominated by theory, with comparatively little experiment. One reason for the lack of experiments is the impracticality of tracking of individual atoms and molecules within a substance. Thus, there is a need for a different kind of experimental system, one where individual particles not only move stochastically as they collide with one another, but also are large enough to allow tracking. A dusty plasma can meet this need. A dusty plasma is a partially ionized gas containing small particles of solid matter. These micron-size particles gain thousands of electronic charges by collecting more electrons than ions. Their motions are dominated by Coulomb collisions with neighboring particles. In this so-called strongly coupled plasma, the dust particles self-organize in much the same way as atoms in a liquid or solid. Unlike atoms, however, these particles are large and slow, so that they can be tracked easily by video microscopy. Advantages of dusty plasma for experimental statistical physics research include particle tracking, lack of frictional contact with solid surfaces, and avoidance of overdamped motion. Moreover, the motion of a collection of dust particles can mimic an equilibrium system with a Maxwellian velocity distribution, even though the dust particles themselves are not truly in thermal equilibrium. Nonequilibrium statistical physics can be studied by applying gradients, for example by imposing a shear flow. In this talk I will review some of our recent experiments with shear flow. First, we performed the first experimental test to verify the Fluctuation Theorem for a shear flow, showing that brief violations of the Second Law of Thermodynamics occur with the predicted probabilities, for a small system. Second, we discovered a skewness of a shear-stress distribution in a shear flow. This skewness is a phenomenon that likely has wide applicability in nonequilibrium steady states

  8. Plasma MRI Experiments at UW-Madison

    NASA Astrophysics Data System (ADS)

    Flanagan, K.; Clark, M.; Desangles, V.; Siller, R.; Wallace, J.; Weisberg, D.; Forest, C. B.

    2015-11-01

    Experiments for driving Keplerian-like flow profiles on both the Plasma Couette Experiment Upgrade (PCX-U) and the Wisconsin Plasma Astrophysics Laboratory (WiPAL) user facility are described. Instead of driving flow at the boundaries, as is typical in many liquid metal Couette experiments, a global drive is implemented. A large radial current is drawn across a small axial field generating torque across the whole profile. This global electrically driven flow is capable of producing profiles similar to Keplerian flow. PCX-U has been purposely constructed for MRI experiments, while similar experiments on the WiPAL device show the versatility of the user facility and provide a larger plasma volume. Numerical calculations show the predicted parameter spaces for exciting the MRI in these plasmas and the equilibrium flow profiles expected. In both devices, relevant MRI parameters appear to be within reach of typical operating characteristics.

  9. Ballistic piston fissioning plasma experiment.

    NASA Technical Reports Server (NTRS)

    Miller, B. E.; Schneider, R. T.; Thom, K.; Lalos, G. T.

    1971-01-01

    The production of fissioning uranium plasma samples such that the fission fragment stopping distance is less than the dimensions of the plasma is approached by using a ballistic piston device for the compression of uranium hexafluoride. The experimental apparatus is described. At room temperature the gun can be loaded up to 100 torr UF6 partial pressure, but at compression a thousand fold increase of pressure can be obtained at a particle density on the order of 10 to the 19th power per cu cm. Limited spectral studies of UF6 were performed while obtaining the pressure-volume data. The results obtained and their implications are discussed.

  10. Magnetized plasma jets in experiment and simulation

    NASA Astrophysics Data System (ADS)

    Schrafel, Peter; Greenly, John; Gourdain, Pierre; Seyler, Charles; Blesener, Kate; Kusse, Bruce

    2013-10-01

    This research focuses on the initial ablation phase of a thing (20 micron) Al foil driven on the 1 MA-in-100 ns COBRA through a 5 mm diameter cathode in a radial configuration. In these experiments, ablated surface plasma (ASP) on the top of the foil and a strongly collimated axial plasma jet can be observed developing midway through current-rise. Our goal is to establish the relationship between the ASP and the jet. These jets are of interest for their potential relevance to astrophysical phenomena. An independently pulsed 200 μF capacitor bank with a Helmholtz coil pair allows for the imposition of a slow (150 μs) and strong (~1 T) axial magnetic field on the experiment. Application of this field eliminates significant azimuthal asymmetry in extreme ultraviolet emission of the ASP. This asymmetry is likely a current filamentation instability. Laser-backlit shadowgraphy and interferometry confirm that the jet-hollowing is correlated with the application of the axial magnetic field. Visible spectroscopic measurements show a doppler shift consistent with an azimuthal velocity in the ASP caused by the applied B-field. Computational simulations with the XMHD code PERSEUS qualitatively agree with the experimental results.

  11. High confinement and high density with stationary plasma energy and strong edge radiation cooling in the upgraded Torus Experiment for Technology Oriented Research (TEXTOR-94)

    SciTech Connect

    Messiaen, A.M.; Ongena, J.; Unterberg, B.; Boedo, J.; Fuchs, G.; Jaspers, R.; Konen, L.; Koslowski, H.R.; Mank, G.; Rapp, J.; Samm, U.; Vandenplas, P.E.; Van Oost, G.; Van Wassenhove, G.; Waidmann, G.; Weynants, R.R.; Wolf, G.H.; Bertschinger, G.; Bonheure, G.; Brix, M.; Dumortier, P.; Durodie, F.; Finken, K.H.; Giesen, B.; Hillis, D.; Hutteman, P.; Koch, R.; Kramer-Flecken, A.; Lyssoivan, A.; Mertens, P.; Pospieszczyk, A.; Post-Zwicker, A.; Sauer, M.; Schweer, B.; Schwelberger, J.; Telesca, G.; Tokar, M.Z.; Uhlemann, R.; Vervier, M.; Winter, J. ||||

    1997-05-01

    An overview of the results obtained so far for the radiative I-mode regime on the upgraded Torus Experiment for Technology Oriented Research (TEXTOR-94) [{ital Proceedings of the 16th IEEE Symposium on Fusion Engineering} (Institute of Electrical and Electronics Engineers, Piscataway, NJ, 1995), Vol. 1, p. 470] is given. This regime is obtained under quasistationary conditions with edge neon seeding in a pumped limiter tokamak with circular cross section. It combines high confinement and high {beta} (up to a normalized beta, {beta}{sub n}=2) with low edge q values (down to q{sub a}=2.8) and high density even above the Greenwald limit together with dominant edge radiative heat exhaust, and therefore shows promise for the future of fusion research. Bulk and edge properties of these discharges are described, and a detailed account is given of the energy and particle confinement and their scaling. Energy confinement scales linearly with density as for the nonsaturated Ohmic Neo-Alcator scaling, but the usual degradation with total power remains. No deleterious effects of the neon seeding on fusion reactivity and plasma stability have been observed. {copyright} {ital 1997 American Institute of Physics.}

  12. Hollow cathode-based plasma contactor experiments for electrodynamic tether

    NASA Astrophysics Data System (ADS)

    Patterson, Michael J.

    1987-01-01

    The role plasma contactors play in effective electrodynamic tether operation is discussed. Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors are reviewed. This research includes the definition of preliminary plasma contactor designs, and the characterization of their operation as electron collectors from a simulated space plasma. The discovery of an 'ignited mode' regime of high contactor efficiency and low impedance is discussed, as well as is the application of recent models of the plasma coupling process to contactor operation. Results indicate that ampere-level electron currents can be exchanged between hollow cathode-based plasma contactors and a dilute plasma in this regime. A discussion of design considerations for plasma contactors is given which includes expressions defining the total mass flow rate and power requirements of plasma contactors operating in both the cathodic and anodic regimes, and correlation of this to the tether current. Finally, future ground and spaceflight experiments are proposed to resolve critical issues of plasma contactor operation.

  13. Hollow cathode-based plasma contactor experiments for electrodynamic tether

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.

    1987-01-01

    The role plasma contactors play in effective electrodynamic tether operation is discussed. Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors are reviewed. This research includes the definition of preliminary plasma contactor designs, and the characterization of their operation as electron collectors from a simulated space plasma. The discovery of an 'ignited mode' regime of high contactor efficiency and low impedance is discussed, as well as is the application of recent models of the plasma coupling process to contactor operation. Results indicate that ampere-level electron currents can be exchanged between hollow cathode-based plasma contactors and a dilute plasma in this regime. A discussion of design considerations for plasma contactors is given which includes expressions defining the total mass flow rate and power requirements of plasma contactors operating in both the cathodic and anodic regimes, and correlation of this to the tether current. Finally, future ground and spaceflight experiments are proposed to resolve critical issues of plasma contactor operation.

  14. Laboratory Plasma Astrophysics Research with Intense Lasers

    NASA Astrophysics Data System (ADS)

    Takabe, Hideaki; Kato, Tsunehiko; Kuramitsu, Yasuhiro; Sakawa, Yuichi

    2008-12-01

    Large scale laser facilities mainly constructed for fusion research can be used to produce high-energy-density plasmas like the interior of stars and planets. They can be also used to reproduce the extreme phenomena of explosion and high Mach number flow in mimic scale in laboratory. With advanced diagnostic technique, we can study the physics of plasma phenomena expected to control a variety of phenomena in Universe. The subjects studied so far are reviewed, for example, in [1], [2]. The project to promote the laboratory astrophysics with Gekko XII laser facility has been initiated from April 1st this year as a project of our institute. It consists of four sub-projects. They are 1. Physics of collisionless shock and particle acceleration, 2. Physics of Non LTE (local thermodynamic equilibrium) photo-ionized plasma, 3. Physics of planets and meteor impact, 4. Development of superconducting Terahertz device. I will briefly explain what the laser astrophysics means and introduce what are the targets of our project. Regarding the first sub-project, we have carried out hydrodynamic and PIC simulation to design the experiments with intense laser. We clarified the physical mechanism of generation of the magnetic field in non-magnetized plasma and the collsionless shock formation caused by the ion orbit modifications by the magnetic fields generated as the result of plasma instability. Note from Publisher: This article contains the abstract only.

  15. Conceptual design of Dipole Research Experiment (DREX)

    NASA Astrophysics Data System (ADS)

    Qingmei, XIAO; Zhibin, WANG; Xiaogang, WANG; Chijie, XIAO; Xiaoyi, YANG; Jinxing, ZHENG

    2017-03-01

    A new terrella-like device for laboratory simulation of inner magnetosphere plasmas, Dipole Research Experiment, is scheduled to be built at the Harbin Institute of Technology (HIT), China, as a major state scientific research facility for space physics studies. It is designed to provide a ground experimental platform to reproduce the inner magnetosphere to simulate the processes of trapping, acceleration, and transport of energetic charged particles restrained in a dipole magnetic field configuration. The scaling relation of hydromagnetism between the laboratory plasma of the device and the geomagnetosphere plasma is applied to resemble geospace processes in the Dipole Research Experiment plasma. Multiple plasma sources, different kinds of coils with specific functions, and advanced diagnostics are designed to be equipped in the facility for multi-functions. The motivation, design criteria for the Dipole Research Experiment experiments and the means applied to generate the plasma of desired parameters in the laboratory are also described. Supported by National Natural Science Foundation of China (Nos. 11505040, 11261140326 and 11405038), China Postdoctoral Science Foundation (Nos. 2016M591518, 2015M570283) and Project Supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (No. 2017008).

  16. Conceptual design of Dipole Research Experiment (DREX)

    NASA Astrophysics Data System (ADS)

    Xiao, Qingmei; Wang, Zhibin; Wang, Xiaogang; Xiao, Chijie; Yang, Xiaoyi; Zheng, Jinxing

    2017-03-01

    A new terrella-like device for laboratory simulation of inner magnetosphere plasmas, Dipole Research Experiment, is scheduled to be built at the Harbin Institute of Technology (HIT), China, as a major state scientific research facility for space physics studies. It is designed to provide a ground experimental platform to reproduce the inner magnetosphere to simulate the processes of trapping, acceleration, and transport of energetic charged particles restrained in a dipole magnetic field configuration. The scaling relation of hydromagnetism between the laboratory plasma of the device and the geomagnetosphere plasma is applied to resemble geospace processes in the Dipole Research Experiment plasma. Multiple plasma sources, different kinds of coils with specific functions, and advanced diagnostics are designed to be equipped in the facility for multi-functions. The motivation, design criteria for the Dipole Research Experiment experiments and the means applied to generate the plasma of desired parameters in the laboratory are also described. Supported by National Natural Science Foundation of China (Nos. 11505040, 11261140326 and 11405038), China Postdoctoral Science Foundation (Nos. 2016M591518, 2015M570283) and Project Supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (No. 2017008).

  17. Plasma-Pulse-Acceleration Experiments

    DTIC Science & Technology

    1987-06-01

    W. Pucher, Testing a new Type of Circuit Breaker for HVDC , Direct Current, Feb. 1966, pp. 3 - 6 /10/ D. Kind, E. Marx, K. Mollenhoff, J. Salge... breakers /4, 5/, exploding wires /6/, plasma jet tubes /7/, and high pressure radiation sources /8/. In particular current limiting circuit breakers ...length, radius, shaping, material to be evaporated etc.). Here it is possible to transfer design criteria from current-limiting circuit breakers and

  18. Plasma crystals: experiments and simulation

    NASA Astrophysics Data System (ADS)

    Piel, A.

    2017-01-01

    Dusty plasmas are a well accessible system to study crystallization of charged-particle systems at room temperature. The large mass compared to atomic particles dramatically slows down the particle velocities. The high transparency of the system allows to trace simultaneously the motion of all particles with quasi-atomic resolution. After a brief overview, the progress in this field is exemplified by studies of spherical three-dimensional plasma crystals, the so-called Yukawa balls. The static structure and eigenmodes are explained in simple terms. It is shown that shielding modifies the expansion of a Yukawa ball from a self-similar explosion to a continuous ablation process that starts at the surface. The experimental progress with three-dimensional diagnostics and laser heating and sophisticated methods for visualising the order inside the shell structure are described. Together with quantifying the diffusion coefficient these investigations reveal the details of the solid-liquid phase transition. Besides thermodynamic aspects, the liquid phase of dusty plasmas also gives access to hydrodynamic phenomena at the individual particle scale.

  19. Experiences of Collaborative Research

    ERIC Educational Resources Information Center

    Kahneman, Daniel

    2003-01-01

    The author's personal history of the research that led to his recognition in economics is described, focusing on the process of collaboration and on the experience of controversy. The author's collaboration with Amos Tversky dealt with 3 major topics: judgment under uncertainty, decision making, and framing effects. A subsequent collaboration,…

  20. Experiences of Collaborative Research

    ERIC Educational Resources Information Center

    Kahneman, Daniel

    2003-01-01

    The author's personal history of the research that led to his recognition in economics is described, focusing on the process of collaboration and on the experience of controversy. The author's collaboration with Amos Tversky dealt with 3 major topics: judgment under uncertainty, decision making, and framing effects. A subsequent collaboration,…

  1. Argonne Plasma Engineering Experiment (APEX) Tokamak

    SciTech Connect

    Norem, J.H.; Balka, L.J.; Kulovitz, E.E.; Magill, S.R.; McGhee, D.G.; Moretti, A.; Praeg, W.F.

    1981-03-01

    The Argonne Plasma Engineering Experiment (APEX) Tokamak was designed to provide hot plasmas for reactor-relevant experiments with rf heating (current drive) and plasma wall experiments, principally in-situ low-Z wall coating and maintenance. The device, sized to produce energetic plasmas at minimum cost, is small (R = 51 cm, r = 15 cm) but capable of high currents (100 kA) and long pulse durations (100 ms). A design using an iron central core with no return legs, pure tension tapewound toroidal field coils, digital radial position control, and UHV vacuum technology was used. Diagnostics include monochrometers, x-ray detectors, and a microwave interferometer and radiometer for density and temperature measurements. Stable 100 ms shots were produced with electron temperatures in the range 500 to 1000 eV. Initial results included studies of thermal desorption and recoating of wall materials.

  2. Research Status of IEC Experiments at NASA Marshall

    NASA Technical Reports Server (NTRS)

    Dobson, Chris; Hrbud, Ivana; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    This presentation provides an overview of IEC (Inertial Electrostatic Confinement) research and experiments at NASA's Marshall Space Flight Center. Topics covered include: apparatus involvement, iec schematics, iec plasma images, iec deuterium experiments, thomson scattering, detector options and experiment results.

  3. Massachusetts Institute of Technology, Plasma Fusion Center, Technical Research Programs

    SciTech Connect

    Davidson, Ronald C.

    1980-08-01

    A review is given of the technical programs carried out by the Plasma Fusion Center. The major divisions of work areas are applied plasma research, confinement experiments, fusion technology and engineering, and fusion systems. Some objectives and results of each program are described. (MOW)

  4. Kinetic simulation of a plasma collision experiment

    NASA Astrophysics Data System (ADS)

    Larroche, Olivier

    1993-08-01

    The ionic Fokker-Planck code which was written for describing plasma shock wave fronts [M. Casanova et al. Phys. Rev. Lett. 67, 2143 (1991)] is applied to model the collision of two plasmas in plane geometry. Improvements brought to the code for that purpose are described. The initial phase of the experiment during which the plasmas interpenetrate is accounted for by a simple fluid model, which yields qualitative insight into the phenomena at play as well as an initial condition to start the kinetic simulation. The kinetic results obtained in the stagnation and thermalization phases are discussed with respect to a specific laser-produced plasma collision experiment, as well as to existing fluid and kinetic (``particle-in-cell'') simulations.

  5. Research by retrieving experiments.

    PubMed

    Blagosklonny, Mikhail V

    2007-06-01

    Newton did not discover that apples fall: the information was available prior to his gravitational hypothesis. Hypotheses can be tested not only by performing experiments but also by retrieving experiments from the literature (via PubMed, for example). Here I show how disconnected facts from known data, if properly connected, can generate novel predictions testable in turn by other published data. With examples from cell cycle, aging, cancer and other fields of biology and medicine, I discuss how new knowledge was and will be derived from old information. Millions of experiments have been already performed to test unrelated hypotheses and the results of those experiments are available to 'test' your hypotheses too. But most data (99% by some estimates) remain unpublished, because they were negative, seemed of low priority, or did not fit the story. Yet for other investigators those data may be valuable. The well-known story of Franklin and Watson is a case in point. By making preliminary data widely available, 'data-owners' will benefit most, receiving the credit for otherwise unused results. If posted (pre-published) on searchable databases, these data may fuel thousands of projects without the need for repetitive experiments. Enormous 'pre-published' databases coupled with Google-like search engines can change the structure of scientific research, and shrinking funding will make this inevitable.

  6. Magnetic Flux Compression Experiments Using Plasma Armatures

    NASA Technical Reports Server (NTRS)

    Turner, M. W.; Hawk, C. W.; Litchford, R. J.

    2003-01-01

    Magnetic flux compression reaction chambers offer considerable promise for controlling the plasma flow associated with various micronuclear/chemical pulse propulsion and power schemes, primarily because they avoid thermalization with wall structures and permit multicycle operation modes. The major physical effects of concern are the diffusion of magnetic flux into the rapidly expanding plasma cloud and the development of Rayleigh-Taylor instabilities at the plasma surface, both of which can severely degrade reactor efficiency and lead to plasma-wall impact. A physical parameter of critical importance to these underlying magnetohydrodynamic (MHD) processes is the magnetic Reynolds number (R(sub m), the value of which depends upon the product of plasma electrical conductivity and velocity. Efficient flux compression requires R(sub m) less than 1, and a thorough understanding of MHD phenomena at high magnetic Reynolds numbers is essential to the reliable design and operation of practical reactors. As a means of improving this understanding, a simplified laboratory experiment has been constructed in which the plasma jet ejected from an ablative pulse plasma gun is used to investigate plasma armature interaction with magnetic fields. As a prelude to intensive study, exploratory experiments were carried out to quantify the magnetic Reynolds number characteristics of the plasma jet source. Jet velocity was deduced from time-of-flight measurements using optical probes, and electrical conductivity was measured using an inductive probing technique. Using air at 27-inHg vacuum, measured velocities approached 4.5 km/s and measured conductivities were in the range of 30 to 40 kS/m.

  7. Experiments on laser-produced plasmas and laser plasma- wall interactions

    NASA Astrophysics Data System (ADS)

    Wang, Quan

    2001-06-01

    The study of the interaction of laser-produced plasmas with a secondary wall has both practical and theoretical significance. The laser-produced plasmas are sources of highly-charged ions, fast electrons, as well as continuum and monochromatic x-ray radiation. Intense x-ray radiation also results when a nanosecond laser-produced plasma collides with a secondary wall positioned close to the target. The study of this interaction is essential to understand the laser-produced plasma expansion, shock wave formation, recombination, collisional excitation and many other transition processes. The laser plasma-wall interaction experiment has been carried out with laser pulses with vastly different time scales. In nanosecond experiment, the plasma-wall interaction was studied with varying target-wall distance. We conclude that the isothermal plasma expansion followed by the shock wave formation near the wall surface contributes to the intense x-ray radiation. We also have done some preliminary research in the femtosecond regime. We claim that the shock wave formation that plays an important role in nanosecond experiment does not play the same role in femtosecond one. We suggest that a femtosecond laser-produced plasma could be an efficient fast electron and monochromatic x- ray source. We also provide some suggestions and predictions for further investigations.

  8. Results from Plasma Wakefield Experiments at FACET

    SciTech Connect

    Li, S.Z.; Clarke, C.I.; England, R.J.; Frederico, J.; Gessner, S.J.; Hogan, M.J.; Jobe, R.K.; Litos, M.D.; Walz, D.R.; Muggli, P.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; Adli, E.; /U. Oslo

    2011-12-13

    We report initial results of the Plasma Wakefield Acceleration (PWFA) Experiments performed at FACET - Facility for Advanced aCcelertor Experimental Tests at SLAC National Accelerator Laboratory. At FACET a 23 GeV electron beam with 1.8 x 10{sup 10} electrons is compressed to 20 {mu}m longitudinally and focused down to 10 {mu}m x 10 {mu}m transverse spot size for user driven experiments. Construction of the FACET facility completed in May 2011 with a first run of user assisted commissioning throughout the summer. The first PWFA experiments will use single electron bunches combined with a high density lithium plasma to produce accelerating gradients > 10 GeV/m benchmarking the FACET beam and the newly installed experimental hardware. Future plans for further study of plasma wakefield acceleration will be reviewed. The experimental hardware and operation of the plasma heat-pipe oven have been successfully commissioned. Plasma wakefield acceleration was not observed because the electron bunch density was insufficient to ionize the lithium vapor. The remaining commissioning time in summer 2011 will be dedicated to delivering the FACET design parameters for the experimental programs which will begin in early 2012. PWFA experiments require the shorter bunches and smaller transverse sizes to create the plasma and drive large amplitude wakefields. Low emittance and high energy will minimize head erosion which was found to be a limiting factor in acceleration distance and energy gain. We will run the PWFA experiments with the design single bunch conditions in early 2012. Future PWFA experiments at FACET are discussed in [5][6] and include drive and witness bunch production for high energy beam manipulation, ramped bunch to optimize tranformer ratio, field-ionized cesium plasma, preionized plasmas, positron acceleration, etc.. We will install a notch collimator for two-bunch operation as well as new beam diagnostics such as the X-band TCAV [7] to resolve the two bunches

  9. Plasma Guns for the Plasma Liner Experiment (PLX)

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. D.; Bomgardner, R.; Case, A.; Messer, S. J.; Brockington, S.; Wu, L.; Elton, R.; Hsu, S. C.; Cassibry, J. T.; Gilmore, M. A.

    2009-11-01

    A spherical array of minirailgun plasma accelerators is planned for the Plasma Liner Experiment (PLX) to be located at LANL. The plasma liner would be formed via merging of 30 dense, high Mach number plasma jets (n˜10^16-17 cm-3, M˜10--35, v˜50--70 km/s, rjet˜5 cm) in a spherically convergent geometry. Small parallel-plate railguns are being developed for this purpose due to their reduced system complexity and cost, with each gun planned to operate at ˜300 kA peak current, and launching up to ˜8000 μg of high-Z plasma using a ˜50 kJ pfn. We describe experimental development of the minirailguns and their current and projected performance. Fast operating repetitive gas valves have recently been added to allow injection of high density gases including helium, argon, and (eventually) xenon. We will present the latest test results with the high-Z gases, and discuss future plans for augmenting the rails, optimizing the nozzle configuration, preionizing the injected gas, and configuring the pulse forming networks with the capacitors available to the program.

  10. Diagnostics for the plasma liner experiment.

    PubMed

    Lynn, A G; Merritt, E; Gilmore, M; Hsu, S C; Witherspoon, F D; Cassibry, J T

    2010-10-01

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical "plasma liners" via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n(i)∼10(16) cm(-3), T(e)≈T(i)∼1 eV at the plasma gun mouth to n(i)>10(19) cm(-3), T(e)≈T(i)∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  11. Diagnostics for the Plasma Liner Experiment

    SciTech Connect

    Lynn, A. G.; Merritt, E.; Gilmore, M.; Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.

    2010-10-15

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical ''plasma liners'' via merging high Mach number plasma jets to reach peak liner pressures of {approx}0.1 Mbar using {approx}1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n{sub i}{approx}10{sup 16} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}1 eV at the plasma gun mouth to n{sub i}>10{sup 19} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  12. Dusty Plasma Experiments Using an Electrodynamic Balance

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Abbas, M. M.; Suess, S. T.; Venturini, C. C.; Comfort, R. H.

    2000-01-01

    Knowledge of the formation, distribution, physical, chemical and optical characteristics of interstellar, interplanetary, and planetary dust grains provide valuable information about many issues dealing with the origin and formation of the solar system bodies, interplanetary and interstellar environments as well as various industrial processes. Understanding the microphysics of individual grains and their interaction with the surrounding environment is key to properly model various conditions and interpret existing data. The theory and models of individual dust grains are well developed for environments that vary from dense planetary atmospheres to dusty plasmas to diffuse environments such is interplanetary space. However, experimental investigations of individual dust grains in equilibrium are less common, perhaps due to the difficult of these experiments. Laboratory measurements of dust grains have primarily measured ensemble properties or transient properties of single grains. A technique developed in the 1950's for ion spectroscopy, known as a quadrupole trap or 'Paul Trap', has recently been used to investigate single micron-sized dust grains. This scaled ion trap called an electrodynamic balance has been used for atmospheric aerosol research. A description of this technique is provided. Recent results from experiments to investigate the equilibrium potential of dust grains exposed to far ultraviolet light or to -,in electron or ion beam are presented. This laboratory technique ]ends itself to many applications that relate to planetary atmospheres, heliospheric environments, pre-stellar and pre-planetary conditions, and industrial settings. Several planned experimental approaches are presented. Potential experiments to investigate the interaction of multiple dust grains using an electrodynamic balance are proposed.

  13. Dusty Plasma Experiments Using an Electrodynamic Balance

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Abbas, M. M.; Suess, S. T.; Venturini, C. C.; Comfort, R. H.

    2000-01-01

    Knowledge of the formation, distribution, physical, chemical and optical characteristics of interstellar, interplanetary, and planetary dust grains provide valuable information about many issues dealing with the origin and formation of the solar system bodies, interplanetary and interstellar environments as well as various industrial processes. Understanding the microphysics of individual grains and their interaction with the surrounding environment is key to properly model various conditions and interpret existing data. The theory and models of individual dust grains are well developed for environments that vary from dense planetary atmospheres to dusty plasmas to diffuse environments such is interplanetary space. However, experimental investigations of individual dust grains in equilibrium are less common, perhaps due to the difficult of these experiments. Laboratory measurements of dust grains have primarily measured ensemble properties or transient properties of single grains. A technique developed in the 1950's for ion spectroscopy, known as a quadrupole trap or 'Paul Trap', has recently been used to investigate single micron-sized dust grains. This scaled ion trap called an electrodynamic balance has been used for atmospheric aerosol research. A description of this technique is provided. Recent results from experiments to investigate the equilibrium potential of dust grains exposed to far ultraviolet light or to -,in electron or ion beam are presented. This laboratory technique ]ends itself to many applications that relate to planetary atmospheres, heliospheric environments, pre-stellar and pre-planetary conditions, and industrial settings. Several planned experimental approaches are presented. Potential experiments to investigate the interaction of multiple dust grains using an electrodynamic balance are proposed.

  14. Space plasma contactor research, 1987

    NASA Technical Reports Server (NTRS)

    Wilbur, Paul J.

    1988-01-01

    A simple model describing the process of electron collection from a low pressure ambient plasma in the absence of magnetic field and contactor velocity effects is presented. Experimental measurments of the plasma surrounding the contactor are used to demonstrate that a double-sheath generally develops and separates the ambient plasma from a higher density, anode plasma located adjacent to the contactor. Agreement between the predictions of the model and experimental measurements obtained at the electron collection current levels ranging to 1 A suggests the surface area at the ambient plasma boundary of the double-sheath is equal to the electron current being collected divided by the ambient plasma random electron current density; the surface area of the higher density anode plasma boundary of the double-sheath is equal to the ion current being emitted across this boundary divided by the ion current density required to sustain a stable sheath; and the voltage drop across the sheath is determined by the requirement that the ion and electron currents counterflowing across the boundaries be at space-charge limited levels. The efficiency of contactor operation is shown to improve when significant ionization and excitation is induced by electrons that stream from the ambient plasma through the double-sheath and collide with neutral atoms being supplied through the hollow cathode.

  15. SPDE: Solar Plasma Diagnostic Experiment

    NASA Technical Reports Server (NTRS)

    Bruner, Marilyn E.

    1995-01-01

    The physics of the Solar corona is studied through the use of high resolution soft x-ray spectroscopy and high resolution ultraviolet imagery. The investigation includes the development and application of a flight instrument, first flown in May, 1992 on NASA sounding rocket 36.048. A second flight, NASA founding rocket 36.123, took place on 25 April 1994. Both flights were successful in recording new observations relevant to the investigation. The effort in this contract covers completion of the modifications to the existing rocket payload, its reflight, and the preliminary day reduction and analysis. Experience gained from flight 36.048 led us to plan several payload design modifications. These were made to improve the sensitivity balance between the UV and EUV spectrographs, to improve the scattered light rejection in the spectrographs, to protect the visible light rejection filter for the Normal Incidence X-ray Imager instrument (NIXI), and to prepare one new multilayer mirror coating to the NIXI. We also investigated the addition of a brassboard CCD camera to the payload to test it as a possible replacement for the Eastman type 101-07 film used by the SPDE instruments. This camera was included in the experimeter's data package for the Project Initiation Conference for the flight of NASA Mission 36.123, held in January, 1994, but for programmatic reasons was deleted from the final payload configuration. The payload was shipped to the White Sands Missile Range on schedule in early April. The launch and successful recovery took place on 25 April, in coordination with the Yohkoh satellite and a supporting ground-based observing campaign.

  16. SPDE: Solar Plasma Diagnostic Experiment

    NASA Astrophysics Data System (ADS)

    Bruner, Marilyn E.

    1995-09-01

    The physics of the Solar corona is studied through the use of high resolution soft x-ray spectroscopy and high resolution ultraviolet imagery. The investigation includes the development and application of a flight instrument, first flown in May, 1992 on NASA sounding rocket 36.048. A second flight, NASA founding rocket 36.123, took place on 25 April 1994. Both flights were successful in recording new observations relevant to the investigation. The effort in this contract covers completion of the modifications to the existing rocket payload, its reflight, and the preliminary day reduction and analysis. Experience gained from flight 36.048 led us to plan several payload design modifications. These were made to improve the sensitivity balance between the UV and EUV spectrographs, to improve the scattered light rejection in the spectrographs, to protect the visible light rejection filter for the Normal Incidence X-ray Imager instrument (NIXI), and to prepare one new multilayer mirror coating to the NIXI. We also investigated the addition of a brassboard CCD camera to the payload to test it as a possible replacement for the Eastman type 101-07 film used by the SPDE instruments. This camera was included in the experimeter's data package for the Project Initiation Conference for the flight of NASA Mission 36.123, held in January, 1994, but for programmatic reasons was deleted from the final payload configuration. The payload was shipped to the White Sands Missile Range on schedule in early April. The launch and successful recovery took place on 25 April, in coordination with the Yohkoh satellite and a supporting ground-based observing campaign.

  17. Plasma Crystal-3 Plus experiment Chamber Leak Check

    NASA Image and Video Library

    2010-07-01

    ISS024-E-007144 (1 July 2010) --- Russian cosmonaut Alexander Skvortsov, Expedition 24 commander, performs chamber leak checks on the new Plasma Crystal-3 Plus experiment in the Poisk Mini-Research Module 2 (MRM2) of the International Space Station.

  18. Plasmas as Antennas - Theory, Experiment and Applications

    NASA Astrophysics Data System (ADS)

    Borg, Gerard

    1999-11-01

    A variety of antennas are employed in telecommunications and radar systems. Some applications pose special problems. Large structures are easily detected by hostile radar. The performance of multi-element HF-VHF arrays is complicated by mutual coupling between large radiating elements. High speed data communications and radar can be limited by signal decay and ringing. A novel solution is an antenna made of plasma that can be made to disappear on microsecond time scales. Recent experiments at the Australian National University (G.G. Borg et. al. App. Phys. Letts. Vol. 74, 3272-3274 [1999]), have shown that highly efficient (25 - 50radiating elements for the range 3 - 300 MHz can be formed using low power (10 - 50 W average) plasma surface waves launched at one end of a tube containing a suitable gas. Only a single capacitive coupler is needed to launch the waves - there is no electrical connection to the other end of the tube. The regimes of wave propagation correlate with expectations from plasma surface wave theory. Actual communications experiments have shown that these plasma antennas can have surprisingly low noise provided they are excited by the rf surface waves and not by a low frequency or DC ohmic current. Applications to HF-VHF communications and radar are being developed. These include both single ruggedised plasma elements and multi-element arrays.

  19. Magnetic Nozzle and Plasma Detachment Experiment

    NASA Technical Reports Server (NTRS)

    Chavers, Gregory; Dobson, Chris; Jones, Jonathan; Martin, Adam; Bengtson, Roger D.; Briezman, Boris; Arefiev, Alexey; Cassibry, Jason; Shuttpelz, Branwen; Deline, Christopher

    2006-01-01

    High power plasma propulsion can move large payloads for orbit transfer (such as the ISS), lunar missions, and beyond with large savings in fuel consumption owing to the high specific impulse. At high power, lifetime of the thruster becomes an issue. Electrodeless devices with magnetically guided plasma offer the advantage of long life since magnetic fields confine the plasma radially and keep it from impacting the material surfaces. For decades, concerns have been raised about the plasma remaining attached to the magnetic field and returning to the vehicle along the closed magnetic field lines. Recent analysis suggests that this may not be an issue of the magnetic field is properly shaped in the nozzle region and the plasma has sufficient energy density to stretch the magnetic field downstream. An experiment was performed to test the theory regarding the Magneto-hydrodynamic (MHD) detachment scenario. Data from this experiment will be presented. The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) being developed by the Ad Astra Rocket Company uses a magnetic nozzle as described above. The VASIMR is also a leading candidate for exploiting an electric propulsion test platform being considered for the ISS.

  20. Fusion ignition research experiment

    SciTech Connect

    Dale Meade

    2000-07-18

    Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.

  1. Effect of Electron Energy Distribution on the Hysteresis of Plasma Discharge: Theory, Experiment, and Modeling

    NASA Astrophysics Data System (ADS)

    Lee, Hyo-Chang; Chung, Chin-Wook

    2016-09-01

    Hysteresis, which is the history dependence of physical systems, indicates that there are more-than-two stable points in a given condition, and it has been considered to one of the most important topics in fundamental physics. Recently, the hysteresis of plasma has become a focus of research because stable plasma operation is very important for fusion reactors, bio-medical plasmas, and industrial plasmas for nano-device fabrication process. Interestingly, the bi-stability characteristics of plasma with a huge hysteresis loop have been observed in inductive discharge plasmas Because hysteresis study in such plasmas can provide a universal understanding of plasma physics, many researchers have attempted experimental and theoretical studies. Despite long plasma research, how this plasma hysteresis occurs remains an unresolved question in plasma physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the electron energy distribution (EED) makes a strong plasma hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the plasma hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the plasma balance model where the EED is considered. Because electrons in plasmas are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in plasma physics. This research was partially supported by Korea Research Institute of Standard and Science.

  2. Plasma Wave Observations during Ion Gun Experiments

    DTIC Science & Technology

    1990-03-20

    Spacecraft Charging by Magnetospheric Plasma , Progress in Aeronautics and Astronautics , Vol. 47, ed. A. Rosen, IAA, pp. 15-30 (1976). 3. H. C. Koons, P. F...AIAA 75-92 (January 20-22, 1975). 2. D. A. McPherson and W. R. Schober, " Spacecraft Charging at High Altitudes: The SCATHA Satellite Program," in...on the AF/NASI P78-2 (SCATHA) satellite were conducted with a plasma /ion source in the inner magnetosphere . These experiments were monitored with

  3. Plasma arc cutting technology: simulation and experiments

    NASA Astrophysics Data System (ADS)

    Cantoro, G.; Colombo, V.; Concetti, A.; Ghedini, E.; Sanibondi, P.; Zinzani, F.; Rotundo, F.; Dallavalle, S.; Vancini, M.

    2011-01-01

    Transferred arc plasma torches are widely used in industrial processes for cutting of metallic materials because of their ability to cut a wide range of metals with very high productivity. The process is characterized by a transferred electric arc established between an electrode inside the torch (the cathode) and another electrode, the metallic workpiece to be cut (the anode). In order to obtain a high quality cut and a high productivity, the plasma jet must be as collimated as possible and must have the higher achievable power density. Plasma modelling and numerical simulation can be very useful tools for the designing and optimizing these devices, but research is still in the making for finding a link between simulation of the plasma arc and a consistent prevision of cut quality. Numerical modelling of the behaviour of different types of transferred arc dual gas plasma torches can give an insight on the physical reasons for the industrial success of various design and process solutions that have appeared over the last years. Diagnostics based on high speed imaging and Schlieren photography can play an important role for investigating piercing, dross generation, pilot arcing and anode attachment location. Also, the behaviour of hafnium cathodes at high current levels at the beginning of their service life can been experimentally investigated, with the final aim of understanding the phenomena that take place during those initial piercing and cutting phases and optimizing the initial shape of the surface of the emissive insert exposed to plasma atmosphere.

  4. Plasma focus experiments powered by explosive generators

    NASA Astrophysics Data System (ADS)

    Freeman, B. L.; Caird, R. S.; Erickson, D. J.; Fowler, C. M.; Garn, W. B.; Kruse, H. W.; King, J. C.; Bartram, D. E.; Kruse, P. J.

    1983-03-01

    The plasma focus project began as an effort to develop an intense, pulsed, expendable neutron radiographic source. Since previous efforts to power a plasma focus with explosive generators were successful, we proposed to couple plate generators to a coaxial-geometry plasma focus to achieve this goal. Utilizing a small capacitor bank and a selected set of diagnostics, the explosive experiments were successfully conducted with maximum currents of 1.5 MA to 2.4 MA. A maximum neutron yield of approx. 3 x 10 (11) (DD) neutrons was achieved at the 2.4 MA level. Since the neutron yield did scale as a power of the maximum delivered current, and the neutron-producing source region was small, this approach is an attractive option to achieve a neutron radiographic source. The need for a reliable open-circuiting switch at several megamperes has resulted in postponement of the project.

  5. Electron--positron beam--plasma experiments

    NASA Astrophysics Data System (ADS)

    Gilbert, S. J.; Kurz, C. K.; Greaves, R. G.; Surko, C. M.

    1997-11-01

    Electron-positron plasmas possess unique properties due to inherent symmetries between the charge species. The ability to accumulate large numbers of cold positrons in Penning-Malmberg traps has made the study of such plasmas possible in the laboratory.(R.G. Greaves, M.D. Tinkle and C.M. Surko, Phys. Plas.) 1 1439 (1994) In the first experiment of this type we studied a beam-plasma system by transmitting an electron beam through a positron plasma in a Penning trap.(R.G. Greaves and C.M. Surko, Phys. Rev. Lett.), 74 3846 (1995) These earlier measurements were obtained using a hot cathode electron source, for which the large beam energy spreads ( ~ 0.5 eV) made it impossible to explore the low energy regime of this beam-plasma system, where the strongest interaction occurs. We report new growth rate measurements obtained using a novel low-energy, cold (Δ E ≈ 0.05 eV) electron beam based on the extraction of electrons stored in a Penning trap.(S.J. Gilbert et al.), Appl. Phys. Lett., 70 1944 (1997). The measured growth rates for a transit time instability are found to be in excellent agreement with a cold fluid theory by D.H.E. Dubin over the range of accessible energies (0.1--3 eV).

  6. Plasma Position Diagnostics for the Ignitor Experiment

    NASA Astrophysics Data System (ADS)

    Pizzicaroli, G.; Alladio, F.; Bombarda, F.; Licciulli, A.; Fersini, M.; Diso, D.; Paulicelli, E.

    2007-11-01

    Prototype coils of the electromagnetic diagnostics for the Ignitor experiment have been manufactured adopting innovative methods to improve the ceramic insulator resilience to neutron and gamma radiation. Thus, real time plasma position measurements should be possible over a broader range of high performance plasma regimes with D-D and D-T fuel. An alternative method is under study to provide the necessary spatial information also at the highest parameters that the Ignitor experiment can achieve (BT˜13 T, Ip˜11 MA, neutron yield˜3x10^19 n/s), where the electromagnetic diagnostics may fail. The new instrument is based on the diffraction and detection of the soft X-ray radiation emitted at the plasma edge. Gas Electron Multiplier (GEM) detectors are considered as the best candidates to provide signals with high counting rates (>1 MHz) and high S/N ratios, to be used by the control systemootnotetextD. Pacella, et al, Nucl. Instr. Meth. A 508, 414 (2003). A curved Multilayer Mirror placed inside one of the equatorial ports will diffract the radiation onto a properly shielded GEM detector that is located outside the machine vacuum and not in direct view of the plasma.

  7. Laboratory plasma physics experiments using merging supersonic plasma jets

    DOE PAGES

    Hsu, S. C.; Moser, A. L.; Merritt, E. C.; ...

    2015-04-01

    We describe a laboratory plasma physics experiment at Los Alamos National Laboratory that uses two merging supersonic plasma jets formed and launched by pulsed-power-driven railguns. The jets can be formed using any atomic species or mixture available in a compressed-gas bottle and have the following nominal initial parameters at the railgun nozzle exit: ne ≈ ni ~ 10¹⁶ cm⁻³, Te ≈ Ti ≈ 1.4 eV, Vjet ≈ 30–100 km/s, mean chargemore » $$\\bar{Z}$$ ≈ 1, sonic Mach number Ms ≡ Vjet/Cs > 10, jet diameter = 5 cm, and jet length ≈ 20 cm. Experiments to date have focused on the study of merging-jet dynamics and the shocks that form as a result of the interaction, in both collisional and collisionless regimes with respect to the inter-jet classical ion mean free path, and with and without an applied magnetic field. However, many other studies are also possible, as discussed in this paper.« less

  8. Laboratory plasma physics experiments using merging supersonic plasma jets

    SciTech Connect

    Hsu, S. C.; Moser, A. L.; Merritt, E. C.; Adams, C. S.; Dunn, J. P.; Brockington, S.; Case, A.; Gilmore, M.; Lynn, A. G.; Messer, S. J.; Witherspoon, F. D.

    2015-04-01

    We describe a laboratory plasma physics experiment at Los Alamos National Laboratory that uses two merging supersonic plasma jets formed and launched by pulsed-power-driven railguns. The jets can be formed using any atomic species or mixture available in a compressed-gas bottle and have the following nominal initial parameters at the railgun nozzle exit: ne ≈ ni ~ 10¹⁶ cm⁻³, Te ≈ Ti ≈ 1.4 eV, Vjet ≈ 30–100 km/s, mean charge $\\bar{Z}$ ≈ 1, sonic Mach number Ms ≡ Vjet/Cs > 10, jet diameter = 5 cm, and jet length ≈ 20 cm. Experiments to date have focused on the study of merging-jet dynamics and the shocks that form as a result of the interaction, in both collisional and collisionless regimes with respect to the inter-jet classical ion mean free path, and with and without an applied magnetic field. However, many other studies are also possible, as discussed in this paper.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Alpha-particle Measurements Needed for Burning Plasma Experiments

    SciTech Connect

    Kenneth M. Young

    2001-09-26

    The next major step in magnetic fusion studies will be the construction of a burning plasma (BP) experiment where the goals will be to achieve and understand the plasma behavior with the internal heating provided by fusion-generated alpha particles. Two devices with these physics goals have been proposed: the International Thermonuclear Experimental Reactor (ITER) and the Fusion Ignition Research Experiment (FIRE). Extensive conceptual design work for the instrumentation to try to meet the physics demands has been done for these devices, especially ITER. This article provides a new look at the measurements specifically important for understanding the physics aspects of the alpha particles taking into account two significant events. The first is the completion of physics experiments on the Joint European Torus (JET) and the Tokamak Fusion Test Reactor (TFTR) with deuterium-tritium fueling with the first chances to study alpha physics and the second is the realization that relatively compact plasmas, making use of advanced tokamak plasma concepts, are the most probable route to burning plasmas and ultimately a fusion reactor.

  11. Telescience operations with the solar array module plasma interaction experiment

    SciTech Connect

    Wald, L.W.; Bibyk, I.K.

    1995-09-01

    The Solar Array Module Plasma Interactions Experiment (SAMPIE) is a flight experiment that flew on the Space Shuttle Columbia (STS-62) in March 1994, as part of the OAST-2 mission. The overall objective of SAMPIE was to determine the adverse environmental interactions within the space plasma of low earth orbit (LEO) on modern solar cells and space power system materials which are artificially biased to high positive and negative direct current (DC) voltages. The two environmental interactions of interest included high voltage arcing from the samples to the space plasma and parasitic current losses. High voltage arcing can cause physical damage to power system materials and shorten expected hardware life. Parasitic current losses can reduce power system efficiency because electric currents generated in a power system drain into the surrounding plasma via parasitic resistance. The flight electronics included two programmable high voltage DC power supplies to bias the experiment samples, instruments to measure the surrounding plasma environment in the STS cargo bay, and the on-board data acquisition system (DAS). The DAS provided in-flight experiment control, data storage, and communications through the Goddard Space Flight Center (GSFC) Hitchhiker flight avionics to the GSFC Payload Operations Control Center (POCC). The DAS and the SAMPIE POCC computer systems were designed for telescience operations; this paper will focus on the experiences of the SAMPIE team regarding telescience development and operations from the GSFC POCC during STS-62. The SAMPIE conceptual development, hardware design, and system verification testing were accomplished at the NASA Lewis Research Center (LeRC). SAMPIE was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology.

  12. Telescience operations with the solar array module plasma interaction experiment

    NASA Technical Reports Server (NTRS)

    Wald, Lawrence W.; Bibyk, Irene K.

    1995-01-01

    The Solar Array Module Plasma Interactions Experiment (SAMPIE) is a flight experiment that flew on the Space Shuttle Columbia (STS-62) in March 1994, as part of the OAST-2 mission. The overall objective of SAMPIE was to determine the adverse environmental interactions within the space plasma of low earth orbit (LEO) on modern solar cells and space power system materials which are artificially biased to high positive and negative direct current (DC) voltages. The two environmental interactions of interest included high voltage arcing from the samples to the space plasma and parasitic current losses. High voltage arcing can cause physical damage to power system materials and shorten expected hardware life. parasitic current losses can reduce power system efficiency because electric currents generated in a power system drain into the surrounding plasma via parasitic resistance. The flight electronics included two programmable high voltage DC power supplies to bias the experiment samples, instruments to measure the surrounding plasma environment in the STS cargo bay, and the on-board data acquisition system (DAS). The DAS provided in-flight experiment control, data storage, and communications through the Goddard Space Flight Center (GSFC) Hitchhiker flight avionics to the GSFC Payload Operations Control Center (POCC). The DAS and the SAMPIE POCC computer systems were designed for telescience operations; this paper will focus on the experiences of the SAMPIE team regarding telescience development and operations from the GSFC POCC during STS-62. The SAMPIE conceptual development, hardware design, and system verification testing were accomplished at the NASA Lewis Research Center (LeRC). SAMPIE was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology. The IN-STEP Program is sponsored by the Office of Space Access and Technology (OSAT).

  13. Effect of Electron Energy Distribution on the Hysteresis of Plasma Discharge: Theory, Experiment, and Modeling

    PubMed Central

    Lee, Hyo-Chang; Chung, Chin-Wook

    2015-01-01

    Hysteresis, which is the history dependence of physical systems, is one of the most important topics in physics. Interestingly, bi-stability of plasma with a huge hysteresis loop has been observed in inductive plasma discharges. Despite long plasma research, how this plasma hysteresis occurs remains an unresolved question in plasma physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the electron energy distribution (EED) makes a strong plasma hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the plasma hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the plasma balance model where the EED is considered. Because electrons in plasmas are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in plasma physics. PMID:26482650

  14. Effect of Electron Energy Distribution on the Hysteresis of Plasma Discharge: Theory, Experiment, and Modeling

    NASA Astrophysics Data System (ADS)

    Lee, Hyo-Chang; Chung, Chin-Wook

    2015-10-01

    Hysteresis, which is the history dependence of physical systems, is one of the most important topics in physics. Interestingly, bi-stability of plasma with a huge hysteresis loop has been observed in inductive plasma discharges. Despite long plasma research, how this plasma hysteresis occurs remains an unresolved question in plasma physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the electron energy distribution (EED) makes a strong plasma hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the plasma hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the plasma balance model where the EED is considered. Because electrons in plasmas are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in plasma physics.

  15. Effect of Electron Energy Distribution on the Hysteresis of Plasma Discharge: Theory, Experiment, and Modeling.

    PubMed

    Lee, Hyo-Chang; Chung, Chin-Wook

    2015-10-20

    Hysteresis, which is the history dependence of physical systems, is one of the most important topics in physics. Interestingly, bi-stability of plasma with a huge hysteresis loop has been observed in inductive plasma discharges. Despite long plasma research, how this plasma hysteresis occurs remains an unresolved question in plasma physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the electron energy distribution (EED) makes a strong plasma hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the plasma hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the plasma balance model where the EED is considered. Because electrons in plasmas are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in plasma physics.

  16. Megajoule Dense Plasma Focus Solid Target Experiments

    NASA Astrophysics Data System (ADS)

    Podpaly, Y. A.; Falabella, S.; Link, A.; Povilus, A.; Higginson, D. P.; Shaw, B. H.; Cooper, C. M.; Chapman, S.; Bennett, N.; Sipe, N.; Olson, R.; Schmidt, A. E.

    2016-10-01

    Dense plasma focus (DPF) devices are plasma sources that can produce significant neutron yields from beam into gas interactions. Yield increases, up to approximately a factor of five, have been observed previously on DPFs using solid targets, such as CD2 and D2O ice. In this work, we report on deuterium solid-target experiments at the Gemini DPF. A rotatable target holder and baffle arrangement were installed in the Gemini device which allowed four targets to be deployed sequentially without breaking vacuum. Solid targets of titanium deuteride were installed and systematically studied at a variety of fill pressures, bias voltages, and target positions. Target holder design, experimental results, and comparison to simulations will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

  17. Perspectives on research and education of space plasma physics

    NASA Astrophysics Data System (ADS)

    Koskinen, Hannu

    Aspects of the long tradition of Finnish research into space plasma physics are outlined. The development of the Aspera instrument (a plasma analyzer of Phobos), manufactured by Sweden and Finland, is viewed as an important achievement. The Aspera instrument was flown onboard a Soviet Phobos spacecraft for the purpose of making plasma measurements. Finnish contributions to several international programs, including Cluster, the Energetic and Relativistic Nuclear and Electron (ERNE) particle analyzer, the European Incoherent Scatter Radar (EISCAT) system, and the Scandinavian Twin Auroral Radar Experiment (STARE) are recalled.

  18. DHS Research Experience Summary

    SciTech Connect

    Venkatachalam, V

    2008-10-24

    I learned a great deal during my summer internship at Lawrence Livermore National Laboratory (LLNL). I plan to continue a career in research, and I feel that my experience at LLNL has been formative. I was exposed to a new area of research, as part of the Single Particle Aerosol Mass Spectrometry (SPAMS) group, and I had the opportunity to work on projects that I would not have been able to work on anywhere else. The projects both involved the use of a novel mass spectrometer that was developed at LLNL, so I would not have been able to do this research at any other facility. The first project that Zachary and I worked on involved using SPAMS to detect pesticides. The ability to rapidly detect pesticides in a variety of matrices is applicable to many fields including public health, homeland security, and environmental protection. Real-time, or near real-time, detection of potentially harmful or toxic chemical agents can offer significant advantages in the protection of public health from accidental or intentional releases of harmful pesticides, and can help to monitor the environmental effects of controlled releases of pesticides for pest control purposes. The use of organophosphate neurotoxins by terrorists is a possibility that has been described; this is a legitimate threat, considering the ease of access, toxicity, and relatively low cost of these substances. Single Particle Aerosol Mass Spectrometry (SPAMS) has successfully been used to identify a wide array of chemical compounds, including drugs, high explosives, biological materials, and chemical warfare agent simulants. Much of this groundbreaking work was carried out by our group at LLNL. In our work, we had the chance to show that SPAMS fulfills a demonstrated need for a method of carrying out real-time pesticide detection with minimal sample preparation. We did this by using a single particle aerosol mass spectrometer to obtain spectra of five different pesticides. Pesticide samples were chosen to

  19. Status and future of the tritium plasma experiment

    SciTech Connect

    Causey, R.A.; Buchenauer, D.; Taylor, D.; Harbin, W.; Anderl, B.

    1995-10-01

    The Tritium Plasma Experiment (TPE) has been recently upgraded and relocated at the Tritium System Test Assembly (TSTA) at Los Alamos National Laboratory. The first tritium plasma in the upgraded system was achieved on May 11, 1995. TPE is a unique facility devoted to experiments on the migration and retention of tritium in fusion reactor materials. This facility is now capable of delivering 100 to 200 eV tritons at a level of 1 A/cm{sup 2} to a 5 mm diameter sample, similar to that expected for the divertor of the International Thermonuclear Experimental Reactor (ITER). An aggressive research plan has been established, and experiments are expected to begin in June of 1995. 4 figs.

  20. Calibration of the ISEE plasma composition experiment

    NASA Technical Reports Server (NTRS)

    Baugher, C. R.; Olsen, R. C.; Reasoner, D. L.

    1986-01-01

    The Plasma Composition experiment on the ISEE-1 satellite was designed to measure ions from 1 to 16 amu, at energies from near zero to 16 keV. The two nearly identical flight instruments were calibrated by means of preflight laboratory tests and in-flight data comparisons. This document presents most of the details of those efforts, with special emphasis on the low energy (0 to 100 eV) portion of the instrument response. The analysis of the instrument includes a ray-tracing calculation, which follows an ensemble of test particles through the detector.

  1. Plasma Experiment for Planetary Exploration (PEPE)

    NASA Astrophysics Data System (ADS)

    Young, D. T.; Nordholt, J. E.; Burch, J. L.; McComas, D. J.; Bowman, R. P.; Abeyta, R. A.; Alexander, J.; Baldonado, J.; Barker, P.; Black, R. K.; Booker, T. L.; Casey, P. J.; Cope, L.; Crary, F. J.; Cravens, J. P.; Funsten, H. O.; Goldstein, R.; Guerrero, D. R.; Hahn, S. F.; Hanley, J. J.; Henneke, B. P.; Horton, E. F.; Lawrence, D. J.; McCabe, K. P.; Reisenfeld, D.; Salazar, R. P.; Shappirio, M.; Storms, S. A.; Urdiales, C.; Waite, J. H.

    2007-04-01

    The Plasma Experiment for Planetary Exploration (PEPE) flown on Deep Space 1 combines an ion mass spectrometer and an electron spectrometer in a single, low-resource instrument. Among its novel features PEPE incorporates an electrostatically swept field-of-view and a linear electric field time-of-flight mass spectrometer. A significant amount of effort went into developing six novel technologies that helped reduce instrument mass to 5.5 kg and average power to 9.6 W. PEPE’s performance was demonstrated successfully by extensive measurements made in the solar wind and during the DS1 encounter with Comet 19P/Borrelly in September 2001.

  2. Research Experiences for Undergraduates.

    ERIC Educational Resources Information Center

    Rettig, Terrence W.; And Others

    1990-01-01

    Reviewed are six programs at different colleges and universities which provide research opportunities for undergraduate students in physics, astronomy, marine biology, meteorology, and anthropology. Background, features, and accomplishments of the programs are discussed. (CW)

  3. Research Experiences for Undergraduates.

    ERIC Educational Resources Information Center

    Rettig, Terrence W.; And Others

    1990-01-01

    Reviewed are six programs at different colleges and universities which provide research opportunities for undergraduate students in physics, astronomy, marine biology, meteorology, and anthropology. Background, features, and accomplishments of the programs are discussed. (CW)

  4. Research in solar plasma theory

    NASA Technical Reports Server (NTRS)

    Vanhoven, Gerard

    1992-01-01

    The main thrust and significance of our research results are presented. The topics covered include: (1) coronal structure and dynamics; (2) coronal heating; (3) filament formation; and (4) flare energy release.

  5. Neon photoionized plasma experiment at Z

    NASA Astrophysics Data System (ADS)

    Mayes, D. C.; Mancini, R. C.; Bailey, J. E.; Loisel, G. P.; Rochau, G. A.

    2016-10-01

    We discuss an experimental effort to study the atomic kinetics in neon photoionized plasmas via K-shell line absorption spectroscopy. The experiment employs the intense x-ray flux emitted at the collapse of a Z-pinch to heat and backlight a photoionized plasma contained within a cm-scale gas cell placed at various distances from the Z-pinch and filled with neon gas pressures in the range from 3.5 to 30 torr. The experimental platform affords an order of magnitude range in the ionization parameter characterizing the photoionized plasma from about 3 to 80 erg*cm/s. An x-ray crystal spectrometer capable of collecting both time-integrated and time-gated spectra is used to collect absorption spectra. A suite of IDL programs has been developed to process the experimental data to produce transmission spectra. The spectra show line absorption by several ionization stages of neon, including Be-, Li-, He-, and H-like ions. Analysis of these spectra yields ion areal-densities and charge state distributions, which can be compared with results from atomic kinetics codes. In addition, the electron temperature is extracted from level population ratios of nearby energy levels in Li- and Be-like ions, which can be used to test heating models of photoionized plasmas. This work was sponsored in part by the DOE National Nuclear Security Administration Grant DE-FG52-09NA29551, DOE Office of Science Grant DE-SC0014451, and the Z Facility Fundamental Science Program of SNL.

  6. Interactive Plasma Physics Education Using Data from Fusion Experiments

    NASA Astrophysics Data System (ADS)

    Calderon, Brisa; Davis, Bill; Zwicker, Andrew

    2010-11-01

    The Internet Plasma Physics Education Experience (IPPEX) website was created in 1996 to give users access to data from plasma and fusion experiments. Interactive material on electricity, magnetism, matter, and energy was presented to generate interest and prepare users to understand data from a fusion experiment. Initially, users were allowed to analyze real-time and archival data from the Tokamak Fusion Test Reactor (TFTR) experiment. IPPEX won numerous awards for its novel approach of allowing users to participate in ongoing research. However, the latest revisions of IPPEX were in 2001 and the interactive material is no longer functional on modern browsers. Also, access to real-time data was lost when TFTR was shut down. The interactive material on IPPEX is being rewritten in ActionScript3.0, and real-time and archival data from the National Spherical Tokamak Experiment (NSTX) will be made available to users. New tools like EFIT animations, fast cameras, and plots of important plasma parameters will be included along with an existing Java-based ``virtual tokamak.'' Screenshots from the upgraded website and future directions will be presented.

  7. Plasma Interaction Experiment (PIX) flight results

    NASA Technical Reports Server (NTRS)

    Grier, N. T.; Stevens, N. J.

    1979-01-01

    An auxiliary payload package called PIX (plasma interaction experiment) was launched on March 5, 1978, on the LANDSAT 3 launch vehicle to study interactions between the space charged-particle environment and surfaces at high applied positive and negative voltages. Three experimental surfaces were used in this package: a plain disk to act as a control, a disk on a Kapton sheet to determine the effect of surrounding insulation on current collection, and a small solar-array segment to evaluate the effect of distributing biased surfaces among an array of insulators. Only half of the results from the 4 hours of PIX operations were recovered. The results did verify effects found in ground simulation testing. The results of this experiment are discussed in detail.

  8. Experiments with laser driven plasma jets

    NASA Astrophysics Data System (ADS)

    Nicolai, Philippe

    2008-04-01

    Laboratory studies can address issues relevant to astrophysics^1 and in some cases improve our understanding of the physical processes that occur in astrophysical objects. So issues related to the jet propagation and collimation over considerable distance and their interactions with surrounding media have begun to be addressed these last years. Laboratory plasmas and astrophysical objects have different length, time and density scales. However, the typical velocities are the same, of a few hundred km/s and the similarity criteria^2 can be applied to scale the laboratory jets to astrophysical conditions. In this presentation, we use a method of jet formation^3 which allows to launch a very fast jet having a velocity around 400 km/s by using a relatively small laser energy, of the order of 100 J. The jet has a Mach number greater than 10, a length of a few mm, and a radius of a few tenths of mm. The interaction of these jets with a gas puff has been recently studied in an experiment carried out at the PALS laser facility. Varying gas pressure and composition, we show that the nature of interaction zone changes from a quasi adiabatic outflow to a strongly radiatively cooling jet. The use of various diagnostics, allows to relate the x-ray emission to the density map of the interaction zone. Already observed in astrophysical objets for strongly different time and space scales, these structures are interpreted in our laboratory experiment by using a semi-analytical model and 2D radiation hydrodynamic simulations. [1] B. Remington et al, Rev. Mod. Phys. 78, 755 (2007) [2] D. Ryutov et al, Phys . Plasmas 8, 1804 (2001) [3] Ph. Nicolai et al, Phys. Plasmas 13, 062701 (2007)

  9. Research in Pulsed Power Plasma Physics

    DTIC Science & Technology

    1993-11-01

    performance into diode loads, leading to the development of a new (and now generally accepted) model of switch behavior. In this final report , all...i~ j O-eaAV,-A274 32 JAW C R I I Research In Pulsed Power Plasma Physics I DTIC ELECTE Final Report JAN 03 1994 November, 1993 A Prepared by: I David...Pulsed Power Plasma PhysicsI I Final Report 1 November, 1993 I Prepared by: I David Hinshelwood David Rose Prepared for: Naval Research Laboratory 4555

  10. Intervention research: GAO experiences.

    PubMed

    Grasso, P G

    1996-04-01

    This paper describes tools of program evaluation that may prove useful in conducting research on occupational health and safety interventions. It presents examples of three studies conducted by the U.S. General Accounting Office that illustrate a variety of techniques for collecting and analyzing data on program interventions, including analysis of extant data, synthesis of results of existing studies, and combining data from administrative files with survey results. At the same time, it stresses the importance and difficulty of constructing an adequate "theory" of how the intervention is expected to affect outcomes, both for guiding data collection and for allowing adequate interpretation of results.

  11. Fundamental Complex Plasma Research on Ground and under Microgravity Conditions

    NASA Astrophysics Data System (ADS)

    Thomas, Hubertus; Fortov, Vladimir; Thoma, Markus; Pustylnik, Mikhail; Lipaev, Andrey; Morfill, Gregor; Molotkov, Vladimir; Usachev, Alexander; Nosenko, Vladimir; Fink, Martin; Petrov, Oleg; Rubin-Zuzic, Milenko

    2016-07-01

    Complex (dusty) plasma is plasma containing small solid particles in the sub-mm range. Those "dust" particles are highly charged due to the collection of electrons and ions and they interact electrostatically. Depending on the charge, density, and kinetic temperature of the particles, the interaction may be strong leading to collective effects and the emergence of liquid or solid behavior. In that sense complex plasmas are perfect model systems for the investigation of fundamental processes in classical condensed matter physics since their constituent mesoscopic particles are individually observable and can be regarded as classically interacting "proxy atoms". The term "complex plasmas" is widely used in the literature to distinguish dusty plasmas composed of a weakly ionized gas and charged microparticles specially "designed" for investigations in classical condensed matter, from naturally occurring systems. Gravity influences the complex plasma, the microparticles sediment and stable systems can only be achieved through counteracting gravity with other volume forces, e.g. electric or thermophoretic force. This allows producing two-dimensional - monolayer - systems, or three-dimensional systems under stress. Only under weightlessness conditions, large and homogeneous 3D systems can be formed. Although phenomena in classical condensed matter physics are in the forefront of complex plasma research the basic know-how gained from experiments, theory and numerical simulations can be of importance for the understanding of naturally occurring dusty plasmas in space. Thus, in this presentation I will show recent work on complex plasmas from the ground and first results from the PK-4 facility onboard the International Space Station ISS. Acknowledgements: We would like to acknowledge the joint ESA-ROSCOSMOS Experiment «Plasma Kristall-4» onboard the International Space Station ISS. This work is partly supported by DLR grant 50WM1441/ 50WM1442 and by the Russian Science

  12. Plasma processing techniques for tritium inventory control in fusion research

    NASA Astrophysics Data System (ADS)

    Tabarés, F. L.; Rohde, V.; ASDEX Upgrade Team

    2004-12-01

    Some techniques with a long tradition in the plasma technology field have already been successfully applied to research in plasma wall interactions of fusion devices. They have produced important advances in the control of particle and energy exhaust. In this paper, the possible application of these techniques to the problem of tritium inventory control in fusion reactors with carbon-based plasma facing materials, as in ITER, is proposed. It is based on a critical analysis of relevant information obtained in the field of hard CN film deposition and consists of the use of chemical scavengers for the inhibition of tritium-rich carbon-film formation in hidden areas of the divertor. The practical implementation of the technique, however, requires a detailed knowledge of the physio-chemical processes involved, and, to date, experiments in cold and divertor plasmas have been performed. Very recent experiments in the ASDEX Upgrade device have shown that the injection of nitrogen in the sub-divertor region can lead to a drastic decrease in the level of deposited material with no significant effects in the performance of the main plasma. This and other findings are interpreted in the light of recent results from laboratory and divertor plasma experiments and the extrapolation to new divertor scenarios is discussed.

  13. Preliminary results on the plasma environment of Saturn from the Pioneer 11 plasma analyzer experiment

    NASA Technical Reports Server (NTRS)

    Wolfe, J. H.; Mihalov, J. D.; Collard, H. R.; Mckibbin, D. D.; Frank, L. A.; Intriligator, D. S.

    1980-01-01

    The Ames Research Center Pioneer 11 plasma analyzer experiment provided measurements of the solar wind interaction with Saturn and the character of the plasma environment within Saturn's magnetosphere. It is shown that Saturn has a detached bow shock wave and magnetopause quite similar to those at earth and Jupiter. The scale size of the interaction region for Saturn is roughly one-third that at Jupiter, but Saturn's magnetosphere is equally responsive to changes in the solar wind dynamic pressure. Saturn's outer magnetosphere is inflated, as evidenced by the observation of large fluxes of corotating plasma. It is postulated that Saturn's magnetosphere may undergo a large expansion when the solar wind pressure is greatly diminished by the presence of Jupiter's extended magnetospheric tail when the two planets are approximately aligned along the same solar radial vector.

  14. Plasma Shock Wave Modification Experiments in a Temperature Compensated Shock Tube

    NASA Technical Reports Server (NTRS)

    Vine, Frances J.; Mankowski, John J.; Saeks, Richard E.; Chow, Alan S.

    2003-01-01

    A number of researchers have observed that the intensity of a shock wave is reduced when it passes through a weakly ionized plasma. While there is little doubt that the intensity of a shock is reduced when it propagates through a weakly ionized plasma, the major question associated with the research is whether the reduction in shock wave intensity is due to the plasma or the concomitant heating of the flow by the plasma generator. The goal of this paper is to describe a temperature compensated experiment in a "large" diameter shock tube with an external heating source, used to control the temperature in the shock tube independently of the plasma density.

  15. Plasma Shock Wave Modification Experiments in a Temperature Compensated Shock Tube

    NASA Technical Reports Server (NTRS)

    Vine, Frances J.; Mankowski, John J.; Saeks, Richard E.; Chow, Alan S.

    2003-01-01

    A number of researchers have observed that the intensity of a shock wave is reduced when it passes through a weakly ionized plasma. While there is little doubt that the intensity of a shock is reduced when it propagates through a weakly ionized plasma, the major question associated with the research is whether the reduction in shock wave intensity is due to the plasma or the concomitant heating of the flow by the plasma generator. The goal of this paper is to describe a temperature compensated experiment in a "large" diameter shock tube with an external heating source, used to control the temperature in the shock tube independently of the plasma density.

  16. Electron density and plasma dynamics of a colliding plasma experiment

    SciTech Connect

    Wiechula, J. Schönlein, A.; Iberler, M.; Hock, C.; Manegold, T.; Bohlender, B.; Jacoby, J.

    2016-07-15

    We present experimental results of two head-on colliding plasma sheaths accelerated by pulsed-power-driven coaxial plasma accelerators. The measurements have been performed in a small vacuum chamber with a neutral-gas prefill of ArH{sub 2} at gas pressures between 17 Pa and 400 Pa and load voltages between 4 kV and 9 kV. As the plasma sheaths collide, the electron density is significantly increased. The electron density reaches maximum values of ≈8 ⋅ 10{sup 15} cm{sup −3} for a single accelerated plasma and a maximum value of ≈2.6 ⋅ 10{sup 16} cm{sup −3} for the plasma collision. Overall a raise of the plasma density by a factor of 1.3 to 3.8 has been achieved. A scaling behavior has been derived from the values of the electron density which shows a disproportionately high increase of the electron density of the collisional case for higher applied voltages in comparison to a single accelerated plasma. Sequences of the plasma collision have been taken, using a fast framing camera to study the plasma dynamics. These sequences indicate a maximum collision velocity of 34 km/s.

  17. The ISPM solar-wind plasma experiment

    NASA Technical Reports Server (NTRS)

    Bame, S. J.; Glore, J. P.; Mccomas, D. J.; Moore, K. R.; Chavez, J. C.; Ellis, T. J.; Peterson, G. R.; Temple, J. H.; Wymer, F. J.

    1983-01-01

    The ISPM solar wind plasma experiment accurately characterizes the bulk flow and internal state conditions of the interplanetary plasma in three dimensions at all heliographic distances and heliographic latitudes reached by the spacecraft. Solar wind electrons, protons, alpha particles, and heavier ions are measured. Oxygen, silicon, and iron ions at various charge levels are resolved. Electrons and ions are measured simultaneously with independent curved-plate electrostatic analysers equipped with multiple continuous channel electron multipliers arranged so that particle velocity distributions are suitably resolved without gaps in spacecraft polar-angle space. Electrons with energies between 1 and 900 eV are detected at 7 polar angles and various combinations of azimuth angle to cover the unit sphere comprehensively. Ions are detected between 257 eV/Q and 35 keV/Q. Data matrices are obtained every 4 min when the spacecraft is actively transmitting and every 8 min during storage periods. These matrices contain sufficient energy and angle resolution to permit detailed calculations of ion velocity distributions.

  18. Chaos in plasma simulation and experiment

    SciTech Connect

    Watts, C.; Newman, D.E.; Sprott, J.C.

    1993-09-01

    We investigate the possibility that chaos and simple determinism are governing the dynamics of reversed field pinch (RFP) plasmas using data from both numerical simulations and experiment. A large repertoire of nonlinear analysis techniques is used to identify low dimensional chaos. These tools include phase portraits and Poincard sections, correlation dimension, the spectrum of Lyapunov exponents and short term predictability. In addition, nonlinear noise reduction techniques are applied to the experimental data in an attempt to extract any underlying deterministic dynamics. Two model systems are used to simulate the plasma dynamics. These are -the DEBS code, which models global RFP dynamics, and the dissipative trapped electron mode (DTEM) model, which models drift wave turbulence. Data from both simulations show strong indications of low,dimensional chaos and simple determinism. Experimental data were obtained from the Madison Symmetric Torus RFP and consist of a wide array of both global and local diagnostic signals. None of the signals shows any indication of low dimensional chaos or other simple determinism. Moreover, most of the analysis tools indicate the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system.

  19. Numerical Experiments In Strongly Coupled Complex (Dusty) Plasmas

    NASA Astrophysics Data System (ADS)

    Hou, L. J.; Ivlev A.; Hubertus M. T.; Morfill, G. E.

    2010-07-01

    Complex (dusty) plasma is a suspension of micron-sized charged dust particles in a weakly ionized plasma with electrons, ions, and neutral atoms or molecules. Therein, dust particles acquire a few thousand electron charges by absorbing surrounding electrons and ions, and consequently interact with each other via a dynamically screened Coulomb potential while undergoing Brownian motion due primarily to frequent collisions with the neutral molecules. When the interaction potential energy between charged dust particles significantly exceeds their kinetic energy, they become strongly coupled and can form ordered structures comprising liquid and solid states. Since the motion of charged dust particles in complex (dusty) plasmas can be directly observed in real time by using a video camera, such systems have been generally regarded as a promising model system to study many phenomena occurring in solids, liquids and other strongly-coupled systems at the kinetic level, such as phase transitions, transport processes, and collective dynamics. Complex plasma physics has now grown into a mature research field with a very broad range of interdisciplinary facets. In addition to usual experimental and theoretical study, computer simulation in complex plasma plays an important role in bridging experimental observations and theories and in understanding many interesting phenomena observed in laboratory. The present talk will focus on a class of computer simulations that are usually non-equilibrium ones with external perturbation and that mimic the real complex plasma experiments (i. e., numerical experiment). The simulation method, i. e., the so-called Brownian Dynamics methods, will be firstly reviewed and then examples, such as simulations of heat transfer and shock wave propagation, will be present.

  20. Plasma gun pellet acceleration modeling and experiment

    SciTech Connect

    Kincaid, R.W.; Bourham, M.A.; Gilligan, J.G.

    1996-12-31

    Modifications to the electrothermal plasma gun SIRENS have been completed to allow for acceleration experiments using plastic pellets. Modifications have been implemented to the 1-D, time dependent code ODIN to include pellet friction, momentum, and kinetic energy with options of variable barrel length. The code results in the new version, POSEIDON, compare favorably with experimental data and with code results from ODIN. Predicted values show an increased pellet velocity along the barrel length, achieving 2 km/s exit velocity. Measured velocity, at three locations along the barrel length, showed good correlation with predicted values. The code has also been used to investigate the effectiveness of longer pulse length on pellet velocity using simulated ramp up and down currents with flat top, and triangular current pulses with early and late peaking. 16 refs., 5 figs.

  1. Complex Plasma Research Under Extreme Conditions

    SciTech Connect

    Ishihara, Osamu

    2008-09-07

    Complex plasma research under extreme conditions is described. The extreme conditions include low-dimensionality for self-organized structures of dust particles, dust magnetization in high magnetic field, criticality in phase transition, and cryogenic environment for Coulomb crystals and dust dynamics.

  2. Adventures in Laser Produced Plasma Research

    SciTech Connect

    Key, M

    2006-01-13

    In the UK the study of laser produced plasmas and their applications began in the universities and evolved to a current system where the research is mainly carried out at the Rutherford Appleton Laboratory Central Laser Facility ( CLF) which is provided to support the universities. My own research work has been closely tied to this evolution and in this review I describe the history with particular reference to my participation in it.

  3. Researchers build a secure plasma prison

    SciTech Connect

    Glanz, J.

    1995-07-28

    Research groups at Princeton University`s Tokamak Fusion Test Reactor and at the DIII-D tokamak at General Atomics in San Diego have made a major breakthrough. By tailoring the magnetic fields with unprecedented finesse, they appear to have tamed the plasma instabilities that rattle and tear the fragile magnetic cage, allowing particles to leak out and limiting a tokamak`s performance. In the process they increased the central density of the plasma by as much as threefold and reduced the particle leakage by a factor of 50.

  4. Development and research of a coaxial microwave plasma thruster

    NASA Astrophysics Data System (ADS)

    Yang, Juan; Xu, Yingqiao; Tang, Jinlan; Mao, Genwang; Yang, Tielian; Tan, Xiaoquen

    2008-08-01

    An overview of the research on a coaxial microwave plasma thruster at Northwestern Polytechnic University is presented. Emphasis is put on the development and research on key components of the thruster system, a microthrust balance, plasma plume diagnostics, and a numerical simulation of the plasma flow field inside the thruster cavity. The developed thruster cavity is chosen from a coaxial resonant cavity with concentrated capacitance, which can operate well in atmosphere and vacuum conditions. The development of a microwave source shows that a magnetron powered by a switch power supply has advantages in the power level and efficiency, but a solid state microwave source synthesized from the arsenide field effect transistor is superior in weight and volume. Through elimination of the effect of large gravity and resistance force induced by a gas pipe line and a microwave transmitting line on the microthrust, 15mN and 340s in the performance of the microwave plasma thruster at 70W and with helium gas are measured. Diagnosing experiment shows that the plasma plume density is in the range of (1-7.2)×1016/m3. Numerical simulation of the plasma flow field inside the coaxial thruster cavity shows that there is a good match between the microwave power and gas flow rate.

  5. Development and research of a coaxial microwave plasma thruster

    SciTech Connect

    Yang Juan; Xu Yingqiao; Tang Jinlan; Mao Genwang; Yang Tielian; Tan Xiaoquen

    2008-08-15

    An overview of the research on a coaxial microwave plasma thruster at Northwestern Polytechnic University is presented. Emphasis is put on the development and research on key components of the thruster system, a microthrust balance, plasma plume diagnostics, and a numerical simulation of the plasma flow field inside the thruster cavity. The developed thruster cavity is chosen from a coaxial resonant cavity with concentrated capacitance, which can operate well in atmosphere and vacuum conditions. The development of a microwave source shows that a magnetron powered by a switch power supply has advantages in the power level and efficiency, but a solid state microwave source synthesized from the arsenide field effect transistor is superior in weight and volume. Through elimination of the effect of large gravity and resistance force induced by a gas pipe line and a microwave transmitting line on the microthrust, 15 mN and 340 s in the performance of the microwave plasma thruster at 70 W and with helium gas are measured. Diagnosing experiment shows that the plasma plume density is in the range of (1-7.2)x10{sup 16}/m{sup 3}. Numerical simulation of the plasma flow field inside the coaxial thruster cavity shows that there is a good match between the microwave power and gas flow rate.

  6. Plasma Source Design for the PWFA Experiments at SLAC

    NASA Astrophysics Data System (ADS)

    Marsh, K. A.; Muggli, P.

    2002-12-01

    We discuss the design issues associated with producing a plasma source for the plasma wake field accelerator (PWFA) experiments at SLAC. There are many possible sources, but for our purposes uv, single photon ionized, lithium vapor, in a heat pipe oven, is our best option. Optimum parameters are derived and the plasma decay rate is estimated.

  7. Research Opportunities at the Basic Plasma Science Facility

    NASA Astrophysics Data System (ADS)

    Gekelman, Walter

    2005-04-01

    The Basic Plasma Science Facility (BAPSF) at (UCLA) is a user facility sponsored by the Department of Energy and the National Science Foundation. The purpose is to provide access, free of charge, to qualified national and international scientists to a state-of-the art, large plasma device (LAPD) which, permits the exploration of frontier topics in plasma science under controlled conditions. Some of the research activities are related to space plasma investigations, others explore fundamental issues of interest to fusion research. The operation is centered on the LAPD device developed by the UCLA research team. The machine produces quiescent and reproducible plasma discharges having typical duration of 10 msec (trep = 1 Hz), accessible throughout the day. The plasma column is 18 meters in length and 60 cm in diameter. The magnetic field can be varied continuously up to 2.5 kG. Fully ionized discharges in He, Ar, and Ne are available. Representative parameters are: The machine has 360 access ports. Qualified users have access to all of the machine diagnostics. Each user group is assigned a staff scientist who runs the machine and provides the necessary technical expertise to implement their research project. To obtain access a prospective user contacts the director and then submits a white paper. Instructions for this can be found at http://plasma.physics.ucla.edu/bapsf. The white paper is reviewed by an external committee. There are currently 11 active projects. This talk will give details of the device and briefly describe some of the experiments in progress.

  8. PlasmaLab/Eco-Plasma - The future of complex plasma research in space

    NASA Astrophysics Data System (ADS)

    Knapek, Christina; Thomas, Hubertus; Huber, Peter; Mohr, Daniel; Hagl, Tanja; Konopka, Uwe; Lipaev, Andrey; Morfill, Gregor; Molotkov, Vladimir

    The next Russian-German cooperation for the investigation of complex plasmas under microgravity conditions on the International Space Station (ISS) is the PlasmaLab/Eco-Plasma project. Here, a new plasma chamber -- the ``Zyflex'' chamber -- is being developed. The chamber is a cylindrical plasma chamber with parallel electrodes and a flexible system geometry. It is designed to extend the accessible plasma parameter range, i.e. neutral gas pressure, plasma density and electron temperature, and also to allow an independent control of the plasma parameters, therefore increasing the experimental quality and expected knowledge gain significantly. With this system it will be possible to reach low neutral gas pressures (which means weak damping of the particle motion) and to generate large, homogeneous 3D particle systems for studies of fundamental phenomena such as phase transitions, dynamics of liquids or phase separation. The Zyflex chamber has already been operated in several parabolic flight campaigns with different configurations during the last years, yielding a promising outlook for its future development. Here, we will present the current status of the project, the technological advancements the Zyflex chamber will offer compared to its predecessors, and the latest scientific results from experiments on ground and in microgravity conditions during parabolic flights. This work and some of the authors are funded by DLR/BMWi (FKZ 50 WP 0700).

  9. Airborne Research Experience for Educators

    NASA Astrophysics Data System (ADS)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  10. NASA Researcher with a Coaxial Plasma Gun

    NASA Image and Video Library

    1962-06-21

    Researcher Charles Michels operates a coaxial plasma gun rig in Cell SW-13 of the Engine Research Building at the National Aeronautics and Space Administration (NASA) Lewis Research Center. From 1962 to 1967 NASA Lewis investigated coaxial plasma guns powered by conventional capacitor banks. The studies were part of a larger effort to identify electromagnetic accelerators for space propulsion. NASA worked with General Dynamics, General Electric, General Motors, and Republic Aviation on the project. NASA Lewis conducted a research program to determine which factors influenced the coaxial gun’s efficiency and analyze the acceleration process. The system had not previously been used for propulsion applications. The single-shot gun’s fast gas valve and capacitor banks with variable-delay ignition source permitted the evaluation of gun performance under controllable propellant quantity and distribution conditions. The coaxial plasma gun was the most basic type of electromagnetic accelerator. It included a charged capacitor in series with a pair of coaxial electrodes. An electrical breakdown occurred when gas was admitted to the inter-electrode region. The gas instantly became a good conductor and formed a conducting sheet that separated the magnetic field from the open region beyond. The highly-conducting gas was basically expelled by the force of the magnetic pressure. This type of thruster could operate at the high instantaneous power levels without decreasing its average power level.

  11. Plasma flow switch experiments on the Pegasus facility

    SciTech Connect

    Cochrane, J.C. Jr.; Anderson, B.; Bartsch, R.R.; Bowers, R.; Findley, C.; Greene, A.; Kruse, H.; Oona, H.; Parker, J.V.; Peterson, D.; Sandoval, G. ); Lee, P.H.Y. ); Turchi, P. )

    1991-01-01

    Plasma flow switch experiments conducted on Pegasus have shown that a conducting layer of plasma shunts the load slot preventing efficient switching of current to the load. This effect is seen computationally. The magnitude of the effect depends on the specific parameters of the switch plasma and current level. Computations have also shown that a plasma boundary layer trap'' would effectively remove enough plasma from the inner conductor of the power flow channel so that efficient switching would occur. This plasma trap has been successfully demonstrated when used with a static load. It has not yet been tested with an imploding load. 3 refs., 8 figs.

  12. Pinch Related Research At Institute For Plasma Research, India

    NASA Astrophysics Data System (ADS)

    Shyam, Anurag

    2006-01-01

    Several pinch related experiment, their drivers and related diagnostics are being developed in our laboratory. The first set of experiments is to investigate various aspects of magnetized target fusion (MTF/MAGO). To drive the liner, in Z or theta pinch configuration, a 1.2 MJ, 3.6 MA capacitor bank is developed. For liner diagnostics flash radiography, VISAR and pyrometery are being developed. To produce magnetized (target) plasma a 120 kJ, 3 MA and several other banks are developed. Hot magnetized Plasma will be diagnosed by optical schlieren, interferometery and X-Ray spectrometry. A terra-watt system consisting of a Marx bank and water line delivering 800 kA at 1.6 MV will be commissioned, soon. The device will be used to study different pinch (wire array) configurations for production of electro-magnetic radiations. Smaller pulsed power systems, consisting of 1MV/500 kV Marx bank/tesla transformer and than water or solid state (cables) pulse forming network (coax) are also being developed for capillary discharge and other experiments. Two plasma foci experiments are also being conducted. The effort is produce a repetitively operating compact plasma focus.

  13. Pinch Related Research At Institute For Plasma Research, India

    SciTech Connect

    Shyam, Anurag

    2006-01-05

    Several pinch related experiment, their drivers and related diagnostics are being developed in our laboratory. The first set of experiments is to investigate various aspects of magnetized target fusion (MTF/MAGO). To drive the liner, in Z or theta pinch configuration, a 1.2 MJ, 3.6 MA capacitor bank is developed. For liner diagnostics flash radiography, VISAR and pyrometery are being developed. To produce magnetized (target) plasma a 120 kJ, 3 MA and several other banks are developed. Hot magnetized Plasma will be diagnosed by optical schlieren, interferometery and X-Ray spectrometry. A terra-watt system consisting of a Marx bank and water line delivering 800 kA at 1.6 MV will be commissioned, soon. The device will be used to study different pinch (wire array) configurations for production of electro-magnetic radiations. Smaller pulsed power systems, consisting of 1MV/500 kV Marx bank/tesla transformer and than water or solid state (cables) pulse forming network (coax) are also being developed for capillary discharge and other experiments. Two plasma foci experiments are also being conducted. The effort is produce a repetitively operating compact plasma focus.

  14. The Plasma Interaction Experiment (PIX) description and test program. [electrometers

    NASA Technical Reports Server (NTRS)

    Ignaczak, L. R.; Haley, F. A.; Domino, E. J.; Culp, D. H.; Shaker, F. J.

    1978-01-01

    The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage.

  15. International Microgravity Plasma Facility IMPF: A Multi-User Modular Research Facility for Complex Plasma Research on ISS

    NASA Astrophysics Data System (ADS)

    Seurig, R.; Burfeindt, J.; Castegini, R.; Griethe, W.; Hofmann, P.

    2002-01-01

    On March 03, 2001, the PKE-Nefedov plasma experiment was successfully put into operation on board ISS. This complex plasma experiment is the predecessor for the semi-autonomous multi-user facility IMPF (International Microgravity Plasma Facility) to be flown in 2006 with an expected operational lifetime of 10 years. IMPF is envisioned to be an international research facility for investigators in the field of multi-component plasmas containing ions, electrons, and charged microparticles. This research filed is often referred to as "complex plasmas". The actual location of IMPF on ISS is not decided yet; potential infrastructure under consideration are EXPRESS Rack, Standard Interface Rack SIR, European Drawer Rack EDR, or a to be designed custom rack infrastructure on the Russian Segment. The actual development status of the DLR funded Pre-phase B Study for IMPF will be presented. For this phase, IMPF was assumed to be integrated in an EXPRESS Rack requiring four middeck lockers with two 4-PU ISIS drawers for accommodation. Technical and operational challenges, like a 240 Mbytes/sec continuous experimental data stream for 60 minutes, will be addressed. The project was funded by the German Space Agency (DLR) and was performed in close cooperation with scientists from the Max-Planck-Institute for Extraterrestical Physics in Munich, Germany.

  16. Transition research using flight experiments

    NASA Technical Reports Server (NTRS)

    Reshotko, Eli

    1990-01-01

    The paper deals with flight experiments as a means of obtaining proper transition information in an uncontaminated environment. Flight transition experiments performed in the early to middle 1950s using rocket-propelled vehicles are outlined. It is noted that the standards for research quality experiments on stability and transition are no different for flight studies than for wind-tunnel experiments. The guidelines formulated by the U.S. Boundary Layer Transition Study Group are listed. Attention is focused on the relationship between the model design and the measurement of disturbance environment, the maintenance and monitoring of test and model-surface conditions, and a need for high data-sampling rates.

  17. From laboratory plasma experiments to space plasma experiments with `CubeSat' nano-satellites

    NASA Astrophysics Data System (ADS)

    Charles, Christine

    2016-09-01

    `CubeSat' nano-satellites provide low-cost access to space. SP3 laboratory's involvement in the European Union `QB50' `CubeSat' project [www.qb50.eu] which will launch into space 50 `CubeSats' from 27 Countries to study the ionosphere and the lower thermosphere will be presented. The Chi Kung laboratory plasma experiment and the Helicon Double Layer Thruster prototype can be tailored to investigate expanding magnetized plasma physics relevant to space physics (solar corona, Earth's aurora, adiabatic expansion and polytropic studies). Chi Kung is also used as a plasma wind tunnel for ground-based calibration of the University College London QB50 Ion Neutral Mass Spectrometer. Space qualification of the three Australian QB50 `CubeSats' (June 2016) is carried out in the WOMBAT XL space simulation chamber. The QB50 satellites have attitude control but altitude control is not a requirement. SP3 is developing end-to-end miniaturised radiofrequency plasma propulsion systems (such as the Pocket Rocket and the MiniHel thrusters with power and propellant sub-systems) for future `CubeSat' missions.

  18. Plasma Reactor Modeling and Validation Experiments

    NASA Technical Reports Server (NTRS)

    Meyyappan, M.; Bose, D.; Hash, D.; Hwang, H.; Cruden, B.; Sharma, S. P.; Rao, M. V. V. S.; Arnold, Jim (Technical Monitor)

    2001-01-01

    Plasma processing is a key processing stop in integrated circuit manufacturing. Low pressure, high density plum reactors are widely used for etching and deposition. Inductively coupled plasma (ICP) source has become popular recently in many processing applications. In order to accelerate equipment and process design, an understanding of the physics and chemistry, particularly, plasma power coupling, plasma and processing uniformity and mechanism is important. This understanding is facilitated by comprehensive modeling and simulation as well as plasma diagnostics to provide the necessary data for model validation which are addressed in this presentation. We have developed a complete code for simulating an ICP reactor and the model consists of transport of electrons, ions, and neutrals, Poisson's equation, and Maxwell's equation along with gas flow and energy equations. Results will be presented for chlorine and fluorocarbon plasmas and compared with data from Langmuir probe, mass spectrometry and FTIR.

  19. The Burning Plasma Experiment conventional facilities

    SciTech Connect

    Commander, J.C.

    1991-01-01

    The Burning Program Plasma Experiment (BPX) is phased to start construction of conventional facilities in July 1994, in conjunction with the conclusion of the Tokamak Fusion Test Reactor (TFTR) project. This paper deals with the conceptual design of the BPX Conventional Facilities, for which Functional and Operational Requirements (F ORs) were developed. Existing TFTR buildings and utilities will be adapted and used to satisfy the BPX Project F ORs to the maximum extent possible. However, new conventional facilities will be required to support the BPX project. These facilities include: The BPX building; Site improvements and utilities; the Field Coil Power Conversion (FCPC) building; the TFTR modifications; the Motor Generation (MG) building; Liquid Nitrogen (LN{sub 2}) building; and the associated Instrumentation and Control (I C) systems. The BPX building will provide for safe and efficient shielding, housing, operation, handling, maintenance and decontamination of the BPX and its support systems. Site improvements and utilities will feature a utility tunnel which will provide a space for utility services--including pulse power duct banks and liquid nitrogen coolant lines. The FCPC building will house eight additional power supplied for the Toroidal Field (TF) coils. The MG building will house the two MG sets larger than the existing TFTR MG sets. This paper also addresses the conventional facility cost estimating methodology and the rationale for the construction schedule developed. 6 figs., 1 tab.

  20. The Burning Plasma Experiment conventional facilities

    SciTech Connect

    Commander, J.C.

    1991-12-01

    The Burning Program Plasma Experiment (BPX) is phased to start construction of conventional facilities in July 1994, in conjunction with the conclusion of the Tokamak Fusion Test Reactor (TFTR) project. This paper deals with the conceptual design of the BPX Conventional Facilities, for which Functional and Operational Requirements (F&ORs) were developed. Existing TFTR buildings and utilities will be adapted and used to satisfy the BPX Project F&ORs to the maximum extent possible. However, new conventional facilities will be required to support the BPX project. These facilities include: The BPX building; Site improvements and utilities; the Field Coil Power Conversion (FCPC) building; the TFTR modifications; the Motor Generation (MG) building; Liquid Nitrogen (LN{sub 2}) building; and the associated Instrumentation and Control (I&C) systems. The BPX building will provide for safe and efficient shielding, housing, operation, handling, maintenance and decontamination of the BPX and its support systems. Site improvements and utilities will feature a utility tunnel which will provide a space for utility services--including pulse power duct banks and liquid nitrogen coolant lines. The FCPC building will house eight additional power supplied for the Toroidal Field (TF) coils. The MG building will house the two MG sets larger than the existing TFTR MG sets. This paper also addresses the conventional facility cost estimating methodology and the rationale for the construction schedule developed. 6 figs., 1 tab.

  1. Developing Effective Undergraduate Research Experience

    NASA Astrophysics Data System (ADS)

    Evans, Michael; Ilie, Carolina C.

    2011-03-01

    Undergraduate research is a valuable educational tool for students pursuing a degree in physics, but these experiences can become problematic and ineffective if not handled properly. Undergraduate research should be planned as an immersive learning experience in which the student has the opportunity to develop his/her skills in accordance with their interests. Effective undergraduate research experiences are marked by clear, measurable objectives and frequent student-professor collaboration. These objectives should reflect the long and short-term goals of the individual undergraduates, with a heightened focus on developing research skills for future use. 1. Seymour, E., Hunter, A.-B., Laursen, S. L. and DeAntoni, T. (2004), ``Establishing the benefits of research experiences for undergraduates in the sciences: First findings from a three-year study''. Science Education, 88: 493--534. 2. Behar-Horenstein, Linda S., Johnson, Melissa L. ``Enticing Students to Enter Into Undergraduate Research: The Instrumentality of an Undergraduate Course.'' Journal of College Science Teaching 39.3 (2010): 62-70.

  2. An Experiment to Tame the Plasma Material Interface

    SciTech Connect

    Goldston, R J; Menard, J E; Allain, J P; Brooks, J N; Canik, J M; Doerner, R; Fu, G; Gates, D A; Gentile, C A; Harris, J H; Hassanein, A; Gorelenkov, N N; Kaita, R; Kaye, S M; Kotschenreuther, M; Kramer, G J; Kugel, H W; Maingi, R; Mahajan, S M; Majeski, R; Neumeyer, C L; Nygren, R E; Ono, M; Owen, L W; Ramakrishnan, S; Rognlien, T D; Ruzic, D N; Ryutov, D D; Sabbagh, S A; Skinner, C H; Soukhanovskii, V A; Stevenson, T N; Ulrickson, M A; Valanju, P M; Woolley, R D

    2009-01-08

    The plasma material interface in Demo will be more challenging than that in ITER, due to requirements for approximately four times higher heat flux from the plasma and approximately five times higher average duty factor. The scientific and technological solutions employed in ITER may not extrapolate to Demo. The key questions to be resolved for Demo and the resulting key requirements for an experiment to 'tame the plasma material interface' are analyzed. A possible design point for such an experiment is outlined.

  3. Analysis and experiments of a whistler-wave plasma thruster

    SciTech Connect

    Hooper, E.B.; Ferguson, S.W.; Makowski, M.A.; Stallard, B.W.; Power, J.L.

    1993-08-06

    A plasma thruster operating at high specific impulse ({ge} 3500 s) has been proposed to be based on electron-cyclotron resonance heating of whistler waves propagating on a plasma column on a magnetic hill. Calculations using a particle-in-cell code demonstrate that the distortion of the electron velocity distribution by the heating significantly reduces the flow of plasma up the field, greatly improving efficiency and reducing material interactions relative to a thermal plasma. These and other calculations are presented together with initial experiments on the plasma generated in the proposed device. The experiments are conducted in a magnetic field (3.3 {times} 10{sup {minus}2} T at resonance) and a magnetic mirror ratio of 5. Microwaves (0.915 GHz, <20 kW) are coupled to the plasma with a helical antenna. Vacuum field measurements are in good agreement with prediction. The desired plasma spatial distribution has not yet been achieved.

  4. The psychiatry resident research experience.

    PubMed

    MacMaster, Frank P; Cohen, Jordan; Waheed, Waqar; Magaud, Emilie; Sembo, Mariko; Langevin, Lisa Marie; Rittenbach, Katherine

    2016-11-14

    Research activity is especially critical in the field of psychiatry as it is evolving rapidly thanks to advances in neuroscience. We administered a 34-item survey regarding research experiences targeted at psychiatry residents and postgraduate residency program directors in Canada. One hundred and nineteen participants answered the survey (16 program directors, 103 residents) allowing for a margin of error of 8.4% at a 95% confidence interval. Research was rated as important in informing clinical practice (87.0% yes, 13.0% no), but only 28.7% of respondents reported that it was taught well at their home institution (33.0% no, 38.3% neutral). Only a small proportion was enthusiastic or very enthusiastic about participating in research (21.7%). While the importance of research is recognized, there is little consensus with respect to whether a standardized research practicum component is included in the resident curriculum.

  5. Designing Effective Undergraduate Research Experiences

    NASA Astrophysics Data System (ADS)

    Severson, S.

    2010-12-01

    I present a model for designing student research internships that is informed by the best practices of the Center for Adaptive Optics (CfAO) Professional Development Program. The dual strands of the CfAO education program include: the preparation of early-career scientists and engineers in effective teaching; and changing the learning experiences of students (e.g., undergraduate interns) through inquiry-based "teaching laboratories." This paper will focus on the carry-over of these ideas into the design of laboratory research internships such as the CfAO Mainland internship program as well as NSF REU (Research Experiences for Undergraduates) and senior-thesis or "capstone" research programs. Key ideas in maximizing student learning outcomes and generating productive research during internships include: defining explicit content, scientific process, and attitudinal goals for the project; assessment of student prior knowledge and experience, then following up with formative assessment throughout the project; setting reasonable goals with timetables and addressing motivation; and giving students ownership of the research by implementing aspects of the inquiry process within the internship.

  6. Experiments and Theory of Dusty Plasmas

    SciTech Connect

    Shukla, P. K.

    2011-11-29

    The purpose of this paper is to present the most important theoretical and experimental discoveries that have been made in the area of dusty plasma physics. We describe the physics and observations of the well celebrated dust acoustic wave (DAW) and the dust ion-acoustic wave (DIAW) in dusty plasmas with weakly coupled dust grains, as well as the dust Coulomb crystal and dust lattice oscillations (DLOs) in dusty plasmas with strongly coupled dust grains. In dusty plasmas, the dust charge fluctuation is a dynamical variable, which provides a novel collisionless damping of the DA and DIA waves. The latter and the DLOs are excited by external sources, which are here discussed. Besides the Debye-Hueckel short-range repulsive force between like charged dust grains, there are novel attractive forces (e.g. due to dipole-dipole dust particle interactions, overlapping Debye spheres, ion focusing and ion wakefields, dipole magnetic moments etc.), which provide unique possibilities for attracting charged dust particles of similar polarity. The dust particle attraction is responsible for the formation of dust Coulomb crystals in laboratory dusty plasmas, as well as for the formation of planets and large astrophysical bodies in the Milky Way galaxy and in interstellar media. Furthermore, the nonlinear DAW, DIAW, and DLOs also appear in the form of solitary and shock waves, the physics and observations of which are briefly discussed. Finally, we discuss possible applications of dust-in-plasmas and dusty plasmas in laboratory and space.

  7. Cryogenics Research and Engineering Experience

    NASA Technical Reports Server (NTRS)

    Toro Medina, Jaime A.

    2013-01-01

    Energy efficient storage, transfer and use of cryogens and cryogenic propellants on Earth and in space have a direct impact on NASA, government and commercial programs. Research and development on thermal insulation, propellant servicing, cryogenic components, material properties and sensing technologies provides industry, government and research institutions with the cross-cutting technologies to manage low-temperature applications. Under the direction of the Cryogenic Testing Lab at Kennedy Space Center, the work experience acquired allowed me to perform research, testing, design and analysis of current and future cryogenic technologies to be applied in several projects.

  8. Plasma Jet Motion Across the Geomagnetic Field in the ``North Star'' Active Geophysical Experiment

    NASA Astrophysics Data System (ADS)

    Gavrilov, B. G.; Zetzer, J. I.; Podgorny, I. M.; Sobyanin, D. B.; Meng, C.-I.; Erlandson, R. E.; Stenbaek-Nielsen, H. C.; Pfaff, R. F.; Lynch, K. A.

    2003-01-01

    The active geophysical rocket experiment ``North Star'' was carried out in the auroral ionosphere on January 22, 1999, at the Poker Flat Research Range (Alaska, USA) using the American research rocket Black Brant XII with explosive plasma generators on board. Separable modules with scientific equipment were located at distances of from 170 to 1595 m from the plasma source. The experiment continued the series of the Russian-American joint experiments started by the ``Fluxus'' experiment in 1997. Two injections of aluminum plasma across the magnetic field were conducted in the ``North Star'' experiment. They were different, since in the first injection a neutral gas cloud was formed in order to increase the plasma ionization due to the interaction of neutrals of the jet and cloud. The first and second injections were conducted at heights of 360 and 280 km, respectively. The measurements have shown that the charged particle density was two orders of magnitude higher in the experiment with the gas release. The magnetic field in the first injection was completely expelled by the dense plasma of the jet. The displacement of the magnetic field in the second injection was negligible. The plasma jet velocity in both injections decreased gradually due to its interaction with the geomagnetic field. One of the most interesting results of the experiment was the conservation of high plasma density during the propagation of the divergent jet to considerable distances. This fact can be explained by the action of the critical ionization velocity mechanism.

  9. Plasma-materials interactions during rf experiments in tokamaks

    SciTech Connect

    Cohen, S.A.; Bernabei, S.; Budny, R.; Chu, T.K.; Colestock, P.; Hinnov, E.; Hooke, W.; Hosea, J.; Hwang, D.; Jobes, F.

    1984-09-01

    Plasma-materials interactions studied in recent ICRF heating and lower hybrid current drive experiments are reviewed. The microscopic processes responsible for impurity generation are discussed. In ICRF experiments, improvements in machine operation and in antenna and feedthrough design have allowed efficient plasma heating at RF powers up to 3 MW. No significant loss of energy from the plasma core due to impurity radiation occurs. Lower hybrid current drive results in the generation and maintenance of hundreds of kiloamperes of plasma current carried by suprathermal electrons. The loss of these electrons and their role in impurity generation are assessed. Methods to avoid this problem are evaluated.

  10. Experiments on the Propagation of Plasma Filaments

    SciTech Connect

    Katz, Noam; Egedal, Jan; Fox, Will; Le, Ari; Porkolab, Miklos

    2008-07-04

    We investigate experimentally the motion and structure of isolated plasma filaments propagating through neutral gas. Plasma filaments, or 'blobs,' arise from turbulent fluctuations in a range of plasmas. Our experimental geometry is toroidally symmetric, and the blobs expand to a larger major radius under the influence of a vertical electric field. The electric field, which is caused by {nabla}B and curvature drifts in a 1/R magnetic field, is limited by collisional damping on the neutral gas. The blob's electrostatic potential structure and the resulting ExB flow field give rise to a vortex pair and a mushroom shape, which are consistent with nonlinear plasma simulations. We observe experimentally this characteristic mushroom shape for the first time. We also find that the blob propagation velocity is inversely proportional to the neutral density and decreases with time as the blob cools.

  11. Non-equilibrium plasma experiments at The Pennsylvania State University

    NASA Astrophysics Data System (ADS)

    Knecht, Sean; Bilen, Sven; Micci, Michael

    2013-10-01

    The authors have recently established the capability at The Pennsylvania State University to generate non-equilibrium plasma in atmospheric-pressure air and liquids such as water and saline. The plasma is generated using a high-voltage pulser (Pacific-Electronics PT-55), which is capable of voltage pulses of 75-ns width, peak voltage >50 kV, with rise-times on the order of nanoseconds. The electrodes are tungsten wires of various diameters (50 μm, 175 μm, 254 μm) insulated with nylon tubing. The spacing of the electrodes is controlled with translating mounts with resolution of tens of microns. Spectroscopy (Ocean Optics Model HR2000) is presently used for line identification only. Current and voltage vs. time will be measured with a 500-MHz bandwidth oscilloscope, a high-voltage probe and a shunt resistor connected to the ground side of the circuit. Research directions presently being pursued include the effects of solution electrical conductivity on plasma production and propellant ignition studies. Data from several types of experiments will be presented.

  12. Lightweight Portable Plasma Medical Device - Plasma Engineering Research Laboratory

    DTIC Science & Technology

    2014-10-01

    over a range of power levels has been used for industrial and materials processing applications ,[1-4] and increasingly applied in biomedical...from already resistant bacteria. To identify the usefulness of the plasma pencil for biomedical applications , we assessed plasma pencil treatment on...Characterization of an Atmospheric Pressure Plasma Jet and its Applications for Disinfection and Cancer Treatment . (San Diego, CA: Annual MMVR20

  13. Proposal for a one GeV plasma wakefield acceleration experiment at SLAC

    SciTech Connect

    Assmann, R.; Chen, P.; Decker, F.J.

    1998-04-01

    A plasma-based wakefield acceleration experiment E-157 has been approved at SLAC to study acceleration of parts of an SLC bunch by up to 1 GeV/m over a length of 1 m. A single SLC bunch is used to both induce wakefields in the one meter long plasma and to witness the resulting beam acceleration. The experiment will explore and further development the techniques that are needed to apply high-gradient plasma wakefield acceleration to large scale accelerators. The one meter length of the experiment is about two orders of magnitude larger than other high gradient plasma wakefield acceleration experiments and the 1 GeV/m accelerating gradient is roughly ten times larger than that achieved with conventional metallic structures. Using existing SLAC facilities, the experiment will study high gradient acceleration at the forefront of advanced accelerator research.

  14. Spectroscopic imaging diagnostics for burning plasma experiments

    SciTech Connect

    Stutman, D.; Finkenthal, M.; Suliman, G.; Tritz, K.; Delgado-Aparicio, L.; Kaita, R.; Johnson, D.; Soukhanovskii, V.; May, M.J.

    2005-02-01

    Spectroscopic imaging of plasma emission profiles from a few electron volts to tens of kilo-electron volts enables basic diagnostics in present day tokamaks. For the more difficult burning plasma conditions, light extraction and detection techniques, as well as instrument designs need to be investigated. As an alternative to light extraction with reflective optics, we discuss normal incidence, transmissive-diffractive optics (e.g., transmission gratings), which might withstand plasma exposure with less degradation of optical properties. Metallic multilayer reflectors are also of interest for light extraction. Although a shift of the diffraction peak might occur, instrument designs that accommodate such shifts are possible. As imaging detectors we consider 'optical' arrays based on conversion of the short-wavelength light into visible light followed by transport of the visible signal with hollow lightguides. The proposed approaches to light extraction and detection could enable radiation resistant diagnostics.

  15. Spectroscopic imaging diagnostics for burning plasma experiments

    NASA Astrophysics Data System (ADS)

    Stutman, D.; Finkenthal, M.; Suliman, G.; Tritz, K.; Delgado-Aparicio, L.; Kaita, R.; Johnson, D.; Soukhanovskii, V.; May, M. J.

    2005-02-01

    Spectroscopic imaging of plasma emission profiles from a few electron volts to tens of kilo-electron volts enables basic diagnostics in present day tokamaks. For the more difficult burning plasma conditions, light extraction and detection techniques, as well as instrument designs need to be investigated. As an alternative to light extraction with reflective optics, we discuss normal incidence, transmissive-diffractive optics (e.g., transmission gratings), which might withstand plasma exposure with less degradation of optical properties. Metallic multilayer reflectors are also of interest for light extraction. Although a shift of the diffraction peak might occur, instrument designs that accommodate such shifts are possible. As imaging detectors we consider "optical" arrays based on conversion of the short-wavelength light into visible light followed by transport of the visible signal with hollow lightguides. The proposed approaches to light extraction and detection could enable radiation resistant diagnostics.

  16. Divertor plasma studies on DIII-D: Experiment and modeling

    SciTech Connect

    West, W.P.; Brooks, N.H.; Allen, S.L.

    1996-09-01

    In a magnetically diverted tokamak, the scrape-off layer (SOL) and divertor plasma provides separation between the first wall and the core plasma, intercepting impurities generated at the wall before they reach the core plasma. The divertor plasma can also serve to spread the heat and particle flux over a large area of divertor structure wall using impurity radiation and neutral charge exchange, thus reducing peak heat and particle fluxes at the divertor strike plate. Such a reduction will be required in the next generation of tokamaks, for without it, the divertor engineering requirements are very demanding. To successfully demonstrate a radiative divertor, a highly radiative condition with significant volume recombination must be achieved in the divertor, while maintaining a low impurity content in the core plasma. Divertor plasma properties are determined by a complex interaction of classical parallel transport, anomalous perpendicular transport, impurity transport and radiation, and plasma wall interaction. In this paper the authors describe a set of experiments on DIII-D designed to provide detailed two dimensional documentation of the divertor and SOL plasma. Measurements have been made in operating modes where the plasma is attached to the divertor strike plate and in highly radiating cases where the plasma is detached from the divertor strike plate. They also discuss the results of experiments designed to influence the distribution of impurities in the plasma using enhanced SOL plasma flow. Extensive modeling efforts will be described which are successfully reproducing attached plasma conditions and are helping to elucidate the important plasma and atomic physics involved in the detachment process.

  17. The INAF/IAPS Plasma Chamber for ionospheric simulation experiment

    NASA Astrophysics Data System (ADS)

    Diego, Piero

    2016-04-01

    The plasma chamber is particularly suitable to perform studies for the following applications: - plasma compatibility and functional tests on payloads envisioned to operate in the ionosphere (e.g. sensors onboard satellites, exposed to the external plasma environment); - calibration/testing of plasma diagnostic sensors; - characterization and compatibility tests on components for space applications (e.g. optical elements, harness, satellite paints, photo-voltaic cells, etc.); - experiments on satellite charging in a space plasma environment; - tests on active experiments which use ion, electron or plasma sources (ion thrusters, hollow cathodes, field effect emitters, plasma contactors, etc.); - possible studies relevant to fundamental space plasma physics. The facility consists of a large volume vacuum tank (a cylinder of length 4.5 m and diameter 1.7 m) equipped with a Kaufman type plasma source, operating with Argon gas, capable to generate a plasma beam with parameters (i.e. density and electron temperature) close to the values encountered in the ionosphere at F layer altitudes. The plasma beam (A+ ions and electrons) is accelerated into the chamber at a velocity that reproduces the relative motion between an orbiting satellite and the ionosphere (≈ 8 km/s). This feature, in particular, allows laboratory simulations of the actual compression and depletion phenomena which take place in the ram and wake regions around satellites moving through the ionosphere. The reproduced plasma environment is monitored using Langmuir Probes (LP) and Retarding Potential Analyzers (RPA). These sensors can be automatically moved within the experimental space using a sled mechanism. Such a feature allows the acquisition of the plasma parameters all around the space payload installed into the chamber for testing. The facility is currently in use to test the payloads of CSES satellite (Chinese Seismic Electromagnetic Satellite) devoted to plasma parameters and electric field

  18. 3-D plasma boundary and plasma wall interaction research at UW-Madison

    NASA Astrophysics Data System (ADS)

    Schmitz, Oliver; Akerson, Adrian; Bader, Aaron; Barbui, Tullio; Effenberg, Florian; Flesch, Kurt; Frerichs, Heinke; Green, Jonathan; Hinson, Edward; Kremeyer, Thierry; Norval, Ryan; Stephey, Laurie; Waters, Ian; Winters, Victoria

    2016-10-01

    The necessity of considering 3-D effects on the plasma boundary and plasma wall interaction (PWI) in tokamaks, stellarators and reversed field pinches has been highlighted by abundant experimental and numerical results in the recent past. Prominent examples with 3-D boundary situations are numerous: ELM controlled H-modes by RMP fields in tokamaks, research on boundary plasmas and PWI in stellarators in general, quasi-helical states in RFPs, asymmetric fueling situations, and structural and wall elements which are not aligned with the magnetic guiding fields. A systematic approach is being taken at UW-Madison to establish a targeted experimental basis for identifying the most significant effects for plasma edge transport and resulting PWI in such 3-D plasma boundary situations. We deploy advanced 3-D modeling using the EMC3-EIRENE, ERO and MCI codes in combination with laboratory experiments at UW-Madison to investigate the relevance of 3-D effects in large scale devices with a concerted approach on DIII-D, NSTX-U, and Wendelstein 7-X. Highlights of experimental results from the on-site laboratory activities at UW-Madison and the large scale facilities are presented and interlinks will be discussed. This work was supported by US DOE DE-SC0013911, DE-SC00012315 and DE-SC00014210.

  19. Parallel collisionless-shock experiments at the Large Plasma Device

    NASA Astrophysics Data System (ADS)

    Weidl, Martin; Heuer, Peter; Bondarenko, Anton; Schaeffer, Derek; Winske, Dan; Constantin, Carmen; Jenko, Frank; Niemann, Christoph

    2017-04-01

    Previous research on parallel collisionless shocks, which constitute an important part of the Earth's bow shock region, has been limited to satellite measurements and simulations. However, whether and how these collisionless shocks form depends on a wide range of parameters and scales, some of which can be established and measured more easily in a laboratory experiment. Using a kJ-class laser, an ongoing experimental campaign at the Large Plasma Device (LAPD) at UCLA in Los Angeles is expected to produce the first laboratory measurements of the formation of a parallel collisionless shock. We present hybrid kinetic/MHD simulations which show how ion-beam instabilities in the background plasma can be driven by ablating carbon ions from a polyethylene target, causing non-linear density oscillations which eventually develop into a propagating shock front. The free-streaming carbon ions can excite both the resonant right-hand instability and the non-resonant firehose mode, the latter of which has also received a lot of attention among astrophysicists as Bell's instability. We present measurements from a first trial experiment at LAPD, in which we have identified these instabilities, and discuss their respective roles for future shock formation and the basic microphysical processes which drive them.

  20. Research on Orbital Plasma Electrodynamics (ROPE)

    NASA Technical Reports Server (NTRS)

    Intriligator, Devrie S.

    1998-01-01

    This final report summarizes some of the important scientific contributions to the Research on Orbital Plasma Electrodynamics (ROPE) investigation, to the Tethered Satellite System (TSS) mission, and to NASA that resulted from the work carried out under this contract at Carmel Research Center. These include Dr. Intriligator's participation in the PIT for the TSS-1R simulations and flight, her participation in ROPE team meetings and IWG meetings, her scientific analyses, and her writing and submitting technical papers to scientific journals. The scientific analyses concentrated on the characterization of energetic ions and their possible relation to pickup ion effects, correlation of particle and other effects (e.g., magnetic field, satellite surface), and collaboration with theorists including with ROPE co-investigators. In addition, scientific analyses were carried out of the effects due to satellite gas releases.

  1. OGO-1 and OGO-3 MIT plasma experiments S4903

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Plasma proton and plasma electron prototype and flight models were designed, fabricated, and tested. Ground support equipment for the models was also prepared. The flight models were launched aboard the first and third Orbiting Geophysical Observatories on 4 Sept. 1964 and 6 June 1966. These experiments have generally functioned in accordance with the design specifications and useful data are still being received.

  2. Advanced simulations of application plasmas: Comparisons with experiments and validations

    NASA Astrophysics Data System (ADS)

    Lee, Jae Koo

    2005-10-01

    Continuum-fluid and particle-in-cell models are the numerical simulation techniques commonly used for simulating low-temperature plasmas for plasma technology applications. Simulations can often identify research guidelines and propose novel designs leading to performance improvements in different plasma systems. We present an overview of the principles, strengths and limitations of the these. These modeling results are benchmarked by comparing in different plasma systems (capacitively and inductively coupled plasmas) with experimentally measured data and with other numerical results. The potential profile and the electron/ion kinetic information such as electron/ion energy distributions and temperatures are important for understanding the plasma phenomena. Kinetic 1d particle-in-cell/Monte-Carlo-collision and fluid modelings of Ar-oxygen plasma sources are carried out in the wide parameter range.

  3. SAMPIE (Solar Array Module Plasma Interactions Experiment). (Videotape)

    SciTech Connect

    Not Available

    1994-02-01

    SAMPIE is an in-space technology experiment that flew on STS-62. Its intent is to investigate the potentially damaging effects of space plasma (gases) on different types, sizes, and shapes of solar cells, solar modules, and spacecraft materials.

  4. The ISPM unified radio and plasma wave experiment

    NASA Technical Reports Server (NTRS)

    Stone, R. G.; Caldwell, J.; Deconchy, Y.; Deschanciaux, C.; Ebbett, R.; Epstein, G.; Groetz, K.; Harvey, C. C.; Hoang, S.; Howard, R.

    1983-01-01

    Hardware for the International Solar Polar Mission (ISPM) Unified Radio and Plasma (URAP) wave experiment is presented. The URAP determines direction and polarization of distant radio sources for remote sensing of the heliosphere, and studies local wave phenomena which determine the transport coefficients of the ambient plasma. Electric and magnetic field antennas and preamplifiers; the electromagnetic compatibility plan and grounding; radio astronomy and plasma frequency receivers; a fast Fourier transformation data processing unit waveform analyzer; dc voltage measurements; a fast envelope sampler for the solar wind, and plasmas near Jupiter; a sounder; and a power converter are described.

  5. Progress toward positron-electron pair plasma experiments

    SciTech Connect

    Stenson, E. V.; Stanja, J.; Hergenhahn, U.; Saitoh, H.; Niemann, H.; Pedersen, T. Sunn; Marx, G. H.; Schweikhard, L.; Danielson, J. R.; Surko, C. M.; Hugenschmidt, C.

    2015-06-29

    Electron-positron plasmas have been of theoretical interest for decades, due to the unique plasma physics that arises from all charged particles having precisely identical mass. It is only recently, though, that developments in non-neutral plasma physics (both in linear and toroidal geometries) and in the flux of sources for cold positrons have brought the goal of conducting electron-positron pair plasma experiments within reach. The APEX/PAX collaboration is working on a number of projects in parallel toward that goal; this paper provides an overview of recent, current, and upcoming activities.

  6. The ISPM unified radio and plasma wave experiment

    NASA Technical Reports Server (NTRS)

    Stone, R. G.; Caldwell, J.; Deconchy, Y.; Deschanciaux, C.; Ebbett, R.; Epstein, G.; Groetz, K.; Harvey, C. C.; Hoang, S.; Howard, R.

    1983-01-01

    Hardware for the International Solar Polar Mission (ISPM) Unified Radio and Plasma (URAP) wave experiment is presented. The URAP determines direction and polarization of distant radio sources for remote sensing of the heliosphere, and studies local wave phenomena which determine the transport coefficients of the ambient plasma. Electric and magnetic field antennas and preamplifiers; the electromagnetic compatibility plan and grounding; radio astronomy and plasma frequency receivers; a fast Fourier transformation data processing unit waveform analyzer; dc voltage measurements; a fast envelope sampler for the solar wind, and plasmas near Jupiter; a sounder; and a power converter are described.

  7. Progress toward positron-electron pair plasma experiments

    NASA Astrophysics Data System (ADS)

    Stenson, E. V.; Saitoh, H.; Stanja, J.; Niemann, H.; Hergenhahn, U.; Pedersen, T. Sunn; Marx, G. H.; Schweikhard, L.; Danielson, J. R.; Surko, C. M.; Hugenschmidt, C.

    2015-06-01

    Electron-positron plasmas have been of theoretical interest for decades, due to the unique plasma physics that arises from all charged particles having precisely identical mass. It is only recently, though, that developments in non-neutral plasma physics (both in linear and toroidal geometries) and in the flux of sources for cold positrons have brought the goal of conducting electron-positron pair plasma experiments within reach. The APEX/PAX collaboration is working on a number of projects in parallel toward that goal; this paper provides an overview of recent, current, and upcoming activities.

  8. Diagnosis in Complex Plasmas for Microgravity Experiments (PK-3 plus)

    SciTech Connect

    Takahashi, Kazuo; Hayashi, Yasuaki; Thomas, Hubertus M.; Morfill, Gregor E.; Ivlev, Alexei V.; Adachi, Satoshi

    2008-09-07

    Microgravity gives the complex (dusty) plasmas, where dust particles are embedded in complete charge neutral region of bulk plasma. The dust clouds as an uncompressed strongly coupled Coulomb system correspond to atomic model with several physical phenomena, crystallization, phase transition, and so on. As the phenomena tightly connect to plasma states, it is significant to understand plasma parameters such as electron density and temperature. The present work shows the electron density in the setup for microgravity experiments currently onboard on the International Space Station.

  9. Electron cyclotron plasma startup in the GDT experiment

    NASA Astrophysics Data System (ADS)

    Yakovlev, D. V.; Shalashov, A. G.; Gospodchikov, E. D.; Solomakhin, A. L.; Savkin, V. Ya.; Bagryansky, P. A.

    2017-01-01

    We report on a new plasma startup scenario in the gas dynamic trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) plasma heating system fires into a sufficiently dense plasma target (‘seed plasma’), which is commonly supplied by an arc plasma generator. In the reported experiments, a different approach to seed plasma generation is explored. One of the channels of the electron cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of plasma to a level suitable for NBI capture. After a short transition of approximately 1 ms the discharge becomes essentially similar to a standard one initiated by the plasma gun. This paper presents the discharge scenario and experimental data on the seed plasma evolution during ECRH, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of the consequent high-power NBI discharge are studied and differences from the conventional scenario are discussed. A theoretical model describing the ECR breakdown and the seed plasma accumulation in a large-scale mirror trap is developed on the basis of the GDT experiment.

  10. The Thermal Ion Dynamics Experiment and Plasma Source Instrument

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Chappell, C. R.; Chandler, M. O.; Fields, S. A.; Pollock, C. J.; Reasoner, D. L.; Young, D. T.; Burch, J. L.; Eaker, N.; Waite, J. H., Jr.; McComas, D. J.; Nordholdt, J. E.; Thomsen, M. F.; Berthelier, J. J.; Robson, R.

    1995-01-01

    The Thermal Ion Dynamics Experiment (TIDE) and the Plasma Source Instrument (PSI) have been developed in response to the requirements of the ISTP Program for three-dimensional (3D) plasma composition measurements capable of tracking the circulation of low-energy (0-500 eV) plasma through the polar magnetosphere. This plasma is composed of penetrating magnetosheath and escaping ionospheric components. It is in part lost to the downstream solar wind and in part recirculated within the magnetosphere, participating in the formation of the diamagnetic hot plasma sheet and ring current plasma populations. Significant obstacles which have previously made this task impossible include the low density and energy of the outflowing ionospheric plasma plume and the positive spacecraft floating potentials which exclude the lowest-energy plasma from detection on ordinary spacecraft. Based on a unique combination of focusing electrostatic ion optics and time of flight detection and mass analysis, TIDE provides the sensitivity (seven apertures of about 1 cm squared effective area each) and angular resolution (6 x 18 degrees) required for this purpose. PSI produces a low energy plasma locally at the POLAR spacecraft that provides the ion current required to balance the photoelectron current, along with a low temperature electron population, regulating the spacecraft potential slightly positive relative to the space plasma. TIDE/PSI will: (a) measure the density and flow fields of the solar and terrestrial plasmas within the high polar cap and magnetospheric lobes; (b) quantify the extent to which ionospheric and solar ions are recirculated within the distant magnetotail neutral sheet or lost to the distant tail and solar wind; (c) investigate the mass-dependent degree energization of these plasmas by measuring their thermodynamic properties; (d) investigate the relative roles of ionosphere and solar wind as sources of plasma to the plasma sheet and ring current.

  11. Contoured-gap coaxial guns for imploding plasma liner experiments

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.

    2014-10-01

    Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

  12. Status of Magnetic Nozzle and Plasma Detachment Experiment

    SciTech Connect

    Chavers, D. Gregory; Dobson, Chris; Jones, Jonathan; Lee, Michael; Martin, Adam; Gregory, Judith; Cecil, Jim; Bengtson, Roger D.; Breizman, Boris; Arefiev, Alexey; Chang-Diaz, Franklin; Squire, Jared; Glover, Tim; McCaskill, Greg; Cassibry, Jason; Li Zhongmin

    2006-01-20

    High power plasma propulsion can move large payloads for orbit transfer, lunar missions, and beyond with large savings in fuel consumption owing to the high specific impulse. At high power, lifetime of the thruster becomes an issue. Electrodeless devices with magnetically guided plasma offer the advantage of long life since magnetic fields confine the plasma radially and keep it from impacting the material surfaces. For decades, concerns have been raised about the plasma remaining attached to the magnetic field and returning to the vehicle along the closed magnetic field lines. Recent analysis suggests that this may not be an issue if the magnetic field is properly shaped in the nozzle region and the plasma has sufficient energy density to stretch the magnetic field downstream. An experiment is being performed to test the theory regarding the MHD detachment scenario. The status of that experiment will be discussed in this paper.

  13. Plasma lens experiments at the Final Focus Test Beam

    SciTech Connect

    Barletta, B. |; Chattopadhyay, S.; Chen, P.

    1993-04-01

    We intend to carry out a series of plasma lens experiments at the Final Focus Test Beam facility at SLAC. These experiments will be the first to study the focusing of particle beams by plasma focusing devices in the parameter regime of interest for high energy colliders, and is expected to lead to plasma lens designs capable of unprecedented spot sizes. Plasma focusing of positron beams will be attempted for the first time. We will study the effects of lens aberrations due to various lens imperfections. Several approaches will be applied to create the plasma required including laser ionization and beam ionization of a working gas. At an increased bunch population of 2.5 {times} 10{sup 10}, tunneling ionization of a gas target by an electron beam -- an effect which has never been observed before -- should be significant. The compactness of our device should prove to be of interest for applications at the SLC and the next generation linear colliders.

  14. Particle Probe Investigations on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    Sherman, Justin; James, R. W.; Lopez, M.; Nolan, S.; Page, E. L.; Schlank, C.; Stutzman, B. S.; Zuniga, J.

    2012-10-01

    A small Helicon Plasma Experiment (HPX) has been constructed at the Coast Guard Academy Plasma Lab (CGAPL) to utilize the reputed high densities at low pressure (.01 T) [1], in high temperature and density diagnostic development for future laboratory investigations. With the initial construction phase complete, HPX has produced its first plasmas. Efforts to develop and enhance the high temperature and density (10^13 cm-3 and higher) helicon plasmas at low pressures (.01 T) reported by Toki, Shinohara, et. al. continue. Currently, particle probes to measure plasmas' temperatures and densities, necessary to discern the plasma mode transitions, are in development. Construction of independent mach and triple probes for single point surface investigations are underway and once installed, they will be followed by a triple probe array to produce a more comprehensive density and surface view. Progress on the construction and findings of these probes on HPX will be reported.

  15. Compact collimated fiber optic array diagnostic for railgun plasma experiments

    SciTech Connect

    Tang, V; Solberg, J; Ferriera, T; Tully, L; Stephan, P

    2008-10-02

    We have developed and tested a compact collimated sixteen channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with {approx}mm spatial and sub-{micro}s temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore Fixed Hybrid Armature experiment are presented and compared with 1-D simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  16. Plasma gasification of carbonaceous wastes: thermodynamic analysis and experiment

    NASA Astrophysics Data System (ADS)

    Messerle, V. E.; Mosse, A. L.; Ustimenko, A. B.

    2016-07-01

    Thermodynamic calculations of the plasma gasification process of carbonaceous wastes in air and steam ambient were carried out. A maximum yield of synthesis gas in such processes is predicted to be achieved at a temperature of 1600 K. On a specially developed plasma facility, plasma gasification experiments were performed for carbonaceous wastes. From the organic mass of carbonaceous waste and from its mineral mass, respectively, a high-calorific syngas and a neutral slag consisting predominantly of ferric carbide, calcium monosilicate, silica and iron, were obtained. A comparison between the experiment and the calculations has shown a good consistency between the data.

  17. Plasma Jog Experiments on MRX in Collaboration with MMS team

    NASA Astrophysics Data System (ADS)

    Yamada, Masaaki; Yoo, Jongsoo; Tharp, Tim; Ji, Hantao; Lawrence, Eric

    2011-10-01

    In the Magnetic Reconnection Experiment (MRX), a multi-probe mock-up system is utilized to investigate the fine structure of the diffusion region of the reconnection layer and to identify data signatures which indicate the nearby presence of a reconnection neutral sheet. The reconnection layer is swept through the probe system in controlled speeds of 0.01-0.2 of the Alfvén velocity. This situation is very similar to the space measurements in which the current sheet moves with respect to satellites as expected in the Magnetosphere Multi-scale Satellite (MMS) cluster configuration. The main objectives of the proposed joint research are (1) to compare basic properties of the reconnection regions in the neutral sheet of space and laboratory plasmas, (2) to study their roles in the process of magnetic reconnection, and (3) to measure fine scale profiles of the thin electron diffusion layer. A series of the first results from the experimental campaign are presented.

  18. A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma

    SciTech Connect

    Yang Min; Li Xiaoping; Xie Kai; Liu Donglin; Liu Yanming

    2013-01-15

    A large volume uniform plasma generator is proposed for the experiments of electromagnetic (EM) wave propagation in plasma, to reproduce a 'black out' phenomenon with long duration in an environment of the ordinary laboratory. The plasma generator achieves a controllable approximate uniform plasma in volume of 260 mm Multiplication-Sign 260 mm Multiplication-Sign 180 mm without the magnetic confinement. The plasma is produced by the glow discharge, and the special discharge structure is built to bring a steady approximate uniform plasma environment in the electromagnetic wave propagation path without any other barriers. In addition, the electron density and luminosity distributions of plasma under different discharge conditions were diagnosed and experimentally investigated. Both the electron density and the plasma uniformity are directly proportional to the input power and in roughly reverse proportion to the gas pressure in the chamber. Furthermore, the experiments of electromagnetic wave propagation in plasma are conducted in this plasma generator. Blackout phenomena at GPS signal are observed under this system and the measured attenuation curve is of reasonable agreement with the theoretical one, which suggests the effectiveness of the proposed method.

  19. The Madison plasma dynamo experiment: A facility for studying laboratory plasma astrophysics

    SciTech Connect

    Cooper, C. M.; Brookhart, M.; Collins, C.; Khalzov, I.; Milhone, J.; Nornberg, M.; Weisberg, D.; Forest, C. B.; Wallace, J.; Clark, M.; Flanagan, K.; Li, Y.; Nonn, P.; Ding, W. X.; Whyte, D. G.; Zweibel, E.

    2014-01-15

    The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic plasma research device designed to investigate flow driven magnetohydrodynamic instabilities and other high-β phenomena with astrophysically relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of alternately oriented 4000 G samarium cobalt magnets, which create an axisymmetric multicusp that contains ∼14 m{sup 3} of nearly magnetic field free plasma that is well confined and highly ionized (>50%). At present, 8 lanthanum hexaboride (LaB{sub 6}) cathodes and 10 molybdenum anodes are inserted into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a low pressure Ar or He fill gas and heating it. Up to 100 kW of electron cyclotron heating power is planned for additional electron heating. The LaB{sub 6} cathodes are positioned in the magnetized edge to drive toroidal rotation through J × B torques that propagate into the unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic Reynolds number Rm > 1000, and an adjustable fluid Reynolds number 10 < Re < 1000, in the regime where the kinetic energy of the flow exceeds the magnetic energy (M{sub A}{sup 2}=(v/v{sub A}){sup 2}>1). Initial results from MPDX are presented along with a 0-dimensional power and particle balance model to predict the viscosity and resistivity to achieve dynamo action.

  20. Lightweight Portable Plasma Medical Device - Plasma Engineering Research Laboratory

    DTIC Science & Technology

    2015-12-01

    treatment. We have developed a portable plasma source and tested on a range of bacteria and cancer cells and results were obtained. We have...source is very efficient in decontaminating wide range of infection and contamination causing bacteria . The direct and indirect exposure of the RBP jet...and post plasma treated bacteria . In these tests, the ROS produced by the RBP source was applied to Escherichia coli ATCC 11775, Bacillus cereus ATCC

  1. Initial Plasma Experiment in the Levitated Ring Trap RT-1

    NASA Astrophysics Data System (ADS)

    Saitoh, H.; Yoshida, Z.; Ogawa, Y.; Morikawa, J.; Watanabe, S.; Yano, Y.; Suzuki, J.

    2006-10-01

    Studies on toroidal flowing plasma have started in a superconductor levitated coil device, Ring Trap 1 (RT-1) [1]. RT-1 generates a magnetosphere-like dipole magnetic field configuration that enables various kinds of experiments related to flowing plasmas. The main purpose of the Ring Trap Experiment is to explore a new high-b relaxation state of plasmas predicted by two-fluid relaxation theory of flowing plasmas [2]. Magnetic surface configuration of RT-1 also enables stable pure-magnetic trap of non-neutral plasmas [3], which is potentially suitable for the confinement of charged particles including anti-matters. As an initial experiment, hydrogen plasma is produced by electron cyclotron heating using 8.2GHz microwave generated by a klystron with the maximum power of 100kW for 1s pulse operation. The high-Tc superconductor (Bi-2223) ring with a total coil current of 250kAT is magnetically levitated in a vacuum chamber using a PID feedback control system. The field strength in the trap region is 0.03T to 0.3T. Diagnostics for the RT-1 experiment includes spectroscopy, soft X-ray pulse-height analysis with Si (Li) detector, magnetic probes, and Langmuir probes for edge plasma measurement. The initial experimental results and basic plasma parameters of RT-1 will be presented in the meeting. 1. Z. Yoshida et al., Plasma Fusion Res. 1, 008 (2006). 2. Z. Yoshida and S. M. Mahajan, Phys. Rev. Lett. 88, 095001 (2002). 3. Z. Yoshida, et al., in Nonneutral Plasma Physics III, IV.

  2. The Orbital Acceleration Research Experiment

    NASA Technical Reports Server (NTRS)

    Blanchard, R. C.; Hendrix, M. K.; Fox, J. C.; Thomas, D. J.; Nicholson, J.

    1986-01-01

    The hardware and software of NASA's proposed Orbital Acceleration Research Experiment (OARE) are described. The OARE is to provide aerodynamic acceleration measurements along the Orbiter's principal axis in the free-molecular flow-flight regime at orbital attitude and in the transition regime during reentry. Models considering the effects of electromagnetic effects, solar radiation pressure, orbiter mass attraction, gravity gradient, orbital centripetal acceleration, out-of-orbital-plane effects, orbiter angular velocity, structural noise, mass expulsion signal sources, crew motion, and bias on acceleration are examined. The experiment contains an electrostatically balanced cylindrical proofmass accelerometer sensor with three orthogonal sensing axis outputs. The components and functions of the experimental calibration system and signal processor and control subsystem are analyzed. The development of the OARE software is discussed. The experimental equipment will be enclosed in a cover assembly that will be mounted in the Orbiter close to the center of gravity.

  3. Researching Abroad: Actual Experiences and Lessons Learned

    ERIC Educational Resources Information Center

    Scott, James Calvert

    2004-01-01

    Although many dream about conducting research abroad, few researchers achieve that dream. From research experiences in different parts of the world involving information access, research material organization, time perceptions, motivating respondents, research requirements, unexpected surprises, inappropriate arrangements, language and cultural…

  4. Burning plasma regime for Fussion-Fission Research Facility

    NASA Astrophysics Data System (ADS)

    Zakharov, Leonid E.

    2010-11-01

    The basic aspects of burning plasma regimes of Fusion-Fission Research Facility (FFRF, R/a=4/1 m/m, Ipl=5 MA, Btor=4-6 T, P^DT=50-100 MW, P^fission=80-4000 MW, 1 m thick blanket), which is suggested as the next step device for Chinese fusion program, are presented. The mission of FFRF is to advance magnetic fusion to the level of a stationary neutron source and to create a technical, scientific, and technology basis for the utilization of high-energy fusion neutrons for the needs of nuclear energy and technology. FFRF will rely as much as possible on ITER design. Thus, the magnetic system, especially TFC, will take advantage of ITER experience. TFC will use the same superconductor as ITER. The plasma regimes will represent an extension of the stationary plasma regimes on HT-7 and EAST tokamaks at ASIPP. Both inductive discharges and stationary non-inductive Lower Hybrid Current Drive (LHCD) will be possible. FFRF strongly relies on new, Lithium Wall Fusion (LiWF) plasma regimes, the development of which will be done on NSTX, HT-7, EAST in parallel with the design work. This regime will eliminate a number of uncertainties, still remaining unresolved in the ITER project. Well controlled, hours long inductive current drive operation at P^DT=50-100 MW is predicted.

  5. Comparing simulation of plasma turbulence with experiment

    NASA Astrophysics Data System (ADS)

    Ross, David W.; Bravenec, Ronald V.; Dorland, William; Beer, Michael A.; Hammett, G. W.; McKee, George R.; Fonck, Raymond J.; Murakami, Masanori; Burrell, Keith H.; Jackson, Gary L.; Staebler, Gary M.

    2002-01-01

    The direct quantitative correspondence between theoretical predictions and the measured plasma fluctuations and transport is tested by performing nonlinear gyro-Landau-fluid simulations with the GRYFFIN (or ITG) code [W. Dorland and G. W. Hammett, Phys. Fluids B 5, 812 (1993); M. A. Beer and G. W. Hammett, Phys. Plasmas 3, 4046 (1996)]. In an L-mode reference discharge in the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)], which has relatively large fluctuations and transport, the turbulence is dominated by ion temperature gradient (ITG) modes. Trapped electron modes and impurity drift waves also play a role. Density fluctuations are measured by beam emission spectroscopy [R. J. Fonck, P. A. Duperrex, and S. F. Paul, Rev. Sci. Instrum. 61, 3487 (1990)]. Experimental fluxes and corresponding diffusivities are analyzed by the TRANSP code [R. J. Hawryluk, in Physics of Plasmas Close to Thermonuclear Conditions, edited by B. Coppi, G. G. Leotta, D. Pfirsch, R. Pozzoli, and E. Sindoni (Pergamon, Oxford, 1980), Vol. 1, p. 19]. The shape of the simulated wave number spectrum is close to the measured one. The simulated ion thermal transport, corrected for E×B low shear, exceeds the experimental value by a factor of 1.5 to 2.0. The simulation overestimates the density fluctuation level by an even larger factor. On the other hand, the simulation underestimates the electron thermal transport, which may be accounted for by modes that are not accessible to the simulation or to the BES measurement.

  6. Transport studies in fusion plasmas: Perturbative experiments

    SciTech Connect

    Cardozo, N.J.L.

    1996-03-01

    By subjecting a plasma in steady state to small perturbations and measuring the response, it is possible to determine elements of the matrix of transport coefficients. Experimentally this is difficult, and results are mainly limited to transport driven by the pressure and temperature gradients. Importantly, off-diagonal elements in the transport matrix appear to be important. This has also implications for the interpretation of the so-called `power balance` diffusivity, determined from the steady state fluxes and gradients. Experimental techniques, analysis techniques, basic formulas, etc., are briefly reviewed. Experimental results are summarized. The fundamental question whether the fluxes are linear functions of the gradients or not is discussed. 31 refs.

  7. Basic Research in Plasma-Enhanced Combustion

    DTIC Science & Technology

    2009-11-04

    Prescribed by ANSI Std Z39-18 PLASMA DYNAMICS FOR AEROSPACE APPLICATIONS TECHNICAL CHALLENGES RUSSIAN AJAX HYPERSONIC FLIGHT VEHICLE (1994) • Uniform...Few Moving Parts • Power generation • Ignition/Combustion Kinetic energy of air stream Air Intake Nozzle M t l h i l i E l e c t r MGD generator MGD...Denisuk 6 Aerodynamics MRTI PLASMA DYNAMICS FOR AEROSPACE APPLICATIONS PAYOFFS Hypersonic Localized Plasma Discharges Drag Reduction Plasma MHD Flow

  8. Plasma-Filled Rod-Pinch Diode for HEDLP Research

    NASA Astrophysics Data System (ADS)

    Richardson, Andrew; Weber, Bruce; Swanekamp, Stephen; Schumer, Joseph; Pereira, Nino; Seely, John; Mosher, David

    2016-10-01

    This poster describes recent progress on research into using the plasma-filled rod-pinch (PFRP) at the Naval Research Laboratory (NRL) for warm dense matter (WDM) studies. The objective of this project is to utilize the PFRP diode and associated diagnostics to experimentally quantify the pressure, temperature, and ionization state via independent measurements in WDM comprised of ionized high-Z materials (tungsten). Previous experiments and preliminary results show that the parameters of the PFRP plasma are approximately Z = 17 , ρm = 0.7 g/cm3, T = 30 eV, P = 16 Mb, and Γ = 35 . The experiments and simulations currently underway will allow for more accurate determination of these parameters, which will contribute to an enhanced understanding of these high-Z materials in a WDM state. To achieve this objective, new diagnostics are being developed and current diagnostics are being refined, experiments are being performed, and numerical modeling is being carried out. This project will refine a new technique for producing WDM that can be replicated on pulsed power generators at several US universities and government laboratories, provide data for benchmarking numerical analysis codes, and develop diagnostics that should prove useful on many other WDM sources. This work was supported under the Department of Energy Office of Science Project DE-SC0014331.

  9. Early flavor experiences: research update.

    PubMed

    Mennella, J A; Beauchamp, G K

    1998-07-01

    Anyone who has observed infants for any period of time can testify to the intense activity occurring in and around their mouths--the primary site for learning in the first few months of life. Before they are even able to crawl, infants have learned much about their new sensory world. Though recent research we have begun to explore the impact of these early experiences on infants' acceptance of solid foods and how they explore objects in their environment. We have also begun to focus on the sensory experiences of the formula-fed infant, in particular, how their responses to particular formulas, which are extremely unpalatable to older children and adults, change during infancy. This is a relatively new and exciting area of study, with much research yet to be done. It is clear, however, that infants are not passive receptacles for flavored foods. Parents who offer a variety of foods will provide both a nutritious, well-balanced diet, as well as an opportunity for their children's own personal preferences to develop.

  10. Scaled Laboratory Collisionless Shock Experiments in the Large Plasma Device

    NASA Astrophysics Data System (ADS)

    Clark, S. E.; Schaeffer, D.; Everson, E.; Bondarenko, A.; Winske, D.; Constantin, C.; Niemann, C.

    2013-12-01

    Collisionless shocks in space plasmas have been investigated since the fifties and are typically studied via in-situ satellite observations, which are limited due to the large structure of collisionless shocks in space environments relative to the satellite observation platform. Scaled, repeatable experiments in the Large Plasma Device (LAPD) at UCLA provide a test bed for studying collisionless shocks in the laboratory, where questions of ion and electron heating and acceleration can be addressed and examined in detail. The experiments are performed by ablating a graphite or plastic target using the Raptor kilojoule-class laser facility at UCLA. The laser provides an on-target energy in the range of 100-500 J that drives a super-Alfvénic (MA > 1) debris plasma across a background magnetic field (200-800 G) into the ambient, magnetized LAPD plasma. Typical plasma parameters in the LAPD consist of a H+ or He+ ambient plasma with a core column (diameter > 20 cm ) density ni ~ 1013 cm-3 and electron temperature Te ~ 10 eV embedded in a larger plasma discharge (diameter ~ 80 cm) of density ni ~ 1012 cm-3 and Te ~ 5 eV. The ambient ion temperature is Ti ~ 1 eV. Experimental results from the latest collisionless shock campaign will be presented and compared with two dimensional hybrid simulations of the experiment. Fielded diagnostics include Thomson scattering, ion spectroscopy, magnetic flux probes, Langmuir probes, and microwave reflectometry.

  11. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    NASA Astrophysics Data System (ADS)

    Filippi, F.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Zigler, A.

    2016-09-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC_LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 1016-1017 cm-3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  12. A 1D (radial) Plasma Jet Propagation Study for the Plasma Liner Experiment (PLX)

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.; Welch, D. R.; Thoma, C.; Golovkin, I.; Macfarlane, J. J.; Case, A.; Messer, S. J.; Witherspoon, F. D.; Cassibry, J. T.; Awe, T. J.; Hsu, S. C.

    2011-10-01

    The Plasma Liner Experiment will explore the formation of imploding spherical ``plasma liners'' that reach peak pressures of 0.1 Mbar upon stagnation. The liners will be formed through the merging of dense, high velocity plasma jets (n ~1017 cm-3, T ~3 eV, v ~50 km/s) in a spherically convergent geometry. The focus of this 1D (radial) study is argon plasma jet evolution during propagation from the rail gun source to the jet merging radius. The study utilizes the Large Scale Plasma (LSP) PIC code with atomic physics included through the use of a non-Local Thermal Equilibrium (NLTE) Equation of State (EOS) table. We will present scenarios for expected 1D (radial) plasma jet evolution, from upon exiting the PLX rail gun to reaching the jet merging radius. The importance of radiation cooling early in the simulation is highlighted. Work supported by US DOE grant DE-FG02-05ER54835.

  13. Low Pressure High Density Plasma Development on a Small Helicon Plasma Experiment (HPX)*

    NASA Astrophysics Data System (ADS)

    James, R. W.; Allen, L. A.; Paolino, R. N.; Thayer, N.; Romano, B.; Stutzman, B. S.; Welicka, C.; Coast Guard Plasma Lab Team

    2011-10-01

    Small helicon plasmas have been employed in various capacities from industry to spacecraft propulsion. At the Coast Guard Academy Plasma Lab (CGAPL), a small Helicon Plasma Experiment (HPX) is being developed to utilize the reputed high densities (1013 cm-3 and higher) at low pressure (.01 T), in high temperature and density diagnostic development for future laboratory investigations. HPX is designed to operate at these high densities and pressure to create repeatedly stable Capacitively Coupled Plasma (CCP) and Inductively Coupled Plasma (ICP) plasmas induced by an RF frequency in the 10 to 70 MHz range. Progress on the development of the RF coupling system, and qualitative observations from the optical and electric diagnostics are to be reported.

  14. Plasma Motor Generator (PMG) electrodynamic tether experiment

    NASA Technical Reports Server (NTRS)

    Grossi, Mario D.

    1995-01-01

    The Plasma Motor Generator (PMG) flight of June 26, 1993 has been the most sophisticated and most successful mission that has been carried out thus far with an electrodynamic tether. Three papers from the Smithsonian Astrophysical Observatory, Washington, DC concerned with the PMG, submitted at the Fourth International Space Conference on Tethers in Space, in Washington, DC, in April 1995, are contained in this document. The three papers are (1) Electromagnetic interactions between the PMG tether and the magneto-ionic medium of the Ionosphere; (2) Tether-current-voltage characteristics, as determined by the Hollow Cathode Operation Modes; and (3) Hawaii-Hilo ground observations on the occasion for the PMG flight of June 23, 1993.

  15. Experimental and theoretical research in applied plasma physics

    SciTech Connect

    Porkolab, M.

    1992-01-01

    This report discusses research in the following areas: fusion theory and computations; theory of thermonuclear plasmas; user service center; high poloidal beta studies on PBX-M; fast ECE fluctuation diagnostic for balloning mode studies; x-ray imaging diagnostic; millimeter/submillimeter-wave fusion ion diagnostics; small scale turbulence and nonlinear dynamics in plasmas; plasma turbulence and transport; phase contrast interferometer diagnostic for long wavelength fluctuations in DIII-D; and charged and neutral fusion production for fusio plasmas.

  16. Lightweight Portable Plasma Medical Device - Plasma Engineering Research Laboratory

    DTIC Science & Technology

    2013-10-01

    quantum numbers of electronic...considering the low rotational level of the OH radicals OH (A-X) and small rotational quantum numbers J. 15, 40-42 The Boltzmann plot of the rotational...2004 – 05. Scientific Consultant, ASI Technology Corporation. (June 2003 - June 2004).  Designed and developed a novel plasma stealth

  17. Laboratory plasma interactions experiments: Results and implications to future space systems

    NASA Technical Reports Server (NTRS)

    Leung, Philip

    1986-01-01

    The experimental results discussed show the significance of the effects caused by spacecraft plasma interactions, in particular the generation of Electromagnetic Interference. As the experimental results show, the magnitude of the adverse effects induced by Plasma Interactions (PI) will be more significant for spacecraft of the next century. Therefore, research is needed to control possible adverse effects. Several techniques to control the selected PI effects are discussed. Tests, in the form of flight experiments, are needed to validate these proposed ideas.

  18. Numerical Investigation of Plasma Detachment in Magnetic Nozzle Experiments

    NASA Technical Reports Server (NTRS)

    Sankaran, Kamesh; Polzin, Kurt A.

    2008-01-01

    At present there exists no generally accepted theoretical model that provides a consistent physical explanation of plasma detachment from an externally-imposed magnetic nozzle. To make progress towards that end, simulation of plasma flow in the magnetic nozzle of an arcjet experiment is performed using a multidimensional numerical simulation tool that includes theoretical models of the various dispersive and dissipative processes present in the plasma. This is an extension of the simulation tool employed in previous work by Sankaran et al. The aim is to compare the computational results with various proposed magnetic nozzle detachment theories to develop an understanding of the physical mechanisms that cause detachment. An applied magnetic field topology is obtained using a magnetostatic field solver (see Fig. I), and this field is superimposed on the time-dependent magnetic field induced in the plasma to provide a self-consistent field description. The applied magnetic field and model geometry match those found in experiments by Kuriki and Okada. This geometry is modeled because there is a substantial amount of experimental data that can be compared to the computational results, allowing for validation of the model. In addition, comparison of the simulation results with the experimentally obtained plasma parameters will provide insight into the mechanisms that lead to plasma detachment, revealing how they scale with different input parameters. Further studies will focus on modeling literature experiments both for the purpose of additional code validation and to extract physical insight regarding the mechanisms driving detachment.

  19. Tritium Plasma Experiment Upgrade for Fusion Tritium and Nuclear Sciences

    NASA Astrophysics Data System (ADS)

    Shimada, Masashi; Taylor, Chase N.; Kolasinski, Robert D.; Buchenauer, Dean A.

    2015-11-01

    The Tritium Plasma Experiment (TPE) is a unique high-flux linear plasma device that can handle beryllium, tritium, and neutron-irradiated plasma facing materials, and is the only existing device dedicated to directly study tritium retention and permeation in neutron-irradiated materials [M. Shimada et.al., Rev. Sci. Instru. 82 (2011) 083503 and and M. Shimada, et.al., Nucl. Fusion 55 (2015) 013008]. Recently the TPE has undergone major upgrades in its electrical and control systems. New DC power supplies and a new control center enable remote plasma operations from outside of the contamination area for tritium, minimizing the possible exposure risk with tritium and beryllium. We discuss the electrical upgrade, enhanced operational safety, improved plasma performance, and development of tritium plasma-driven permeation and optical spectrometer system. This upgrade not only improves operational safety of the worker, but also enhances plasma performance to better simulate extreme plasma-material conditions expected in ITER, Fusion Nuclear Science Facility (FNSF), and Demonstration reactor (DEMO). This work was prepared for the U.S. Department of Energy, Office of Fusion Energy Sciences, under the DOE Idaho Field Office contract number DE-AC07-05ID14517.

  20. Research in Dense Plasma Atomic Physics.

    DTIC Science & Technology

    1984-04-19

    atomic properties up to r of order two (for neon). Debye - Huckel theory is not a meaningful approximation in strongly coupled plasmas. Nor can we...consequently one can expect that the Debye - Huckel theory would be inadequate for the description of plasma properties. This is demonstrated by...the Debye - Huckel (DH) and ion-sphere (IS) calculations when 13 < r < 1 Models We consider an ion of nuclear charge Z in a plasma in which the average

  1. Shuttle wave experiments. [space plasma investigations: design and instrumentation

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1976-01-01

    Wave experiments on shuttle are needed to verify dispersion relations, to study nonlinear and exotic phenomena, to support other plasma experiments, and to test engineering designs. Techniques based on coherent detection and bistatic geometry are described. New instrumentation required to provide modules for a variety of missions and to incorporate advanced signal processing and control techniques is discussed. An experiment for Z to 0 coupling is included.

  2. Light Weight Portable Plasma Medical Device - Plasma Engineering Research Laboratory

    DTIC Science & Technology

    2011-10-01

    acting on the objective lens. Great care was taken to position the objective lens together with the plasma chamber precisely in the line of sight...pressure as that of the chamber pressure in order to avoid differential pressures acting on the objective lens. Great care was taken to position the...Mohid, in Experimental micromachining of silicon with Nd-YAG laser, Malaysia , 2011 (Trans Tech Publications), p. 244. 5 P. G. Ashmore, Photochemistry

  3. Development of high energy pulsed plasma simulator for plasma-lithium trench experiment

    NASA Astrophysics Data System (ADS)

    Jung, Soonwook

    To simulate detrimental events in a tokamak and provide a test-stand for a liquid lithium infused trench (LiMIT) device, a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. An overall objective of the project is to develop a compact device that can produce 100 MW/m2 to 1 GW/m2 of plasma heat flux (a typical heat flux level in a major fusion device) in ~ 100 mus (≤ 0.1 MJ/m2) for a liquid lithium plasma facing component research. The existing theta pinch device, DEVeX, was built and operated for study on lithium vapor shielding effect. However, a typical plasma energy of 3 - 4 kJ/m2 is too low to study an interaction of plasma and plasma facing components in fusion devices. No or little preionized plasma, ringing of magnetic field, collisions of high energy particles with background gas have been reported as the main issues. Therefore, DEVeX is reconfigured to mitigate these issues. The new device is mainly composed of a plasma gun for a preionization source, a theta pinch for heating, and guiding magnets for a better plasma transportation. Each component will be driven by capacitor banks and controlled by high voltage / current switches. Several diagnostics including triple Langmuir probe, calorimeter, optical emission measurement, Rogowski coil, flux loop, and fast ionization gauge are used to characterize the new device. A coaxial plasma gun is manufactured and installed in the previous theta pinch chamber. The plasma gun is equipped with 500 uF capacitor and a gas puff valve. The increase of the plasma velocity with the plasma gun capacitor voltage is consistent with the theoretical predictions and the velocity is located between the snowplow model and the weak - coupling limit. Plasma energies measured with the calorimeter ranges from 0.02 - 0.065 MJ/m2 and increases with the voltage at the capacitor bank. A cross-check between the plasma energy measured with the calorimeter and the triple probe

  4. Analysis of Next-Step Burning Plasma Experiments

    NASA Astrophysics Data System (ADS)

    Jardin, S.; Kessel, C.; Meade, D.; Rutherford, P.; Pletzer, A.; Neumeyer, C.

    2001-10-01

    We present comparison studies of candidate next-step burning plasma experiments. A new systems-level code, BPSC, has been developed to find optimal designs for a particular design concept subject to a given set of engineering and physics constraints. We have applied this to liquid Nitrogen cooled compact devices of either the ST concept, where the poloidal field (PF) coils link the toroidal field (TF) coil, or the high-field tokamak concept, where the PF and TF coils are unlinked. For the latter class, we show that the FIRE* design is near optimal for an inductively driven burning plasma experiment with Q = 10 and pulse length exceeding two current redistribution times. We also present MHD and TSC transport analysis of the FIRE* design and compare this with other proposed burning plasma experiments. It is further shown that LHCD can reduce the consequences of neoclassical tearing modes in FIRE-class devices through reduction of delta-prime.

  5. Solar Array Module Plasma Interaction Experiment (SAMPIE): Technical requirements document

    NASA Technical Reports Server (NTRS)

    Hillard, G. Barry; Ferguson, Dale C.

    1992-01-01

    The Solar Array Module Plasma Interactions Experiment (SAMPIE) is a NASA shuttle space flight experiment scheduled for launch in early 1994. The SAMPIE experiment will investigate plasma interactions of high voltage space power systems in low earth orbit. Solar cell modules, representing several technologies, will be biased to high voltages to characterize both arcing and plasma current collection. Other solar modules, specially modified in accordance with current theories of arcing and breakdown, will demonstrate the possibility of arc suppression. Finally, several test modules will be included to study the basic nature of these interactions. The science and technology goals for the project are defined in the Technical Requirements Document (TRD) which is presented here.

  6. Trends in laser-plasma-instability experiments for laser fusion

    SciTech Connect

    Drake, R.P. Lawrence Livermore National Lab., CA )

    1991-06-06

    Laser-plasma instability experiments for laser fusion have followed three developments. These are advances in the technology and design of experiments, advances in diagnostics, and evolution of the design of high-gain targets. This paper traces the history of these three topics and discusses their present state. Today one is substantially able to produce controlled plasma conditions and to diagnose specific instabilities within such plasmas. Experiments today address issues that will matter for future laser facilities. Such facilities will irradiate targets with {approx}1 MJ of visible or UV light pulses that are tens of nanoseconds in duration, very likely with a high degree of spatial and temporal incoherence. 58 refs., 4 figs.

  7. Experiments on Plasma Physics : Experience is the Mother of Wisdom 2.Q Machine Plasmas

    NASA Astrophysics Data System (ADS)

    Hatakeyama, Rikizo

    Q machines, which produce low-temperature, stationary and fully-ionized plasmas in magnetic fields, have been operated for over four decades. The results obtained using the Q machine have greatly contributed toward systematizing plasma physics. Their typical examples are the clarification of Landau-damping based linear/nonlinear phenomena on ion acoustic , electron plasma , ion Bernstein waves, etc. , instability phenomena such as drift and ion-cyclotron waves, particle acceleration/heating/transport phenomena, and formation phenomena of charge-nonneutrality induced local electrostatic structure. In addition, transport coefficients in velocity and real spaces have been directly measured in quiescent and turbulent Q machine plasmas. Furthermore, as an extension to technological application, it is tried to control materials structure on nanometer scale using basic properties of the Q machine plasma.

  8. CO2 Laser Beat-Wave Experiment in an Unmagnetized Plasma

    NASA Astrophysics Data System (ADS)

    Liu, Fei; Hwang, David; Horton, Robert; Hong, Sean; Evans, Russell

    2012-10-01

    The ability to remotely generate plasma current in dense plasmas is a basic yet important investigation in experimental plasma physics and fusion energy research. It is even more advantageous if the wave penetration is independent of the electron acceleration process. Plasma current can be generated through beat-wave mixing process by launching two intense electromagnetic waves (φ>>φpe) into plasma. The beat wave formation process can be efficient if the difference frequency of the two pump waves is matched to a local resonant frequency of the medium, i.e. in this case the local plasma frequency. Beat wave can accelerate plasma electrons via quasi-linear Landau process, which has been demonstrated in a low-density plasma using microwaves.footnotetextRogers, J. H. and Hwang, D. Q., Phys. Rev. Lett. v68 p3877 (1992). The CO2 lasers provide the high tunability for the wave-particle interaction experiment at a variety of plasma densities with plasma frequency in THz range. Two sections of Lumonics TEA CO2 lasers have been modified to serve as the two pump wave sources with peak power over 100MW. The development of the tunable CO2 lasers, a high-density plasma target source and diagnostics system will be presented. The initial results of unbalanced beat-wave experiment using one high-power pulsed and one low-power CW CO2 lasers will be presented and discussed using the independent plasma source to control the φpe of the interaction region. This work is supported by U.S. DOE under Contract No. DE-FG02-10ER55083.

  9. Stark broadening data for stellar plasma research.

    NASA Astrophysics Data System (ADS)

    Dimitrijević, M. S.

    Results of an effort to provide to astrophysicists and physicists an as much as possible complete set of Stark broadening parameters needed for stellar opacity calculations, stellar atmosphere modelling, abundance determinations and diagnostics of different plasmas in astrophysics, physics and plasma technology, are presented. Stark broadening has been considered within the semiclassical perturbation, and the modified semiempirical approaches.

  10. Plasma Physics Research at an Undergraduate Institution

    NASA Astrophysics Data System (ADS)

    Padalino, Stephen

    2007-11-01

    Undergraduate research experiences have motivated many physics majors to continue their studies at the graduate level. The Department of Physics and Astronomy at SUNY Geneseo, a primarily undergraduate institution, recognizes this simple reality and is committed to ensuring research opportunities are available to interested majors beginning as early as their freshman year. Every year for more than a decade, as many as two dozen students and 8 faculty members have worked on projects related to high energy density physics and inertial confinement fusion during the summer months and the academic year. By working with their research sponsors, it has been possible to identify an impressive number of projects suitable for an institution such as Geneseo. These projects tend to be hands-on and require teamwork and innovation to be successful. They also take advantage of in-house capabilities such as the 2 MV tandem pelletron accelerator, a scanning electron microscope, a duoplasmatron ion deposition system and a 64 processor computing cluster. The end products of their efforts are utilized at the sponsoring facilities in support of nationally recognized programs. In this talk, I will discuss a number of these projects and point out what made them attractive and appropriate for an institution like Geneseo, the direct and indirect benefits of the research opportunities for the students and faculty, and how the national programs benefited from the cost-effective use of undergraduate research. In addition, I will discuss the importance of exposure for both students and faculty mentors to the larger scientific community through posters presentations at annual meetings such as the DPP and DNP. Finally, I will address the need for even greater research opportunities for undergraduate students in the future and the importance of establishing longer ``educational pipelines'' to satisfy the ever growing need for top-tier scientists and engineers in industry, academia and the

  11. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    SciTech Connect

    Not Available

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations.

  12. Freestanding film structures for laser plasma experiments

    SciTech Connect

    Klyuenkov, E B; Lopatin, A Ya; Luchin, V I; Salashchenko, Nikolai N; Tsybin, N N

    2013-04-30

    The technique is developed for fabricating 5-500-nm-thick freestanding films of various materials and multilayer compositions. Apart from the traditional use in spectral filtration of soft X-ray and extreme ultraviolet radiation, the possibility of using the ultrathin films fabricated by this technique as targets in experiments on laser acceleration of ions is considered. A sample of the target in the form of a 5-nm-thick carbon film on a supporting net is fabricated. (extreme light fields and their applications)

  13. Research on atmospheric pressure plasma processing sewage

    NASA Astrophysics Data System (ADS)

    Song, Gui-cai; Na, Yan-xiang; Dong, Xiao-long; Sun, Xiao-liang

    2013-08-01

    The water pollution has become more and more serious with the industrial progress and social development, so it become a worldwide leading environmental management problem to human survival and personal health, therefore, countries are looking for the best solution. Generally speaking, in this paper the work has the following main achievements and innovation: (1) Developed a new plasma device--Plasma Water Bed. (2) At atmospheric pressure condition, use oxygen, nitrogen, argon and helium as work gas respectively, use fiber spectrometer to atmospheric pressure plasma discharge the emission spectrum of measurement, due to the different work gas producing active particle is different, so can understand discharge, different particle activity, in the treatment of wastewater, has the different degradation effects. (3) Methyl violet solution treatment by plasma water bed. Using plasma drafting make active particles and waste leachate role, observe the decolorization, measurement of ammonia nitrogen removal.

  14. Research in space science and technology. [including X-ray astronomy and interplanetary plasma physics

    NASA Technical Reports Server (NTRS)

    Beckley, L. E.

    1977-01-01

    Progress in various space flight research programs is reported. Emphasis is placed on X-ray astronomy and interplanetary plasma physics. Topics covered include: infrared astronomy, long base line interferometry, geological spectroscopy, space life science experiments, atmospheric physics, and space based materials and structures research. Analysis of galactic and extra-galactic X-ray data from the Small Astronomy Satellite (SAS-3) and HEAO-A and interplanetary plasma data for Mariner 10, Explorers 47 and 50, and Solrad is discussed.

  15. Experiments on planar plasma flow switches at Los Alamos

    SciTech Connect

    Benage, J.F. Jr.; Wysocki, F.J.; Bowers, R.; Oona, H.

    1997-12-01

    The authors have performed a series of experiments on the Colt facility at Los Alamos to study the performance of plasma flow switches and to understand the important physics issues which affect that performance. These experiments were done in planar geometry on a small machine to allow for better diagnostic access and a higher repetition rate. The Colt facility is a capacitor bank which stores 300 kJ at maximum charge and produced a peak current of 1.1 MA in 2.0 microseconds for these experiments. The diagnostics used for these experiments included an array of b-dot probes, visible framing pictures, visible spectroscopy, and laser interferometry. Characteristics of the switch are determined from spatial and temporal profiles of the magnetic field and the spatial profile and temperature of the switch plasma. Here the authors present results from experiments for a variety of switch conditions.

  16. Research Activities at Plasma Research Laboratory at NASA Ames Research Center

    NASA Technical Reports Server (NTRS)

    Sharma, S. P.; Rao, M. V. V. S.; Meyyappan, Meyya

    2000-01-01

    In order to meet NASA's requirements for the rapid development and validation of future generation electronic devices as well as associated materials and processes, enabling technologies are being developed at NASA-Ames Research Center using a multi-discipline approach. The first step is to understand the basic physics of the chemical reactions in the area of plasma reactors and processes. Low pressure glow discharges are indispensable in the fabrication of microelectronic circuits. These plasmas are used to deposit materials and also etch fine features in device fabrication. However, many plasma-based processes suffer from stability and reliability problems leading to a compromise in performance and a potentially increased cost for the semiconductor manufacturing industry. Although a great deal of laboratory-scale research has been performed on many of these processing plasmas, little is known about the gas-phase and surface chemical reactions that are critical in many etch and deposition processes, and how these reactions are influenced by the variation in operating conditions. Such a lack of understanding has hindered the development of process models that can aid in the scaling and improvement of plasma etch and deposition systems. Our present research involves the study of such plasmas. An inductively-coupled plasma (ICP) source in place of the standard upper electrode assembly of the Gaseous Electronics Conference (GEC) radio-frequency (RF) Reference Cell is used to investigate the discharge characteristics. This ICP source generates plasmas with higher electron densities and lower operating pressures than obtainable with the original parallel-plate version of the GEC Cell. This expanded operating regime is more relevant to new generations of industrial plasma systems being used by the microelectronics industry. The research goal is to develop an understanding of the physical phenomena involved in plasma processing and to measure much needed fundamental

  17. A structured architecture for advanced plasma control experiments

    SciTech Connect

    Penaflor, B.G.; Ferron, J.R.; Walker, M.L.

    1996-10-01

    Recent new and improved plasma control regimes have evolved from enhancements to the systems responsible for managing the plasma configuration on the DIII-D tokamak. The collection of hardware and software components designed for this purpose is known at DIII-D as the Plasma Control System or PCS. Several new user requirements have contributed to the rapid growth of the PCS. Experiments involving digital control of the plasma vertical position have resulted in the addition of new high performance processors to operate in real-time. Recent studies in plasma disruptions involving the use of neural network based software have resulted in an increase in the number of input diagnostic signals sampled. Better methods for estimating the plasma shape and position have brought about numerous software changes and the addition of several new code modules. Furthermore, requests for performing multivariable control and feedback on the current profile are continuing to add to the demands being placed on the PCS. To support all of these demands has required a structured yet flexible hardware and software architecture for maintaining existing capabilities and easily adding new ones. This architecture along with a general overview of the DIII-D Plasma Control System is described. In addition, the latest improvements to the PCS are presented.

  18. Particle Probe Investigations on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    Sherman, Justin; James, R. W.; Nolan, S.; Page, E. J.; Romano, B.; Zuniga, J.; Schlank, C.; Lopez, M.; Karama, J.; Duke-Tinson, O.; Stutzman, B. S.

    2013-10-01

    Coast Guard Academy Plasma Lab(CGAPL) has constructed a Helicon Plasma Experiment. Plasmas will be used in high-temperature and -density diagnostic development for future lab investigations of fusion-grade plasma. Efforts to develop and enhance high temperature and density (1013cm-3 and up) helicon plasmas at low pressures (.01T) reported by Toki et al., continue. HPX will integrate a 32-channel National Instruments DAQ(Data Acquisition) board, designed to digitize data from tests. With LabView as the programing language, CGAPL will take samples at 12bits of precision at 2MS/s to create a Graphical User Interface (GUI). The GUI will control experimental variables (one or several concurrent tests) and monitor systems during data collection. Data collection will be conducted with particle probes, currently under construction. Probes, used to discern the plasma mode transitions, will measure plasma particle velocity, temperature, density and floating potential at different regimes. Once independent triple and mach probes for surface point investigations are installed, a triple probe array to produce a more comprehensive density and surface view will follow. Progress on development of GUI and construction of probes will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY12.

  19. Plasma Rotation Control Experiment in a Strongly Diverging Magnetic Field

    NASA Astrophysics Data System (ADS)

    Terasaka, Kenichiro; Furuta, Kanshi; Yoshimura, Shinji; Aramaki, Mitsutoshi; Tanaka, Masayoshi Y.

    2016-10-01

    It has been recognized that the plasma rotation affects the plasma flow structure along the magnetic field line. However, the effect of plasma rotation on structure formation in a strongly diverging magnetic field with magnetized electrons and unmagnetized ions has not been fully understood, so far. Understanding the flow structure formation in an ion-unmagnetized plasma is essential to control ion streamline detachment from the magnetic field line and also necessary to study the astrophysical phenomena in laboratory. In order to clarify the effect of plasma rotation in a diverging magnetic field, we have performed the plasma rotation control experiment in the HYPER-II device at Kyushu Univ., Japan. A set of cylindrical electrode was utilized to control the radial electric field, and the profile of azimuthal E × B rotation has been changed. We present the experimental results on the electron density pileup and the flow reversal appeared in the rotating plasma. This study was supported by JSPS KAKENHI Grant Number 16K05633.

  20. Experiment and simulation on one-dimensional plasma photonic crystals

    SciTech Connect

    Zhang, Lin; Ouyang, Ji-Ting

    2014-10-15

    The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5 Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range.

  1. New advances in thermal plasma research. [in upper atmosphere

    NASA Technical Reports Server (NTRS)

    Chappell, C. R.; Baugher, C. R.; Horwitz, J. L.

    1980-01-01

    Recent measurements obtained of the cold or thermal plasma of the earth's magnetosphere, which is believed to originate in the ionosphere, are reviewed. Consideration is given to the results of ATS 6 measurements which indicated unexpectedly high plasma temperatures and varied pitch-angle distributions, and the data from the low-energy plasma experiments on board GEOS 1 and 2 and ISEE 1, which were intended to clarify the ATS 6 results. These later measurements of ion composition, plasma energy and plasma distribution are noted to have confirmed earlier data and discovered new plasma components (D(+) or He(+2)), an intermixing of cold ionospheric plasma and hot magnetospheric plasma, the ordering of the plasma by the magnetic field rather than the ram direction in the outer magnetosphere, and wave phenomena. Questions remaining concerning the temperature and composition distributions of the plasmasphere and plasma trough, the relative densities of the cold and warmer components of the magnetosphere, plasma energization mechanisms, and the relative mix of the various plasma distributions are indicated.

  2. Partnership in Undergraduate Research Experience

    USDA-ARS?s Scientific Manuscript database

    Practical laboratory and work experience has been helpful in reinforcing the undergraduate educational experience. With limited resources, individual organizations may struggle to give a student a well rounded opportunity. Most undergraduates work within internships or cooperative educational fram...

  3. Combining the Strong Drive Regime with Evaporative Cooling to Control Plasma Parameters in the ALPHA Experiment

    NASA Astrophysics Data System (ADS)

    Carruth, Celeste; Fajans, Joel; Alpha Collaboration

    2016-10-01

    To make antihydrogen at the ALPHA experiment at CERN, we need to produce antiproton and positron plasmas with consistent plasma parameters. We developed a technique that allows us to eliminate initial variations in the density and the number of particles by combining evaporative cooling and the strong drive regime. The strong drive regime is a non-neutral plasma regime driven by a rotating electric field, where the drive frequency synchronizes with the plasma rotation frequency; this controls the density. Evaporative cooling is a space-charge dominated effect where a potential well is completely filled with the space charge of a plasma and one side is lowered, which sets the on-axis potential. For cold non-neutral plasmas, the density and on-axis potential give a unique solution to the plasma parameters, so we want to simultaneously combine these two techniques. Experimental results using electron plasmas show this combination of techniques does an excellent job at producing plasmas with the same number of particles and densities from a wide range of initial conditions. Special thanks to the United States Department of Energy and to the ALPHA collaboration for supporting this research.

  4. Design Experiments in Educational Research.

    ERIC Educational Resources Information Center

    Cobb, Paul; Confrey, Jere; diSessa, Andrea; Lehrer, Richard; Schauble, Leona

    2003-01-01

    Indicates the range of purposes and variety of settings in which design experiments have been conducted, delineating five crosscutting features that collectively differentiate design experiments from other methodologies. Clarifies what is involved in preparing for and carrying out a design experiment and in conducting a retrospective analysis of…

  5. Design Experiments in Educational Research.

    ERIC Educational Resources Information Center

    Cobb, Paul; Confrey, Jere; diSessa, Andrea; Lehrer, Richard; Schauble, Leona

    2003-01-01

    Indicates the range of purposes and variety of settings in which design experiments have been conducted, delineating five crosscutting features that collectively differentiate design experiments from other methodologies. Clarifies what is involved in preparing for and carrying out a design experiment and in conducting a retrospective analysis of…

  6. Recent Data Research Activities on Basic Plasma Research in Korea

    SciTech Connect

    Yoon, Jung-Sik; Song, Mi-Young; Kwon, Deuk-Chul; Chang, Won-Seok

    2011-05-11

    Since the characteristics of plasmas depend strongly on the interactions between plasma particles such as electron, ion, and neutrals, a well-established atomic and molecular database is needed to understand and produce various types of plasma. Thus, here the work conducted at the Data Center for Plasma Properties over last 5 years on the systematic synthesis and assessment of fundamental knowledge on low-energy electron interactions with plasma processing gases is briefly summarized and discussed. This work mostly emphasis on the electron interaction processes.

  7. Plasma flow switch and foil implosion experiments on Pegasus II

    SciTech Connect

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.R.; Forman, P.R.; Gribble, R.F.; Ladish, J.S.; Oona, H.; Parker, J.V.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

    1993-07-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10`s of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy.

  8. Plasma flow switch and foil implosion experiments on Pegasus II

    SciTech Connect

    Cochrane, J.C.; Bartsch, R.R.; Benage, J.R.; Forman, P.R.; Gribble, R.F.; Ladish, J.S.; Oona, H.; Parker, J.V.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

    1993-01-01

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10's of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy.

  9. Simulation studies of plasma lens experiments at Daresbury laboratory

    NASA Astrophysics Data System (ADS)

    Hanahoe, K.; Mete, O.; Xia, G.; Angal-Kalinin, D.; Jones, J.; Smith, J.

    2016-03-01

    Experiments are planned to study plasma lensing using the VELA and CLARA Front End accelerators at Daresbury Laboratory. This paper presents results of 2-dimensional particle-in-cell simulations of the proposed experiments. The variation in focusing strength and emittance growth with beam and plasma parameters are studied in the overdense (plasma density much greater than bunch density) regime for the VELA beam. The effect of spherical and longitudinal aberrations on the beam emittance was estimated through numerical and theoretical studies. Simulation results show that a focusing strength equivalent to a magnetic field gradient of 10 T m-1 can be achieved using VELA, and a gradient of 247 T m-1 can be achieved using CLARA Front End.

  10. Plasma Response to Lithium-Coated Plasma-Facing Components in the National Spherical Torus Experiment

    SciTech Connect

    M.G. Bell, H.W. Kugel, R. Kaita, L.E. Zakharov, H. Schneider, B.P. LeBlanc, D. Mansfield, R.E. Bell, R. Maingi, S. Ding, S.M. Kaye, S.F. Paul, S.P. Gerhardt, J.M. Canik, J.C. Hosea, G. Taylor and the NSTX Research Team

    2009-08-20

    Experiments in the National Spherical Torus Experiment (NSTX) have shown beneficial effects on the performance of divertor plasmas as a result of applying lithium coatings on the graphite and carbonfiber- composite plasma-facing components. These coatings have mostly been applied by a pair of lithium evaporators mounted at the top of the vacuum vessel which inject collimated streams of lithium vapor towards the lower divertor. In NBI-heated, deuterium H-mode plasmas run immediately after the application of lithium, performance modifications included decreases in the plasma density, particularly in the edge, and inductive flux consumption, and increases in the electron and ion temperatures and the energy confinement time. Reductions in the number and amplitude of ELMs were observed, including complete ELM suppression for periods up to 1.2 s, apparently as a result of altering the stability of the edge. However, in the plasmas where ELMs were suppressed, there was a significant secular increase in the effective ion charge Zeff and the radiated power as a result of increases in the carbon and medium-Z metallic impurities, although not of lithium itself which remained at a very low level in the plasma core, <0.1%. The impurity buildup could be inhibited by repetitively triggering ELMs with the application of brief pulses of an n = 3 radial field perturbation. The reduction in the edge density by lithium also inhibited parasitic losses through the scrape-off layer of ICRF power coupled to the plasma, enabling the waves to heat electrons in the core of H-mode plasmas produced by NBI. Lithium has also been introduced by injecting a stream of chemically stabilized, fine lithium powder directly into the scrape-off layer of NBI-heated plasmas. The lithium was ionized in the SOL and appeared to flow along the magnetic field to the divertor plates. This method of coating produced similar effects to the evaporated lithium but at lower amounts.

  11. Web life: The Internet Plasma Physics Education Experience

    NASA Astrophysics Data System (ADS)

    2009-02-01

    An educational outreach site maintained by the Princeton Plasma Physics Laboratory in the US, IPPEX features several interactive, game-like tools (applets) for exploring the physics of fusion, the doughnut-shaped "tokamak" reactors used in fusion experiments around the world, and related topics.

  12. First Laser-Plasma Interaction and Hohlraum Experiments on NIF

    SciTech Connect

    Dewald, E L; Glenzer, S H; Landen, O L; Suter, L J; Jones, O S; Schein, J; Froula, D; Divol, L; Campbell, K; Schneider, M S; McDonald, J W; Niemann, C; Mackinnon, A J

    2005-06-17

    Recently the first hohlraum experiments have been performed at the National Ignition Facility (NIF) in support of indirect drive Inertial Confinement Fusion (ICF) designs. The effects of laser beam smoothing by spectral dispersion (SSD) and polarization smoothing (PS) on the beam propagation in long scale gas-filled pipes has been studied at plasma scales as found in indirect drive gas filled ignition hohlraum designs. The long scale gas-filled target experiments have shown propagation over 7 mm of dense plasma without filamentation and beam break up when using full laser smoothing. Vacuum hohlraums have been irradiated with laser powers up to 6 TW, 1-9 ns pulse lengths and energies up to 17 kJ to activate several diagnostics, to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. Subsequently, novel long laser pulse hohlraum experiments have tested models of hohlraum plasma filling and long pulse hohlraum radiation production. The validity of the plasma filling assessment in analytical models and in LASNEX calculations has been proven for the first time. The comparison of these results with modeling will be discussed.

  13. Plasma medicine—current state of research and medical application

    NASA Astrophysics Data System (ADS)

    Weltmann, K.-D.; von Woedtke, Th

    2017-01-01

    Plasma medicine means the direct application of cold atmospheric plasma (CAP) on or in the human body for therapeutic purposes. Further, the field interacts strongly with results gained for biological decontamination. Experimental research as well as first practical application is realized using two basic principles of CAP sources: dielectric barrier discharges (DBD) and atmospheric pressure plasma jets (APPJ). Originating from the fundamental insights that the biological effects of CAP are most probably caused by changes of the liquid environment of cells, and are dominated by reactive oxygen and nitrogen species (ROS, RNS), basic mechanisms of biological plasma activity are identified. It was demonstrated that there is no increased risk of cold plasma application and, above all, there are no indications for genotoxic effects. The most important biological effects of cold atmospheric pressure plasma were identified: (1) inactivation of a broad spectrum of microorganisms including multidrug resistant ones; (2) stimulation of cell proliferation and tissue regeneration with lower plasma treatment intensity (treatment time); (3) inactivation of cells by initialization of programmed cell death (apoptosis) with higher plasma treatment intensity (treatment time). In recent years, the main focus of clinical applications was in the field of wound healing and treatment of infective skin diseases. First CAP sources are CE-certified as medical devices now which is the main precondition to start the introduction of plasma medicine into clinical reality. Plasma application in dentistry and, above all, CAP use for cancer treatment are becoming more and more important research fields in plasma medicine. A further in-depth knowledge of control and adaptation of plasma parameters and plasma geometries is needed to obtain suitable and reliable plasma sources for the different therapeutic indications and to open up new fields of medical application.

  14. Synergy Between Experiments and Simulations in Laser and Beam-Driven Plasma Acceleration and Light Sources

    NASA Astrophysics Data System (ADS)

    Mori, Warren B.

    2015-11-01

    Computer simulations have been an integral part of plasma physics research since the early 1960s. Initially, they provided the ability to confirm and test linear and nonlinear theories in one-dimension. As simulation capabilities and computational power improved, then simulations were also used to test new ideas and applications of plasmas in multi-dimensions. As progress continued, simulations were also used to model experiments. Today computer simulations of plasmas are ubiquitously used to test new theories, understand complicated nonlinear phenomenon, model the full temporal and spatial scale of experiments, simulate parameters beyond the reach of current experiments, and test the performance of new devices before large capital expenditures are made to build them. In this talk I review the progress in simulations in a particular area of plasma physics: plasma based acceleration (PBA). In PBA a short laser pulse or particle beam propagates through long regions of plasma creating plasma wave wakefields on which electrons or positrons surf to high energies. In some cases the wakefields are highly nonlinear, involve three-dimensional effects, and the trajectories of plasma particles cross making it essential that fully kinetic and three-dimensional models are used. I will show how particle-in-cell (PIC) simulations were initially used to propose the basic idea of PBA in one dimension. I will review some of the dramatic progress in the experimental demonstration of PBA and show how this progress was dramatically helped by a synergy between experiments and full-scale multi-dimensional PIC simulations. This will include a review of how the capability of PIC simulation tools has improved. I will also touch on some recent progress on improvements to PIC simulations of PBA and discuss how these improvements may push the synergy further towards real time steering of experiments and start to end modeling of key components of a future linear collider or XFEL based on PBA

  15. X-ray GEM Detectors for Burning Plasma Experiments

    NASA Astrophysics Data System (ADS)

    Puddu, S.; Bombarda, F.; Pizzicaroli, G.; Murtas, F.

    2009-11-01

    The harsh environment and higher values of plasma parameters to be expected in future burning plasma experiments (and even more so in future power producing fusion reactors) is prompting the development of new, advanced diagnostic systems. The detection of radiation emitted by the plasma in the X-ray spectral region is likely to play the role that visible or UV radiation have in present day experiments. GEM gas detectors, developed at CERN, are the natural evolution of Multiwire Proportional Chambers, with a number of advantages: higher counting rates, lower noise, good energy resolution, low sensitivity to background radiation. GEM's can be used in several different ways, but two specific applications are being explored in the framework of the Ignitor program, one for plasma position control and the other for high resolution spectroscopy. The diagnostic layout on the Ignitor machine is such that the detectors will not be in direct view of the plasma, at locations where they can be efficiently screened by the background radiation. Prototype detectors 10 x 10 cm^2 in area have been assembled and will be tested to assess the optimal geometrical parameters and operating conditions, regarding in particular the choice between Single and Triple GEM configurations, the gas mixture, and the problem of fan-out associated with the high number of output channels required for high resolution crystal spectrometers.

  16. Development of a plasma driven permeation experiment for TPE

    DOE PAGES

    Buchenauer, Dean; Kolasinski, Robert; Shimada, Masa; ...

    2014-04-18

    Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 ?C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 ?C, a new TPE membrane holder has been built to hold test specimens (=1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ionmore » chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE’s vacuum chamber has been demonstrated by sealing tests performed up to 1000 ?C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (~700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 ?C are expected at the highest TPE fluxes.« less

  17. Development of a plasma driven permeation experiment for TPE

    SciTech Connect

    Buchenauer, Dean; Kolasinski, Robert; Shimada, Masa; Donovan, David; Youchison, Dennis; Merrill, Brad

    2014-04-18

    Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 ?C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 ?C, a new TPE membrane holder has been built to hold test specimens (=1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ion chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE’s vacuum chamber has been demonstrated by sealing tests performed up to 1000 ?C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (~700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 ?C are expected at the highest TPE fluxes.

  18. Tritium Plasma Experiment (TPE) - parameters and potentials for fusion plasma-wall interaction studies

    SciTech Connect

    Masashi Shimada; Robert D. Kolasinski; J. Phillip Sharpe; Rion A. Causey

    2011-08-01

    The Tritium plasma experiment (TPE) is a unique facility devoted to experiments on the behavior of deuterium/tritium in toxic (e.g. beryllium) and radioactive materials for fusion plasma-wall interaction (PWI) studies. A Langmuir probe was added to the system to characterize the plasma conditions in TPE. With this new diagnostic, we found the achievable electron temperature ranged from 5.0 to 10.0 eV, the electron density varied from 5.0 x 10{sup 16} to 2.5 x 10{sup 18} m{sup -3}, and the ion flux density varied between 5.0 x 10{sup 20} to 2.5 x 10{sup 22} m{sup -2}s{sup -1} along the centerline of the plasma. A comparison of these plasma parameters with the conditions expected for the plasma facing components (PFCs) in ITER shows that TPE is capable of achieving most (approximately 800 m{sup 2} of 850 m{sup 2} total PFCs area) of the expected ion flux density and electron density conditions.

  19. Tritium plasma experiment: Parameters and potentials for fusion plasma-wall interaction studies

    SciTech Connect

    Shimada, Masashi; Sharpe, J. Phillip; Kolasinski, Robert D.; Causey, Rion A.

    2011-08-15

    The tritium plasma experiment (TPE) is a unique facility devoted to experiments on the behavior of deuterium/tritium in toxic (e.g., beryllium) and radioactive materials for fusion plasma-wall interaction studies. A Langmuir probe was added to the system to characterize the plasma conditions in TPE. With this new diagnostic, we found the achievable electron temperature ranged from 5.0 to 10.0 eV, the electron density varied from 5.0 x 10{sup 16} to 2.5 x 10{sup 18} m{sup -3}, and the ion flux density varied between 5.0 x 10{sup 20} to 2.5 x 10{sup 22} m{sup -2} s{sup -1} along the centerline of the plasma. A comparison of these plasma parameters with the conditions expected for the plasma facing components (PFCs) in ITER shows that TPE is capable of achieving most ({approx}800 m{sup 2} of 850 m{sup 2} total PFCs area) of the expected ion flux density and electron density conditions.

  20. Freak waves in negative-ion plasmas: an experiment revisited

    NASA Astrophysics Data System (ADS)

    Kourakis, Ioannis; Elkamash, Ibrahem; Reville, Brian

    2016-10-01

    Extreme events in the form of rogue waves (freak waves) occur widely in the open sea. These are space- and time-localised excitations, which appear unexpectedly and are characterised by a significant amplitude. Beyond ocean dynamics, the mechanisms underlying rogue wave formation are now being investigated in various physical contexts, including materials science, nonlinear optics and plasma physics, to mention but a few. We have undertaken an investigation, from first principles, of the occurrence of rogue waves associated with the propagation of electrostatic wavepackets in plasmas. Motivated by recent experimental considerations involving freak waves in negative-ion plasmas (NIP), we have addresed the occurrence of freak waves in NIP from first principles. An extended range of plasma parameter values was identified, where freak wave formation is possible, in terms of relevant plasma parameters. Our results extend -and partly contradict- the underlying assumptions in the interpretation of the aforementioned experiment, where a critical plasma configuration was considered and a Gardner equation approach was adopted. This work was supported from CPP/QUB funding. One of us (I. Elkamash) acknowledges financial support by an Egyptian Government fellowship.

  1. Design and Construction of the Plasma Bubble Expansion Experiment

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Lynn, A. G.; Hsu, S. C.; Gilmore, M.; Watts, Christopher

    2007-11-01

    We will present the design and construction of a new compact coaxial magnetized plasma gun and its associated hardware systems. The plasma gun will be used for experimental studies of ``magnetic bubble'' expansion into a pre-existing lower density background plasma on the HELCAT facility at UNM. These experiments will address key nonlinear plasma physics issues pertinent to plasma models of the formation and evolution of extra-galactic radio lobes. The gun will be powered by a 120μF 10kV ignitron-switched capacitor bank. High pressure gas, controlled by a gas valve system, will be puffed into an annular gap between inner and outer coaxial electrodes. An applied high voltage ionizes the gas and creates a radial current sheet. The ˜ 100kA discharge current generates toroidal flux, and an external magnet will provide poloidal ``bias'' flux. This poster will describe in detail the design and construction of the various power systems for the new plasma gun source.

  2. Progress in Development of Low Pressure High Density Plasmas on a Small Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    James, Royce; Lopez, M.; Nolan, S.; Page, E. L.; Schlank, C.; Sherman, J.; Stutzman, B. S.; Zuniga, J.

    2012-10-01

    At the Coast Guard Academy Plasma Lab (CGAPL), a small Helicon Plasma Experiment (HPX) is being developed to utilize the reputed high densities (10^13 cm-3 and higher) at low pressure (.01 T) [1], for eventual high temperature and density diagnostic development in future laboratory investigations. HPX is designed to create repeatedly stable plasmas induced by an RF frequency in the 10 to 70 MHz range and employs an electromagnet to provide the external energy in the plasma's magnetic field to transition from the H-Mode to the Helicon Mode. An acceleration coil, currently under construction, will place the plasma in the vacuum chamber for optical and particle probing. With the initial construction phase complete and first plasmas attained, HPX is constructing triple and mach particle probes, magnetic probes, and a single point 300 W Thompson Scattering system backed by a 32-channel DAQ system capable 12 bits of sampling precision at 2 MS/s for plasma property investigations. Progress on the development of the RF coupling system, magnetic coils, and qualitative observations from the optical and electric diagnostics are to be reported. [4pt] [1] K. Toki, et al., Thin Solid Films 506-507 (2005).

  3. Material Surface Characteristics and Plasma Performance in the Lithium Tokamak Experiment

    SciTech Connect

    Lucia, Matthew James

    2015-09-01

    The performance of a tokamak plasma and the characteristics of the surrounding plasma facing component (PFC) material surfaces strongly influence each other. Despite this relationship, tokamak plasma physics has historically been studied more thoroughly than PFC surface physics. The disparity is particularly evident in lithium PFC research: decades of experiments have examined the effect of lithium PFCs on plasma performance, but the understanding of the lithium surface itself is much less complete. This latter information is critical to identifying the mechanisms by which lithium PFCs affect plasma performance. This research focused on such plasma-surface interactions in the Lithium Tokamak Experiment (LTX), a spherical torus designed to accommodate solid or liquid lithium as the primary PFC. Surface analysis was accomplished via the novel Materials Analysis and Particle Probe (MAPP) diagnostic system. In a series of experiments on LTX, the MAPP x-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS) capabilities were used for in vacuo interrogation of PFC samples. This represented the first application of XPS and TDS for in situ surface analysis of tokamak PFCs. Surface analysis indicated that the thin (d ~ 100nm) evaporative lithium PFC coatings in LTX were converted to Li2O due to oxidizing agents in both the residual vacuum and the PFC substrate. Conversion was rapid and nearly independent of PFC temperature, forming a majority Li2O surface within minutes and an entirely Li2O surface within hours. However, Li2O PFCs were still capable of retaining hydrogen and sequestering impurities until the Li2O was further oxidized to LiOH, a process that took weeks. For hydrogen retention, Li2O PFCs retained H+ from LTX plasma discharges, but no LiH formation was observed. Instead, results implied that H+ was only weakly-bound, such that it almost completely outgassed as H2 within minutes. For impurity sequestration, LTX plasma performance

  4. Eulerian and Lagrangian Plasma Jet Modeling for the Plasma Liner Experiment

    NASA Astrophysics Data System (ADS)

    Hatcher, Richard; Cassibry, Jason; Stanic, Milos; Loverich, John; Hakim, Ammar

    2011-10-01

    The Plasma Liner Experiment (PLX) aims to demonstrate the feasibility of using spherically-convergent plasma jets to from an imploding plasma liner. Our group has modified two hydrodynamic simulation codes to include radiative loss, tabular equations of state (EOS), and thermal transport. Nautilus, created by TechX Corporation, is a finite-difference Eulerian code which solves the MHD equations formulated as systems of hyperbolic conservation laws. The other is SPHC, a smoothed particle hydrodynamics code produced by Stellingwerf Consulting. Use of the Lagrangian fluid particle approach of SPH is motivated by the ability to accurately track jet interfaces, the plasma vacuum boundary, and mixing of various layers, but Eulerian codes have been in development for much longer and have better shock capturing. We validate these codes against experimental measurements of jet propagation, expansion, and merging of two jets. Precursor jets are observed to form at the jet interface. Conditions that govern evolution of two and more merging jets are explored.

  5. Resonant Plasma Wakefield Experiment: Plasma Simulations and Multibunched Electron Beam Diagnostics

    NASA Astrophysics Data System (ADS)

    Kallos, Efthymios; Muggli, Patric; Katsouleas, Thomas; Yakimenko, Vitaly; Stolyarov, Daniil; Pogorelsky, Igor; Pavlishin, Igor; Kusche, Karl; Babzien, Marcus; Ben-Zvi, Ilan; Kimura, Wayne D.

    2006-11-01

    In the multibunch plasma wakefield acceleration experiment at the Brookhaven National Lab's Accelerator Test Facility a 45 MeV electron beam is initially modulated through the IFEL interaction with a CO2 laser beam at 10.6 μm into a train of short microbunches, which are spaced at the laser wavelength. It is then fed into a high-density capillary plasma with a density resonant at this spacing (1.0 × 1019cm-3). The microbunched beam can resonantly excite a plasma wakefield much larger than the wakefield excited from the non-bunched beam. Here we present plasma simulations that confirm the wakefield enhancement and the results of a series of CTR measurements performed of the multibunched electron beam.

  6. Research on Orbital Plasma: Electrodynamics (ROPE)

    NASA Technical Reports Server (NTRS)

    Samir, Uri; Fontheim, Ernest G.

    2000-01-01

    Enhancements of the temperature of electrons in spacecraft plasma wakes have been reported for numerous cases and this phenomenon has been discussed both empirically and theoretically. However, very few measurements seem to have been made of the ion temperature within plasma wakes-possibly because the great majority of ion measurements were focussed on obtaining geophysical parameters and, hence, were confined to the region ahead of the spacecraft. Recently, however, an enhancement of the temperature of ions was discovered in data obtained in the wake of the Space Shuttle during the Spacelab-2 mission. At the time of that publication, this was the only known observation of this type. Herein, we report an additional case of ion temperature enhancement in a plasma wake. The data were taken during the Tethered Satellite System Reflight mission (TSS-1R) in the wake of the tethered satellite during passive (no current flow) operations. The measurements were obtained with the Differential Ion Flux Probe, or DIFP.

  7. The plasma dynamics of hypersonic spacecraft: Applications of laboratory simulations and active in situ experiments

    NASA Technical Reports Server (NTRS)

    Stone, N. H.; Samir, Uri

    1986-01-01

    Attempts to gain an understanding of spacecraft plasma dynamics via experimental investigation of the interaction between artificially synthesized, collisionless, flowing plasmas and laboratory test bodies date back to the early 1960's. In the past 25 years, a number of researchers have succeeded in simulating certain limited aspects of the complex spacecraft-space plasma interaction reasonably well. Theoretical treatments have also provided limited models of the phenomena. Several active experiments were recently conducted from the space shuttle that specifically attempted to observe the Orbiter-ionospheric interaction. These experiments have contributed greatly to an appreciation for the complexity of spacecraft-space plasma interaction but, so far, have answered few questions. Therefore, even though the plasma dynamics of hypersonic spacecraft is fundamental to space technology, it remains largely an open issue. A brief overview is provided of the primary results from previous ground-based experimental investigations and the preliminary results of investigations conducted on the STS-3 and Spacelab 2 missions. In addition, several, as yet unexplained, aspects of the spacecraft-space plasma interaction are suggested for future research.

  8. Research experiments at Hangar L

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Research assistant Trisha Bruno performs an analysis on potato samples at Hangar L at the Cape Canaveral Air Force Station. The research she is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long-duration spaceflight and environmental/ecological stewardship.

  9. Research experiments at Hangar L

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Research scientist Greg Goins monitors radish growth under a sulfur-microwave light at Hangar L at the Cape Canaveral Air Force Station. The research he is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long- duration spaceflight and environmental/ecological stewardship.

  10. Research experiments at Hangar L

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Research scientist Greg Goins monitors radish growth under a sulfur-microwave light at Hangar L at the Cape Canaveral Air Force Station. The research he is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long- duration spaceflight and environmental/ecological stewardship.

  11. Research experiments at Hangar L

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Research assistant Trisha Bruno performs an analysis on potato samples at Hangar L at the Cape Canaveral Air Force Station. The research she is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long-duration spaceflight and environmental/ecological stewardship.

  12. Monitoring Trends in Research Student Experience

    ERIC Educational Resources Information Center

    Grebennikov, Leonid; Shah, Mahsood

    2017-01-01

    Purpose: The purpose of this paper is to present approaches effectively used by a large multi-campus Australian university to improve the research student experience as a direct result of their feedback. These approaches include: identifying trends in the research student experience and areas needing improvement through the Research Student…

  13. Experience Effect in E-Learning Research

    NASA Astrophysics Data System (ADS)

    Wu, Bing; Xu, WenXia; Ge, Jun

    This study is a productivity review on the literature gleaned from SSCI, SCIE databases concerning experience in E-Learning research. The result indicates that the number of literature productions on experience effect in ELearning research is still growing from 2005. The main research development country is Croatia, and from the analysis of the publication year, the number of papers is increasing to the peaking in 2010. And the main source title is British Journal of Educational Technology. In addition the subject area concentrated on Education & Educational Research. Moreover the research focuses on are mainly survey research and empirical research, in order to explore experience effect in E-Learning research. Also the limitations and future research of these research were discussed, so that the direction for further research work can be exploited

  14. Magnetospheric radio and plasma wave research - 1987-1990

    SciTech Connect

    Kurth, W.S. )

    1991-01-01

    This review covers research performed in the area of magnetospheric plasma waves and wave-particle interactions as well as magnetospheric radio emissions. The report focuses on the near-completion of the discovery phase of radio and plasma wave phenomena in the planetary magnetospheres with the successful completion of the Voyager 2 encounters of Neptune and Uranus. Consideration is given to the advances made in detailed studies and theoretical investigations of radio and plasma wave phenomena in the terrestrial magnetosphere or in magnetospheric plasmas in general.

  15. Current status of IMS plasma wave research. [International Magnetospheric Study

    NASA Technical Reports Server (NTRS)

    Anderson, R. R.

    1982-01-01

    The present investigation is concerned with a review of the status of magnetospheric plasma wave science as a result of the International Magnetospheric Study (IMS). The presence of an international effort has supported the development and completion of the numerous magnetospheric science spacecraft launched during the IMS, including GEOS, ISEE, and EXOS B. Ground-based VLF observations are considered along with coordinated ground-based and satellite observations. During the IMS, plasma wave research using satellite data has covered a wide range of subjects. Attention is given to magnetospheric electrostatic emissions, magnetospheric electromagnetic plasma waves, continuum radiation, auroral kilometric radiation, auroral zone plasma waves, plasma waves in the magnetosheath and near the mangetopause, and plasma waves at the bow shock.

  16. Updates to the Development of Low Pressure High Density Plasmas on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    James, Royce; Azzari, Phil; Crilly, Paul; Duke-Tinson, Omar; Karama, Jackson; Paolino, Richard; Schlank, Carter; Sherman, Justin; Emami, Tooran; Turk, Jeremy

    2016-10-01

    The small Helicon Plasma Experiment (HPX) at the Coast Guard Academy Plasma Lab (CGAPL), continues to progress toward utilizing the reputed high densities (1013 cm-3 and higher) at low pressure (.01 T) [1] of helicons, for eventual high temperature and density diagnostic development in future laboratory investigations. HPX is designed to create repeatedly stable plasmas ( 20 - 30 ns) induced by an RF frequency in the 10 to 70 MHz range. HPX is constructing RF field corrected Langmuir probe raw data will be collected and used to measure the plasma's density, temperature, and potentially the structure and behavior during experiments. Our 2.5 J YAG laser Thomson Scattering system backed by a 32-channel Data Acquisition (DAQ) system is capable 12 bits of sampling precision at 2 MS/s for HPX plasma property investigations are being developed and tested. Progress on the construction of the RF coupling system, Helicon Mode development, and magnetic coils, along with observations from the Thomson Scattering, particle, and electromagnetic scattering diagnostics will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY15-16.

  17. Progress on Development of Low Pressure High Density Plasmas on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    James, Royce; Azzari, Phillip; Duke-Tinson, Omar; Frank, John; Karama, Jackson; Hopson, Jordan; Paolino, Richard; Sandri, Eva; Sherman, Justin; Wright, Erin; Turk, Jeremy

    2015-11-01

    The small Helicon Plasma Experiment (HPX) at the Coast Guard Academy Plasma Lab (CGAPL), continues to progress toward utilizing the reputed high densities (1013 cm-3 and higher) at low pressure (.01 T) [1] of helicons, for eventual high temperature and density diagnostic development in future laboratory investigations. HPX is designed to create repeatedly stable plasmas (~ 20 - 30 ns) induced by an RF frequency in the 10 to 70 MHz range. HPX is constructing RF field corrected Langmuir probe raw data will be collected and used to measure the plasma's density, temperature, and potentially the structure and behavior during experiments. Our 2.5 J YAG laser Thomson Scattering system backed by a 32-channel Data Acquisition (DAQ) system is capable 12 bits of sampling precision at 2 MS/s for HPX plasma property investigations. Progress on the development of the RF coupling system, Helicon Mode development, magnetic coils, and observations from the Thomson Scattering, particle, and electromagnetic scattering diagnostics will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY15.

  18. Progress on Development of Low Pressure High Density Plasmas on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    James, R. W.; Duke-Tinson, O.; Nolan, S.; Page, E. J.; Lopez, M.; Karama, J.; Paolino, R. N.; Schlank, C.; Sherman, J.; Stutzman, B. S.; Crilly, P. B.

    2013-10-01

    At the Coast Guard Academy Plasma Lab (CGAPL), a small Helicon Plasma Experiment (HPX) is being developed to utilize the reputed high densities (1013 cm-3 and higher) at low pressure (.01 T), for eventual high temperature and density diagnostic development in future laboratory investigations. HPX is designed to create repeatedly stable plasmas induced by an RF frequency in the 10 to 70 MHz range. We employ a 400 to 1000 Gauss electromagnet that promotes energy conservation in the plasma via external energy production in the magnetic field facilitated by decreased inertial effects, in order to reach the Helicon Mode. With the initial construction phase complete and repeatable plasmas attained, HPX is constructing triple and mach particle probes, magnetic probes, and a single point 300 W Thompson Scattering system backed by a 32-channel Data Acquisition (DAQ) system capable 12 bits of sampling precision at 2 MS/s for HPX plasma property investigations. Progress on the development of the RF coupling system, Helicon Mode development, magnetic coils, and observations from the optical, particle, and electromagnetic scattering diagnostics will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY12.

  19. Development of a non-ideal plasma target for non-linear beam plasma interaction experiments

    NASA Astrophysics Data System (ADS)

    Katagiri, K.; Nishinomiya, S.; Niinou, T.; Kaneko, J.; Hasegawa, J.; Ogawa, M.; Oguri, Y.

    2007-07-01

    A shock-driven plasma target was developed to examine non-linear interactions between low-energy heavy ions and cold-dense plasmas. MD calculations predicted that beam-plasma coupling constant γ˜0.1 must be achieved to observe the non-linearity, which corresponds to the plasma coupling constant Γ≈0.2 for projectiles of vproj≈10 keV/u and q≈2. One-dimensional numerical estimations using SESAME equation of state showed that a shock wave propagating in 5-Torr H2 gas with 47 km/s must be produced to satisfy Γ≈0.2. Utilizing an electromagnetic shock tube with a peak current of 50 kA and a current rise time of 800 ns, we achieved a shock speed of 45 km/s. The electron density distribution of the shock-produced plasma along the beam axis was measured by a Mach-Zehnder interferometer. From this measurement we confirmed that the electron density was over 1017 cm-3 and the homogeneity was acceptable during several hundred nanoseconds. The electron temperature was also determined by optical spectroscopic measurements. The Coulomb coupling constant was evaluated using these experimental data to investigate feasibility of the beam-plasma interaction experiments.

  20. Research experiments at Hangar L

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Visiting scientist Cheryl Frazier monitors a prototype composting machine in Hangar L at the Cape Canaveral Air Force Station. The research she is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long-duration spaceflight and environmental/ecological stewardship.

  1. Atomic kinetics of a neon photoionized plasma experiment at Z

    NASA Astrophysics Data System (ADS)

    Mayes, Daniel C.; Mancini, Roberto; E Bailey, James; Loisel, Guillaume; Rochau, Gregory

    2017-06-01

    We discuss an experimental effort to study the atomic kinetics in neon photoionized plasmas via K-shell line absorption spectroscopy. The experiment employs the intense x-ray flux emitted at the collapse of a Z-pinch to heat and backlight a photoionized plasma contained within a cm-scale gas cell placed at various distances from the Z-pinch and filled with neon gas pressures in the range from 3.5 to 30 torr. The experimental platform affords an order of magnitude range in the ionization parameter characterizing the photoionized plasma from about 3 to 80 erg*cm/s. Thus, the experiment allows for the study of trends in ionization distribution as a function of the ionization parameter. An x-ray crystal spectrometer capable of collecting both time-integrated and time-gated spectra is used to collect absorption spectra. A suite of IDL programs has been developed to process the experimental data to produce transmission spectra. The spectra show line absorption by several ionization stages of neon, including Be-, Li-, He-, and H-like ions. Analysis of these spectra yields ion areal-densities and charge state distributions, which can be compared with results from atomic kinetics codes. In addition, the electron temperature is extracted from level population ratios of nearby energy levels in Li- and Be-like ions, which can be used to test heating models of photoionized plasmas.

  2. Commercialization of Plasma-Assisted Technologies: The Indian Experience

    NASA Astrophysics Data System (ADS)

    John, P. I.

    The paper describes an initiative by the Institute for Plasma Research (IPR), India in establishing links with the Indian industry for developing and commercialising advanced plasma-based industrial technologies. This has culminated in the creation of a self-financing technology development, incubation, demonstration and delivery facility. A business plan for converting the knowledge base to commercially viable technologies conceived technology as a product and the industry as the market and addressed issues like resistance to new technologies, the key role of entrepreneur, thrust areas and the necessity of technology incubation and delivery. Success of this strategy is discussed in a few case studies. We conclude by identifying the cost, environmental, strategic and techno-economic aspects, which would be the prime drivers for plasma-assisted manufacturing technology in India.

  3. Los Alamos research in nozzle based coaxial plasma thrusters

    NASA Technical Reports Server (NTRS)

    Scheuer, Jay; Schoenberg, Kurt; Gerwin, Richard; Henins, Ivars; Moses, Ronald, Jr.; Wurden, Glen

    1992-01-01

    The topics are presented in viewgraph form and include the following: research approach; perspectives on efficient magnetoplasmadynamic (MPD) operation; NASA and DOE supported research in ideal magnetohydrodynamic plasma acceleration and flow, electrode phenomena, and magnetic nozzles; and future research directions and plans.

  4. On 45 Years of Space Plasma Research

    NASA Astrophysics Data System (ADS)

    Kelley, M. C.

    2011-12-01

    After 47 years of immersion in space physics, I have many stories to tell, some of which are not suitable for all audiences and will remain untold today. But after a few such tales, I will recount the most satisfying research I have done and then outline a new book I am working on entitled "The Earth's Electric Field". I also will outline five sources of electric fields: thunderstorms, motions of the atmosphere, the solar wind, the magnetosphere, and wave phenomena. The most satisfying work I have published involves proof that the Earth was hit by a comet in 1908, studies of the long-lasting meteor trail during Leonids1998/9, and results of barium/TMA releases. On the human side, the most satisfying work has been with Cornell students, both undergraduate and graduate. Although many books have been written on the Earth's magnetic field, to my knowledge, none have been written on the electric field. This is not surprising since Gauss first noted that the Earth is a giant magnet hundreds of years ago. The first evidence of an electric field in the atmosphere was provided by Ben Franklin with his kite/thunderstorm experiments. We began considering the possibility of an electric field in space about 50 years ago, using the motion of auroral patches. Then, in the 1960s, Forrest Mozer and Ulf Fahleson showed that the electric field could be measured using rockets and, eventually, satellites. Luckily, I was Forrest's second student and Ulf was in Berkeley for a year, so I was in the perfect place for a graduate student. Thus began the quest for knowledge of the Earth's electric field, which continues today.

  5. Plasma Simulation for the SHIP Experiment at GDT

    SciTech Connect

    Anikeev, A.V.; Bagryansky, P.A.; Collatz, S.; Noack, K

    2005-01-15

    The concept of the Synthesized Hot Ion Plasmoid (SHIP) experiment at the gas dynamic trap (GDT) facility of the Budker Institute Novosibirsk was presented at the 29{sup th} EPS Conference. During the last year several numerical simulations were made by means of the Integrated Transport Code System (ITCS) to determine the best experimental scenario for getting high plasma parameters. This contribution presents important results of the recent numerical simulations of SHIP by means of the ITCS modules.

  6. Radiative Shocks And Plasma Jets As Laboratory Astrophysics Experiments

    SciTech Connect

    Koenig, M.; Loupias, B.; Vinci, T.; Ozaki, N.; Benuzzi-Mounaix, A.; Rabec le Goahec, M.; Falize, E.; Bouquet, S.; Courtois, C.; Nazarov, W.; Aglitskiy, Y.; Faenov, A. Ya.; Pikuz, T.; Schiavi, A.

    2007-08-02

    Dedicated laboratory astrophysics experiments have been developed at LULI in the last few years. First, a high velocity (70 km/s) radiative shock has been generated in a xenon filled gas cell. We observed a clear radiative precursor, measure the shock temperature time evolution in the xenon. Results show the importance of 2D radiative losses. Second, we developed specific targets designs in order to generate high Mach number plasma jets. The two schemes tested are presented and discussed.

  7. The Tordo 1 polar cusp barium plasma injection experiment

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Jeffries, R. A.; Roach, W. H.

    1978-01-01

    In January 1975, two barium plasma injection experiments were carried out with rockets launched into the upper atmosphere where field lines from the dayside cusp region intersect the ionosphere. The Tordo 1 experiment took place near the beginning of a worldwide magnetic storm. It became a polar cap experiment almost immediately as convection perpendicular to the magnetic field moved the fluorescent plasma jet away from the cusp across the polar cap in an antisunward direction. Convection across the polar cap with an average velocity of more than 1 km/s was observed for nearly 40 min until the barium flux tubes encountered large electron fields associated with a poleward bulge of the auroral oval near Greenland. Prior to the encounter with the aurora near Greenland there is evidence of upward acceleration of the barium ions while they were in the polar cap. The three-dimensional observations of the plasma orientation and motion give an insight into convection from the cusp region across the polar cap, the orientation of the polar cap magnetic field lines out to several earth radii, the causes of polar cap magnetic perturbations, and parallel acceleration processes.

  8. Theory and Simulation of the LBNL Plasma Lens Experiment

    NASA Astrophysics Data System (ADS)

    Backhaus, E. Yu.; Wurtele, J. S.; Govil, R.; Leemans, W. P.

    1998-11-01

    A theoretical analysis and Particle-in-cell (PIC) simulation of the LBNL plasma lens experiment is presented. The envelope equation is used which includes the self-consistent evolution of the beam (i.e. `thick lens' effect), effects of nonlinear aberrations and full plasma return currents.(R. Govil and W.P.Leemans, proceedings of 8th workshop on advanced accelerator concepts.)^,(E. Yu. Backhaus, D. Whittum and J. S.Wurtele, proceedings of 8th workshop on advanced accelerator concepts.) The envelope equation is simplified in the limit of small k_pσ_r. It is shown that the effects of the aberrations can be of the same order as the effect of the return currents for k_pσ_r<=0.5. The full envelope equation is used to model the experiment for a wide range of k_pσ_r. The 2D relativistic, fully electromagnetic PIC code (XOOPIC) is used to simulate the experiment including the finite plasma effect. The validity of the envelope equation is discussed.

  9. SUMMA hot-ion plasma heating research at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Patch, R. W.; Lauver, M. R.

    1975-01-01

    The SUMMA superconducting magnetic mirror facility and the associated hot-ion plasma research were described. SUMMA is characterized by intense magnetic fields and a large-diameter working bore (41 cm diameter) with room-temperature access. The goal of the plasma research program is to produce steady-state plasmas of fusion reactor densities and temperatures (but not confinement times). The program includes electrode development to produce a hot, dense, large-volume, steady-state plasma and diagnostics development to document the plasma properties. SUMMA and its hot-ion plasma are ideally suited to develop advanced plasma diagnostics methods. Two such methods whose requirements are well matched to SUMMA are: (1) heavy ion beam probing to measure plasma space potential; and (2) submillimeter wavelength laser Thomson scattering to measure local ion temperature.

  10. Supersonic gas jets for laser-plasma experiments.

    PubMed

    Schmid, K; Veisz, L

    2012-05-01

    We present an in-depth analysis of De Laval nozzles, which are ideal for gas jet generation in a wide variety of experiments. Scaling behavior of parameters especially relevant to laser-plasma experiments as jet collimation, sharpness of the jet edges and Mach number of the resulting jet is studied and several scaling laws are given. Special attention is paid to the problem of the generation of microscopic supersonic jets with diameters as small as 150 μm. In this regime, boundary layers dominate the flow formation and have to be included in the analysis.

  11. Constituting Information Technology Research: The Experience of IT Researchers

    ERIC Educational Resources Information Center

    Pham, Binh; Bruce, Christine; Stoodley, Ian

    2005-01-01

    The collective consciousness of effective groups of researchers is characterized by shared understandings of their research object or territory. In this study, we adopted a phenomenographic approach to investigate information technology (IT) research, and its objects and territories, as they are constituted in the experience of IT researchers.…

  12. Academic Factors that Affect Undergraduate Research Experiences

    ERIC Educational Resources Information Center

    Taraban, Roman; Logue, Erin

    2012-01-01

    Undergraduate research experiences are considered an essential component in college curricula, and there is an ideological push to provide these experiences to all students. However, it is not clear whether engagement in research is better suited for higher ability undergraduates late in their programs or for all undergraduates and whether…

  13. Limitations of Experiments in Education Research

    ERIC Educational Resources Information Center

    Schanzenbach, Diane Whitmore

    2012-01-01

    Research based on randomized experiments (along with high-quality quasi-experiments) has gained traction in education circles in recent years. There is little doubt this has been driven in large part by the shift in research funding strategy by the Department of Education's Institute of Education Sciences under Grover Whitehurst's lead, described…

  14. NASA Researcher Adjusts a Travelling Magnetic Wave Plasma Engine

    NASA Image and Video Library

    1964-02-21

    Raymond Palmer, of the Electromagnetic Propulsion Division’s Plasma Flow Section, adjusts the traveling magnetic wave plasma engine being operated in the Electric Power Conversion at the National Aeronautics and Space Administration (NASA) Lewis Research Center. During the 1960s Lewis researchers were exploring several different methods of creating electric propulsion systems, including the traveling magnetic wave plasma engine. The device operated similarly to alternating-current motors, except that a gas, not a solid, was used to conduct the electricity. A magnetic wave induced a current as it passed through the plasma. The current and magnetic field pushed the plasma in one direction. Palmer and colleague Robert Jones explored a variety of engine configurations in the Electric Propulsion Research Building. The engine is seen here mounted externally on the facility’s 5-foot diameter and 16-foot long vacuum tank. The four magnetic coils are seen on the left end of the engine. The researchers conducted two-minute test runs with varying configurations and used of both argon and xenon as the propellant. The Electric Propulsion Research Building was built in 1942 as the Engine Propeller Research Building, often called the Prop House. It contained four test cells to study large reciprocating engines with their propellers. After World War II, the facility was modified to study turbojet engines. By the 1960s, the facility was modified again for electric propulsion research and given its current name.

  15. Experiments on Negative Ion Plasmas in a Q-Machine

    NASA Astrophysics Data System (ADS)

    An, Tao

    Three experiments on negative ion plasmas in the University of Iowa Q-machine IQ-2 are described in this thesis. In the Lower-Hybrid wave experiment, the low-frequency (ion-ion mode) waves are excited, waves propagate at a right angle to the magnetic field. The wave frequencies increase as the negative ion concentration increases, in agreement with the dispersion relation obtained from fluid theory. In the Kelvin-Helmholtz instability experiment, the negative ions have a generally destabilizing effect on the instability driven by a relative drift between ions in adjacent layers. However, for large negative ion concentrations, enhanced radial diffusion associated with the Kelvin-Helmholtz oscillations tends to have a stabilizing effect due to a "mixing" of ion flows in adjacent layer. In the diffusion experiment, the K^ {+} ions experience a displacement across the magnetic filed on the order of their gyroradius upon collision with a negative ion, leading to an enhancement in the rate of cross-field diffusion over that expected in the ordinary K^{+}/electron plasma.

  16. Empirical modeling of plasma clouds produced by the Metal Oxide Space Clouds experiment

    NASA Astrophysics Data System (ADS)

    Pedersen, Todd R.; Caton, Ronald G.; Miller, Daniel; Holmes, Jeffrey M.; Groves, Keith M.; Sutton, Eric

    2017-05-01

    The Advanced Research Project Agency (ARPA) Long-Range Tracking And Instrumentation Radar (ALTAIR) radar at Kwajalein Atoll was used in incoherent scatter mode to measure plasma densities within two artificial clouds created by the Air Force Research Laboratory (AFRL) Metal Oxide Space Clouds (MOSC) experiment in May 2013. Optical imager, ionosonde, and ALTAIR measurements were combined to create 3-D empirical descriptions of the plasma clouds as a function of time, which match the radar measurements to within 15%. The plasma clouds closely track the location of the optical clouds, and the best fit plasma cloud widths are generally consistent with isotropic neutral diffusion. Cloud plasma densities decreased as a power of time, with exponents between -0.5 and -1.0, or much more slowly than the -1.5 predicted by diffusion. These exponents and estimates of total ion number from integration through the model volume are consistent with a scenario of slow ionization and a gradually increasing total number of ions with time, reaching a net ionization fraction of 20% after approximately half an hour. These robust representations of the plasma density are being used to study impacts of the artificial clouds on the dynamics of the background ionosphere and on RF propagation.

  17. Designing Effective Research Experiences for Undergraduates (Invited)

    NASA Astrophysics Data System (ADS)

    Jones Whyte, P.; Dalbotten, D. M.

    2009-12-01

    The undergraduate research experience has been recognized as a valuable component of preparation for graduate study. As competition for spaces in graduate schools become more keen students benefit from a formal introduction to the life of a scholar. Over the last twenty years a model of preparing students for graduate study with the research experience as the base has been refined at the University of Minnesota. The experience includes assignment with a faculty member and a series of seminars that support the experience. The seminars cover topics to include academic writing, scholarly literature review, writing of the abstract, research subject protection protocols, GRE test preparation, opportunities to interact with graduate student, preparing the graduate school application, and preparation of a poster to demonstrate the results of the research. The next phase of the process is to determine the role of the undergraduate research experience in the graduate school admission process.

  18. Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

    SciTech Connect

    Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

    2015-04-15

    We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH{sub 2} with 2.8% H{sub 2} served as the discharge medium. H{sub 2} was chosen in order to observe the broadening of the H{sub β} emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 10{sup 16} cm{sup −3}. Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

  19. Initial experiments of RF gas plasma source for heavy ionfusion

    SciTech Connect

    Ahle, L.; Hall, R.; Molvik, A.W.; Chacon-Golcher, E.; Kwan, J.W.; Leung, K.N.; Reijonen, J.

    2002-05-22

    The Source Injector Program for the US Heavy Ion Fusion Virtual National Laboratory is currently exploring the feasibility of using RF gas plasma sources for a HIF driver. This source technology is presently the leading candidate for the multiple aperture concept, in which bright millimeter size beamlets are extracted and accelerated electrostatically up to 1 MeV before the beamlets are allowed to merge and form 1 A beams. Initial experiments have successfully demonstrated simultaneously high current density, {approx} 100 mA/cm{sup 2} and fast turn on, {approx} 1 {micro}s. These experiments were also used to explore operating ranges for pressure and RF power. Results from these experiments are presented as well as progress and plans for the next set of experiments for these sources.

  20. The language of 'experience' in nursing research.

    PubMed

    Allen, David; Cloyes, Kristin

    2005-06-01

    This paper is an analysis of how the signifier 'experience' is used in nursing research. We identify a set of issues we believe accompany the use of experience but are rarely addressed. These issues are embedded in a spectrum that includes ontological commitments, visions of the person/self and its relation to 'society', understandings of research methodology and the politics of nursing. We argue that a poststructuralist understanding of the language of experience in research opens up additional ways to analyze the relationship between the conduct of nursing research and cultural/political commitments.

  1. Development of Low Pressure High Density Plasmas on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    James, Royce; Azzari, Phillip; Crilly, Paul; Duke-Tinson, Omar; Karama, Jackson; Paolino, Richard; Schlank, Carter; Sherman, Justin

    2014-10-01

    The small Helicon Plasma Experiment (HPX) at the Coast Guard Academy Plasma Lab (CGAPL), continues to progress toward utilizing the reputed high densities (10 cm-3 and higher) at low pressure (.01 T) of helicons, for eventual high temperature and density diagnostic development in future laboratory investigations. HPX is designed to create repeatedly stable plasmas induced by an RF frequency in the 10 to 70 MHz range. We employ a 400 to 1000 Gauss electromagnet that promotes energy conservation in the plasma via external energy production in the magnetic field facilitated by decreased inertial effects, in order to reach the Helicon Mode. HPX is completing construction of triple and mach particle probes, magnetic probes, and is designing a single point 300 W Thompson Scattering system backed by a 32-channel Data Acquisition (DAQ) system capable 12 bits of sampling precision at 2 MS/s for HPX plasma property investigations. Progress on the development of the RF coupling system, Helicon Mode development, magnetic coils, and observations from the optical, particle, and electromagnetic scattering diagnostics will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY13.

  2. Ion Heating Experiments in a Supersonic Plasma Flow for an Advanced Plasma Thruster

    NASA Astrophysics Data System (ADS)

    Ando, Akira; Hosokawa, Yohei; Hatanaka, Motoi; Yagai, Tsuyoshi; Tobari, Hiroyuki; Hattori, Kunihiko; Inutake, Masaaki

    2003-10-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) project in NASA, the combined system of the ion cyclotron heating and the magnetic nozzle is proposed to control a ratio od specific impulse to thrust at constant power. By now, few attempt of a direct ion heating for fast flowing plasma by waves has been done. Ion heating in a fast flowing plasma might be difficult because of the short transit time for ions to pass through a heating region only once and the modification of ion cyclotron resonance due to the effect of Doppler shift. Ion heating experiments are performed in a fast flowing plasma produced by Magneto-Plasma-Dynamic Arcjet (MPDA) operated with an externally-applied magnetic field. RF waves with an ion cyclotron range of frequency is excited by a pair of loop antennas or a helical antenna. An increase of plasma stored energy measured by a diamagnetic loop coil is observed when the waves are excited with various azimuthal mode numbers in several magnetic nozzle configurations. It is most effective to heat ions to excite the waves with an azimuthal mode number of m=±1. Dispersion relations of the propagating wave are obtained and compared with theoretical ones.

  3. Feminist research or humanistic research? Experiences of studying prostatectomy.

    PubMed

    Pateman, B

    2000-03-01

    This paper highlights issues related to men's health research arising from a small-scale study, carried out by a male researcher, to identify the experience of men following transuretheral resection of prostate (TURP) for benign prostatic hypertrophy (BPH). The intention of this paper is to stimulate methodological debate rather than to be a research report. For the study, an informal interview approach was used within a phenomenological framework, and interview experiences raised issues which have been previously discussed under the rubric of feminist research. The conclusion drawn is that a style of research which attempts to gain a holistic view of patients' experiences is better termed 'humanistic research' because the term 'feminist research' clearly cannot be applied to men studying men's health-related experiences.

  4. Modeling of Spherical Torus Plasmas for Liquid Lithium Wall Experiments

    SciTech Connect

    R. Kaita; S. Jardin; B. Jones; C. Kessel; R. Majeski; J. Spaleta; R. Woolley; L. Zakharo; B. Nelson; M. Ulrickson

    2002-01-29

    Liquid metal walls have the potential to solve first-wall problems for fusion reactors, such as heat load and erosion of dry walls, neutron damage and activation, and tritium inventory and breeding. In the near term, such walls can serve as the basis for schemes to stabilize magnetohydrodynamic (MHD) modes. Furthermore, the low recycling characteristics of lithium walls can be used for particle control. Liquid lithium experiments have already begun in the Current Drive eXperiment-Upgrade (CDX-U). Plasmas limited with a toroidally localized limiter have been investigated, and experiments with a fully toroidal lithium limiter are in progress. A liquid surface module (LSM) has been proposed for the National Spherical Torus Experiment (NSTX). In this larger ST, plasma currents are in excess of 1 MA and a typical discharge radius is about 68 cm. The primary motivation for the LSM is particle control, and options for mounting it on the horizontal midplane or in the divertor region are under consideration. A key consideration is the magnitude of the eddy currents at the location of a liquid lithium surface. During plasma start up and disruptions, the force due to such currents and the magnetic field can force a conducting liquid off of the surface behind it. The Tokamak Simulation Code (TSC) has been used to estimate the magnitude of this effect. This program is a two dimensional, time dependent, free boundary simulation code that solves the MHD equations for an axisymmetric toroidal plasma. From calculations that match actual ST equilibria, the eddy current densities can be determined at the locations of the liquid lithium. Initial results have shown that the effects could be significant, and ways of explicitly treating toroidally local structures are under investigation.

  5. Studies of dynamic processes related to active experiments in space plasmas

    NASA Technical Reports Server (NTRS)

    Banks, Peter M.; Neubert, Torsten

    1992-01-01

    This is the final report for grant NAGw-2055, 'Studies of Dynamic Processes Related to Active Experiments in Space Plasmas', covering research performed at the University of Michigan. The grant was awarded to study: (1) theoretical and data analysis of data from the CHARGE-2 rocket experiment (1keV; 1-46 mA electron beam ejections) and the Spacelab-2 shuttle experiment (1keV; 100 mA); (2) studies of the interaction of an electron beam, emitted from an ionospheric platform, with the ambient neutral atmosphere and plasma by means of a newly developed computer simulation model, relating model predictions with CHARGE-2 observations of return currents observed during electron beam emissions; and (3) development of a self-consistent model for the charge distribution on a moving conducting tether in a magnetized plasma and for the potential structure in the plasma surrounding the tether. Our main results include: (1) the computer code developed for the interaction of electrons beams with the neutral atmosphere and plasma is able to model observed return fluxes to the CHARGE-2 sounding rocket payload; and (2) a 3-D electromagnetic and relativistic particle simulation code was developed.

  6. Researching the experience of kidney cancer patients.

    PubMed

    Taylor, K

    2002-09-01

    The author's personal experience as a kidney cancer patient, researcher and founder of a kidney cancer support group forms the basis for consideration of the challenges involved in researching patients' experiences. The researcher needs to understand the variability of those experiences in both clinical and psychological-emotional terms, and in relation to the personal, familial and social contexts of the patient. It is also essential to define the purpose of the research and to show how an understanding of personal experiences of cancer can be used to enhance the quality of care for cancer patients. The research encounter with a patient is also in some respects a therapeutic encounter requiring a considerable degree of sensitivity on the part of the researcher. The person-centred approach of Carl Rogers is of value in supporting such an encounter.

  7. Evaluation of a BSW Research Experience: Improving Student Research Competency

    ERIC Educational Resources Information Center

    Whipple, Ellen E.; Hughes, Anne; Bowden, Susan

    2015-01-01

    This article examines the experience of 24 BSW students in a faculty-mentored undergraduate research experience (URE) over the course of 1 academic year. In particular, we sought to better understand students' self-perceived sense of competency across 15 specific research skills. In addition, we examined the URE's impact on students' knowledge…

  8. Radiographic research of the Bi plasma jet formed by the vacuum arc discharge

    NASA Astrophysics Data System (ADS)

    Artyomov, A. P.; Rousskikh, A. G.; Fedunin, A. V.; Chaikovsky, S. A.; Zhigalin, A. S.; Oreshkin, V. I.

    2017-05-01

    The results of experiments on a soft x-ray radiography (≈ 1-2 keV) of a bismuth plasma formed by the high-current vacuum arc discharge are represented. The plasma gun with the arc current ≈ 60 kA and the current rise time ≈ 7 μs was used to produce the Bi plasma jet. The compact pulsed radiograph XPG-1 (250 kA, 220 ns) with an X-pinch load consisting of four Mo wires with a diameter 25 μm was used as a source of the soft X-ray radiation. The X-ray backlighting images of the researched plasma jet and the Bi step-wedge with a step thickness of ≈ 100 nm were recorded simultaneously in the course of the experiment. A comparison of the plasma jet x-ray image with the current trace has enabled to estimate dependencies of the linear mass on the arc current. The experiments have shown that when the arc current density reaches ≈ 3·105 A/cm2, the evaporation rate of the electrode material reaches ≈ 100 μg/μs, that under the plasma velocity ≈ 0.5 cm/μs, provides a plasma jet linear mass ≈ 200 μg/cm. At a distance of ≈ 1-2 mm from the arc cathode surface, the sharp increase of the jet linear mass (up to ≈ 500 μg/cm) occurred.

  9. Swirling Annular Flow Experiments with Application to Plasma Torches

    NASA Astrophysics Data System (ADS)

    Fisher, L. E.; Settles, G. S.; Miller, J. D.

    2001-11-01

    Swirling flows have many applications such as combustors and cyclone separators. Here, a turbulent swirling annular cold-flow experiment is conducted in order to gain insight into conditions within a plasma cutting torch. Compressed air is forced through six circumferentially-spaced holes that impart tangential velocity to the flow at the annulus inlet. The flow subsequently traverses an annulus of L/D1 =1.8 before exiting through a sonic nozzle. The annulus (created by a cylindrical cathode in the center of the actual plasma torch) is viewable through an outer plexiglass cylinder in our 11:1 scaled-up cold-flow apparatus. Surface oil-flow visualization and laser sheet imaging are employed to investigate the annular flowfield at a Reynolds number of about 1000 based on gap width D2-D1. Results of these experiments, leading to a physical model of the flowfield, are shown. These results are helpful in understanding and improving the fluid-dynamic behavior of actual plasma torches, widely used to cut sheet metal in manufacturing. Supported by Hypertherm Inc.

  10. Surface-wave capillary plasmas in helium: modeling and experiment

    NASA Astrophysics Data System (ADS)

    Santos, M.; Alves, L. L.; Noel, C.; Belmonte, T.

    2012-10-01

    In this paper we use both simulations and experiments to study helium discharges (99.999% purity) sustained by surface-waves (2.45 GHz frequency), in capillary tubes (3 mm radius) at atmospheric pressure. Simulations use a self-consistent homogeneous and stationary collisional-radiative model that solves the rate balance equations for the different species present in the plasma (electrons, the He^+ and He2^+ ions, the He(n<7) excited states and the He2* excimers) and the gas thermal balance equation, coupled to the two-term electron Boltzmann equation (including direct and stepwise collisions as well as electron-electron collisions). Experiments use optical emission spectroscopy diagnostics to measure the electron density (Hβ Stark broadening), the gas temperature (ro-vibrational transitions of OH, present at trace concentrations), and the populations of different excited states. Model predictions at 1.7x10^13 cm-3 electron density (within the range estimated experimentally) are in good agreement with measurements (deviations < 10%) of (i) the excitation spectrum and the excitation temperatures (2795 ± 115 K, obtained from the Boltzmann-plot of the excited state populations, with energies lying between 22.7 and 24.2 eV), (ii) the power coupled to the plasma (˜ 180 ± 10 W), and (iii) the gas temperature (˜ 1700 ± 100 K). We discuss the extreme dependence of model results (particularly the gas temperature) on the power coupled to the plasma.

  11. TRW plasma wave experiment for the IMP-H mission

    NASA Technical Reports Server (NTRS)

    Virobik, P. F.; Scarf, F. L.

    1973-01-01

    The IMP-H plasma wave experiment is designed to extend knowledge of wave-particle interactions in the disturbed cislunar region, the distant geomagnetic tail, the upstream solar wind, and the flanks of the magnetosheath-shock interface. It is expected to identify plasma instabilities, study particle acceleration and heating at collisionless shocks and other discontinuities, analyze turbulent conductivity and field line merging, and provide new information on dissipation processes for suprathermal particles. Instrumentation for the plasma wave experiment is designed to measure local electric and magnetic field oscillations over the frequency range 10 Hz to 100 kHz. A 24 inch electric dipole, a 7 inch diameter air core search coil, and the associated preamplifiers are mounted on a spacecraft counterweight boom. The frequency range of 10 Hz to 100 kHz for both E and B is processed using an eight-channel spectrum analyzer located in the instrument main-body package (a standard IMP trapezoidal module, 3 inches high). Electric fields as small as 10-100 microvolts/meter and magnetic signals as small as 1-3 milligamma will be detected.

  12. Task toward a Realization of Commercial Tokamak Fusion Plants in 2050 -The Role of ITER and the Succeeding Developments- 3.Fusion Plasma Research toward Fusion Power Plants

    NASA Astrophysics Data System (ADS)

    Kamada, Yutaka; Shimada, Michiya; Miura, Yukitoshi; Ogawa, Yuichi

    This section discusses fusion plasma research that needs to be carried out to develop fusion power plants. Burning plasma, in which self-heating by energetic alph aparticles plays an essential role, should be recognized as autonomous system. This is quite different from present plasma experiments, suggesting a possibility to yield some qualitative changes in fusion plasma research. Research with ITER is strongly expected to contribute to this burning plasma physics. In addition, plasma performance in steady-state and at high beta is very important in fusion power plants from the engineering and economical viewpoints. Plasma parameters expected for fusion power plants are discussed, and present status of experimental research is reviewed. Research in devices other than ITER with unique features would be instrumental for exploring high performance plasmas. A necessity of research complementary to ITER plasma is discussed.

  13. Doctoral Students' Experience of Information Technology Research

    ERIC Educational Resources Information Center

    Bruce, Christine; Stoodley, Ian; Pham, Binh

    2009-01-01

    As part of their journey of learning to research, doctoral candidates need to become members of their research community. In part, this involves coming to be aware of their field in ways that are shared amongst longer-term members of the research community. One aspect of candidates' experience we need to understand, therefore, involves how they…

  14. Progress toward positron-electron pair plasma experiments

    NASA Astrophysics Data System (ADS)

    Stanja, J.; Hergenhahn, U.; Niemann, H.; Paschkowski, N.; Sunn Pedersen, T.; Saitoh, H.; Stenson, E. V.; Hugenschmidt, Ch.; Marx, G. H.; Schweikhard, L.; Danielson, J. R.; Surko, C. M.

    2014-10-01

    Matter-antimatter pair plasmas have been of great theoretical and astrophysical interest for a long time. A Positron-Electron Experiment (APEX) aims for the creation and study of such a plasma in the laboratory. It will be operated at the NEPOMUC facility which provides a cold and high-intensity positron beam. To achieve at least 10 Debye length within APEX's flux surfaces the beam needs to initially pass through several stages of manipulation. Presented here is an overview of work from the APEX team. Topics include E-> × B-> beam handling for separation into multiple beams in order to reduce the energy spread of the positron beam; injection and trapping of electrons in a prototype dipole field device with a permanent magnet; and design plans for the next generation of confinement device. on behalf of the APEX/PAX Team and Collaborators.

  15. A research program in magnetogasdynamics utilizing hypervelocity coaxial plasma generators

    NASA Technical Reports Server (NTRS)

    Spight, C.

    1976-01-01

    A broadly-gauged research program in magnetogasdynamics utilizing hypervelocity coaxial plasma generators is presented. A complete hypervelocity coaxial plasma generator facility was assembled and tested. Significant progress was made in the direction of understanding the important processes in the interaction of hypervelocity MGD flow with transverse applied fields. It is now proposed to utilize the accumulated experimental capability and theoretical analysis in application to the analysis and design parameterization of pulsed magnetogasdynamic direct energy convertor configurations.

  16. High Performance Plasmas on the National Spherical Torus Experiment

    SciTech Connect

    D.A. Gates; M.G. Bell; R.E. Bell; J. Bialek; T. Bigelow; M. Bitter; P. Bonoli; D. Darrow; P. Efthimion; J. Ferron; E. Fredrickson; L. Grisham; J. Hosea; D. Johnson; R. Kaita; S. Kaye; S. Kubota; H. Kugel; B. LeBlanc; R. Maingi; J. Manickam; T.K. Mau; R.J. Maqueda; E. Mazzucato; J. Menard; D. Mueller; B. Nelson; N. Nishino; M. Ono; F. Paoletti; S. Paul; Y-K.M. Peng; C.K. Phillips; R. Raman; P. Ryan; S.A. Sabbagh; M. Schaffer; C.H. Skinner; D. Stutman; D. Swain; E. Synakowski; Y. Takase; J. Wilgen; J.R. Wilson; W. Zhu; S. Zweben; A. Bers; M. Carter; B. Deng; C. Domier; E. Doyle; M. Finkenthal; K. Hill; T. Jarboe; S. Jardin; H. Ji; L. Lao; K.C. Lee; N. Luhmann; R. Majeski; H. Park; T. Peebles; R.I. Pinsker; G. Porter; A. Ram; M. Rensink; T. Rognlien; D. Stotler; B. Stratton; G. Taylor; W. Wampler; G.A. Wurden; X.Q. Xu; L. Zeng; and the NSTX Team

    2001-07-10

    The National Spherical Torus Experiment (NSTX) has produced toroidal plasmas at low aspect ratio (A = R/a = 0.86 m/0.68 m approximately equal to 1.3, where R is the major radius and a is the minor radius of the torus) with plasma currents of 1.4 MA. The rapid development of the machine has led to very exciting physics results during the first full year of physics operation. Pulse lengths in excess of 0.5 sec have been obtained with inductive current drive. Up to 4 MW of High Harmonic Fast Wave (HHFW) heating power has been applied with 6 MW planned. Using only 2 MW of HHFW heating power clear evidence of electron heating is seen with HHFW, as observed by the multi-point Thomson scattering diagnostic. A noninductive current drive concept known as Coaxial Helicity Injection (CHI) has driven 260 kA of toroidal current. Neutral-beam heating power of 5 MW has been injected. Plasmas with beta toroidal (= 2 mu(subscript ''0'')

    /B(superscript ''2'') = a measure of magnetic confinement efficiency ) of 22% have been achieved, as calculated using the EFIT equilibrium reconstruction code. Beta-limiting phenomena have been observed, and the maximum beta toroidal scales with I(subscript ''p'')/aB(subscript ''t''). High frequency (>MHz) magnetic fluctuations have been observed. High-confinement mode plasmas are observed with confinement times of >100 msec. Beam-heated plasmas show energy confinement times in excess of those predicted by empirical scaling expressions. Ion temperatures in excess of 2.0 keV have been measured, and power balance suggests that the power loss from the ions to the electrons may exceed the calculated classical input power to the ions.

  17. Plasmas in compact traps: From ion sources to multidisciplinary research

    NASA Astrophysics Data System (ADS)

    Mascali, D.; Musumarra, A.; Leone, F.; Galatà, A.; Romano, F. P.; Gammino, S.

    2017-09-01

    In linear (minimum-B) magneto-static traps dense and hot plasmas are heated by electromagnetic radiation in the GHz domain via the Electron Cyclotron Resonance (ECR). The values of plasma density, temperature and confinement times ( n_eτ_i>10^{13} cm ^{-3} s; T_e>10 keV) are similar to the ones of thermonuclear plasmas. The research in this field -devoted to heating and confinement optimization- has been supported by numerical modeling and advanced diagnostics, for probing the plasma especially in a non-invasive way. ECR-based systems are nowadays able to produce extremely intense (tens or hundreds of mA) beams of light ions (p, d, He), and relevant currents of heavier elements (C, O, N) up to heavy ions like Xe, Pb, U. Such beams can be extracted from the trap by a proper electrostatic system. The above-mentioned properties make these plasmas very attractive for interdisciplinary researches also, such as i) nuclear decays rates measurements in stellar-like conditions, ii) energy conversion studies, being exceptional sources of short-wavelength electromagnetic radiation (EUV, X-rays, hard X-rays and gammas, useful in material science and archaeometry), iii) environments allowing precise spectroscopical measurements as benchmarks for magnetized astrophysical plasmas. The talk will give an overview about the state-of-the-art in the field of intense ion sources, and some new perspectives for interdisciplinary research, with a special attention to the developments based at INFN-LNS.

  18. The Skylab barium plasma injection experiments. I - Convection observations

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Peek, H. M.

    1976-01-01

    Two barium-plasma injection experiments were carried out during magnetically active periods in conjunction with the Skylab 3 mission. The high-explosive shaped charges were launched near dawn on November 27 and December 4, 1973, UT. In both cases, the AE index was near 400 gammas, and extensive pulsating auroras covered the sky. The first experiment, Skylab Alpha, occurred in the waning phase of a 1000-gamma substorm, and the second, Skylab Beta, occurred in the expansive phase of an 800-gamma substorm. In both, the convection was generally magnetically eastward, with 100-km-level electric fields near 40 mV/m. However, in the Alpha experiment the observed orientation of the barium flux tube fit theoretical field lines having no parallel current, but the Beta flux-tube orientation indicated a substantial upward parallel sheet current.

  19. Volumetric-driven flows on the Plasma Couette Experiment

    NASA Astrophysics Data System (ADS)

    Flanagan, Ken; Clark, M. M.; Lynn, J.; Siller, R.; Tabbutt, M.; Wallace, J.; Xu, Y.; Forest, C. B.

    2016-10-01

    Experiments for driving Keplerian-like flow profiles with the goal of exciting the magnetorotational instability (MRI) on the Plasma Couette Experiment Upgrade (PCX-U) are described. Instead of driving flow at the boundaries as is typical in many liquid metal Couette experiments, a global drive is implemented. A large (20+ A) radial current is drawn across a small (1-3 G) axial field generating torque across the whole profile. This volumetric-driven flow (VDF) is capable of producing profiles similar to Keplerian flow with Alfvén Mach numbers of order unity-ideal for MRI studies. Experimental measurements will be compared to numerical calculations that show that at sufficiently high magnetic and fluid Reynolds numbers, VDF can drive the MRI. This work is supported by the NSF.

  20. Research on Orbital Plasma-Electrodynamics (ROPE)

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Wright, K.

    1994-01-01

    Since the development of probe theory by Langmuir and Blodgett, the problem of current collection by a charged spherically or cylindrically symmetric body has been investigated by a number of authors. This paper overviews the development of a fully three-dimensional particle simulation code which can be used to understand the physics of current collection in three dimensions and can be used to analyze data resulting from the future tethered satellite system (TSS). According to the TSS configurations, two types of particle simulation models were constructed: a simple particle simulation (SIPS) and a super particle simulation (SUPS). The models study the electron transient response and its asymptotic behavior around a three dimensional, highly biased satellite. The potential distribution surrounding the satellite is determined by solving Laplace's equation in the SIPS model and by solving Poisson's equation in the SUPS model. Thus, the potential distribution in space is independent of the density distribution of the particles in the SUPS model but it does depend on the density distribution of the particles in the SUPS model. The evolution of the potential distribution in the SUPS model is described. When the spherical satellite is charged to a highly positive potential and immersed in a plasma with a uniform magnetic field, the formation of an electron torus in the equatorial plane (the plane in perpendicular to the magnetic field) and elongation of the torus along the magnetic field are found in both the SIPS and the SUPS models but the shape of the torus is different. The areas of high potential that exist in the polar regions in the SUPS model exaggerate the elongation of the electron torus along the magnetic field. The current collected by the satellite for different magentic field strengths is investigated in both models. Due to the nonlinear effects present in SUPS, the oscillating phenomenon of the current collection curve during the first 10 plasma periods

  1. Advanced electric propulsion and space plasma contactor research

    NASA Technical Reports Server (NTRS)

    Wilbur, P. J.

    1986-01-01

    A series of experiments performed on an 8 cm dia. ring cusp magnetic field ion thruster are described. The results show the effects of anode and cathode position and size, ring cusp axial location and discharge chamber length on plasma ion energy cost and extracted ion fraction. Thruster performance is shown to be improved substantially when optimum values of these parameters are used. Investigations into the basic plasma phenomena associated with the process of plasma contacting are described. The results show the process of electron collection from a background plasma to a hollow cathode plasma contactor exhibits a higher impedance than the process of electron emission from the hollow cathode. The importance of having cold ions present to facilitate the plasma contacting process is shown. Results of experiments into the behavior of hollow cathodes operating at high interelectrode pressures (up to approx. 100 Torr) on nitrogen and ammonia are presented. They suggest that diffuse emission from the insert of a hollow cathode can be sustained at high interelectrode pressures if the cathode is made of non-conducting material and the cathode internal pressure is reduced by evacuating the cathode interior. A theoretical model of discharge chamber operation developed for inert gas thrusters is extended so it can be used to evaluste the performance of mercury ion thrusters. Predictions of the model are compared to experimental results obtained on two 30 cm dia. thrusters.

  2. Gas-injection experiments on a dense plasma focus

    SciTech Connect

    Barnouin, O.; Javedani, J.; Del Medico, S.; Miley, G.H.; Bromley, B.

    1994-12-31

    Rockford Technology Associates, Inc. (RTA) has been doing experiments on the Dense Plasma focus (DPF) device at the Fusion Studies Laboratory of the University of Illinois. This DPF consists of four racks of five 2-{mu}F capacitors whose charge is switched onto the inner electrode of a plasma focus by four Trigatron spark gaps. The stored energy is 12.5 kJ at 25 kV. The bank is usually discharged in a static fill of H{sub 2} at {approx} 6 torr. Preliminary experiments aimed at exploring the potential of the DPF device as a magnetoplasmadynamic (MPD) thruster and as an x-ray source for lithography have investigated various alternative ways of injecting gas between the electrodes. One of those approaches consists of injecting gas from the tip of the inner electrode at a steady rate. In this operation, the DPF chamber pressure was held constant by running the vacuum pump at full throttle. This operation simulated simultaneous pulsed injection at the base insulator and electrode tip. Hydrogen was fed through a 1/16th-inch hole at a flow rate of {approx} 90 cm/s. Pulsing was then performed at 23 kV, and the corresponding variations of the current were observed using a Rogowski coil. It is found that the plasma collapses into a pinch at the same time as in conventional experiments using a static fill. The singularity in the current waveform is slightly smaller with tip injection, but its size and shape are easily reproducible. Further details and comparison of this operation with conventional pulsing will be presented.

  3. Medicinal herb research: serum pharmacological method and plasma pharmacological method.

    PubMed

    Ge, Jinwen; Wang, Dongsheng; He, Rong; Zhu, Huibin; Wang, Yuhong; He, Shilin

    2010-01-01

    Serum pharmacological method has generally been used in herb studies. However, preparation of test serum for ex vivo experiment is an intricate process: besides pretreatment (heat or chemicals), it involves the proteolytic cascades of coagulation along with fibrinolysis, complement and kinin systems, as well as platelet and leukocyte activation resulting in release reactions. These processes deviate serum sample components away from the original in vivo state, and possibly also have effects on the absorbed herbal components and their downstream effectors in blood. The conclusions drawn from serum pharmacological method are at least partially uncertain in its validity. These processes can be avoided by anticoagulation. Compared to those of the serum, constituents of plasma are better reflectors of the in vivo physiological/pathological state and medicinal herb-induced changes. Therefore, we have advocated the adoption of plasma pharmacological method in ex vivo experiments of herb studies. Recent studies including our work demonstrated that the constituents and biological activities are partially different between absorbed medicinal herbs in plasma and serum. This review summarizes the experimental evidence supporting the feasibility of plasma pharmacological method and discusses the reasons and facts that flaw the serum pharmacological method. But serum pharmacological method can be used if anticoagulants interfere with experiments. It should be emphasized that the domination between plasma and serum pharmacological methods is different depending on the usage. Indeed, the pros and cons of both methods as well as the appropriate choices of coagulants in different ex vivo experimental settings remain to be further elucidated.

  4. The AMPTE/CCE Hot-Plasma Composition Experiment (HPCE)

    NASA Astrophysics Data System (ADS)

    Shelley, E. G.; Ghielmetti, A.; Hertzberg, E.; Battel, S. J.; Altwegg-von Burg, K.; Balsiger, H.

    1985-05-01

    The Hot-Plasma Composition Experiment (HPCE) on the AMPTE-CCE spacecraft consists of an energetic ions-mass spectrometer and an electron background-environment monitor (EBEM). The mass spectrometer covers the entire mass per charge range from below 1 to greater than 150 amu/e and the energy per charge range from 0 eV/e (spacecraft potential) to 17 keV/e. The EBEM measures electrons between 50 eV and 25 keV in eight broad energy bands. The ion and electron data are processed into color spectrogram formats for the data pool.

  5. The AMPTE/CCE Hot-Plasma Composition Experiment (HPCE)

    NASA Technical Reports Server (NTRS)

    Shelley, E. G.; Ghielmetti, A.; Hertzberg, E.; Battel, S. J.; Altwegg-Von Burg, K.; Balsiger, H.

    1985-01-01

    The Hot-Plasma Composition Experiment (HPCE) on the AMPTE-CCE spacecraft consists of an energetic ions-mass spectrometer and an electron background-environment monitor (EBEM). The mass spectrometer covers the entire mass per charge range from below 1 to greater than 150 amu/e and the energy per charge range from 0 eV/e (spacecraft potential) to 17 keV/e. The EBEM measures electrons between 50 eV and 25 keV in eight broad energy bands. The ion and electron data are processed into color spectrogram formats for the data pool.

  6. Flowing dusty plasma experiments: generation of flow and measurement techniques

    NASA Astrophysics Data System (ADS)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2016-12-01

    A variety of experimental techniques for the generation of subsonic/supersonic dust fluid flows and means of measuring such flow velocities are presented. The experiments have been carried out in a \\Pi -shaped dusty plasma experimental device with micron size kaolin/melamine formaldehyde particles embedded in a background of argon plasma created by a direct current glow discharge. A stationary dust cloud is formed over the cathode region by precisely balancing the pumping speed and gas flow rate. A flow of dust particles/fluid is generated by additional gas injection from a single or dual locations or by altering the dust confining potential. The flow velocity is then estimated by three different techniques, namely, by super particle identification code, particle image velocimetry analysis and the excitation of dust acoustic waves. The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral drag force responsible for the generation as well as the attenuation of the dust fluid flow is made. These techniques can be usefully employed in laboratory devices to investigate linear and non-linear collective excitations in a flowing dusty plasma.

  7. Plasma interaction experiment 2 (PIX 2): Laboratory and flight results

    NASA Technical Reports Server (NTRS)

    Grier, N. T.

    1985-01-01

    The Plasma Interaction Experiments 1 and 2 (PIX 1 and 2) were designed as first steps toward understanding interactions between high-voltage solar arrays and the surrounding plasma. The PIX 2 consisted of an approximately 2000-sq cm array divided into four equal segments. Each of the segments could be biased independently and the current measured separately. In addition to the solar array segments, PIX 2 had a hot-wire-filament electron emitter and a spherical Langmuir probe. The emitter was operated when the array segments were biased positively bove 125 V. Thermal electrons from the emitter aided in balancing the electron currents collected by the array. Laboratory and flight results of PIX 2 are presented. At high positive voltages on the solar array segments, the flight currents were approximately an order of magnitude larger than the ground test currents. This is attributed to the tank walls in the laboratory interfering with the electron currents to the array segments. From previous tests it is known that the tank walls limit the electron currents at high voltages. This was the first verification of the extent of the laboratory tank effect on the plasma coupling current.

  8. THz Radiation Generation via Laser Plasma Interaction Experiments

    NASA Astrophysics Data System (ADS)

    Yugami, Noboru; Higashiguchi, Takeshi

    2008-12-01

    Recently radiation generation from the interaction between laser and plasma is studied. Terahertz radiation from photo-conductive antenna which is based on semiconductor technology is widely used, The power is in the order of nano-watt level so that it is hard to use for application. On the other hand, terahertz radiation from laser plasma interaction is much higher than that of semiconductor technology. In our experiments, we have studied by use DARC (dc to ac radiation converter) mechanism by using YAG laser with nano-second pulse duration. DARC is novel radiation source using the interaction between laser-created ionization front and static electric field. The frequency of radiation is determined by both plasma density of ionization front and the geometry of DARC structure. We observed radiation pulse of frequency of 1.2 THz and pulse duration of 2 ps with ZnSe crystal as media detected by EO (electro-optics) sampling technique. Note from Publisher: This article contains the abstract only.

  9. Magnetic helicity balance in the Sustained Spheromak Plasma Experiment

    NASA Astrophysics Data System (ADS)

    Stallard, B. W.; Hooper, E. B.; Woodruff, S.; Bulmer, R. H.; Hill, D. N.; McLean, H. S.; Wood, R. D.

    2003-07-01

    The magnetic helicity balance between the helicity input injected by a magnetized coaxial gun, the rate-of-change in plasma helicity content, and helicity dissipation in electrode sheaths and Ohmic losses have been examined in the Sustained Spheromak Plasma Experiment (SSPX) [E. B. Hooper, L. D. Pearlstein, and R. H. Bulmer, Nucl. Fusion 39, 863 (1999)]. Helicity is treated as a flux function in the mean-field approximation, allowing separation of helicity drive and losses between closed and open field volumes. For nearly sustained spheromak plasmas with low fluctuations, helicity balance analysis implies a decreasing transport of helicity from the gun input into the spheromak core at higher spheromak electron temperature. Long pulse discharges with continuously increasing helicity and larger fluctuations show higher helicity coupling from the edge to the spheromak core. The magnitude of the sheath voltage drop, inferred from cathode heating and a current threshold dependence of the gun voltage, shows that sheath losses are important and reduce the helicity injection efficiency in SSPX.

  10. OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

    SciTech Connect

    Warren, Harry P.; Doschek, George A.; Mariska, John T.

    2013-06-20

    One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.

  11. Relaunch of the Interactive Plasma Physics Educational Experience (IPPEX)

    NASA Astrophysics Data System (ADS)

    Dominguez, A.; Rusaitis, L.; Zwicker, A.; Stotler, D. P.

    2015-11-01

    In the late 1990's PPPL's Science Education Department developed an innovative online site called the Interactive Plasma Physics Educational Experience (IPPEX). It featured (among other modules) two Java based applications which simulated tokamak physics: A steady state tokamak (SST) and a time dependent tokamak (TDT). The physics underlying the SST and the TDT are based on the ASPECT code which is a global power balance code developed to evaluate the performance of fusion reactor designs. We have relaunched the IPPEX site with updated modules and functionalities: The site itself is now dynamic on all platforms. The graphic design of the site has been modified to current standards. The virtual tokamak programming has been redone in Javascript, taking advantage of the speed and compactness of the code. The GUI of the tokamak has been completely redesigned, including more intuitive representations of changes in the plasma, e.g., particles moving along magnetic field lines. The use of GPU accelerated computation provides accurate and smooth visual representations of the plasma. We will present the current version of IPPEX as well near term plans of incorporating real time NSTX-U data into the simulation.

  12. LHCD experiments in high performance plasmas in JET

    NASA Astrophysics Data System (ADS)

    Ekedahl, A.; Baranov, Y.; Dobbing, J. A.; Fischer, B.; Goniche, M.; Gormezano, C.; Romero, J. A.; Schild, P.; Söldner, F. X.; Challis, C. D.; Sips, A. C. C.; Tubbing, B.

    1997-04-01

    Lower Hybrid Current Drive (LHCD) has been used for current profile shaping in the shear optimisation experiments in 1996/97 in JET. PLH≲3MW has been applied in the initial current ramp-up in order to control the internal inductance. An internal transport barrier with improved central electron confinement has been produced in this phase with LHCD alone. This has resulted in a peaking of the electron temperature profile and Te0 above 10keV at ne0⩽1.5×1019 m-3. The profile of the LH driven current, as determined by hard X-ray mesurements, is peaked at approximately mid-radius in these conditions. Good coupling of the LH waves has been obtained by the use of a near gas feed. This method reduces the risk of plasma-launcher interaction, since the launcher can be positioned in the shadow of the poloidal limiters. A reflection coefficient of 5% has been maintained at a plasma-launcher distance of 8 cm and PLH=5 MW has been coupled to divertor plasmas in L-mode with this method.

  13. Developing a plasma focus research training system for the fusion energy age

    NASA Astrophysics Data System (ADS)

    Lee, S.

    2014-08-01

    The 3 kJ UNU/ICTP Plasma Focus Facility is the most significant device associated with the AAAPT (Asian African Association for Plasma Training). In original and modified/upgraded form it has trained generations of plasma focus (PF) researchers internationally, producing many PhD theses and peer-reviewed papers. The Lee Model code was developed for the design of this PF. This code has evolved to cover all PF machines for design, interpretation and optimization, for derivation of radiation scaling laws; and to provide insights into yield scaling limitations, radiative collapse, speed-enhanced and current-stepped PF variants. As example of fresh perspectives derivable from this code, this paper presents new results on energy transfers of the axial and radial phases of generalized PF devices. As the world moves inexorably towards the Fusion Energy Age it becomes ever more important to train plasma fusion researchers. A recent workshop in Nepal shows that demand for such training continues. Even commercial project development consultants are showing interest. We propose that the AAAPT-proven research package be upgraded, by modernizing the small PF for extreme modes of operation, switchable from the typical strong-focus mode to a slow-mode which barely pinches, thus producing a larger, more uniform plasma stream with superior deposition properties. Such a small device would be cost-effective and easily duplicated, and have the versatility of a range of experiments from intense multi-radiation generation and target damage studies to superior advanced-materials deposition. The complementary code is used to reference experiments up to the largest existing machine. This is ideal for studying machine limitations and scaling laws and to suggest new experiments. Such a modernized versatile PF machine complemented by the universally versatile code would extend the utility of the PF experience; so that AAAPT continues to provide leadership in pulsed plasma research training in

  14. Faculty Experiences in a Research Learning Community

    ERIC Educational Resources Information Center

    Holmes, Courtney M.; Kozlowski, Kelly A.

    2014-01-01

    The current study examines the experiences of faculty in a research learning community developed to support new faculty in increasing scholarly productivity. A phenomenological, qualitative inquiry was used to portray the lived experiences of faculty within a learning community. Several themes were found including: accountability, belonging,…

  15. Reflection on Lived Experience in Educational Research

    ERIC Educational Resources Information Center

    Barnacle, Robyn

    2004-01-01

    While debate about the meaning of hermeneutics and phenomenology for educational research continues, the notion of lived experience, and its application to reflective practice, has become a feature of much that goes by the name of phenomenological within this area. The prevalence of the lived experience model can be attributed in large part to the…

  16. Embodied Experience in Educational Practice and Research

    ERIC Educational Resources Information Center

    Bengtsson, Jan

    2013-01-01

    The intention of this article is to make an educational analysis of Merleau-Ponty's theory of experience in order to see what it implicates for educational practice as well as educational research. In this way, we can attain an understanding what embodied experience might mean both in schools and other educational settings and in researching…

  17. Reflection on Lived Experience in Educational Research

    ERIC Educational Resources Information Center

    Barnacle, Robyn

    2004-01-01

    While debate about the meaning of hermeneutics and phenomenology for educational research continues, the notion of lived experience, and its application to reflective practice, has become a feature of much that goes by the name of phenomenological within this area. The prevalence of the lived experience model can be attributed in large part to the…

  18. Translational Research and Plasma Proteomic in Cancer.

    PubMed

    Santini, Annamaria Chiara; Giovane, Giancarlo; Auletta, Adelaide; Di Carlo, Angelina; Fiorelli, Alfonso; Cito, Letizia; Astarita, Carlo; Giordano, Antonio; Alfano, Roberto; Feola, Antonia; Di Domenico, Marina

    2016-04-01

    Proteomics is a recent field of research in molecular biology that can help in the fight against cancer through the search for biomarkers that can detect this disease in the early stages of its development. Proteomic is a speedily growing technology, also thanks to the development of even more sensitive and fast mass spectrometry analysis. Although this technique is the most widespread for the discovery of new cancer biomarkers, it still suffers of a poor sensitivity and insufficient reproducibility, essentially due to the tumor heterogeneity. Common technical shortcomings include limitations in the sensitivity of detecting low abundant biomarkers and possible systematic biases in the observed data. Current research attempts are trying to develop high-resolution proteomic instrumentation for high-throughput monitoring of protein changes that occur in cancer. In this review, we describe the basic features of the proteomic tools which have proven to be useful in cancer research, showing their advantages and disadvantages. The application of these proteomic tools could provide early biomarkers detection in various cancer types and could improve the understanding the mechanisms of tumor growth and dissemination.

  19. Final Technical Report on DOE Grant for Modeling of Plasma Rotation in the National Spherical Torus Experiment

    SciTech Connect

    Shaing, K. C.

    2009-07-09

    This is the final technical report on the Modeling of Plasma Rotation in National Spherical Torus Experiment (NSTX) DOE Grant No. DE-FG02-02ER54679. The research subjects, technical abstracts, and publications where details of the research results can be found are reported here.

  20. Scientific Reports of Plasma Medicine and its Mechanism for Therapy in Plasma Bioscience Research Center

    NASA Astrophysics Data System (ADS)

    Choi, Eun Ha

    2015-09-01

    Scientific reports of plasma medicine and its basic mechanism for therapy will be introduced, especially, performed in Plasma Bioscience Research Center, Korea. We have investigated enhanced anticancer effect of monocytes and macrophages activated by nonthermal plasma which act as immune-modulator on these immune cells. Further, we investigated the action of the nanosecond pulsed plasma activated media (NPPAM) on the lung cancer cells and its DNA oxidation pathway. We observed OD induced apoptosis on melanocytes G361 cancer cells through DNA damage signaling cascade. We also studied DNA oxidation by extracting DNA from treated cancer cell and analyzed the effects of OD/OH/D2O2/H2O2 on protein modification and oxidation. Additionally, we attempted molecular docking approaches to check the action of D2O2 on the apoptosis related genes.

  1. Behavior, Experience and Expression: Some Research Considerations.

    ERIC Educational Resources Information Center

    Romanyshyn, Robert D.

    Utilizing research conducted on nostalgia, this paper shows how a phenomenological approach assists in understanding behavior, experience and expression. Moreover, a clearer understanding of them aids one's research with and comprehension of nostalgia. Human action can be studied from the experiential, behavioral and expressive perspectives. These…

  2. ISEE-1 data reduction and analysis plasma composition experiment

    NASA Astrophysics Data System (ADS)

    Lennartsson, W.; Sharp, R. D.

    1985-03-01

    The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given.

  3. Modeling Hohlraum-Based Laser Plasma Instability Experiments

    NASA Astrophysics Data System (ADS)

    Meezan, N. B.

    2005-10-01

    Laser fusion targets must control laser-plasma instabilities (LPI) in order to perform as designed. We present analyses of recent hohlraum LPI experiments from the Omega laser facility. The targets, gold hohlraums filled with gas or SiO2 foam, are preheated by several 3φ beams before an interaction beam (2φ or 3φ) is fired along the hohlraum axis. The experiments are simulated in 2-D and 3-D using the code hydra. The choice of electron thermal conduction model in hydra strongly affects the simulated plasma conditions. This work is part of a larger effort to systematically explore the usefulness of linear gain as a design tool for fusion targets. We find that the measured Raman and Brillouin backscatter scale monotonically with the peak linear gain calculated for the target; however, linear gain is not sufficient to explain all trends in the data. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-ENG-48.

  4. ISEE-1 data reduction and analysis plasma composition experiment

    NASA Technical Reports Server (NTRS)

    Lennartsson, W.; Sharp, R. D.

    1985-01-01

    The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given.

  5. Research on Radiation Characteristic of Plasma Antenna through FDTD Method

    PubMed Central

    Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

    2014-01-01

    The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic. PMID:25114961

  6. Research on radiation characteristic of plasma antenna through FDTD method.

    PubMed

    Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

    2014-01-01

    The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

  7. Moral experience: a framework for bioethics research.

    PubMed

    Hunt, Matthew R; Carnevale, Franco A

    2011-11-01

    Theoretical and empirical research in bioethics frequently focuses on ethical dilemmas or problems. This paper draws on anthropological and phenomenological sources to develop an alternative framework for bioethical enquiry that allows examination of a broader range of how the moral is experienced in the everyday lives of individuals and groups. Our account of moral experience is subjective and hermeneutic. We define moral experience as "Encompassing a person's sense that values that he or she deem important are being realised or thwarted in everyday life. This includes a person's interpretations of a lived encounter, or a set of lived encounters, that fall on spectrums of right-wrong, good-bad or just-unjust". In our conceptualisation, moral experience is not limited to situations that are heavily freighted with ethically-troubling ramifications or are sources of debate and disagreement. Important aspects of moral experience are played out in mundane and everyday settings. Moral experience provides a research framework, the scope of which extends beyond the evaluation of ethical dilemmas, processes of moral justification and decision-making, and moral distress. This broad research focus is consistent with views expressed by commentators within and beyond bioethics who have called for deeper and more sustained attention in bioethics scholarship to a wider set of concerns, experiences and issues that better captures what is ethically at stake for individuals and communities. In this paper we present our conceptualisation of moral experience, articulate its epistemological and ontological foundations and discuss opportunities for empirical bioethics research using this framework.

  8. Inverse time-of-flight spectrometer for beam plasma research

    SciTech Connect

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

    2014-08-15

    The paper describes the design and principle of operation of an inverse time-of-flight spectrometer for research in the plasma produced by an electron beam in the forevacuum pressure range (5–20 Pa). In the spectrometer, the deflecting plates as well as the drift tube and the primary ion beam measuring system are at high potential with respect to ground. This provides the possibility to measure the mass-charge constitution of the plasma created by a continuous electron beam with a current of up to 300 mA and electron energy of up to 20 keV at forevacuum pressures in the chamber placed at ground potential. Research results on the mass-charge state of the beam plasma are presented and analyzed.

  9. Participatory Action Research Experiences for Undergraduates

    NASA Astrophysics Data System (ADS)

    Sample McMeeking, L. B.; Weinberg, A. E.

    2013-12-01

    Research experiences for undergraduates (REU) have been shown to be effective in improving undergraduate students' personal/professional development, ability to synthesize knowledge, improvement in research skills, professional advancement, and career choice. Adding to the literature on REU programs, a new conceptual model situating REU within a context of participatory action research (PAR) is presented and compared with data from a PAR-based coastal climate research experience that took place in Summer 2012. The purpose of the interdisciplinary Participatory Action Research Experiences for Undergraduates (PAREU) model is to act as an additional year to traditional, lab-based REU where undergraduate science students, social science experts, and community members collaborate to develop research with the goal of enacting change. The benefits to traditional REU's are well established and include increased content knowledge, better research skills, changes in attitudes, and greater career awareness gained by students. Additional positive outcomes are expected from undergraduate researchers (UR) who participate in PAREU, including the ability to better communicate with non-scientists. With highly politicized aspects of science, such as climate change, this becomes especially important for future scientists. Further, they will be able to articulate the relevance of science research to society, which is an important skill, especially given the funding climate where agencies require broader impacts statements. Making science relevant may also benefit URs who wish to apply their science research. Finally, URs will gain social science research skills by apprenticing in a research project that includes science and social science research components, which enables them to participate in future education and outreach. The model also positively impacts community members by elevating their voices within and outside the community, particularly in areas severely underserved

  10. Plasma kinetic effects on interfacial mix in settings relevant to inertial confinement fusion and laboratory experiments

    NASA Astrophysics Data System (ADS)

    Yin, L.; Albright, B. J.; Bergen, B.; Bowers, K. J.; Vold, E. L.; Molvig, K.; Fernández, J. C.; Bang, W.; Bradley, P. A.; Gautier, D. C.; Hamilton, C. E.; Palaniyappan, S.; Santiago Cordoba, M. A.; Hegelich, B. M.; Dyer, G.; Roycroft, R.

    2015-11-01

    Mixing of high-Z/low-Z interfaces in dense plasma media is a problem of importance for understanding mix in inertial confinement fusion experiments and recent experiments at the LANL Trident facility. In this presentation, we apply the VPIC particle-in-cell code with a binary collision model to explore kinetic effects of the atomic mixing. Comparisons are made to published analytic theory and hybrid modeling results and conditions are identified under which plasma kinetic behavior may lead to anomalously rapid atomic mixing. Work performed under the auspices of the U.S. DOE by the LANS, LLC, Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. Funding provided by the Los Alamos National Laboratory Directed Research and Development Program.

  11. Dusty Plasma Research under Microgravity: from the Orbital Station ``Mir'' to the International Space Station

    NASA Astrophysics Data System (ADS)

    Fortov, Vladimir

    Dusty, or complex plasmas are composed of a weakly ionized gas and charged microparticles. Dust and dusty plasmas are ubiquitous in space -- they are present in planetary rings, cometary tails, interplanetary and interstellar clouds, the mesosphere, thunderclouds, they are found in the vicinity of artificial satellites and space stations, etc. Dusty plasmas formed by micronsize particles are actively investigated in many laboratories. This research has many interesting applications like nanomaterial synthesis, nanoparticle handling or particle waste removal just to mention a few. But, the most interesting application of dusty plasmas is the use as model systems for fundamental physics. It allows investigation on the most fundamental -- the kinetic level and provides insights into physics of solids and liquids with a precision not achievable in natural systems. Experiments performed on Earth are always altered or even hindered by gravity. Microgravity conditions are necessary to make investigations of large homogeneous 3-dimensional dusty plasma systems. Here we present the survey of results of the dusty plasma physics investigations under microgravity conditions with the help of experimental installations ``Plasma Crystal-1'' (PK-1) and ``PK-2'' used on the Orbital Station ``Mir'', and the unique experimental installations ``PK-3'' and ``PK-3 Plus'' used on the International Space Station. The use of these installations has given a possibility to obtain new knowledge on the dusty plasma properties. The phase transition from the isotropic liquid dusty plasma system to the so-called electrorheological plasma has been performed. The transition is the isotropic one and is fully reversible. The other interesting phenomenon is an interpenetration of two clouds of microparticles of different sizes. When a velocity of the penetrating particles is rather high the lane formation has been observed. This phenomenon is the non-equilibrium transition, depends upon peculiarities

  12. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated June 22, 1988: 'A dwarf wheat variety known as Yecoro Rojo flourishes in KSC's Biomass Production Chamber. Researchers are gathering information on the crop's ability to produce food, water and oxygen, and then remove carbon dioxide. The confined quarters associated with space travel require researchers to focus on smaller plants that yield proportionately large amounts of biomass. This wheat crop takes about 85 days to grow before harvest.' Plant experiments such as this are the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  13. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated June 22, 1988: 'A dwarf wheat variety known as Yecoro Rojo flourishes in KSC's Biomass Production Chamber. Researchers are gathering information on the crop's ability to produce food, water and oxygen, and then remove carbon dioxide. The confined quarters associated with space travel require researchers to focus on smaller plants that yield proportionately large amounts of biomass. This wheat crop takes about 85 days to grow before harvest.' Plant experiments such as this are the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  14. Across the Arctic Teachers Experience Field Research

    NASA Astrophysics Data System (ADS)

    Warnick, W. K.; Warburton, J.; Wiggins, H. V.; Marshall, S. A.; Darby, D. A.

    2005-12-01

    From studying snow geese on the North Slope of Alaska to sediment coring aboard the U.S. Coast Guard Cutter Healy in the Arctic Ocean, K-12 teachers embark on scientific expeditions as part of a program that strives to make science in the Arctic a "virtual" reality. In the past two years, seventeen K-12 teachers have participated in Teachers and Researchers Exploring and Collaborating (TREC), a program that pairs teachers with researchers to improve science education through arctic field experiences. TREC builds on the scientific and cultural opportunities of the Arctic, linking research and education through topics that naturally engage students and the wider public. TREC includes expeditions as diverse as studying plants at Toolik Field Station, a research facility located 150 miles above the Arctic Circle; climate change studies in Norway's Svalbard archipelago; studying rivers in Siberia; or a trans-arctic expedition aboard the USCGC Healy collecting an integrated geophysical data set. Funded by the National Science Foundation Office of Polar Programs, TREC offers educators experiences in scientific inquiry while encouraging the public and students to become active participants in the scientific inquiry by engaging them virtually in arctic research. TREC uses online outreach elements to convey the research experience to a broad audience. While in remote field locations, teachers and researchers interact with students and the public through online seminars and live calls from the field, online journals with accompanying photos, and online bulletin boards. Since the program's inception in 2004, numerous visitors have posted questions or interacted with teachers, researchers, and students through the TREC website (http://www.arcus.org/trec). TREC teachers are required to transfer their experience of research and current science into their classroom through the development of relevant activities and resources. Teachers and researchers are encouraged to participate

  15. Present status of plasma-wall interactions research and materials development activities in the US

    SciTech Connect

    Hirooka, Y.; Conn, R.W.

    1989-08-01

    It is well known in the fusion engineering community that the plasma confinement performance in magnetic fusion devices is strongly affected by edge-plasma interactions with surface components. These plasma-material interactions (PMI) include fuel particle recycling and impurity generation both during normal and off-normal operation. To understand and then to control PMI effects, considerable effort has been made, particularly over the last decade in US, supported by Department of Energy, Division of Development and Technology. Also, because plasma-facing components are generally expected to receive significant amount of heat due to plasma bombardment and run-away electrons, materials must tolerate high-heat fluxes (HHF). The HHF-component research has been conducted in parallel with PMI research. One strong motivation for these research activities is that DT-burning experiments are currently planned in the Tokamak Test Fusion Reactor (TFTR) in early 1990s. Several different but mutually complementary approaches have been taken in the PMI+HHF research. The first approach is to conduct PMI experiments using toroidal fusion devices such as TFTR. The second one is to simulate elemental processes involved in PMI using ion beams and electron beams, etc. The last one but not least is to use non-tokamak plasma facilities. Along with these laboratory activities, new materials have been developed and evaluated from the PMI+HHF point of view. In this paper, several major PMI+HHF research facilities in US and their activities are briefly reviewed. 21 refs., 10 figs., 2 tabs.

  16. Electric Field Double Probe Measurements for Ionospheric Space Plasma Experiments

    NASA Technical Reports Server (NTRS)

    Pfaff, R.

    1999-01-01

    Double probes represent a well-proven technique for gathering high quality DC and AC electric field measurements in a variety of space plasma regimes including the magnetosphere, ionosphere, and mesosphere. Such experiments have been successfully flown on a variety of spacecraft including sounding rockets and satellites. Typical instrument designs involve a series of trades, depending on the science objectives, type of platform (e.g., spinning or 3-axis stabilized), expected plasma regime where the measurements will be made, available telemetry, budget, etc. In general, ionospheric DC electric field instruments that achieve accuracies of 0.1 mV/m or better, place spherical sensors at large distances (10m or more) from the spacecraft body in order to extend well beyond the spacecraft wake and sheath and to achieve large signal-to-noise ratios for DC and long wavelength measurements. Additional sets of sensors inboard of the primary, outermost sensors provide useful additional information, both for diagnostics of the plasma contact potentials, which particularly enhance the DC electric field measurements on non-spinning spacecraft, and for wavelength and phase velocity measurements that use the spaced receiver or "interferometer" technique. Accurate attitude knowledge enables B times V contributions to be subtracted from the measured potentials, and permits the measured components to be rotated into meaningful geophysical reference frames. We review the measurement technique for both DC and wave electric field measurements in the ionosphere discussing recent advances involving high resolution burst memories, multiple baseline double probes, new sensor surface materials, biasing techniques, and other considerations.

  17. Transition of the BELLA PW laser system towards a collaborative research facility in laser plasma science

    NASA Astrophysics Data System (ADS)

    Toth, Csaba; Evans, Dave; Gonsalves, Anthony J.; Kirkpatrick, Mark; Magana, Art; Mannino, Greg; Mao, Hann-Shin; Nakamura, Kei; Riley, Joe R.; Steinke, Sven; Sipla, Tyler; Syversrud, Don; Ybarrolaza, Nathan; Leemans, Wim P.

    2017-03-01

    The advancement of Laser-Plasma Accelerators (LPA) requires systematic studies with ever increasing precision and reproducibility. A key component of such a research endeavor is a facility that provides reliable, well characterized laser sources, flexible target systems, and comprehensive diagnostics of the laser pulses, the interaction region, and the produced electron beams. The Berkeley Lab Laser Accelerator (BELLA), a PW laser facility, now routinely provides high quality focused laser pulses for high precision experiments. A description of the commissioning process, the layout of the laser systems, the major components of the laser and radiation protection systems, and a summary of early results are given. Further scientific plans and highlights of operational experience that serve as the basis for transition to a collaborative research facility in high-peak power laser-plasma interaction research are reviewed.

  18. Cryogenic heat loads analysis from SST-1 plasma experiments

    NASA Astrophysics Data System (ADS)

    Bairagi, N.; Tanna, V. L.; Pradhan, S.

    2017-02-01

    Cryogenic heat load analysis is an important aspect for stable operation of Tokamaks employing large scale superconducting magnets. Steady State Superconducting Tokamak (SST-1) at IPR is equipped with superconducting magnets system (SCMS) comprising sixteen numbers of modified ‘D’ shaped toroidal field (TF) and nine poloidal field (PF) superconducting coils which are wound using NbTi/Cu based cable-in conduit conductor (CICC). SST-1 magnets operation has flexibility to cool either in two-phase with sub-cooling, two-phase without sub-cooling or single phase (supercritical) helium using a dedicated 1.3 kW helium refrigerator cum liquefier (HRL). Here, we report gross heat losses for integrated TF superconducting magnets of SST-1 during the plasma campaign using cryogenic helium supply/return thermodynamic data from cryoplant. Heat loads mainly comprising of steady state as well as transient loads are smoothly absorbed by SST-1 cryogenic helium plant during plasma experiments. The corresponding heat produced in the coils is totally released to the helium flowing through the TF coils, which in turn is dumped into liquid helium stored in main control Dewar. These results are very useful reference for heat loss analysis for TF as well as PF coils and provides database for future operation of SST-1 machine.

  19. Fundamental investigations of capacitive radio frequency plasmas: simulations and experiments

    NASA Astrophysics Data System (ADS)

    Donkó, Z.; Schulze, J.; Czarnetzki, U.; Derzsi, A.; Hartmann, P.; Korolov, I.; Schüngel, E.

    2012-12-01

    Capacitive radio frequency (RF) discharge plasmas have been serving hi-tech industry (e.g. chip and solar cell manufacturing, realization of biocompatible surfaces) for several years. Nonetheless, their complex modes of operation are not fully understood and represent topics of high interest. The understanding of these phenomena is aided by modern diagnostic techniques and computer simulations. From the industrial point of view the control of ion properties is of particular interest; possibilities of independent control of the ion flux and the ion energy have been utilized via excitation of the discharges with multiple frequencies. ‘Classical’ dual-frequency (DF) discharges (where two significantly different driving frequencies are used), as well as discharges driven by a base frequency and its higher harmonic(s) have been analyzed thoroughly. It has been recognized that the second solution results in an electrically induced asymmetry (electrical asymmetry effect), which provides the basis for the control of the mean ion energy. This paper reviews recent advances on studies of the different electron heating mechanisms, on the possibilities of the separate control of ion energy and ion flux in DF discharges, on the effects of secondary electrons, as well as on the non-linear behavior (self-generated resonant current oscillations) of capacitive RF plasmas. The work is based on a synergistic approach of theoretical modeling, experiments and kinetic simulations based on the particle-in-cell approach.

  20. Comparing MHD simulations of RFP plasmas to RELAX experiments

    NASA Astrophysics Data System (ADS)

    McCollam, K. J.; den Hartog, D. J.; Jacobson, C. M.; Sauppe, J. P.; Masamune, S.; Sanpei, A.

    2015-11-01

    Standard reversed-field pinch (RFP) plasmas provide a nonlinear dynamical system as a validation domain for numerical MHD simulation codes, which can be applied to general toroidal confinement scenarios including tokamaks. Using the NIMROD code, we calculate linear stability and simulate the nonlinear evolution of plasmas similar to those in the RELAX RFP experiment, whose relatively modest Lundquist numbers of order 104 make the simulations tractable given present computing resources. The chosen RELAX cases cover a broad range of RFP reversal parameters and have also been previously simulated with the MIPS code (N. Mizuguchi et al., TH/P3-26, IAEA FEC, 2012). Experimental diagnostics that can be used for validation purposes include Thomson scattering for electron temperature, interferometry for electron density, SXR imaging, and external and internal magnetic probes. RELAX's small aspect ratio (~ 2) motivates a comparison study using toroidal and cylindrical geometries in NIMROD. This work is supported by the U.S. DOE and NSF and by the Japan Society for the Promotion of Science.

  1. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    SciTech Connect

    Eck, H. J. N. van; Koppers, W. R.; Rooij, G. J. van; Goedheer, W. J.; Cardozo, N. J. Lopes; Kleyn, A. W.; Engeln, R.; Schram, D. C.

    2009-03-15

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial magnetic field. In this way, the neutrals are prevented to reach the target region. The neutral flux to the target must be lower than the plasma flux to enable ITER relevant plasma-surface interaction (PSI) studies. It is therefore essential to control the neutral gas dynamics. The DSMC method was used to model the expansion of a hot gas in a low pressure vessel where a small discrepancy in shock position was found between the simulations and a well-established empirical formula. Two stage differential pumping was modeled and applied in the linear plasma devices Pilot-PSI and PLEXIS. In Pilot-PSI a factor of 4.5 pressure reduction for H{sub 2} has been demonstrated. Both simulations and experiments showed that the optimum skimmer position depends on the position of the shock and therefore shifts for different gas parameters. The shape of the skimmer has to be designed such that it has a minimum impact on the shock structure. A too large angle between the skimmer and the forward direction of the gas flow leads to an influence on the expansion structure. A pressure increase in front of the skimmer is formed and the flow of the plasma beam becomes obstructed. It has been shown that a skimmer with an angle around 53 deg. gives the best performance. The use of skimmers is implemented in the design of the large linear plasma generator Magnum-PSI. Here, a three stage differentially pumped vacuum system is used to reach low enough neutral pressures near the target, opening a door to PSI research in the ITER relevant regime.

  2. Plasma flow switch experiments on Pegasus-II

    SciTech Connect

    Shlachter, J.S.; Bartsch, R.R.; Benage, J.F.

    1994-12-31

    Pegasus-II, a 4.3 MJ capacitor bank facility at Los Alamos National Laboratory, has a current rise time of 5 {mu}s and requires the use of a fast ({approx} 500 ns) opening switch with long conduction time for some applications. Development of plasma flow opening switches (PFS), based on the design of the Shiva Star experiments, has been conducted during the last year. The PFS for these experiments consisted of two components: an annular aluminum conductor bridging the gap between the coaxial conductors in the Pegasus-II power-flow channel and an annular mylar foil located 6.3 mm downstream of the aluminum. The authors have investigated assemblies with 1/r{sup 2} mass distributions, designed to produce planar motion down the power flow channel. The total mass of the PFS assembly has been varied as has the construction of the aluminum component. The downstream load in the load slot was either a high inductance, 1-cm radius non-imploding pipe or a cylindrical, 12.7-mg pure aluminum imploding foil with 5-cm radius. Experiments have been conducted both with and without a trap region in the downstream inner conductor; the trap is one mechanism for preventing PFS material from entering the load slot.

  3. Convex crystal x-ray spectrometer for laser plasma experiments

    SciTech Connect

    May, M.; Heeter, R.; Emig, J.

    2004-10-01

    Measuring time and space-resolved spectra is important for understanding Hohlraum and Halfraum plasmas. Experiments at the OMEGA laser have used the Nova TSPEC which was not optimized for the OMEGA diagnostic space envelope or for the needed spectroscopic coverage and resolution. An improved multipurpose spectrometer snout, the MSPEC, has been constructed and fielded on OMEGA. The MSPEC provides the maximal internal volume for mounting crystals without any beam interferences at either 2x or 3x magnification. The RAP crystal is in a convex mounting geometry bent to a 20 cm radius of curvature. The spectral resolution, E/dE, is about 200 at 2.5 keV. The spectral coverage is 2 to 4.5 keV. The MSPEC can record four separate spectra on the framing camera at time intervals of up to several ns. The spectrometer design and initial field-test performance will be presented and compared to that of the TSPEC.

  4. Research of surface plasma resonance optical fiber hydrogen sensor

    NASA Astrophysics Data System (ADS)

    Ou, Zhonghua; Guo, Xiaowei; Chen, Dejun; Dai, Zhiyong; Peng, Zengshou; Liu, Yongzhi

    2008-12-01

    An optical fiber hydrogen sensor based on the measuring principle of surface plasma resonance is introduced. The structure of the hydrogen-sensitive head which is coated with Pd-Ag alloy film on the surface of the etched optical fiber is investigated theoretically. When hydrogen gas is absorbed into the Pd thin layer of the sensing head, the Pd hydride is formed and then the refraction index of the etched optical fiber surface will be changed with different hydrogen gas concentration. The surface plasma wave is stimulated by the light wave in optical fiber and the surface plasma resonance occurs between the thin metal layer and the medium surface of hydrogen gas. The Pd-Ag alloy film thickness versus the sensitivity of hydrogen sensing head is analyzed and optimized via the numerical method. The sensing head which is based on surface plasma resonance is manufactured and used in the experiment system of hydrogen gas detecting, and the experiment results demonstrate that the detecting system has high sensitivity with the hydrogen concentration in the range of 0%-4%, the accuracy, resolution and response time are respectively 5%, 0.1% and 30s. This sensor structure can be applied to detecting the low concentration of hydrogen gas.

  5. SUMMA hot-ion plasma heating research at NASA Lewis Research Center. [SUperconducting Magnetic Mirror Apparatus

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Patch, R. W.; Lauver, M. R.; Englert, G. W.; Snyder, A.

    1975-01-01

    This report describes the SUMMA superconducting magnetic mirror facility at the NASA Lewis Research Center and the hot-ion plasma research conducted therein. SUMMA is characterized by intense magnetic fields (designed for 8.6 T at the mirrors) and a large-diameter working bore (41 cm diameter) with room-temperature access. The goal of the plasma research program is to produce steady-state plasmas of fusion reactor densities and temperatures (but not confinement times). The program includes electrode development to produce a hot, dense, large-volume, steady-state plasma and diagnostics development to document the plasma properties. SUMMA and its hot-ion plasma are ideally suited to develop advanced plasma diagnostics methods. Two such methods whose requirements are well matched to SUMMA are: (1) heavy ion beam probing to measure plasma space potential, and (2) submillimeter wavelength laser Thomson scattering to measure local ion temperature. Two NASA University Grants were established to identify major requirements for developing these two diagnostic techniques in SUMMA.

  6. Los Alamos NEP research in advanced plasma thrusters

    NASA Technical Reports Server (NTRS)

    Schoenberg, Kurt; Gerwin, Richard

    1991-01-01

    Research was initiated in advanced plasma thrusters that capitalizes on lab capabilities in plasma science and technology. The goal of the program was to examine the scaling issues of magnetoplasmadynamic (MPD) thruster performance in support of NASA's MPD thruster development program. The objective was to address multi-megawatt, large scale, quasi-steady state MPD thruster performance. Results to date include a new quasi-steady state operating regime which was obtained at space exploration initiative relevant power levels, that enables direct coaxial gun-MPD comparisons of thruster physics and performance. The radiative losses are neglible. Operation with an applied axial magnetic field shows the same operational stability and exhaust plume uniformity benefits seen in MPD thrusters. Observed gun impedance is in close agreement with the magnetic Bernoulli model predictions. Spatial and temporal measurements of magnetic field, electric field, plasma density, electron temperature, and ion/neutral energy distribution are underway. Model applications to advanced mission logistics are also underway.

  7. ITER research plan of plasma-wall interaction

    NASA Astrophysics Data System (ADS)

    Shimada, M.; Pitts, R.; Loarte, A.; Campbell, D. J.; Sugihara, M.; Mukhovatov, V.; Kukushkin, A.; Chuyanov, V.

    2009-06-01

    This paper describes an important part of ITER Research Plan, on plasma-wall interaction (PWI). In order to maximize the flexibility of the machine during the initial operation (H and D phases), CFC will be used for the targets. Tungsten will be used for the other plasma-facing components of the divertor. In order to minimize the tritium retention, tungsten will fully cover the divertor targets before the DT phase. Extrapolation of heat loads on plasma-facing components (PFCs) during disruption and ELMs to ITER parameters indicates serious consequences of these phenomena. Therefore schemes for prediction and mitigation or avoidance of these phenomena need to be developed during construction and demonstrated in the early phase of ITER operation. T-retention and dust have important impacts on safety. Therefore the methods of measurement and removal of tritium and dust must be developed during construction and demonstrated in the early phase of ITER operation.

  8. Understanding Solar Coronal Heating through Atomic and Plasma Physics Experiments

    NASA Astrophysics Data System (ADS)

    Savin, Daniel Wolf; Arthanayaka, Thusitha; Bose, Sayak; Hahn, Michael; Beiersdorfer, Peter; Brown, Gregory V.; Gekelman, Walter; Vincena, Steve

    2017-08-01

    Recent solar observations suggest that the Sun's corona is heated by Alfven waves that dissipate at unexpectedly low heights in the corona. These observations raise a number of questions. Among them are the problems of accurately quantifying the energy flux of the waves and that of describing the physical mechanism that leads to the wave damping. We are performing laboratory experiments to address both of these issues.The energy flux depends on the electron density, which can be measured spectroscopically. However, spectroscopic density diagnostics have large uncertainties, because they depend sensitively on atomic collisional excitation, de-excitation, and radiative transition rates for multiple atomic levels. Essentially all of these data come from theory and have not been experimentally validated. We are conducting laboratory experiments using the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory that will provide accurate empirical calibrations for spectroscopic density diagnostics and which will also help to guide theoretical calculations.The observed rapid wave dissipation is likely due to inhomogeneities in the plasma that drive flows and currents at small length scales where energy can be more efficiently dissipated. This may take place through gradients in the Alfvén speed along the magnetic field, which causes wave reflection and generates turbulence. Alternatively, gradients in the Alfvén speed across the field can lead to dissipation through phase-mixing. Using the Large Plasma Device (LAPD) at the University of California Los Angeles, we are studying both of these dissipation mechanisms in the laboratory in order to understand their potential roles in coronal heating.

  9. Understanding Solar Coronal Heating through Atomic and Plasma Physics Experiments

    NASA Astrophysics Data System (ADS)

    Savin, Daniel Wolf; Arthanayaka, Thusitha; Beiersdorfer, Peter; Brown, Gregory V.; Gekelman, Walter; Hahn, Michael; Vincena, Steve

    2017-06-01

    Recent solar observations suggest that the Sun's corona is heated by Alfven waves that dissipate at unexpectedly low heights in the corona. These observations raise a number of questions. Among them are the problems of accurately quantifying the energy flux of the waves and that of describing the physical mechanism that leads to the wave damping. We are performing laboratory experiments to address both of these issues.The energy flux depends on the electron density, which can be measured spectroscopically. However, spectroscopic density diagnostics have large uncertainties, because they depend sensitively on atomic collisional excitation, de-excitation, and radiative transition rates for multiple atomic levels. Essentially all of these data come from theory and have not been experimentally validated. We are conducting laboratory experiments using the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory that will provide accurate empirical calibrations for spectroscopic density diagnostics and which will also help to guide theoretical calculations.The observed rapid wave dissipation is likely due to inhomogeneities in the plasma that drive flows and currents at small length scales where energy can be more efficiently dissipated. This may take place through gradients in the Alfven speed along the magnetic field, which causes wave reflection and generates turbulence. Alternatively, gradients in the Alfven speed across the field can lead to dissipation through phase-mixing. Using the Large Plasma Device (LAPD) at the University of California Los Angeles, we are studying both of these dissipation mechanisms in the laboratory in order to understand their potential roles in coronal heating.

  10. MACH2 modeling of LANL plasma-flow-switch experiments

    SciTech Connect

    Wysocki, F.J.

    1994-12-31

    The plasma-flow opening-switch (PFS) is being developed at the Los Alamos National Laboratory as part of the Athena Program. The present goal is to switch 10--20 MA of current into a cylindrical-foil implosion load in 300--400 ns. Primary drivers currently in use include the Pegasus-II capacitor bank which delivers 8--10 MA to the PFS in 3--4 {mu}s and the Procyon explosively-driven flux-compression generator which delivers 15--18 MA in 2--3 {mu}s. A series of experiments using Pegasus-II and Procyon have characterized the PFS performance for a variety of experimental conditions. Issues examined with Pegasus-II include switch-mass (50-mg vs. 100-mg), switch fabrication (wire-array vs. graded-thickness-foil), current level (7 MA vs. 10 MA), presence or absence of a plasma trap, and static load vs. implosion load. Procyon has been used to characterize a PFS with a 1/r aerial-mass-density profile (as opposed to the Pegasus-II 1/r{sup 2} profile). The MACH2 two-dimensional magnetohydrodynamic code has been used to model these experiments and comparison of simulation data to the experimental data has been made. This includes direct comparison of data from an array of B-dot probes present on all tests (19--23 probes), direct comparison of x-ray yield and power for those tests with implosion loads, and qualitative comparison to framing and streak data. The agreement between simulation data and experimental data is reasonably good.

  11. Flight research experiments on ride quality

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.; Kuhlthau, A. R.

    1975-01-01

    The results and analysis of several flight research experiments in ride quality are described. These tests were carried out aboard the NASA Flight Research Center, JetStar Aircraft equipped with the General Purpose Airborne Simulator; and aboard a specially instrumented Boeing 747 flown in actual commercial flight. The data was analyzed to determine appropriate models for subjective reaction to the motion environment. Specifically, vertical and transverse acceleration inputs and aircraft bank angle were studied along with duration of exposure.

  12. Experiments on hot and dense laser-produced plasmas

    SciTech Connect

    Back, C.A.; Woolsey, N.C.; Asfaw, A.; Glenzer, S.H.; Hammel, B.A.; Keane, C.J.; Lee, R.W.; Liedahl, D.; Moreno, J.C.; Nash, J.K.; Osterheld, A.L.; Calisti, A.; Stamm, R.; Talin, B.; Godbert, L.; Mosse, C.; Ferri, S.; Klein, L.

    1996-08-05

    Plasmas generated by irradiating targets with {approx}20 kJ of laser energy are routinely created in inertial confinement fusion research. X-ray spectroscopy provides one of the few methods for diagnosing the electron temperature and electron density. For example, electron densities approaching 10{sup 24} cm{sup -3} have been diagnosed by spectral linewidths. However, the accuracy of the spectroscopic diagnostics depends on the population kinetics, the radiative transfer, and the line shape calculations. Analysis for the complex line transitions has recently been improved and accelerated by the use of a database where detailed calculations can be accessed rapidly and interactively. Examples of data from Xe and Ar doped targets demonstrate the current analytic methods. First we will illustrate complications that arise from the presence of a multitude of underlying spectral lines. Then, we will consider the Ar He-like 1s{sup 2}({sup 1}S{sub 0}) - 1s3p({sup 1}P{sub 0}) transition where ion dynamic effects may affect the profile. Here, the plasma conditions are such that the static ion microfield approximation is no longer valid; therefore in addition to the width, the details of the line shape can be used to provide additional information. We will compare the data to simulations and discuss the possible pitfalls involved in demonstrating the effect of ion dynamics on lineshapes.

  13. A candidate's experience doing research during training.

    PubMed

    Hadge, Luke

    2012-10-01

    A psychoanalytic candidate explores his experience of participating in a research project at his institute during his training. The candidate has been a member of Sabrina Cherry's prospective study of psychoanalytic practice and professional development conducted at the Columbia University Center for Psychoanalytic Training and Research. While much as been written about candidacy from numerous perspectives, there is little in the literature about how being engaged in research affects a candidate's overall training experience. In particular, attention is paid to understanding the benefits, synergies, conflicts, and tensions in combining research with such aspects of analytic training as the training analysis, control cases, supervision, classes, and institute life. A parallel is drawn between the listening and interpretive skills learned in order to practice analysis and the method of textual analysis employed in the research project. The author believes that his research training and the impact of the specific research topic have enriched and deepened his analytic training, while at the same time revealing certain anxieties in integrating research with the development of his analytic skills and identity.

  14. Active experiments in space in conjunction with Skylab. [barium plasma injection experiment and magnetic storm of March 7, 1972

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.

    1974-01-01

    Two papers are presented which relate to the Skylab barium shaped charge experiments. The first describes the L=6.6 OOSIK barium plasma injection experiment and magnetic storm of March 7, 1972. Rocket payload, instrumentation, data reduction methods, geophysical environment at the time of the experiment, and results are given. The second paper presents the observation of an auroral Birkeland current which developed from the distortion of a barium plasma jet during the above experiment.

  15. Assessing research participants' perceptions of their clinical research experiences.

    PubMed

    Kost, Rhonda G; Lee, Laura M; Yessis, Jennifer; Coller, Barry S; Henderson, David K

    2011-12-01

    Participants' perceptions of their research experiences provide valuable measures of ethical treatment, yet no validated instruments exist to measure these experiences. We conducted focus groups of research participants and professionals as the initial step in developing a validated instrument. Research participants enrolled in 12 focus groups, consisting of: (1) individuals with disorders undergoing interventions; (2) in natural history studies; or (3) healthy volunteers. Research professionals participated in six separate groups of: (1) institutional review board members, ethicists, and Research Subject Advocates; (2) research nurses/coordinators; or (3) investigators. Focus groups used standard methodologies. Eighty-five participants and 29 professionals enrolled at eight academic centers. Altruism and personal relevance of the research were commonly identified motivators; financial compensation was less commonly mentioned. Participants were satisfied with informed consent processes but disappointed if not provided test results, or study outcomes. Positive relationships with research teams were valued highly. Research professionals were concerned about risks, undue influence, and informed consent. Participants join studies for varied, complex reasons, notably altruism and personal relevance. They value staff relationships, health gains, new knowledge, and compensation, and expect professionalism and good organization. On the basis of these insights, we propose specific actions to enhance participant recruitment, retention, and satisfaction. © 2011 Wiley Periodicals, Inc.

  16. Research Experiences in Community College Science Programs

    NASA Astrophysics Data System (ADS)

    Beauregard, A.

    2011-12-01

    The benefits of student access to scientific research opportunities and the use of data in curriculum and student inquiry-driven approaches to teaching as effective tools in science instruction are compelling (i.e., Ledley, et al., 2008; Gawel & Greengrove, 2005; Macdonald, et al., 2005; Harnik & Ross. 2003). Unfortunately, these experiences are traditionally limited at community colleges due to heavy faculty teaching loads, a focus on teaching over research, and scarce departmental funds. Without such hands-on learning activities, instructors may find it difficult to stimulate excitement about science in their students, who are typically non-major and nontraditional. I present two different approaches for effectively incorporating research into the community college setting that each rely on partnerships with other institutions. The first of these is a more traditional approach for providing research experiences to undergraduate students, though such experiences are limited at community colleges, and involves student interns working on a research project under the supervision of a faculty member. Specifically, students participate in a water quality assessment study of two local bayous. Students work on different aspects of the project, including water sample collection, bio-assay incubation experiments, water quality sample analysis, and collection and identification of phytoplankton. Over the past four years, nine community college students, as well as two undergraduate students and four graduate students from the local four-year university have participated in this research project. Aligning student and faculty research provides community college students with the unique opportunity to participate in the process of active science and contribute to "real" scientific research. Because students are working in a local watershed, these field experiences provide a valuable "place-based" educational opportunity. The second approach links cutting-edge oceanographic

  17. Laser-induced fluorescence measurements on plasma science experiments at PPPL

    SciTech Connect

    Koepke, Mark

    2011-12-20

    Collaborative research between WVU and PPPL was carried out at WVU for the purpose of incorporating the sophisticated diagnostic technique known as laser-induced fluorescence (LIF) in the Paul-Trap Simulation Experiment (PTSX) at PPPL. WVU assembled a LIF system at WVU, transported it to PPPL, helped make LIF experiments on the PTSX device, participated in PTSX science, and trained PPPL staff in LIF techniques. In summary, WVU refurbished a non-operational LIF system being loaned from University of Maryland to PPPL and, by doing so, provided PPPL with additional diagnostic capability for its PTSX device and other General Plasma Science experiments. WVU students, staff, and faculty will visit PPPL to collaborate on PTSX experiments in the future.

  18. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated October 8, 1991: 'Plant researchers Neil Yorio and Lisa Ruffe prepare to harvest a crop of Waldann's Green Lettuce from KSC's Biomass Production Chamber (BPC). KSC researchers have grown several different crops in the BPC to determine which plants will better produce food, water and oxygen on long-duration space missions.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  19. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated October 8, 1991: 'Plant researchers Lisa Ruffe and Neil Yorio prepare to harvest a crop of Waldann's Green Lettuce from KSC's Biomass Production Chamber (BPC). KSC researchers have grown several different crops in the BPC to determine which plants will better produce food, water and oxygen on long-duration space missions.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  20. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated October 8, 1991: 'Plant researchers Neil Yorio and Lisa Ruffe prepare to harvest a crop of Waldann's Green Lettuce from KSC's Biomass Production Chamber (BPC). KSC researchers have grown several different crops in the BPC to determine which plants will better produce food, water and oxygen on long-duration space missions.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  1. Undergraduate Research Experiences from a Longitudinal Perspective

    ERIC Educational Resources Information Center

    Harsh, Joseph A.; Maltese, Adam V.; Tai, Robert H.

    2011-01-01

    Undergraduate research experiences (UREs) have been endorsed as a powerful instructional tool in higher education; however, relatively little is known about the long-term effects of participation in these programs. The purpose of this study was to investigate the educational enhancements of URE participation from the perspective of practicing…

  2. International Research Students' Experiences in Academic Success

    ERIC Educational Resources Information Center

    Yeoh, Joanne Sin Wei; Terry, Daniel R.

    2013-01-01

    The flow of international students to study in Australia increases each year. It is a challenge for students to study abroad in a different sociocultural environment, especially for postgraduate research students, as they experience numerous difficulties in an unfamiliar and vastly different study environment. A study aimed to investigate the…

  3. Lithium As Plasma Facing Component for Magnetic Fusion Research

    SciTech Connect

    Masayuki Ono

    2012-09-10

    The use of lithium in magnetic fusion confinement experiments started in the 1990's in order to improve tokamak plasma performance as a low-recycling plasma-facing component (PFC). Lithium is the lightest alkali metal and it is highly chemically reactive with relevant ion species in fusion plasmas including hydrogen, deuterium, tritium, carbon, and oxygen. Because of the reactive properties, lithium can provide strong pumping for those ions. It was indeed a spectacular success in TFTR where a very small amount (~ 0.02 gram) of lithium coating of the PFCs resulted in the fusion power output to improve by nearly a factor of two. The plasma confinement also improved by a factor of two. This success was attributed to the reduced recycling of cold gas surrounding the fusion plasma due to highly reactive lithium on the wall. The plasma confinement and performance improvements have since been confirmed in a large number of fusion devices with various magnetic configurations including CDX-U/LTX (US), CPD (Japan), HT-7 (China), EAST (China), FTU (Italy), NSTX (US), T-10, T-11M (Russia), TJ-II (Spain), and RFX (Italy). Additionally, lithium was shown to broaden the plasma pressure profile in NSTX, which is advantageous in achieving high performance H-mode operation for tokamak reactors. It is also noted that even with significant applications (up to 1,000 grams in NSTX) of lithium on PFCs, very little contamination (< 0.1%) of lithium fraction in main fusion plasma core was observed even during high confinement modes. The lithium therefore appears to be a highly desirable material to be used as a plasma PFC material from the magnetic fusion plasma performance and operational point of view. An exciting development in recent years is the growing realization of lithium as a potential solution to solve the exceptionally challenging need to handle the fusion reactor divertor heat flux, which could reach 60 MW/m2 . By placing the liquid lithium (LL) surface in the path of the main

  4. The Microgravity Research Experiments (MICREX) Data Base

    NASA Technical Reports Server (NTRS)

    Winter, C. A.; Jones, J. C.

    1996-01-01

    An electronic data base identifying over 800 fluids and materials processing experiments performed in a low-gravity environment has been created at NASA Marshall Space Flight Center. The compilation, called MICREX (MICrogravity Research Experiments) was designed to document all such experimental efforts performed (1) on U.S. manned space vehicles, (2) on payloads deployed from U.S. manned space vehicles, and (3) on all domestic and international sounding rockets (excluding those of China and the former U.S.S.R.). Data available on most experiments include (1) principal and co-investigator (2) low-gravity mission, (3) processing facility, (4) experimental objectives and results, (5) identifying key words, (6) sample materials, (7) applications of the processed materials/research area, (8) experiment descriptive publications, and (9) contacts for more information concerning the experiment. This technical memorandum (1) summarizes the historical interest in reduced-gravity fluid dynamics, (2) describes the importance of a low-gravity fluids and materials processing data base, (4) describes thE MICREX data base format and computational World Wide Web access procedures, and (5) documents (in hard-copy form) the descriptions of the first 600 fluids and materials processing experiments entered into MICREX.

  5. Small satellite attitude determination during plasma brake deorbiting experiment

    NASA Astrophysics Data System (ADS)

    Khurshid, Osama; Selkäinaho, Jorma; Soken, Halil Ersin; Kallio, Esa; Visala, Arto

    2016-12-01

    This paper presents a study on attitude estimation during the Plasma Brake Experiment (PBE) onboard a small satellite. The PBE demands that the satellite be spun at a very high angular velocity, up to 200 deg/s, to deploy the tether using centrifugal force. The spin controller, based on purely magnetic actuation, and the PBE demands accurate attitude estimation for the successful execution of the experiment. The biases are important to be estimated onboard small satellites due to the closely integrated systems and relatively higher interference experienced by the sensors. However, bias estimation is even more important for PBE due to the presence of a high voltage unit, onboard the satellite, that is used to charge the tether and can be the source of interference. The attitude and the biases, when estimated simultaneously, results in an augmented state vector that poses a challenge to the proper tuning of process noise. The adaptation of process noise covariance has, therefore, been studied and analysed for the challenging PBE. It has been observed that adapting the process noise covariance improves the estimation accuracy during the spin-up phase. Therefore, it is very important to use adaptive process noise covariance estimation.

  6. Some diagnostic interpretations from railgun plasma profile experiments

    SciTech Connect

    Stainsby, D.F.; Bedford, A.J.

    1984-03-01

    Some aspects of a railgun experimental series to investigate plasma profiles are reviewed. Certain diagnostic records clearly show plasma leakage past the projectile, and correspondence between various in-bore events and muzzle voltage. A muzzle flash detector is shown to have a useful role as a plasma diagnostic tool.

  7. Plasma wave experiment for the ISEE-3 mission

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1983-01-01

    Sensitive, high resolution plasma probes for analysis of the distribution functions and plasma wave instruments for measurements of electromagnetic and electrostatic wave modes are commonly flown together to provide information on plasma instabilities and wave particle interactions. Analysis of the data for the ISEE 3 mission is provided.

  8. Experiments with Plasmas Produced by Potassium-Seeded Cyanogen Oxygen Flames for Study of Radio Transmission at Simulated Reentry Vehicle Plasma Conditions

    NASA Technical Reports Server (NTRS)

    Huber, Paul W.; Gooderum, Paul B.

    1961-01-01

    A method for the chemical production of an ionized gas stream for application to radio transmission studies is described. Involved is the combustion of gaseous cyanogen and oxygen with the addition of vaporized potassium in some cases to further increase the ionization. Experiments are described in which a 3-inch-diameter subsonic free jet at atmospheric pressure is used, and the results are presented. The plasma obtained by using this method is sufficient to simulate plasma conditions expected for reentering hypersonic vehicles. The unseeded plasma stream temperature is indicated to be about 4,200 K, with the degree of ionization indicated to be that expected from thermal equilibrium considerations. Measurements of radio-signal loss due to the unseeded flame plasma are presented for microwaves of 8 to 20 kmc transmitted through the stream and for a dipole transmitting model of 219.5 mc immersed in the stream. Favorable comparison of these results with the simple plane-wave signal-attenuation theory was obtained. In the case of a 9.4-kmc microwave signal of 30-kw peak power, the preliminary indication is that the plasma characteristics were not changed due to this strong signal. Comparison of a simplified concept of radio-signal attenuation due to plasmas is made with some hypersonic reentry vehicle signal-loss data. Other areas of plasma research using this method for the transmission problem are indicated.

  9. Experiments with Plasmas Produced by Potassium-Seeded Cyanogen Oxygen Flames for Study of Radio Transmission at Simulated Reentry Vehicle Plasma Conditions

    NASA Technical Reports Server (NTRS)

    Huber, Paul W.; Gooderum, Paul B.

    1961-01-01

    A method for the chemical production of an ionized gas stream for application to radio transmission studies is described. Involved is the combustion of gaseous cyanogen and oxygen with the addition of vaporized potassium in some cases to further increase the ionization. Experiments are described in which a 3-inch-diameter subsonic free jet at atmospheric pressure is used, and the results are presented. The plasma obtained by using this method is sufficient to simulate plasma conditions expected for reentering hypersonic vehicles. The unseeded plasma stream temperature is indicated to be about 4,200 K, with the degree of ionization indicated to be that expected from thermal equilibrium considerations. Measurements of radio-signal loss due to the unseeded flame plasma are presented for microwaves of 8 to 20 kmc transmitted through the stream and for a dipole transmitting model of 219.5 mc immersed in the stream. Favorable comparison of these results with the simple plane-wave signal-attenuation theory was obtained. In the case of a 9.4-kmc microwave signal of 30-kw peak power, the preliminary indication is that the plasma characteristics were not changed due to this strong signal. Comparison of a simplified concept of radio-signal attenuation due to plasmas is made with some hypersonic reentry vehicle signal-loss data. Other areas of plasma research using this method for the transmission problem are indicated.

  10. Shaping the research experiences of graduate students using action research.

    PubMed

    Lindo, J L M; Holder-Nevins, D; Dover Roberts, D; Dawkins, P; Bennett, J

    2013-12-01

    Nursing research capacity is often not optimal in developing countries. Capacity building at the graduate nurse level presents an opportunity for improved research output. Students pursuing a research methods course at a nursing school in Jamaica expressed fear and anxiety towards the course. Action research was used to address this fear and improve learning outcomes. To determine attitudes towards research and to improve the experience of graduate students pursuing a research methods course at a nursing school in Jamaica. Students (n=44) registered in the Research Methods course of the MScN at a nursing school in Kingston, Jamaica for the academic year 2010/2011, were invited to participate. Each student was assigned a main supervisor and an alternate supervisor and all had equal access to the course leader and content. On completion of the course three focus group discussions of 10-14 students per group were conducted to determine how students felt about the course experience and their attitude towards the course. Thirty-seven students (mean age of 41.4 ± 1.5 years; 94% female) participated in the exploratory course evaluation exercise. The participants reported that they entered research methods with feelings of apprehension and anxiety. However, these fears were allayed by a combination of factors including interest in students' welfare, affirmation of students, respect for and understanding of students' needs and resourcefulness, and the use of a panel of experts. Barriers included faculty's unrealistic expectations of students' research competencies and the limited time in which to learn and apply concepts. While students thought the course as challenging they felt more confident that they could be successful on completion of the course. Significant improvement in attitudes to research was realized among graduate nursing students using action research at an urban school of nursing in Jamaica. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Results from D-T experiments on TFTR and implications for achieving an ignited plasma

    SciTech Connect

    Hawryluk, R.J.; Blanchard, W.; Batha, S.

    1998-07-01

    Progress in the performance of tokamak devices has enable not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain. In this paper, the implications for the TFTR experiments for overcoming these remaining issues will be discussed.

  12. Results from D-T Experiments on TFTR and Implications for Achieving an Ignited Plasma

    SciTech Connect

    Hawryluk, R.J. and the TFTR Group

    1998-07-14

    Progress in the performance of tokamak devices has enabled not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain for achieving a magnetic fusion energy reactor. In this paper, the implications of the TFTR experiments for overcoming these remaining issues will be discussed.

  13. Systems Analysis of a Compact Next Step Burning Plasma Experiment

    SciTech Connect

    S.C. Jardin; C.E. Kessel; D. Meade; C. Neumeyer

    2002-02-06

    A new burning plasma systems code (BPSC) has been developed for analysis of a next step compact burning plasma experiment with copper-alloy magnet technology. We consider two classes of configurations: Type A, with the toroidal field (TF) coils and ohmic heating (OH) coils unlinked, and Type B, with the TF and OH coils linked. We obtain curves of the minimizing major radius as a function of aspect ratio R(A) for each configuration type for typical parameters. These curves represent, to first order, cost minimizing curves, assuming that device cost is a function of major radius. The Type B curves always lie below the Type A curves for the same physics parameters, indicating that they lead to a more compact design. This follows from that fact that a high fraction of the inner region, r < R-a, contains electrical conductor material. However, the fact that the Type A OH and TF magnets are not linked presents fewer engineering challenges and should lead to a more reliable design. Both the Type A and Type B curves have a minimum in major radius R at a minimizing aspect ratio A typically above 2.8 and at high values of magnetic field B above 10 T. The minimizing A occurs at larger values for longer pulse and higher performance devices. The larger A and higher B design points also have the feature that the ratio of the discharge time to the current redistribution time is largest so that steady-state operation can be more realistically prototyped. A sensitivity study is presented for the baseline Type A configuration showing the dependence of the results on the parameters held fixed for the minimization study.

  14. Absorption spectroscopy of a laboratory photoionized plasma experiment at Z

    SciTech Connect

    Hall, I. M.; Durmaz, T.; Mancini, R. C.; Bailey, J. E.; Rochau, G. A.; Golovkin, I. E.; MacFarlane, J. J.

    2014-03-15

    The Z facility at the Sandia National Laboratories is the most energetic terrestrial source of X-rays and provides an opportunity to produce photoionized plasmas in a relatively well characterised radiation environment. We use detailed atomic-kinetic and spectral simulations to analyze the absorption spectra of a photoionized neon plasma driven by the x-ray flux from a z-pinch. The broadband x-ray flux both photoionizes and backlights the plasma. In particular, we focus on extracting the charge state distribution of the plasma and the characteristics of the radiation field driving the plasma in order to estimate the ionisation parameter.

  15. A Next-Generation Experiment To Study Magnetic Reconnection and Related Explosive Phenomena in Large and Collisionless Plasmas

    NASA Astrophysics Data System (ADS)

    Ji, H.; Yamada, M.; Prager, S.; Daughton, W.; Roytershteyn, V.

    2009-11-01

    Magnetic reconnection, a topological change in magnetic field in plasmas, often occurs explosively leading to rapid conversion of magnetic energy to plasma particle energy in space, astrophysical and laboratory fusion plasmas. The Magnetic Reconnection Experiment (MRX, http://mrx.pppl.gov) is a primary dedicated experiment to study reconnection in a controlled environment. However, further critical understanding and contributions to space and astrophysical plasmas are limited by the parameters achievable in MRX and other dedicated experiments. The MRX plasmas are relatively collisional (Lundquist numbers S ˜10^3) and effectively small (plasma size normalized by ion skin depth or ion sound radius ˜10). In this paper, we discuss plans for a next-generation reconnection experiment based on MRX. By a combination of larger physical size, stronger magnetic field, and higher heating power, we aim to increase S by a factor of 100 and effective size by a factor of 10, representing a very large jump in the laboratory capabilities. Kinetic simulations in realistic boundaries will be used to guide the experimental design. Research topics include: (1) transition of collisional to collisionless reconnection and its scaling with collisionality and size, (2) interacting multiple reconnections as a possible cause of explosive phenomena, (3) particle energization by reconnection, (4) relation between local reconnection and global magnetic self-organization in 3D realistic geometry and boundary.

  16. Public Data Set: H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment

    DOE Data Explorer

    Thome, Kathreen E. [University of Wisconsin-Madison; Oak Ridge Associated Universities] (ORCID:0000000248013922); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Barr, Jayson L. [University of Wisconsin-Madison] (ORCID:0000000177685931); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Kriete, David M. [University of Wisconsin-Madison] (ORCID:0000000236572911); Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

    2016-09-30

    This data set contains openly-documented, machine readable digital research data corresponding to figures published in K.E. Thome et al., 'H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment,' Nucl. Fusion 57, 022018 (2017).

  17. Advanced electric propulsion and space plasma contactor research

    NASA Technical Reports Server (NTRS)

    Wilbur, Paul J.

    1987-01-01

    A theory of the plasma contacting process is described and experimental results obtained using three different hollow cathode-based plasma contactors are presented. The existence of a sheath across which the bulk of the voltage drop associated with the contacting process occurs is demonstrated. Test results are shown to agree with a model of a spherical, space-charge-limited double sheath. The concept of ignited mode contactor operation is discussed, which is shown to enhance contactor efficiency when it is collecting electrons. An investigation of the potentials in the plasma plumes downstream of contactors operating at typical conditions is presented. Results of tests performed on hollow cathodes operating at high interelectrode pressures (up to about 1000 Torr) on ammonia are presented and criteria that are necessary to ensure that the cathode will operate properly in this regime are presented. These results suggest that high pressure hollow cathode operation is difficult to achieve and that special care must be taken to assure that the electron emission region remains diffuse and attached to the low work function insert. Experiments conducted to verify results obtained previously using a ring cusp ion source equipped with a moveable anode are described and test results are reported. A theoretical study of hollow cathode operation at high electron emission currents is presented. Preliminary experiments using the constrained sheath optics concept to achieve ion extraction under conditions of high beam current density, low net accelerating voltage and well columniated beamlet formation are discussed.

  18. A capstone research experience for physics majors

    NASA Astrophysics Data System (ADS)

    Jackson, David

    2013-03-01

    Dickinson College is a small liberal arts college with a thriving physics program. For years, one of the key features of our program has been a year-long senior research project that was required for each student. Unfortunately, as our number of majors increased, it became more and more difficult to supervise such a large number of senior research projects. To deal with this growing challenge, we developed a capstone research experience that involves a larger number of students working together on an independent group project. In this talk I will give a broad overview of our new senior research model and provide a few examples of projects that have been carried out over the past few years. I will also briefly describe the positive and negative aspects of this model from the perspective of faculty and students.

  19. Laboratory experiments on plasma jets in a magnetic field using high-power lasers

    NASA Astrophysics Data System (ADS)

    Nishio, K.; Sakawa, Y.; Kuramitsu, Y.; Morita, T.; Ide, T.; Kuwada, M.; Koga, M.; Kato, T.; Norimatsu, T.; Gregory, C.; Woolsey, N.; Murphy, C.; Gregori, G.; Schaar, K.; Diziere, A.; Koenig, M.; Pelka, A.; Wang, S.; Dong, Q.; Li, Y.; Takabe, H.

    2013-11-01

    The experiments to simulate astrophysical jet generation are performed using Gekko XII (GXII) HIPER laser system at the Institute of Laser Engineering. In the experiments a fast plasma flow generated by shooting a CH plane (10 μm thickness) is observed at the rear side of the plane. By separating the focal spot of the main beams, a non-uniform plasma is generated. The non-uniform plasma flow in an external magnetic field (0.2˜0.3 T) perpendicular to the plasma is more collimated than that without the external magnetic field. The plasma β, the ratio between the plasma and magnetic pressure, is ≫ 1, and the magnetic Reynolds number is ˜150 in the collimated plasma. It is considered that the magnetic field is distorted by the plasma flow and enhances the jet collimation.

  20. Texas Experimental Tokamak, a plasma research facility: Technical progress report

    SciTech Connect

    Wootton, A.J.

    1995-08-01

    In the year just past, the authors made major progress in understanding turbulence and transport in both core and edge. Development of the capability for turbulence measurements throughout the poloidal cross section and intelligent consideration of the observed asymmetries, played a critical role in this work. In their confinement studies, a limited plasma with strong, H-mode-like characteristics serendipitously appeared and received extensive study though a diverted H-mode remains elusive. In the plasma edge, they appear to be close to isolating a turbulence drive mechanism. These are major advances of benefit to the community at large, and they followed from incremental improvements in diagnostics, in the interpretation of the diagnostics, and in TEXT itself. Their general philosophy is that the understanding of plasma physics must be part of any intelligent fusion program, and that basic experimental research is the most important part of any such program. The work here demonstrates a continuing dedication to the problems of plasma transport which continue to plague the community and are an impediment to the design of future devices. They expect to show here that they approach this problem consistently, systematically, and effectively.

  1. The Plasma Interaction Experiment /PIX/ - Description and flight qualification test program

    NASA Technical Reports Server (NTRS)

    Ignaczak, L. R.; Haley, F. A.; Domino, E. J.; Culp, D. H.; Shaker, F. J.

    1978-01-01

    The Plasma Interaction Experiment (PIX) is a battery powered preprogrammed auxiliary payload on the Landsat-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus 1 kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage-biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage.

  2. The Plasma Interaction Experiment /PIX/ - Description and flight qualification test program

    NASA Technical Reports Server (NTRS)

    Ignaczak, L. R.; Haley, F. A.; Domino, E. J.; Culp, D. H.; Shaker, F. J.

    1978-01-01

    The Plasma Interaction Experiment (PIX) is a battery powered preprogrammed auxiliary payload on the Landsat-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus 1 kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage-biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage.

  3. Instrumentation of Reentry Plasma Experiments on Trail-Blazer II Rocket A21.220-1

    DTIC Science & Technology

    1974-07-31

    June 1974 BLAZER II ROCKET A21. 220-1 9. PIF~~GOG REPORT NUMBER 7. &TMORCO) J. Spencer Rocbefort L. CONTRACT OR GRANT NUNIIEN(sJ Raimundas Sukys F19628...Fnittei) AFCRL-TR-74-0385 ( INSTRUMENTATION OF REENTRY PLASMA EXPERIMENTS ON TRAILBLAZER II ROCKET A21. 220-1 J. Spencer Rochefort Raimundas Sukys ...J.S. Rochefort, L. J. O’Connor, C.H. Price, Jr., and R, Sukys , "Data Transmission and ’I rajectory Determining Devices For Research Rockets and

  4. Measurements of Plasma Expansion due to Background Gas in the Electron Diffusion Gauge Experiment

    SciTech Connect

    Kyle A. Morrison; Stephen F. Paul; Ronald C. Davidson

    2003-08-11

    The expansion of pure electron plasmas due to collisions with background neutral gas atoms in the Electron Diffusion Gauge (EDG) experiment device is observed. Measurements of plasma expansion with the new, phosphor-screen density diagnostic suggest that the expansion rates measured previously were observed during the plasma's relaxation to quasi-thermal-equilibrium, making it even more remarkable that they scale classically with pressure. Measurements of the on-axis, parallel plasma temperature evolution support the conclusion.

  5. Swashzone Fellowships: a 6-month research experience

    NASA Astrophysics Data System (ADS)

    Raubenheimer, B.

    2011-12-01

    The Swashzone Fellowships funded by the CAREER program were designed to provide sufficient time for undergraduates with little knowledge of ocean processes and minimal prior research experience to participate in observational nearshore oceanographic studies. The fellows learned background material, developed hypotheses, planned field experiments, designed sensor arrays, tested and debugged instrumentation, collected and analyzed data, and communicated the results through oral and written presentations. The program funded 12 undergraduate student fellows (4 male and 8 female), with backgrounds in math (3 students), physics (4), geology (1), and environmental sciences (4). Preference was given to applicants who had not taken oceanography classes and who were unsure of career plans. All the students presented their results at department seminars, and most presented their results at a professional conference (eg, AGU or Ocean Sciences). The results often were incorporated in peer-reviewed manuscripts. Evaluations conducted following the fellowships and again several years after each fellowship indicated that many of the students pursued STEM careers: 5 are pursuing PhD degrees, including bio-mathematics, physics, atmospheric physics, and ocean physics; 2 are employed at environmental engineering and consulting firms; 4 are employed as research technicians at WHOI; and 1 is a lawyer (currently being considered as a clerk for the Supreme Court). Many of the students were excited to learn about the range of oceanographic career options, including engineering and technical staff, as well as science research. The graduating seniors expressed their appreciation for the fellowship opportunity, stating that there were few science positions available to students without significant prior research experience. Several students noted that the fellowships were critical to their later employment and to their decisions to pursue careers in science. In particular, the students noted

  6. Megagauss field generation for high-energy-density plasma science experiments.

    SciTech Connect

    Rovang, Dean Curtis; Struve, Kenneth William; Porter, John Larry Jr.

    2008-10-01

    There is a need to generate magnetic fields both above and below 1 megagauss (100 T) with compact generators for laser-plasma experiments in the Beamlet and Petawatt test chambers for focused research on fundamental properties of high energy density magnetic plasmas. Some of the important topics that could be addressed with such a capability are magnetic field diffusion, particle confinement, plasma instabilities, spectroscopic diagnostic development, material properties, flux compression, and alternate confinement schemes, all of which could directly support experiments on Z. This report summarizes a two-month study to develop preliminary designs of magnetic field generators for three design regimes. These are, (1) a design for a relatively low-field (10 to 50 T), compact generator for modest volumes (1 to 10 cm3), (2) a high-field (50 to 200 T) design for smaller volumes (10 to 100 mm3), and (3) an extreme field (greater than 600 T) design that uses flux compression. These designs rely on existing Sandia pulsed-power expertise and equipment, and address issues of magnetic field scaling with capacitor bank design and field inductance, vacuum interface, and trade-offs between inductance and coil designs.

  7. Convex Crystal X-ray Spectrometer for Laser Plasma Experiments

    SciTech Connect

    May, M; Heeter, R; Emig, J

    2004-04-15

    Measuring time and space-resolved spectra is important for understanding Hohlraum and Halfraum plasmas. Experiments at the OMEGA laser have used the Nova TSPEC which was not optimized for the OMEGA diagnostic space envelope or for the needed spectroscopic coverage and resolution. An improved multipurpose spectrometer snout, the MSPEC, has been constructed and fielded on OMEGA. The MSPEC provides the maximal internal volume for mounting crystals without any beam interferences at either 2x or 3x magnification. The RAP crystal is in a convex mounting geometry bent to a 20 cm radius of curvature. The spectral resolution, E/dE, is about 200 at 2.5 keV. The spectral coverage is 2 to 4.5 keV. The MSPEC can record four separate spectra on the framing camera at time intervals of up to several ns. The spectrometer design and initial field-test performance will be presented and compared to that of the TSPEC. Work supported by U. S. DoE/UC LLNL contract W-7405-ENG-48

  8. Turbulent hydrodynamics experiments using a new plasma piston

    SciTech Connect

    Edwards, J.; Glendinning, S. G.; Suter, L. J.; Remington, B. A.; Landen, O.; Turner, R. E.; Shepard, T. J.; Lasinski, B.; Budil, K.; Robey, H.

    2000-05-01

    A new method for performing compressible hydrodynamic instability experiments using high-power lasers is presented. A plasma piston is created by supersonically heating a low-density carbon based foam with x-rays from a gold hohlraum heated to {approx}200 eV by a {approx}1 ns Nova laser pulse [E. M. Campbell et al., Laser Part. Beams 9, 209 (1991)]. The piston causes an almost shockless acceleration of a thin, higher-density payload consisting of a layer of gold, initially 1/2 {mu}m thick, supported on 10 {mu}m of solid plastic, at {approx}45 {mu}m/ns{sup 2}. The payload is also heated by hohlraum x-rays to in excess of 150 eV so that the Au layer expands to {approx}20 {mu}m prior to the onset of instability growth. The Atwood number between foam and Au is {approx}0.7. Rayleigh-Taylor instability, seeded by the random fibrous structure of the foam, causes a turbulent mixing region with a Reynolds number >10{sup 5} to develop between piston and Au. The macroscopic width of the mixing region was inferred from the change in Au layer width, which was recorded via time resolved x-radiography. The mix width thus inferred is demonstrated to depend on the magnitude of the initial foam seed. For a small initial seed, the bubble front in the turbulent mixing region is estimated indirectly to grow as {approx}0.036{+-}0.19 [{integral}{radical}(Ag)dt]{sup 2} which would imply for a constant acceleration 0.036{+-}0.019 Agt{sup 2}. More direct measurement techniques must be developed in larger scale experiments to remove potential complicating factors and reduce the error bar to a level that would permit the measurements to discriminate between various theories and models of turbulent mixing. (c) 2000 American Institute of Physics.

  9. Laser Plasma Instability Experiments with KrF Lasers

    DTIC Science & Technology

    2007-01-01

    L. Phillips, A. J. Schmitt, J. D. Sethain, R . K. McCrory, W. Seka, C. Verdon, J. P. Knauer, B. B. Afeyan, H. T . Powell, Physics of Plasmas, 5, 5...Physics of Plasmas. 8 R . Betti, K. Anderson, J. Knauer, T . J. B. Collins, R . L. McCrory, R . W. McKenty, S. Skupsky, Physics of Plasmas, 12, 4, 042703...2005). 9 W. L. Kruer, The Physics of Laser Plasma Interactions (Addison-Wesley, Boulder, 1988). 10 J. M. McMahon, R . P. Burns, T . H. DeRieux, R

  10. Drift kinetic effects on the plasma response in high beta spherical tokamak experiments

    DOE PAGES

    Wang, Zhirui; Park, Jong-Kyu; Menard, Jonathan E.; ...

    2017-09-21

    Highmore » $$\\beta$$ plasma response to the rotating n=1 external magnetic perturbations is numerically studied and compared with National Spherical Torus eXperiment (NSTX). The hybrid magnetohydrodynamic(MHD)-kinetic modeling shows the drift kinetic effects are important to resolve the disagreement of plasma response between the ideal MHD prediction and the NSTX experimental observation when plasma pressure reaches and exceeds the no-wall limit [F. Troyon et al., Plasma Phys. Control. Fusion 26, 209 (1984)]. Thus, since the external rotating fields and high plasma rotation are presented in NSTX experiments, the importance of resistive wall effect and plasma rotation on determining the plasma response is also identified, where the resistive wall suppresses the plasma response through the wall eddy current. The inertial energy, due to plasma rotation, destabilizes the plasma. Finally, the complexity of plasma response, in this study, indicates that MHD modeling, including comprehensive physics e.g. the drift kinetic effects, resistive wall and plasma rotation, is essential to reliably predict the plasma behavior in high beta spherical tokamak device.« less

  11. Research results and utility experience workshop: Proceedings

    SciTech Connect

    Not Available

    1994-08-01

    This workshop was sponsored by the Distributed Utility Valuation (DUV) Project-a joint effort of the National Renewable Energy Laboratory (NREL) Department of Energy (DOE), Electric Power Research Institute (EPRI), Pacific Northwest Laboratory (PNL) Department of Energy (DOE), and Pacific Gas & Electric Company (PG&E). The purpose of the workshop is to provide a forum for utilities, other research organizations, and regulatory agencies to share results and data on Distributed Utility (DU)-related research and applications. Up-to-date information provided insight into the various technologies available to utilities, the methods used to select the technologies, and case study results. The workshop was divided into three sessions: Planning Tools; Utility Experience; and Policy and Technology Implications. Brief summaries of the individual presentations from each session are attached as appendices.

  12. Characterization of a linear device developed for research on advanced plasma imaging and dynamicsa)

    NASA Astrophysics Data System (ADS)

    Chung, J.; Lee, K. D.; Seo, D. C.; Nam, Y. U.; Choi, M. C.

    2010-10-01

    Within the scope of long term research on imaging diagnostics for steady-state plasmas and understanding of edge plasma physics through diagnostics with conventional spectroscopic methods, we have constructed a linear electron cyclotron resonance (ECR) plasma device named Research on Advanced Plasma Imaging and Dynamics (RAPID). It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. Here, a 6 kW 2.45 GHz magnetron is used to produce steady-state hydrogen, helium, and argon plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). In order to achieve the highest possible plasma performance within the limited input parameters, wall conditioning experiments were carried out. Chamber bake-out was achieved with heating coils that were wound covering the vessel, and long-pulse electron cyclotron heating discharge cleaning was also followed after 4 days of bake-out. A uniform bake-out temperature (150 °C) was achieved by wrapping the vessel in high temperature thermal insulation textile and by controlling the heating coil current using a digital control system. The partial pressure changes were observed using a residual gas analyzer, and a total system pressure of 5×10-8 Torr was finally reached. Diagnostic systems including a millimeter-wave interferometer, a high resolution survey spectrometer, a Langmuir probe, and an ultrasoft x-ray detector were used to provide the evidence that the plasma performance was improved as we desired. In this work, we present characterization of the RAPID device for various system conditions and configurations.

  13. Characterization of a linear device developed for research on advanced plasma imaging and dynamics

    SciTech Connect

    Chung, J.; Lee, K. D.; Seo, D. C.; Nam, Y. U.; Choi, M. C.

    2010-10-15

    Within the scope of long term research on imaging diagnostics for steady-state plasmas and understanding of edge plasma physics through diagnostics with conventional spectroscopic methods, we have constructed a linear electron cyclotron resonance (ECR) plasma device named Research on Advanced Plasma Imaging and Dynamics (RAPID). It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. Here, a 6 kW 2.45 GHz magnetron is used to produce steady-state hydrogen, helium, and argon plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). In order to achieve the highest possible plasma performance within the limited input parameters, wall conditioning experiments were carried out. Chamber bake-out was achieved with heating coils that were wound covering the vessel, and long-pulse electron cyclotron heating discharge cleaning was also followed after 4 days of bake-out. A uniform bake-out temperature (150 deg. C) was achieved by wrapping the vessel in high temperature thermal insulation textile and by controlling the heating coil current using a digital control system. The partial pressure changes were observed using a residual gas analyzer, and a total system pressure of 5x10{sup -8} Torr was finally reached. Diagnostic systems including a millimeter-wave interferometer, a high resolution survey spectrometer, a Langmuir probe, and an ultrasoft x-ray detector were used to provide the evidence that the plasma performance was improved as we desired. In this work, we present characterization of the RAPID device for various system conditions and configurations.

  14. Characterization of a linear device developed for research on advanced plasma imaging and dynamics.

    PubMed

    Chung, J; Lee, K D; Seo, D C; Nam, Y U; Choi, M C

    2010-10-01

    Within the scope of long term research on imaging diagnostics for steady-state plasmas and understanding of edge plasma physics through diagnostics with conventional spectroscopic methods, we have constructed a linear electron cyclotron resonance (ECR) plasma device named Research on Advanced Plasma Imaging and Dynamics (RAPID). It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. Here, a 6 kW 2.45 GHz magnetron is used to produce steady-state hydrogen, helium, and argon plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). In order to achieve the highest possible plasma performance within the limited input parameters, wall conditioning experiments were carried out. Chamber bake-out was achieved with heating coils that were wound covering the vessel, and long-pulse electron cyclotron heating discharge cleaning was also followed after 4 days of bake-out. A uniform bake-out temperature (150 °C) was achieved by wrapping the vessel in high temperature thermal insulation textile and by controlling the heating coil current using a digital control system. The partial pressure changes were observed using a residual gas analyzer, and a total system pressure of 5×10(-8) Torr was finally reached. Diagnostic systems including a millimeter-wave interferometer, a high resolution survey spectrometer, a Langmuir probe, and an ultrasoft x-ray detector were used to provide the evidence that the plasma performance was improved as we desired. In this work, we present characterization of the RAPID device for various system conditions and configurations.

  15. The Electron and ion Plasma Experiment for Fast

    NASA Astrophysics Data System (ADS)

    Carlson, C. W.; McFadden, J. P.; Turin, P.; Curtis, D. W.; Magoncelli, A.

    2001-08-01

    The ion and electron plasma experiment on the Fast Auroral Snapshot satellite (FAST) is designed to measure pitch-angle distributions of suprathermal auroral electrons and ions with high sensitivity, wide dynamic range, good energy and angular resolution, and exceptional time resolution. These measurements support the primary scientific goal of the FAST mission to understand the physical processes responsible for auroral particle acceleration and heating, and associated wave-particle interactions. The instrument includes a complement of 8 pairs of `Top Hat' electrostatic analyzer heads with microchannel plate (MCP) electron multipliers and discrete anodes to provide angle resolved measurements. The analyzers are packaged in four instrument stacks, each containing four analyzers. These four stacks are equally spaced around the spacecraft spin plane. Analyzers mounted on opposite sides of the spacecraft operate in pairs such that their individual 180° fields of view combine to give an unobstructed 360° field of view in the spin plane. The earth's magnetic field is within a few degrees of the spin plane during most auroral crossings, so the time resolution for pitch-angle distribution measurements is independent of the spacecraft spin period. Two analyzer pairs serve as electron and ion spectrometers that obtain distributions of 48 energies at 32 angles every 78 ms. Their standard energy ranges are 4 eV to 32 keV for electrons and 3 eV to 24 keV for ions. These sensors also have deflection plates that can track the magnetic field direction within 10° of the spin plane to resolve narrow, magnetic field-aligned beams of electrons and ions. The remaining six analyzer pairs collectively function as an electron spectrograph, resolving distributions with 16 contiguous pitch-angle bins and a selectable trade-off of energy and time resolution. Two examples of possible operating modes are a maximum time resolution mode with 16 angles and 6 energies every 1.63 ms, or a

  16. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated August 14, 1995: 'KSC plant physiologist Dr. Gary Stutte harvests a potato grown in the Biomass Production Chamber of the Controlled environment Life Support system (CELSS) in Hangar L at Cape Canaveral Air Station. During a 418-day 'human rated' experiment, potato crops grown in the chamber provided the equivalent of a continuous supply of the oxygen for one astronaut, along with 55 percent of that long-duration space flight crew member's caloric food requirements and enough purified water for four astronauts while absorbing their expelled carbon dioxide. The experiment provided data that will help demonstarte the feasibility of the CELSS operating as a bioregenerative life support system for lunar and deep-space missions that can operate independently without the need to carry consumables such as air, water and food, while not requiring the expendable air and water system filters necessary on today's human-piloted spacecraft.' His work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  17. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated August 14, 1995: 'KSC plant physiologist Dr. Gary Stutte (right) and Cheryl Mackowiak harvest potatoes grown in the Biomass Production Chamber of the Controlled Enviornment Life Support System (CELSS in Hangar L at Cape Canaveral Air Station. During a 418-day 'human rated' experiment, potato crops grown in the chamber provided the equivalent of a continuous supply of the oxygen for one astronaut, along with 55 percent of that long-duration space flight crew member's caloric food requirements and enough purified water for four astronauts while absorbing their expelled carbon dioxide. The experiment provided data that will help demonstarte the feasibility of the CELSS operating as a bioregenerative life support system for lunar and deep-space missions that can operate independently without the need to carry consumables such as air, water and food, while not requiring the expendable air and water system filters necessary on today's human-piloted spacecraft.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  18. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated August 14, 1995: 'KSC plant physiologist Dr. Gary Stutte (right) and Cheryl Mackowiak harvest potatoes grown in the Biomass Production Chamber of the Controlled Enviornment Life Support System (CELSS in Hangar L at Cape Canaveral Air Station. During a 418-day 'human rated' experiment, potato crops grown in the chamber provided the equivalent of a continuous supply of the oxygen for one astronaut, along with 55 percent of that long-duration space flight crew member's caloric food requirements and enough purified water for four astronauts while absorbing their expelled carbon dioxide. The experiment provided data that will help demonstarte the feasibility of the CELSS operating as a bioregenerative life support system for lunar and deep-space missions that can operate independently without the need to carry consumables such as air, water and food, while not requiring the expendable air and water system filters necessary on today's human-piloted spacecraft.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  19. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated August 14, 1995: 'KSC plant physiologist Dr. Gary Stutte harvests a potato grown in the Biomass Production Chamber of the Controlled environment Life Support system (CELSS) in Hangar L at Cape Canaveral Air Station. During a 418-day 'human rated' experiment, potato crops grown in the chamber provided the equivalent of a continuous supply of the oxygen for one astronaut, along with 55 percent of that long-duration space flight crew member's caloric food requirements and enough purified water for four astronauts while absorbing their expelled carbon dioxide. The experiment provided data that will help demonstarte the feasibility of the CELSS operating as a bioregenerative life support system for lunar and deep-space missions that can operate independently without the need to carry consumables such as air, water and food, while not requiring the expendable air and water system filters necessary on today's human-piloted spacecraft.' His work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  20. ISEE-1 and ISEE-2 fast plasma experiment and the ISEE-1 solar wind experiment

    NASA Technical Reports Server (NTRS)

    Bame, S. J.; Asbridge, J. R.; Felthauser, H. E.; Glore, J. P.; Paschmann, G.; Hemmerich, P.; Lehmann, K.; Rosenbauer, H.

    1978-01-01

    Identical fast plasma experiment (FPE) systems were placed on the ISEE-1 and ISEE-2 spacecraft. The FPE consists of three high efficiency 90 deg spherical section electrostatic analyzers using large secondary emitters and discrete dynode multipliers to detect analyzed particles. Two of them, viewing in opposite directions, produce complete 2D velocity distribution measurements of both protons and electrons every spacecraft revolution. A third FPE analyzer with a divided emitter measures 3D distributions at a slower rate. ISEE-1 also carries a solar-wind experiment (SWE) to measure solar-wind ions with high resolution. The SWE is composed of two 150 deg spherical section analyzers using the same set of plates. The two acceptance fans are tilted with respect to each other so that 3D characteristics of the ion distributions can be derived.

  1. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms 12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy ( 15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  2. Electron beam-plasma interaction experiments with the Versatile Toroidal Facility (VTF)

    SciTech Connect

    Murphy, S.M.; Lee, M.C.; Moriarty, D.T.; Riddolls, R.J.

    1995-12-31

    The laboratory investigation of electron beam-plasma interactions is motivated by the recent space shuttle experiments. Interesting but puzzling phenomena were observed in the shuttle experiments such as the bulk heating of background ionospheric plasmas by the injected electron beams and the excitation of plasma waves in the frequency range of ELF waves. The plasma machine, the Versatile Toroidal Facility (VTF) can generate a large magnetized plasma with the electron plasma frequency greater than the electron gyrofrequency by a factor of 3--5 similar to the plasma condition in the ionosphere. Short pulses of electron beams are injected into the VTF plasmas in order to simulate the beam injection from spacecrafts in the ionosphere. A Langmuir probe installed at a bottom port of VTF monitors the spatial variation of electron beams emitted from LaB6 filaments. An energy analyzer has been used to determine the particle energy distribution in the VTF plasmas. Several mechanisms will be tested as potential causes of the bulk heating of background plasmas by the injected electron beams as seen in the space shuttle experiments. It is speculated that the observed ELF emissions result from the excitation of purely growing modes detected by the space shuttle-borne detectors. Results of the laboratory experiments will be reported to corroborate this speculation.

  3. The role of magnetohydrodynamics in heliospheric space plasma physics research

    NASA Technical Reports Server (NTRS)

    Dryer, Murray; Smith, Zdenka Kopal; Wu, Shi Tsan

    1988-01-01

    Magnetohydrodynamics (MHD) is a fairly recent extension of the field of fluid mechanics. While much remains to be done, it has successfully been applied to the contemporary field of heliospheric space plasma research to evaluate the 'macroscopic picture' of some vital topics via the use of conducting fluid equations and numerical modeling and simulations. Some representative examples from solar and interplanetary physics are described to demonstrate that the continuum approach to global problems (while keeping in mind the assumptions and limitations therein) can be very successful in providing insight and large scale interpretations of otherwise intractable problems in space physics.

  4. Plasma-filled applied B ion diode experiments using a plasma opening switch

    NASA Astrophysics Data System (ADS)

    Renk, T. J.

    1994-12-01

    In order for a plasma opening switch (POS) to open quickly and transfer power efficiently from an inductively charged vacuum transmission line to an applied B ion diode, the load impedance of the ion diode may be required to have an initial low impedance phase. A plasma-filled diode has such an impedance history. To test the effect of a plasma-filled diode on POS-diode coupling, a drifting plasma was introduced from the cathode side of an applied B ion diode operated on the LION accelerator (1.5 MV, 4 Ohm, 40 ns) at Cornell University. This plasma readily crossed the 2.1 T magnetic insulation field of the diode, and resulted in both increased diode electrical power, and an increased ability of the ion beam to remove material from a target. The plasma did not appear to have a noticeable effect on local beam steering angle.

  5. Plasma-filled applied B ion diode experiments using a plasma opening switch

    SciTech Connect

    Renk, T.J. )

    1994-12-15

    In order for a plasma opening switch (POS) to open quickly and transfer power efficiently from an inductively charged vacuum transmission line to an applied B ion diode, the load impedance of the ion diode may be required to have an initial low impedance phase. A plasma-filled diode has such an impedance history. To test the effect of a plasma-filled diode on POS-diode coupling, a drifting plasma was introduced from the cathode side of an applied B ion diode operated on the LION accelerator (1.5 MV, 4 [Omega], 40 ns) at Cornell University. This plasma readily crossed the 2.1 T magnetic insulation field of the diode, and resulted in both increased diode electrical power, and an increased ability of the ion beam to remove material from a target. The plasma did not appear to have a noticeable effect on local beam steering angle.

  6. Opening switch research on a dense plasma focus

    NASA Astrophysics Data System (ADS)

    Gerdin, G.

    1987-02-01

    Experiments were performed to enhance power coupling to the load by placing the load electrode opposite the muzzle end of the Dense Plasma Focus plasma gun. The impaler concept, whereby the current sheath is run into a knife edge insulator, was tested in two configurations. However, the power coupled to the load was always less than one tenth that of the experiments where the load was coupled to the breach of the gun. Other load coupling schemes where the load electrode was brought near the outside of the central electrode prevented pinches (voltage surges) when placed too close and the power coupled to the load was reduced when the load electrodes were moved away. The results were not as good as those of the impaler concept. Measurements of the dynamics of the current sheath in various stages were performed and compared with theory. Generally the velocity of the current sheath falls below theoretical expectations suggesting the presence of electrode drag, a phenomenon not present in the model. During the radial collapse phase the model and the experimental estimates of dL/dt are in substantiaL agreement before pinch time but disagree afterward due to two dimensional effects not present in the theory.

  7. Engaging Students in Authentic Astronomy Research Experiences

    NASA Astrophysics Data System (ADS)

    Spuck, Timothy; Boocks, C.; Coogan, N.; Culbertson, E.; Davis, J.; Reinsel, N.; Saathoff, I.; Sampsell, D.; Yashinski, N.

    2010-05-01

    According to the National Science Standards science is something you do, not something that is done to you. The presentation explores citizen science projects such as GalaxyZoo and Citizen Sky-epsilon Aurigae, a search for young stellar objects, asteroid hunting with the International Astronomical Search Collaboration, a Cepheid variable study, and a local light pollution project; all taking place at the Oil City Area Sr. High School in Northwestern Pennsylvania. Students will be presenting their research and discuss the value of these real science experiences.

  8. Investigation of iron opacity experiment plasma gradients with synthetic data analyses.

    PubMed

    Nagayama, T; Bailey, J E; Rochau, G A; Hansen, S B; Mancini, R C; MacFarlane, J J; Golovkin, I

    2012-10-01

    Experiments have been performed at Sandia National Laboratories Z-facility to validate iron opacity models relevant to the solar convection/radiation zone boundary. Sample conditions were measured by mixing Mg with the Fe and using Mg K-shell line transmission spectra, assuming that the plasma was uniform. We develop a spectral model that accounts for hypothetical gradients, and compute synthetic spectra to quantitatively evaluate the plasma gradient size that can be diagnosed. Two sample designs are investigated, assuming linear temperature and density gradients. First, Mg uniformly mixed with Fe enables temperature gradients greater than 10% to be detected. The second design uses Mg mixed into one side and Al mixed into the other side of the sample in an attempt to more accurately infer the sample gradient. Both temperature and density gradients as small as a few percent can be detected with this design. Experiments have successfully recorded spectra with the second design. In future research, the spectral model will be used to place bounds on gradients that exist in Z opacity experiments.

  9. Plasma skin resurfacing: personal experience and long-term results.

    PubMed

    Bentkover, Stuart H

    2012-05-01

    This article presents a comprehensive clinical approach to plasma resurfacing for skin regeneration. Plasma technology, preoperative protocols, resurfacing technique, postoperative care, clinical outcomes, evidence-based results, and appropriate candidates for this procedure are discussed. Specific penetration depth and specific laser energy measurements are provided. Nitrogen plasma skin regeneration is a skin-resurfacing technique that offers excellent improvement of mild to moderate skin wrinkles and overall skin rejuvenation. It also provides excellent improvement in uniformity of skin color and texture in patients with hyperpigmentation with Fitzpatrick skin types 1 through 4.

  10. UCLA/FNPL Underdense Plasma Lens Experiment: Results and Analysis

    SciTech Connect

    Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Fliller, R; Kazakevich, G M; Piot, P; Santucci, J; Li, J; Tikhoplav, R

    2006-08-04

    Focusing of a 15 MeV, 16 nC electron bunch by a gaussian underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated. The strong 1.9 cm focal length plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Time resolved measurements of the focused electron bunch are also reported and compared to simulations.

  11. Experiments With Radiatively Cooled Supersonic Plasma Jets Generated in Conical Wire Array Z-Pinches

    NASA Astrophysics Data System (ADS)

    Lebedev, S. V.; Ampleford, D. J.; Bland, S. N.; Chittenden, J. P.; Ciardi, A.; Naz, N.; Haines, M. G.; Frank, A.; Blackman, E.; Gardiner, T.

    2002-12-01

    We present results of astrophysically relevant experiments where highly supersonic plasma jets are generated via conically convergent plasma flows in a conical wire array Z-pinch. Stagnation of plasma flow on the axis of symmetry forms a standing conical shock effectively collimating the flow in the axial direction. This scenario is essentially similar to that discussed by Canto and collaborators [1] as a purely hydrodynamic mechanism for jet formation in astrophysical systems. Experiments using different materials (Al, Fe and W) show that a hypersonic (M ~ 20), well-collimated jet is generated when the radiative cooling rate of the plasma is significant.

  12. Plasma wave experiment for the ISEE-3 mission

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1982-01-01

    Analysis of data from a scientific instrument designed to study solar wind and plasma wave phenomena on the ISEE-3 mission is presented. The performance of work on the data analysis phase is summarized.

  13. Ion cyclotron heating experiments in magnetosphere plasma device RT-1

    SciTech Connect

    Nishiura, M. Yoshida, Z.; Yano, Y.; Kawazura, Y.; Saitoh, H.; Yamasaki, M.; Mushiake, T.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-12-10

    The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ∼10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ∼50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

  14. Ion cyclotron heating experiments in magnetosphere plasma device RT-1

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Yoshida, Z.; Yano, Y.; Kawazura, Y.; Saitoh, H.; Yamasaki, M.; Mushiake, T.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-12-01

    The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ˜10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ˜50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

  15. Experiments on viscous transport in pure-electron plasmas

    NASA Astrophysics Data System (ADS)

    Kriesel, Jason M.; Driscoll, C. Fred

    1999-12-01

    Viscous transport in pure-electron plasmas is a rearrangement of particles due to like-particle interactions, eventually leading to a confined global thermal equilibrium state. The measured transport is observed to be proportional to the shear in the total (E×B+diamagnetic) fluid rotation of the plasma, for both hollow and monotonic rotation profiles. We determine the local kinematic viscosity, κ, from measurements of the local flux of electrons. The measured viscosity is 50-104 times larger than expected from classical transport due to short-range velocity-scattering collisions, but is within a factor of 10 of recent theories by O'Neil and Dubin of transport due to long-range drift collisions. The measured viscosity scales with magnetic field and plasma length roughly as κ∝B/L. This scaling suggests a finite-length transport enhancement caused by particles interacting multiple times as they bounce axially between the ends of the plasma.

  16. Analysis of higher harmonics on bidirectional heat pulse propagation experiment in helical and tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ida, K.; Inagaki, S.; Tsuchiya, H.; Tamura, N.; Choe, G. H.; Yun, G. S.; Park, H. K.; Ko, W. H.; Evans, T. E.; Austin, M. E.; Shafer, M. W.; Ono, M.; López-bruna, D.; Ochando, M. A.; Estrada, T.; Hidalgo, C.; Moon, C.; Igami, H.; Yoshimura, Y.; Tsujimura, T. Ii.; Itoh, S.-I.; Itoh, K.

    2017-07-01

    In this contribution we analyze modulation electron cyclotron resonance heating (MECH) experiment and discuss higher harmonic frequency dependence of transport coefficients. We use the bidirectional heat pulse propagation method, in which both inward propagating heat pulse and outward propagating heat pulse are analyzed at a radial range, in order to distinguish frequency dependence of transport coefficients due to hysteresis from that due to other reasons, such as radially dependent transport coefficients, a finite damping term, or boundary effects. The method is applied to MECH experiments performed in various helical and tokamak devices, i.e. Large Helical Device (LHD), TJ-II, Korea Superconducting Tokamak Advanced Research (KSTAR), and Doublet III-D (DIII-D) with different plasma conditions. The frequency dependence of transport coefficients are clearly observed, showing a possibility of existence of transport hysteresis in flux-gradient relation.

  17. Laboratory-scale uranium RF plasma confinement experiments

    NASA Technical Reports Server (NTRS)

    Roman, W. C.

    1976-01-01

    An experimental investigation was conducted using 80 kW and 1.2 MW RF induction heater facilities to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor. Pure uranium hexafluoride (UF6) was injected into argon-confined, steady-state, RF-heated plasmas in different uranium plasma confinement tests to investigate the characteristics of plamas core nuclear reactors. The objectives were: (1) to confine as high a density of uranium vapor as possible within the plasma while simultaneously minimizing the uranium compound wall deposition; (2) to develop and test materials and handling techniques suitable for use with high-temperature, high-pressure gaseous UF6; and (3) to develop complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma and residue deposited on the test chamber components. In all tests, the plasma was a fluid-mechanically-confined vortex-type contained within a fused-silica cylindrical test chamber. The test chamber peripheral wall was 5.7 cm ID by 10 cm long.

  18. Experiments on a current-toggled plasma-opening switch

    SciTech Connect

    Mendel, C.W. Jr.; Savage, M.E.; Zagar, D.M.; Simpson, W.W.; Grasser, T.W.; Quintenz, J.P. )

    1992-04-15

    Plasma-opening switches have been used to improve pulsed-power wave shapes for over a decade. These switches have used the inertia of the plasma to hold the switch closed. This results in conflicting requirements when long hold-off time and fast opening are required, and also results in variation in opening current due to variation in initial plasma fill. The current-toggled plasma-opening switch attempts to overcome these problems by using external magnetic fields rather than inertia to control the plasma conductor. Data will be presented showing several features of the operation of this switch. These data will be compared to models used to design the switch. The comparisons indicate that the mass can be measured approximately from fast coil data and that the slow coil flux does set the opening level of the current. They also indicate that the opening current is somewhat dependent upon plasma mass, and that the design of the field coils that provide the control fields must be done more carefully to provide a switch that opens satisfactorily.

  19. Cultural adaptation in translational research: field experiences.

    PubMed

    Dévieux, Jessy G; Malow, Robert M; Rosenberg, Rhonda; Jean-Gilles, Michèle; Samuels, Deanne; Ergon-Pérez, Emma; Jacobs, Robin

    2005-06-01

    The increase in the incidence of HIV/AIDS among minorities in the United States and in certain developing nations has prompted new intervention priorities, stressing the adaptation of efficacious interventions for diverse and marginalized groups. The experiences of Florida International University's AIDS Prevention Program in translating HIV primary and secondary prevention interventions among these multicultural populations provide insight into the process of cultural adaptations and address the new scientific emphasis on ecological validity. An iterative process involving forward and backward translation, a cultural linguistic committee, focus group discussions, documentation of project procedures, and consultations with other researchers in the field was used to modify interventions. This article presents strategies used to ensure fidelity in implementing the efficacious core components of evidence-based interventions for reducing HIV transmission and drug use behaviors and the challenges posed by making cultural adaptation for participants with low literacy. This experience demonstrates the importance of integrating culturally relevant material in the translation process with intense focus on language and nuance. The process must ensure that the level of intervention is appropriate for the educational level of participants. Furthermore, the rights of participants must be protected during consenting procedures by instituting policies that recognize the socioeconomic, educational, and systemic pressures to participate in research.

  20. Baseline geoenvironmental experiments for in-situ soil transformation by plasma torch

    SciTech Connect

    Beaver, J.R.; Mayne, P.W.

    1995-12-31

    The advent of the nontransferred plasma arc torch has implicated a range of in-situ geoenvironmental applications that can revolutionize methods of ground modification and field remediation of contaminated sites. With reverse polarity nontransferred arc type plasma torches, temperatures of 4,000 C to 7,000 C can be directed at specific targets of contaminated soil or waste. At these extreme temperatures, all organic materials within the soil undergo pyrolysis, while the bulk composition is transformed into a magma that subsequently cools to form a vitrified mass resembling volcanic obsidian or a dense partially crystalline material resembling microcrystalline igneous rock. Simulations of in-situ transformation of soil have been conducted using both 100-kW and 240-kW torches to alter clay, silty sand, and sand in chamber tests. Although these materials are primarily composed of silica and alumina oxides having melting temperatures of 1,100 C to 1,600 C, the formation of a spheroidal magma core occurred within the first five minutes of exposure to the plasma flame. Experiments were conducted to quantify the improved engineering properties that occur after transformation and to demonstrate the relative effects of power level, water content, and soil type on the size and strength of the altered material. The ongoing research also serves as a baseline study for further experimentation that will focus on the in-situ remediation of soils with varied contaminants.

  1. Electron beam injection experiments - The beam-plasma discharge at low pressures and magnetic field strengths

    NASA Technical Reports Server (NTRS)

    Bernstein, W.; Leinbach, H.; Kellogg, P.; Monson, S.; Hallinan, T.; Garriott, O. K.; Konradi, A.; Mccoy, J.; Daly, P.; Baker, B.

    1978-01-01

    The paper describes electron beam injection experiments which clarify observational results obtained in rocket flights. A column of enhanced density plasma, exceeding the density expected from ionization by primary beam electrons, was observed in a large vacuum system at low magnetic fields (1 to 1.5 G) and low ambient pressures (10 to the minus 6 to 10 to the minus 5 torr). The peak luminosity of the discharge was about 10 times that of the beam alone, and the radius increased by a factor of three. In the absence of the discharge, RF emission is observed at 1.1 to 1.2 times the cyclotron frequency, and a strong band of RF noise with upper frequency cutoff at about the cyclotron frequency is observed in the discharge mode, along with higher frequency noise at or near the plasma frequency. The onset of the plasma discharge is critically dependent on beam current. The described results agree with observations obtained at much higher densities and magnetic fields in fusion research studies.

  2. Waves In Space Plasmas (WISP): A space plasma lab active experiment

    NASA Technical Reports Server (NTRS)

    Fredricks, R. W.

    1983-01-01

    The Waves in Space Plasmas (WISP) series of Spacelab Space Plasma Labs devoted to active experimentation, are introduced. Space Plasma Lab-1 is keyed to active probing of the ionosphere and magnetosphere using controlled wave injections by the WISP VLF and HF transmitters, supported by a free-flying plasma diagnostics package instrumented with wave receivers and particle probe diagnostics, designed to measure radiation and propagation of plasma waves, precipitated particle fluxes due to wave/particle interactions, and similar phenomena resulting from wave injectons. The VLF transmitter delivers up to 1 kW of RF power into the antenna terminals over the range from 0.3 to 30 kHz. The HF transmitter delivers up to 500 W to the antenna over the range from 1 to 30 MHz. A dipole antenna commandable to any extension up to 300 m tip-to-tip is available.

  3. Research Coordinators Experiences with Scientific Misconduct and Research Integrity

    PubMed Central

    Habermann, Barbara; Broome, Marion; Pryor, Erica R.; Ziner, Kim Wagler

    2010-01-01

    Background Most reports of scientific misconduct have been focused on principal investigators and other scientists (e.g., biostatisticians) involved in the research enterprise. However, by virtue of their position, research coordinators are often closest to the research field where much of misconduct occurs. Objective To describe research coordinators’ experiences with scientific misconduct in their clinical environment. Design The descriptive design was embedded in a larger, cross-sectional national survey. A total of 266 respondents, predominately registered nurses, who answered yes to having first hand knowledge of scientific misconduct in the past year provided open-ended question responses. Methods Content analysis was conducted by the research team, ensuring agreement of core categories and subcategories of misconduct. Findings Research coordinators most commonly learned about misconduct via first-hand witness of the event, with the principal investigator being the person most commonly identified as the responsible party. Five major categories of misconduct were identified: protocol violations, consent violations, fabrication, falsification, and financial conflict of interest. In 70% of cases, the misconduct was reported. In the majority of instances where misconduct was reported, some action was taken. However, in approximately 14% of cases, no action or investigation ensued; in 6.5% of cases the coordinator was either fired or resigned. Conclusions The study demonstrates the need to expand definitions of scientific misconduct beyond fabrication, falsification, and plagiarism to include other practices. The importance of the ethical climate in the institution in ensuring a safe environment to report and an environment where evidence is reviewed cannot be overlooked. PMID:20010045

  4. Review of upconverted Nd-glass laser plasma experiments at the Lawrence Livermore National Laboratory

    SciTech Connect

    Manes, K.R.

    1982-05-01

    Systematic scaling experiments aimed at deducing the dependence of laser-plasma interaction phenomena on target plasma material and target irradiation history have been underway in laboratories all over the world in recent years. During 1980 and 1981 the Livermore program undertook to measure the laser light absorption of high and low Z plasmas and the partition of the absorbed energy amongst the thermal and suprathermal electron populations as a function of both laser intensity and wavelength. Simulations suggested that short wavelength laser light would couple more efficiently than longer wavelengths to target plasmas. Shorter wavelength heating of higher electron plasma densities would, it was felt, lead to laser-plasma interactions freer of anomalous absorption processes. The following sections review LLNL experiments designed to test these hypotheses.

  5. Collaborative Research: Experimental and Theoretical Study of the Plasma Physics of Antihydrogen Generation and Trapping

    SciTech Connect

    Robicheaux, Francis

    2013-03-29

    Ever since Dirac predicted the existence of antimatter in 1928, it has excited our collective imagination. Seventy-four years later, two collaborations at CERN, ATHENA and ATRAP, created the first slow antihydrogen. This was a stunning achievement, but the most important antimatter experiments require trapped, not just slow, antihydrogen. The velocity, magnetic moment, and internal energy and state of the antihydrogen depend strongly on how it is formed. To trap antihydrogen, physicists face two broad challenges: (1) Understanding the behavior of the positron and antiprotons plasmas from which the antihydrogen is synthesized; and (2) Understanding the atomic processes by which positrons and antiprotons recombine. Recombination lies on the boundary between atomic and plasma physics, and cannot be studied properly without employing tools from both fields. The proposed collaborative research campaign will address both of these challenges. The collaboration members have unique experience in the relevant fields of experimental and theoretical non-neutral plasma physics, numerical modeling, nonlinear dynamics and atomic physics. This expertise is not found elsewhere amongst antihydrogen researchers. The collaboration members have strong ties already, and seek to formalize them with this proposal. Three of the four PIs are members of the ALPHA collaboration, an international collaboration formed by most of the principal members of the ATHENA collaboration.

  6. Research on plasma-puff initiation of high Coulomb transfer switches

    NASA Technical Reports Server (NTRS)

    Venable, Demetrius D.; Han, Kwang S.

    1993-01-01

    The plasma-puff triggering mechanism based on hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for an azimuthally uniform surface flashover which initiates plasma-puff under wide ranges of fill gas pressures of Ar, He and N2. Research is presented and resulting conference papers are attached. These papers include 'Characteristics of Plasma-Puff Trigger for an Inverse-Pinch Plasma Switch'; 'Ultra-High-Power Plasma Switch INPUTS for Pulse Power Systems'; 'Characteristics of Switching Plasma in an Inverse-Pinch Switch'; 'Comparative Study of INPIStron and Spark Gap'; and 'INPIStron Switched Pulsed Power for Dense Plasma Pinches.'

  7. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    SciTech Connect

    Rosenberg, M. J.; Li, C. K.; Fox, W.; Igumenshchev, I.; Seguin, F. H.; Town, R. P.; Frenje, J. A.; Stoeckl, C.; Glebov, V.; Petrasso, R. D.

    2015-04-08

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β~10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell (PIC) simulations predict a stronger flux compression and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.

  8. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    SciTech Connect

    Rosenberg, M. J. Li, C. K.; Séguin, F. H.; Frenje, J. A.; Petrasso, R. D.; Fox, W.; Igumenshchev, I.; Stoeckl, C.; Glebov, V.; Town, R. P. J.

    2015-04-15

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β ∼ 10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell simulations predict a stronger flux compression and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.

  9. Plasma action on helium flow in cold atmospheric pressure plasma jet experiments

    NASA Astrophysics Data System (ADS)

    Darny, T.; Pouvesle, J.-M.; Fontane, J.; Joly, L.; Dozias, S.; Robert, E.

    2017-10-01

    In this work, helium flow modifications, visualized by schlieren imaging, induced by the plasma generated in a plasma jet have been studied in conditions used for biomedical treatments (jet being directed downwards with a low helium flow rate). It has been shown that the plasma action can shift up to few centimeters downstream the effects of buoyancy, which allows to the helium flow to reach a target below in conditions for which it is not the case when the plasma is off. This study reveals the critical role of large and long lifetime negative ions during repetitive operations in the kHz regime, inducing strong modifications in the gas propagation. The cumulative added streamwise momentum transferred to ambient air surrounding molecules resulting from a series of applied voltage pulses induces a gradual built up of a helium channel on tens of millisecond timescale. In some conditions, a remarkable stable cylindrical helium channel can be generated to the target with plasma supplied by negative polarity voltage pulses whereas a disturbed flow results from positive polarity operation. This has a direct effect on air penetration in the helium channel and then on the reactive species production over the target which is of great importance for biomedical applications. It has also been shown that with an appropriate combination of negative and positive polarity pulses, it is possible to benefit from both polarity features in order to optimize the plasma plume propagation and plasma delivery to a target.

  10. Experiment and Results on Plasma Etching of SRF cavities

    SciTech Connect

    Upadhyay, Janardan; Im, Do; Peshl, J.; Vuskovic, Leposova; Popovic, Svetozar; Valente, Anne-Marie; Phillips, H. Lawrence

    2015-09-01

    The inner surfaces of SRF cavities are currently chemically treated (etched or electropolished) to achieve the state of the art RF performance. We designed an apparatus and developed a method for plasma etching of the inner surface for SRF cavities. The process parameters (pressure, power, gas concentration, diameter and shape of the inner electrode, temperature and positive dc bias at inner electrode) are optimized for cylindrical geometry. The etch rate non-uniformity has been overcome by simultaneous translation of the gas point-of-entry and the inner electrode during the processing. A single cell SRF cavity has been centrifugally barrel polished, chemically etched and RF tested to establish a baseline performance. This cavity is plasma etched and RF tested afterwards. The effect of plasma etching on the RF performance of this cavity will be presented and discussed.

  11. Driving Flows in Laboratory Astrophysical Plasma Jets: The Mochi.LabJet Experiment

    NASA Astrophysics Data System (ADS)

    Carroll, Evan G.

    Mochi.Labjet is a new experiment at the University of Washington developed to investigate the interaction of shear flows in plasma jets with boundary conditions similar to an accretion disc system. This thesis details the engineering design and first plasmas of the Mochi.Labjet experiment. The experiment required construction of a new three electrode plasma gun with azimuthal symmetric gas injection, two optically-isolated pulsed power supplies for generating and sustaining plasma, and one optically-isolated pulsed power supply for generating a background magnetic field. Optical isolation is achieved with four custom circuits: the TTL-optical transmitter, optical-TTL receiver, optical-relay, and optical-tachometer circuits. First plasmas, during the commissioning phase of the apparatus, show evidence of flared jet structures with significant azimuthal symmetry.

  12. Numerical simulation of the plasma thermal disturbances during ionospheric modification experiments at the SURA heating facility

    NASA Astrophysics Data System (ADS)

    Belov, Alexey; Huba, J. D.

    indent=1cm We present the results of numerical simulation of the near-Earth plasma disturbances produced by resonant heating of the ionospheric F-region by high-power HF radio emission from the SURA facility. The computational model is based on the modified version of the SAMI2 code (release 1.00). The model input parameters are appropriated to the conditions of the SURA-DEMETER experiment. In this work, we study the spatial structure and temporal characteristics of stimulated large-scale disturbances of the electron number density and temperature. It is shown that the stimulated disturbances are observed throughout the ionosphere. Disturbances are recorded both in the region below the pump wave reflection level and in the outer ionosphere (up to 3000 km). At the DEMETER altitude, an increase in the ion number density is stipulated by the oxygen ions O (+) , whereas the number density of lighter H (+) ions decreases. A typical time of the formation of large-scale plasma density disturbances in the outer ionosphere is 2-3 min. After the heater is turned off, the disturbances relaxation time is approximately 30 min. The simulation results are important for planning future promising experiments on the formation of ionospheric artificial density ducts. This work was supported by the Russian Foundation for Basic Research (project No. 12-02-00747-a), and the Government of the Russian Federation (contract No. 14.B25.31.0008).

  13. Experiences with remote collaborations in fusion research

    SciTech Connect

    Wurden, G.A.; Davis, S.; Barnes, D.

    1998-03-01

    The magnetic fusion research community has considerable experience in placing remote collaboration tools in the hands of real user. The ability to remotely view operations and to control selected instrumentation and analysis tasks has been demonstrated. University of Wisconsin scientists making turbulence measurements on TFTR: (1) were provided with a remote control room from which they could operate their diagnostic, while keeping in close contact with their colleagues in Princeton. LLNL has assembled a remote control room in Livermore in support of a large, long term collaboration on the DIII-D tokamak in San Diego. (2) From the same control room, a joint team of MIT and LLNL scientists has conducted full functional operation of the Alcator C-Mod tokamak located 3,000 miles away in Cambridge Massachusetts. (3) These early efforts have been highly successful, but are only the first steps needed to demonstrate the technical feasibility of a complete facilities on line environment. These efforts have provided a proof of principle for the collaboratory concept and they have also pointed out shortcomings in current generation tools and approaches. Current experiences and future directions will be discussed.

  14. Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow

    NASA Astrophysics Data System (ADS)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2015-11-01

    A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.

  15. High temperature UF6 RF plasma experiments applicable to uranium plasma core reactors

    NASA Technical Reports Server (NTRS)

    Roman, W. C.

    1979-01-01

    An investigation was conducted using a 1.2 MW RF induction heater facility to aid in developing the technology necessary for designing a self critical fissioning uranium plasma core reactor. Pure, high temperature uranium hexafluoride (UF6) was injected into an argon fluid mechanically confined, steady state, RF heated plasma while employing different exhaust systems and diagnostic techniques to simulate and investigate some potential characteristics of uranium plasma core nuclear reactors. The development of techniques and equipment for fluid mechanical confinement of RF heated uranium plasmas with a high density of uranium vapor within the plasma, while simultaneously minimizing deposition of uranium and uranium compounds on the test chamber peripheral wall, endwall surfaces, and primary exhaust ducts, is discussed. The material tests and handling techniques suitable for use with high temperature, high pressure, gaseous UF6 are described and the development of complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma, effluent exhaust gases, and residue deposited on the test chamber and exhaust system components is reported.

  16. Experiments with an rf dusty plasma and an external plasma jet

    SciTech Connect

    Ticos, C. M.

    2010-12-14

    A plasma jet produced in a coaxial plasma gun was aimed at a cloud of dust particles levitated in the sheath of a radio-frequency (rf) plasma produced between two parallel-plate electrodes. A high-speed camera with a side-view on the dust cloud was used to track the dust particles. Several cases of dust motion could be observed. When the jet was parallel with the horizontal electrodes of the rf plasma the dust particles were either pushed out of the trapping region by the plasma jet or were only perturbed from their equilibrium position, oscillating with a frequency of the order of a few kHz. In the first case the trajectory of the dust particles followed the curvature of the sheath. In the second case, when the jet was fired at a small angle with the horizontal electrodes the dust particles hit the bottom electrode and ricocheted back into the sheath. Finally, another situation was observed when the jet perturbed the rf plasma and its sheath and the whole dust crystal fell to the electrode.

  17. Experiments with an rf dusty plasma and an external plasma jet

    NASA Astrophysics Data System (ADS)

    Ticoş, C. M.

    2010-12-01

    A plasma jet produced in a coaxial plasma gun was aimed at a cloud of dust particles levitated in the sheath of a radio-frequency (rf) plasma produced between two parallel-plate electrodes. A high-speed camera with a side-view on the dust cloud was used to track the dust particles. Several cases of dust motion could be observed. When the jet was parallel with the horizontal electrodes of the rf plasma the dust particles were either pushed out of the trapping region by the plasma jet or were only perturbed from their equilibrium position, oscillating with a frequency of the order of a few kHz. In the first case the trajectory of the dust particles followed the curvature of the sheath. In the second case, when the jet was fired at a small angle with the horizontal electrodes the dust particles hit the bottom electrode and ricocheted back into the sheath. Finally, another situation was observed when the jet perturbed the rf plasma and its sheath and the whole dust crystal fell to the electrode.

  18. Slowing of magnetic reconnection concurrent with weakening plasma inflows and increasing collisionality in strongly-driven laser-plasma experiments

    SciTech Connect

    Rosenberg, M.  J.; Li, C.  K.; Fox, W.; Zylstra, A.  B.; Stoeckl, C.; Séguin, F.  H.; Frenje, J.  A.; Petrasso, R. D.

    2015-05-20

    An evolution of magnetic reconnection behavior, from fast jets to the slowing of reconnection and the establishment of a stable current sheet, has been observed in strongly-driven, β ≲ 20 laser-produced plasma experiments. This process has been inferred to occur alongside a slowing of plasma inflows carrying the oppositely-directed magnetic fields as well as the evolution of plasma conditions from collisionless to collisional. High-resolution proton radiography has revealed unprecedented detail of the forced interaction of magnetic fields and super-Alfvénic electron jets (Vjet~ 20VA) ejected from the reconnection region, indicating that two-fluid or collisionless magnetic reconnection occurs early in time. The absence of jets and the persistence of strong, stable magnetic fields at late times indicates that the reconnection process slows down, while plasma flows stagnate and plasma conditions evolve to a cooler, denser, more collisional state. These results demonstrate that powerful initial plasma flows are not sufficient to force a complete reconnection of magnetic fields, even in the strongly-driven regime.

  19. Slowing of magnetic reconnection concurrent with weakening plasma inflows and increasing collisionality in strongly-driven laser-plasma experiments

    DOE PAGES

    Rosenberg, M.  J.; Li, C.  K.; Fox, W.; ...

    2015-05-20

    An evolution of magnetic reconnection behavior, from fast jets to the slowing of reconnection and the establishment of a stable current sheet, has been observed in strongly-driven, β ≲ 20 laser-produced plasma experiments. This process has been inferred to occur alongside a slowing of plasma inflows carrying the oppositely-directed magnetic fields as well as the evolution of plasma conditions from collisionless to collisional. High-resolution proton radiography has revealed unprecedented detail of the forced interaction of magnetic fields and super-Alfvénic electron jets (Vjet~ 20VA) ejected from the reconnection region, indicating that two-fluid or collisionless magnetic reconnection occurs early in time. Themore » absence of jets and the persistence of strong, stable magnetic fields at late times indicates that the reconnection process slows down, while plasma flows stagnate and plasma conditions evolve to a cooler, denser, more collisional state. These results demonstrate that powerful initial plasma flows are not sufficient to force a complete reconnection of magnetic fields, even in the strongly-driven regime.« less

  20. Chemical release experiments to induce F region ionospheric plasma irregularities at the magnetic equator

    NASA Astrophysics Data System (ADS)

    Sultan, Peter Jared

    1994-01-01

    during both experiments. The successes in being able to model the natural occurrence of ESF, as well as being able to initiate it artificially, lend support to the physical model adopted for the equatorial ionosphere, and open up new avenues of research into ESF predictability on a night-to-night, and even an hour-to-hour, basis.

  1. Plasma wave experiment for the ISEE-3 mission

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1983-01-01

    An analysis of data from a scientific instrument designed to study solar wind and plasma wave phenomena on the ISEE-3 Mission is provided. Work on the data analysis phase of the contract from 1 October 1982 through 30 March 1983 is summarized.

  2. Plasma Chamber and First Wall of the Ignitor Experiment^*

    NASA Astrophysics Data System (ADS)

    Cucchiaro, A.; Coppi, B.; Bianchi, A.; Lucca, F.

    2005-10-01

    The new designs of the Plasma Chamber (PC) and of the First Wall (FW) system are based on updated scenarios for vertical plasma disruption (VDE) as well as estimates for the maximum thermal wall loadings at ignition. The PC wall thickness has been optimized to reduce the deformation during the worst disruption event without sacrificing the dimensions of the plasma column. A non linear dynamic analysis of the PC has been performed on a 360^o model of it, taking into account possible toroidal asymmetries of the halo current. Radial EM loads obtained by scaling JET measurements have been also considered. The low-cycle fatigue analysis confirms that the PC is able to meet a lifetime of few thousand cycles for the most extreme combinations of magnetic fields and plasma currents. The FW, made of Molybdenum (TZM) tiles covering the entire inner surface of the PC, has been designed to withstand thermal and EM loads, both under normal operating conditions and in case of disruption. Detailed elasto-plastic structural analyses of the most (EM) loaded tile-carriers show that these are compatible with the adopted fabrication requirements. ^*Sponsored in part by ENEA of Italy and by the U.S. DOE.

  3. Collisional processes of interest in MFE plasma research

    SciTech Connect

    Olson, R.E.

    1990-05-24

    Research on this grant is devoted to the calculation of heavy particle collision cross sections needed for diagnostic studies of magnetic fusion plasmas. This work requires the development and testing of new theoretical methods, with the implementation of benchmarked techniques to collisions pertinent to fusion reactors. Within the last context, we have provided charge-exchange-recombination cross sections to specific n,1-levels for diagnostic studies on TFTR and for a major compilation for IAEA. We have also completed a cross section study related to the planned neutral beam current drive for ITER. In addition, calculations were completed to assess the use of He neutral atom angular scattering measurements for JT-60. Also, new theoretical methods have been developed to more accurately calculate cross sections involving either He or H{sub 2} targets and partially stripped multiply-charged ions.

  4. [Research progress of preparation and components of platelet rich plasma].

    PubMed

    Fu, Weili; Li, Qi; Li, Jian

    2014-12-01

    To review the research progress of the preparation and components of the platelet rich plasma (PRP). The recent literature concerning the biological mechanism, preparation, and components of PRP was analyzed and summarized. The biological function of PRP depends on a series of intricate cascade of cellular and molecular events. PRP contains different concentrations of platelets, which would release a large number of the activated molecules, and also contains a small amount of white blood cells and red blood cells. The preparation of PRP is based on platelet concentration. Different preparation techniques would lead to different platelet concentrations, recovery ratios, and components. There is no uniform standard for the preparation of PRP. Different preparation methods and technical parameters of PRP will get different components and different concentrations of PRP, which also provide a reference for clinicians to select the most appropriate PRP for individual patient.

  5. Electrons precipitation stimulated by plasma jets injection in FLUXUS and NORTH STAR active rocket experiments

    NASA Astrophysics Data System (ADS)

    Gavrilov, B.; Erlandson, R.; Lynch, K.; Meng, C.; Podgorny, I.; Pfaff, R.; Stenbaek-Nielsen, H.; Sobyanin, D.; Zetzer, J.

    In Russian-American active rocket experiments FLUXUS (49? N, 47? E, 1997) and NORTH STAR (70? N, 148? W, 1999) high-velocity plasma jets were injected along and across the geomagnetic field respectively. In the both experiments high- density plasma jets pushed out the magnetic field. Later, when the magnetic field penetrated into the plasma jet, plasma was polarized and E=-VxB/c electric field was registered. As a result, Alfvén waves, carrying the field-aligned currents, propagate along the magnetic field lines. If the current density is rather high, the field-aligned electric fields can appear, and electrons would be accelerated along the magnetic field lines. Electron fluxes with energy from several eV to 2 keV were revealed in the both experiments. During NORTH STAR experiment electron fluxes caused by auroral precipitation were also registered

  6. Kotov works with Plasma Crystal-3 Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-25

    ISS022-E-035439 (25 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, is pictured while working with the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  7. Kotov works with Plasma Crystal-3 Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-25

    ISS022-E-035438 (25 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, uses a computer while servicing the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  8. Kotov works with Plasma Crystal-3+ Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-28

    ISS022-E-040615 (28 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, uses a computer while servicing the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  9. Kotov works with Plasma Crystal-3+ Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-25

    ISS022-E-035434 (25 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, works with the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  10. Kotov works with Plasma Crystal-3+ Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-25

    ISS022-E-035436 (25 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, works with the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  11. Kotov works with Plasma Crystal-3+ Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-28

    ISS022-E-040617 (28 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, is pictured while working with the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  12. Kotov works with Plasma Crystal-3+ Experiment in the SM during Expedition 22

    NASA Image and Video Library

    2010-01-28

    ISS022-E-040614 (28 Jan. 2010) --- Russian cosmonaut Oleg Kotov, Expedition 22 flight engineer, is pictured while working with the Plasma Crystal-3 experiment in the Zvezda Service Module of the International Space Station.

  13. Experiment study of edge localized mode with plasma vertical jogging in HL-2A tokamak

    NASA Astrophysics Data System (ADS)

    Wu, N.; Chen, S. Y.; Song, X. M.; Mou, M. L.; Huang, J.; Wang, Z. T.; Tang, C. J.; Song, X.; Xia, F.; Jiang, M.; HL-2A Team

    2017-09-01

    The effect of plasma vertical jogging on edge localized modes (ELMs) is investigated in HL-2A tokamak. During the experiment, plasma jogging with a period of about 75 ms is performed, and the results show that both the ELM amplitude and period decrease when the plasma moves upward, which are qualitatively explained by the simulation based on the theory of peeling-ballooning mode including the resistivity effect. The upward movement of plasma causes a change in pedestal parameters, and then the dominant toroidal mode shifts to a relatively high-n mode with the effects of resistivity and diamagnetic, which lead to smaller ELM amplitudes.

  14. Benchmark Experiment for Photoionized Plasma Emission from Accretion-Powered X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Loisel, G. P.; Bailey, J. E.; Liedahl, D. A.; Fontes, C. J.; Kallman, T. R.; Nagayama, T.; Hansen, S. B.; Rochau, G. A.; Mancini, R. C.; Lee, R. W.

    2017-08-01

    The interpretation of x-ray spectra emerging from x-ray binaries and active galactic nuclei accreted plasmas relies on complex physical models for radiation generation and transport in photoionized plasmas. These models have not been sufficiently experimentally validated. We have developed a highly reproducible benchmark experiment to study spectrum formation from a photoionized silicon plasma in a regime comparable to astrophysical plasmas. Ionization predictions are higher than inferred from measured absorption spectra. Self-emission measured at adjustable column densities tests radiation transport effects, demonstrating that the resonant Auger destruction assumption used to interpret black hole accretion spectra is inaccurate.

  15. An enhancement of plasma density by neutral gas injection observed in SEPAC Spacelab-1 experiment

    NASA Technical Reports Server (NTRS)

    Sasaki, S.; Kawashima, N.; Kuriki, K.; Yanagisawa, M.; Obayashi, T.; Kubota, S.; Roberts, W. T.; Reasoner, D. L.; Taylor, W. W. L.; Williamson, P. R.

    1985-01-01

    An enhancement of plasma density observed during a neutral gas injection in Space Experiments with Particle Accelerators by the Space Shuttle/Spacelab-1 is presented. When a plume of nitrogen gas was injected from the orbiter into space, a large amount of plasma was detected by an onboard plasma probe. The observed density often increased beyond the background plasma density and was strongly dependent on the attitude of the orbiter with respect to the velocity vector. This effect has been explained by a collisional interaction between the injected gas molecules and the ionospheric ions relatively drifting at the orbital speed.

  16. Early results of microwave transmission experiments through an overly dense rectangular plasma sheet with microparticle injection

    SciTech Connect

    Gillman, Eric D.; Amatucci, W. E.

    2014-06-15

    These experiments utilize a linear hollow cathode to create a dense, rectangular plasma sheet to simulate the plasma layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Injection of fine dielectric microparticles significantly reduces the electron density and therefore lowers the electron plasma frequency by binding a significant portion of the bulk free electrons to the relatively massive microparticles. Measurements show that microwave transmission through this previously overly dense, impenetrable plasma layer increases with the injection of alumina microparticles approximately 60 μm in diameter. This method of electron depletion is a potential means of mitigating the radio communications blackout experienced by hypersonic vehicles.

  17. Early results of microwave transmission experiments through an overly dense rectangular plasma sheet with microparticle injection

    NASA Astrophysics Data System (ADS)

    Gillman, Eric D.; Amatucci, W. E.

    2014-06-01

    These experiments utilize a linear hollow cathode to create a dense, rectangular plasma sheet to simulate the plasma layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Injection of fine dielectric microparticles significantly reduces the electron density and therefore lowers the electron plasma frequency by binding a significant portion of the bulk free electrons to the relatively massive microparticles. Measurements show that microwave transmission through this previously overly dense, impenetrable plasma layer increases with the injection of alumina microparticles approximately 60 μm in diameter. This method of electron depletion is a potential means of mitigating the radio communications blackout experienced by hypersonic vehicles.

  18. [Research on the atomic emission spectroscopy of atmospheric pressure plasma process].

    PubMed

    Jin, Jiang; Li, Na; Xu, Lu; Wang, Bo; Jin, Hui-Liang

    2013-02-01

    In the reaction of the atmospheric pressure plasma process, the heat stable process of the atmospheric pressure plasma jet has a direct impact on the removal rate, CF4 is the provider of active F* atom, O2 is important auxiliary gas, and they play an important role in the process. In order to research the rule of the concentration of the 3 parameters upon the atmospheric pressure plasma processing, the atmospheric pressure plasma jet was used for processing and the spectrometer was used to monitor the changes in the process. The experiment indicates that: when the heat is stable, the concentration of the active F* atom essentially remains unchanged; with increasing the concentration of gas CF4, the spectrum of the active F* atom has self-absorption phenomena, so using the atomic emission spectroscopy method to monitor the changes in the concentration of active F* atom generated by CF4 is not completely exact; because O2 can easily react with the dissociation product of CF4, which inhibits the compound of the active F* atom, so in a certain range with increasing the concentration of gas O2, the concentration of the active F* atom becomes strong.

  19. ECH/EBW Plasma Coupling and Heating Experiments on the Proto-MPEX

    NASA Astrophysics Data System (ADS)

    Bigelow, Tim; Caughman, John; Caneses, Juan; Diem, Stephanie; Goulding, Richard; Kafle, Nischal; Rapp, Juergen

    2016-10-01

    ECH and EBW have been under development on the Proto-Material Plasma Exposure eXperiment device (Proto-MPEX) to provide additional plasma electron heating. Proto-MPEX has a linear magnetic field configuration and a helicon plasma source that forms a high-density medium-temperature central core plasma of typically 0.08m diameter. A plasma density of up to 6x1019m-3 is generated which is >6 times over-dense for 28 GHz microwave power available from the experiment's gyrotron system. Modeling using Genray-C code has indicated that some heating of the plasma core should be possible at this frequency using the optimum O-X-EBW coupling scheme. Several improvements to the waveguide system have been made to increase the reliable operating power level and launch beam quality. To improve the plasma heating efficiency, work is underway to optimize the beam launch by adding a remotely adjustable launch angle, adding a polarization rotating miter bend, moving the launch point closer to the plasma edge and providing some beam focusing. Preliminary heating experiments have indicated some over-dense heating has been achieved. A launch power of 75 kW has been achieved out of a possible 150 kW. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.

  20. High power microwave source for a plasma wakefield experiment

    NASA Astrophysics Data System (ADS)

    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.

  1. Drift waves and chaos in a LAPTAG plasma physics experiment

    NASA Astrophysics Data System (ADS)

    Gekelman, Walter; Pribyl, Patrick; Birge-Lee, Henry; Wise, Joe; Katz, Cami; Wolman, Ben; Baker, Bob; Marmie, Ken; Patankar, Vedang; Bridges, Gabriel; Buckley-Bonanno, Samuel; Buckley, Susan; Ge, Andrew; Thomas, Sam

    2016-02-01

    In a project involving an alliance between universities and high schools, a magnetized plasma column with a steep pressure gradient was established in an experimental device. A two-dimensional probe measured fluctuations in the plasma column in a plane transverse to the background magnetic field. Correlation techniques determined that the fluctuations were that of electrostatic drift waves. The time series data were used to generate the Bandt-Pompe entropy and Jensen-Shannon complexity for the data. These quantities, when plotted against one another, revealed that a combination of drift waves and other background fluctuations were a deterministically chaotic system. Our analysis can be used to tell the difference between deterministic chaos and random noise, making it a potentially useful technique in nonlinear dynamics.

  2. Experiments on pure electron plasmas confined in a toroidal geometry

    SciTech Connect

    Nakashima, Chihiro; Yoshida, Zensho; Morikawa, Junji; Himura, Haruhiko; Kakuno, Hidekazu; Tahara, Shigeru; Shibayama, Norihisa

    1999-12-10

    The toroidal magnetic trap has an advantage in achieving long orbit lengths, which allows us to apply a slow process of energy reduction to the trapped particles. On Proto-RT (Prototype Ring Trap), we have demonstrated the confinement of a pure electron plasma without the help of external electric fields. We have injected electrons with the energy of 2 keV inside a separatrix. The electrostatic potential of the electron cloud is of order 100 V. The corresponding density of the electron plasma is calculated to be of order 10{sup 13} m{sup -3}. In order to modulate the kinetic energy of the electrons we are now planning RF assisted injection of electrons.

  3. Plasma wave experiment for the ISEE-3 mission

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1982-01-01

    Results of analyses of data received from a scientific instrument designed to study solar wind and plasma wave phenomena on the ISEE-3 mission are discussed in two papers prepared for publication. A study of plasma wave levels in and interplanetary magnetic field orientation preceding observations of interplanetary shocks by the satellite infers that quasi-parallel, interplanetary shocks are preceded by foreshocks whose presence is not obviously attributable to scattering of ion beams generated at quasi-perpendicular zones of these interplanetary shocks. Investigations of whistler mode turbulence in the disturbed solar wind resulted in various indirect lines of evidence indicating that these whistler waves are generated propagating at large angles to the local interplanetary field, a fact which helps identify possible free energy sources for their growth.

  4. My Rewarding Summer Research Experience at NASA

    NASA Technical Reports Server (NTRS)

    Aviles, Andres

    2007-01-01

    My summer research experience at the Kennedy Space Center has been a truly rewarding one. As an electrical engineering student at the University of South Florida, I was blessed with a beneficial opportunity to gain valuable knowledge in my career, and also apply it through working at NASA. One of my inspirations in becoming an engineer is to work at NASA someday, and I was very excited and honored to have this opportunity. My goal in this internship was to strengthen my preparation in becoming an engineer by learning new material, acquiring skills by practicing what I learned, and discovering the expectations of engineering work at NASA. Through this summer research, I was able to learn new computer programs and perform various tasks that gave me experience and skills as an engineer. My primary job was to conduct work on the Constellation Test article, which is a simulation model of the Crew Launch Vehicle (CLV) tanking system. This is a prototype of a launch facility and an Ares I Vehicle, which God willing will transport astronauts to the moon. Construction of the CLV is in progress and a test launch is anticipated for 2010. Moreover, the Test Article serves as a demonstration too, training test bed, and may be expanded for new simulation of launch system elements, which could be applied to real life operations. The test article is operated and run by a Programmable Logic Controller (PLC), which is a digital computer that is used to control all forms of machinery such as those in manufacturing buildings and other industries. PLCs are different than other computers because of the physical protection they have against damaging environmental conditions that would destroy other computers. Also, PLCs are equipped with lots of input and output connections that allow extensive amounts of commands to be executed, which would normally require many computers to do. Therefore, PLCs are small, rugged, and extremely powerful tools that may continue to be employed at NASA

  5. Restrike Particle Beam Experiments on a Dense Plasma Focus.

    DTIC Science & Technology

    1980-11-30

    soft Xray spectrometer should enable the formation of a fairly complete picture of the plasma phenomena as well as that of the beams for input into the...SSNTD are insensitive to light, electrons or Xrays 2) Record is virtually permanent 3) Direct measurement of fast particles is possible and (detection...detectors. The bands are delimited by Ross balanced filtering technique. This technique uses the fact that the stopping power for xrays has 3narp edges at

  6. High Performance Plasmas on the National Spherical Torus Experiment

    DTIC Science & Technology

    2001-06-01

    time as determined by magnetic analysis using the EFIT code [11] plotted against two conventional tokamak scaling relations, ITER89P and ITER98y2...injected. Plasmas with βt (=2µ0<p>/B 2 = a measure of magnetic confinement efficiency) of 22% have been achieved, as calculated using the EFIT ...efficiency) of 22% have been achieved, as calculated using the EFIT equilibrium reconstruction code. â limiting phenomena have been observed, and the

  7. Rayleigh-Taylor instability in dusty plasma experiment

    SciTech Connect

    Avinash, K.; Sen, A.

    2015-08-15

    The stability of a stratified dust cloud levitated in an anodic plasma is studied in the weakly and strongly coupled dust regimes. It is shown that the cloud is predominantly unstable to a Rayleigh-Taylor (RT) instability driven by a component of the ambient gravity in a direction opposite to the direction of dust density stratification in the cloud. The elasticity of the strongly coupled dust is shown to set a threshold for the RT instability, which is consistent with experimental observations.

  8. High Magnetic field generation for laser-plasma experiments

    SciTech Connect

    Pollock, B B; Froula, D H; Davis, P F; Ross, J S; Fulkerson, S; Bower, J; Satariano, J; Price, D; Glenzer, S H

    2006-05-01

    An electromagnetic solenoid was developed to study the effect of magnetic fields on electron thermal transport in laser plasmas. The solenoid, which is driven by a pulsed power system suppling 30 kJ, achieves magnetic fields of 13 T. The field strength was measured on the solenoid axis with a magnetic probe and optical Zeeman splitting. The measurements agree well with analytical estimates. A method for optimizing the solenoid design to achieve magnetic fields exceeding 20 T is presented.

  9. The effect of artificial gravity on plasma and tissue lipids in rats: The Cosmos 936 experiment

    NASA Astrophysics Data System (ADS)

    Ahlers, I.; Praslička, M.; Tigranyan, R. A.

    Plasma and tissue lipids in male SPF Wistar rats flown for 18.5 days aboard the Cosmos 936 biosatellite were analyzed. One group of rats was subjected to artificial gravity by use of a centrifuge during the flight. An experiment simulating known space flight factors other than weightlessness was done on Earth. An increase of total cholesterol in plasma, of nonesterified fatty acids in plasma and brown adipose tissue, of triacylglycerols in plasma, liver, thymus and bone marrow was noted several hours after biosatellite landing. Smaller changes were observed in the terrestrial control experiment. With the exception of triacylglycerol accumulation in bone marrow, these increases disappeared 25 days after biosatellite landing. Exposing the rats aboard the biosatellite to artificial gravity was beneficial in the sense that such exposure inhibited the phospholipid and triacylglycerol increase in plasma and inhibited the increase of triacylglycerol in liver and especially in bone marrow.

  10. Incorporation of the Data Acquisition System with a Small Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    Nolan, Stephen; James, R. W.; Page, E. L.; Zuniga, J.; Schlank, C.; Lopez, M.; Sherman, J.; Stutzman, B. S.

    2012-10-01

    At the Coast Guard Academy Plasma Lab (CGAPL), a small Helicon Plasma Experiment (HPX) is being developed to utilize the reputed high densities (10^13 cm-3 and higher) at low pressure (.01 T) [1], in high temperature and density diagnostic development for future laboratory investigations. With first plasmas at hand, HPX is constructing triple and mach particle probes, magnetic probes, and a single point Thompson Scattering system for HPX plasma property investigations. A 32-channel National Instruments Data Acquisition (DAQ) Board capable of sampling at 12 bits of precision at 2 MS/s and running multiple simultaneous experiments is currently under construction. This DAQ System with integrated storage and GUI's will gather and digitize plasma data from the associated diagnostics for further analysis. Progress on the current implementation of the DAQ system will be reported.

  11. Radar observations of field-aligned plasma propagations associated with NASA's PMG experiment

    NASA Astrophysics Data System (ADS)

    Olson, Darren M.

    1994-09-01

    NASA's Plasma Motor Generator (PMG) tethered satellite mission was launched in June 1993 to verify the ability of hollow cathode plasma sources to couple electric currents from an electrodynamic tether into the ambient ionospheric plasma. This large-scale coupling process resulted in turbulent plasma signatures associated with the orbiting plasma generator, which propagated over great distances along the earth's geomagnetic field lines. VHF radars in Hilo, Hawaii and Jicamarca, Peru recorded observations of these field-aligned disturbances as part of the experiment. Based on analysis of these radar observations and tracking data of PMG's orbit, the effective propagation velocity of these traveling plasma waveforms was calculated to be of the order of 1000 meters per second. Detection of these disturbances, associated with PMG's passage overhead, supports the existence of a phantom current loop allowing current flow along the magnetic field lines of the earth and into the lower ionosphere from either end of an electrodynamic tether.

  12. Radiation hydrodynamic simulation of a photoionised plasma experiment at the Z facility

    NASA Astrophysics Data System (ADS)

    Hall, I. M.; Durmaz, T.; Mancini, R. C.; Bailey, J. E.; Rochau, G. A.

    2011-11-01

    New, high spectral resolution X-ray observations from astrophysical photoionised plasmas have been recorded in recent years by the Chandra and XMM-Newton orbiting telescopes. These observations provide a wealth of detailed information and have motivated new efforts at developing a detailed understanding of the atomic kinetics and radiation physics of photoionised plasmas. The Z facility at Sandia National Laboratories is a powerful source of X-rays that enables us to produce and study photoionised plasmas in the laboratory under well characterised conditions. We discuss a series of radiation-hydrodynamic simulations to help understand the X-ray environment, plasma hydrodynamics and atomic kinetics in experiments where a collapsing wire array at Z is used as an ionising source of radiation to create a photoionised plasma. The numerical simulations are used to investigate the role that the key experimental parameters have on the photoionised plasma characteristics.

  13. Radar observations of field-aligned plasma propagations associated with nasa's PMG experiment. Master's thesis

    SciTech Connect

    Olson, D.M.

    1994-09-01

    NASA's Plasma Motor Generator (PMG) tethered satellite mission was launched in June 1993 to verify the ability of hollow cathode plasma sources to couple electric currents from an electrodynamic tether into the ambient ionospheric plasma. This large-scale coupling process resulted in turbulent plasma signatures associated with the orbiting plasma generator, which propagated over great distances along the earth's geomagnetic field lines. VHF radars in Hilo, Hawaii and Jicamarca, Peru recorded observations of these field-aligned disturbances as part of the experiment. Based on analysis of these radar observations and tracking data of PMG's orbit, the effective propagation velocity of these traveling plasma waveforms was calculated to be of the order of 1000 meters per second. Detection of these disturbances, associated with PMG's passage overhead, supports the existence of a phantom current loop allowing current flow along the magnetic field lines of the earth and into the lower ionosphere from either end of an electrodynamic tether.

  14. Simulation of ionization effects for high-density positron drivers in future plasma wakefield experiments

    SciTech Connect

    Bruhwiler, D.L.; Dimitrov, D.A.; Cary, J.R.; Esarey, E.; Leemans, W.P.

    2003-05-12

    The plasma wakefield accelerator (PWFA) concept has been proposed as a potential energy doubler for present or future electron-positron colliders. Recent particle-in-cell (PIC) simulations have shown that the self-fields of the required electron beam driver can tunnel ionize neutral Li, leading to plasma wake dynamics differing significantly from that of a preionized plasma. It has also been shown, for the case of a preionized plasma, that the plasma wake of a positron driver differs strongly from that of an electron driver. We will present new PIC simulations, using the OOPIC code, showing the effects of tunneling ionization on the plasma wake generated by high-density positron drivers. The results will be compared to previous work on electron drivers with tunneling ionization and positron drivers without ionization. Parameters relevant to the energy doubler and the upcoming E-164x experiment at the Stanford Linear Accelerator Center will be considered.

  15. Results from the Ucla/fnpl Underdense Plasma Lens Experiment

    NASA Astrophysics Data System (ADS)

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travish, G.; Edwards, H.; Fuller, R.; Kazakevich, G. M.; Piot, P.; Santucci, J.; Li, J.; Tikhoplav, R.

    2007-09-01

    A gaussian underdense plasma lens with peak density 5 × 1012 cm-3 and a full width half maximum (FWHM) length of 2.2 cm has been used to focus a relativistic electron beam. This plasma lens is equivalent in strength to a quadrupole magnet with a 150 T/m field gradient. The lens focused a 15 MeV, 16 nC electron beam with initial dimensions σx,y ≈ 650 μm and σz ≈ 6.5 mm onto an optical transition radiation (OTR) screen ~2 cm downstream of the lens. The average transverse area of the plasma focused electron beam was typically demagnified by a factor of 23. The evolution of the beam envelope in the area near the beam waist was measured for both round beams and asymmetric beams with x:y aspect ratios as large as 1:5. The light from the OTR screen in the round beam case was also imaged into a streak camera in order to directly measure the correlation between z and σr within the beam.

  16. Results from the Ucla/fnpl Underdense Plasma Lens Experiment

    NASA Astrophysics Data System (ADS)

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travish, G.; Edwards, H.; Fliller, R.; Kazakevich, G. M.; Piot, P.; Santucci, J.; Li, J.; Tikhoplav, R.

    A gaussian underdense plasma lens with peak density 5 × 1012 cm-3 and a full width half maximum (FWHM) length of 2.2 cm has been used to focus a relativistic electron beam. This plasma lens is equivalent in strength to a quadrupole magnet with a 150 T/m field gradient. The lens focused a 15 MeV, 16 nC electron beam with initial dimensions σx,y ≈ 650 μm and σz ≈ 6.5 mm onto an optical transition radiation (OTR) screen ~2 cm downstream of the lens. The average transverse area of the plasma focused electron beam was typically demagnified by a factor of 23. The evolution of the beam envelope in the area near the beam waist was measured for both round beams and asymmetric beams with x:y aspect ratios as large as 1:5. The light from the OTR screen in the round beam case was also imaged into a streak camera in order to directly measure the correlation between z and σr within the beam.

  17. Results from the UCLA/FNPL underdense plasma lens experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Edwards, H.; Fliller, R.; Kazakevich, G.M.; Piot, P.; Santucci, J.; Li, J.; Tikhoplav, R.; /Rochester U.

    2007-01-01

    A gaussian underdense plasma lens with peak density 5 x 10{sup 12} cm{sup -3} and a full width half maximum (FWHM) length of 2.2 cm has been used to focus a relativistic electron beam. This plasma lens is equivalent in strength to a quadrupole magnet with a 150 T/m field gradient. The lens focused a 15 MeV, 16 nC electron beam with initial dimensions {sigma}{sub x,y} {approx} 650 {micro}m and {sigma}{sub z} {approx} 6.5 mm onto an optical transition radiation (OTR) screen {approx}2 cm downstream of the lens. The average transverse area of the plasma focused electron beam was typically demagnified by a factor of 23. The evolution of the beam envelope in the area near the beam waist was measured for both round beams and asymmetric beams with x:y aspect ratios as large as 1:5. The light from the OTR screen in the round beam case was also imaged into a streak camera in order to directly measure the correlation between z and {sigma}{sub r} within the beam.

  18. Experiments on Viscous Transport in Pure-Electron Plasmas.

    NASA Astrophysics Data System (ADS)

    Kriesel, J. M.; Driscoll, C. F.

    1999-11-01

    Viscous transport in pure-electron plasmas is a rearrangement of particles due to like-particle interactions, leading to the confined global thermal equilibrium state. The measured transport is observed to be proportional to the shear in the total (E × B + diamagnetic) fluid rotation of the plasma for both hollow and monotonic rotation profiles. We determine the local viscosity coefficient η in the plasma from measurements of the local flux of particles. The measured viscosity is 50-10^4 times larger than expected from classical transport due to short-range velocity-scattering collisions, but is within a factor of 10 agreement with recent theories by O'Neil and Dubin of transport due to long-range drift collisions. The measured viscosity scales with magnetic field B and length L roughly as η ∝ B/L. This scaling suggests a finite length enhancement of the viscosity, which occurs because particles interact many times as they bounce axially before they are sheared apart azimuthally.

  19. Uncovering Students' Preconceptions of Undergraduate Research Experiences

    ERIC Educational Resources Information Center

    Adedokun, Omolola A.; Burgess, Wilella D.

    2011-01-01

    Like all learners, undergraduate research interns bring to their research internships a variety of initial ideas, opinions, expectations, beliefs and attitudes about research internships. However, there is little published research on students' preconceptions about research internships and the relationships of these preconceptions to actual…

  20. Uncovering Students' Preconceptions of Undergraduate Research Experiences

    ERIC Educational Resources Information Center

    Adedokun, Omolola A.; Burgess, Wilella D.

    2011-01-01

    Like all learners, undergraduate research interns bring to their research internships a variety of initial ideas, opinions, expectations, beliefs and attitudes about research internships. However, there is little published research on students' preconceptions about research internships and the relationships of these preconceptions to actual…

  1. Simulation of laser-driven, ablated plasma flows in collisionless shock experiments on OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Grosskopf, M. J.; Drake, R. P.; Kuranz, C. C.; Rutter, E. M.; Ross, J. S.; Kugland, N. L.; Plechaty, C.; Remington, B. A.; Spitkovsky, A.; Gargate, L.; Gregori, G.; Bell, A.; Murphy, C. D.; Meinecke, J.; Reville, B.; Sakawa, Y.; Kuramitsu, Y.; Takabe, H.; Froula, D. H.; Fiksel, G.; Miniati, F.; Koenig, M.; Ravasio, A.; Liang, E.; Fu, W.; Woolsey, N.; Park, H.-S.

    2013-03-01

    Experiments investigating the physics of interpenetrating, collisionless, ablated plasma flows have become an important area of research in the high-energy-density field. In order to evaluate the feasibility of designing experiments that will generate a collisionless shock mediated by the Weibel instability on the National Ignition Facility (NIF) laser, computer simulations using the Center for Radiative Shock Hydrodynamics (CRASH) radiation-hydrodynamics model have been carried out. This paper reports assessment of whether the experiment can reach the required scale size while maintaining the low interflow collisionality necessary for the collisionless shock to form. Comparison of simulation results with data from Omega experiments shows the ability of the CRASH code to model these ablated systems. The combined results indicate that experiments on the NIF are capable of reaching the regimes necessary for the formation of a collisionless shock in a laboratory experiment.

  2. Research and Development of Large Area Color AC Plasma Displays

    NASA Astrophysics Data System (ADS)

    Shinoda, Tsutae

    1998-10-01

    Plasma display is essentially a gas discharge device using discharges in small cavities about 0. 1 m. The color plasma displays utilize the visible light from phosphors excited by the ultra-violet by discharge in contrast to monochrome plasma displays utilizing visible light directly from gas discharges. At the early stage of the color plasma display development, the degradation of the phosphors and unstable operating voltage prevented to realize a practical color plasma display. The introduction of the three-electrode surface-discharge technology opened the way to solve the problems. Two key technologies of a simple panel structure with a stripe rib and phosphor alignment and a full color image driving method with an address-and-display-period-separated sub-field method have realized practically available full color plasma displays. A full color plasma display has been firstly developed in 1992 with a 21-in.-diagonal PDP and then a 42-in.-diagonal PDP in 1995 Currently a 50-in.-diagonal color plasma display has been developed. The large area color plasma displays have already been put into the market and are creating new markets, such as a wall hanging TV and multimedia displays for advertisement, information, etc. This paper will show the history of the surface-discharge color plasma display technologies and current status of the color plasma display.

  3. Plasma Diagnostics for Plasma Polymer Coatings Used in Fabrication of Thin Wall CH Shells for Direct Drive OMEGA Cryogenic Experiments

    NASA Astrophysics Data System (ADS)

    Ross, P.; Nikroo, A.; Czechowicz, D.; Dicken, M.

    2002-11-01

    High aspect ratio CH shells, 1 μm thick, 9001 μm diameter, are crucial for the success of the cryogenic direct drive inertial confinement fusion (ICF) experiments at the OMEGA laser facility at the University of Rochester's Laboratory for Laser Energetics (LLE). Plasma polymer coatings are currently used in fabrication of such shells, which can be made substantially stronger by altering parameters. High strength is important for inherently fragile high aspect ratio shells. The plasma characteristics used in the deposition process were studied in order to determine a correlation between the plasma parameters and the strength of shells. Several plasma processing parameters such as deposition pressure, power and relative and absolute gas flow rates were varied. The plasma was studied using several techniques such as optical emission spectroscopy, Langmuir probe diagnostics, and mass spectrometry. These diagnostic results were then correlated with direct measurements of the target strength (burst testing and buckle testing) and permeability to determine the ideal parameters for creating the strongest and most permeable ICF targets.

  4. Langmuir probe-based observables for plasma-turbulence code validation and application to the TORPEX basic plasma physics experiment

    SciTech Connect

    Ricci, Paolo; Theiler, C.; Fasoli, A.; Furno, I.; Labit, B.; Mueller, S. H.; Podesta, M.; Poli, F. M.

    2009-05-15

    The methodology for plasma-turbulence code validation is discussed, with focus on the quantities to use for the simulation-experiment comparison, i.e., the validation observables, and application to the TORPEX basic plasma physics experiment [A. Fasoli et al., Phys. Plasmas 13, 055902 (2006)]. The considered validation observables are deduced from Langmuir probe measurements and are ordered into a primacy hierarchy, according to the number of model assumptions and to the combinations of measurements needed to form each of them. The lowest levels of the primacy hierarchy correspond to observables that require the lowest number of model assumptions and measurement combinations, such as the statistical and spectral properties of the ion saturation current time trace, while at the highest levels, quantities such as particle transport are considered. The comparison of the observables at the lowest levels in the hierarchy is more stringent than at the highest levels. Examples of the use of the proposed observables are applied to a specific TORPEX plasma configuration characterized by interchange-driven turbulence.

  5. Experiments on the interaction of heavy ions with dense plasma at GSI-Darmstadt

    NASA Astrophysics Data System (ADS)

    Stöckl, C.; Boine-Frankenheim, O.; Geißel, M.; Roth, M.; Wetzler, H.; Seelig, W.; Iwase, O.; Spiller, P.; Bock, R.; Süß, W.; Hoffmann, D. H. H.

    One of the main objectives of the experimental plasma physics activities at the Gesellschaft für Schwerionenforschung (GSI) are the interaction processes of heavy ions with dense ionized matter. Gas-discharge plasma targets were used for energy loss and charge state measurements in a regime of electron density and temperature up to 10 19 cm -3 and 20 eV, respectively. An improved model of the charge exchange processes in fully ionized hydrogen plasma, taking into account multiple excited electronic configurations which subsequently ionize, has removed the discrepancies of previous theoretical descriptions. The energy loss of the ion beam in partially ionized plasmas such as argon was found to agree very well with our simple theoretical model based on the modified Bethe-Bloch theory. A new setup with a 100 J/5 GW Nd-glass laser now provides access to density ranges up to 10 21 cm -3 and temperatures of up to 100 eV. First results of interaction experiments with laser-produced plasma are presented. To fully exploit the experimental possibilities of the new laser-plasma setup both improved charge state detection systems and better plasma diagnostics are indispensable. Present developments and future possibilities in these fields are presented. This paper summarizes the following contributions: Interaction of heavy-ion beams with laser plasma by C. Stöckl et al. Energy Loss of Heavy Ions in a laser-produced plasma by M. Roth et al. Charge state measurements of heavy ions passing a laser produced plasma with high time resolution by W. Süß et al. Plasma diagnostics for laser-produced plasma by O. Iwase et al. Future possibilities of plasma diagnostics at GSI by M. Geißel et al.

  6. Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    Kaye, S.; Peng, Yueng Kay Martin

    2005-01-01

    The major objective of the National Spherical Torus Experiment (NSTX) is to understand basic toroidal confinement physics at low aspect ratio and high T in order to advance the spherical torus (ST) concept. In order to do this, NSTX utilizes up to 7.5MW of neutral beam injection, up to 6MW of high harmonic fast waves (HHFWs), and it operates with plasma currents up to 1.5MA and elongations of up to 2.6 at a toroidal field up to 0.45 T. New facility, and diagnostic and modelling capabilities developed over the past two years have enabled the NSTX research team to make significant progress towards establishing this physics basis for future ST devices. Improvements in plasma control have led to more routine operation at high elongation and high T (up to 40%) lasting for many energy confinement times. T can be limited by either internal or external modes. The installation of an active error field (EF) correction coil pair has expanded the operating regime at low density and has allowed for initial resonant EF amplification experiments. The determination of the confinement and transport properties of NSTX plasmas has benefitted greatly from the implementation of higher spatial resolution kinetic diagnostics. The parametric variation of confinement is similar to that at conventional aspect ratio but with values enhanced relative to those determined from conventional aspect ratio scalings and with a BT dependence. The transport is highly dependent on details of both the flow and magnetic shear. Core turbulence was measured for the first time in an ST through correlation reflectometry. Non-inductive start-up has been explored using PF-only and transient co-axial helicity injection techniques, resulting in up to 140 kA of toroidal current generated by the latter technique. Calculated bootstrap and beam-driven currents have sustained up to 60% of the flat-top plasma current in NBI discharges. Studies of HHFW absorption have indicated parametric decay of the wave and

  7. Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    Kaye, S. M.; Bell, M. G.; Bell, R. E.; Bernabei, S; Bialek, J.; Biewer, T.; Blanchard, W.; Boedo, J.; Bush, C.; Carter, M. D.; Choe, W.; Crocker, N.; Darrow, D. S.; Davis, W.; Delgado-Aparicio, L.; Diem, S.; Ferron, J.; Field, A.; Foley, J.; Fredrickson, E. D.; Gates, D. A.; Gibney, T.; Harvey, R.; Hatcher, R. E.; Heidbrink, W.; Hill, K.; Hosea, J. C.; Jarboe, T. R.; Johnson, D. W.; Kaita, R.; Kessel, C.; Kubota, S.; Kugel, H. W.; Lawson, J.; LeBlanc, B. P.; Lee, K. C.; Levinton, F.; Maingi, R.; Manickam, J.; Maqueda, R.; Marsala, R.; Mastrovito, D.; Mau, T. K.; Medley, S. S.; Menard, J.; Meyer, H.; Mikkelsen, D. R.; Mueller, D.; Munsat, T.; Nelson, B. A.; Neumeyer, C.; Nishino, N.; Ono, M.; Park, H.; Park, W.; Paul, S.; Peebles, T.; Peng, M.; Phillips, C.; Pigarov, A.; Pinsker, R.; Ram, A.; Ramakrishnan, S.; Raman, R.; Rasmussen, D.; Redi, M.; Rensink, M.; Rewoldt, G; Robinson, J.; Roney, P.; Roquemore, A. L.; Ruskov, E; Ryan, P.; Sabbagh, S. A.; Schneider, H.; Skinner, C. H.; Smith, D. R.; Sontag, A.; Soukhanovskii, V.; Stevenson, T.; Stotler, D.; Stratton, B.; Stutman, D.; Swain, D.; Synakowski, E.; Takase, Y.; Taylor, G.; Tritz, K.; Halle, A. von; Wade, M.; White, R.; Wilgen, J.; Williams, M.; Wilson, J. R.; Zhu, W.; Zweben, S. J.; Akers, R.; Beiersdorfer, P.; Betti, R.; Bigelow, T.; Bitter, M.; Bonoli, P.; Bourdelle, C.; Chang, C. S.; Chrzanowski, J.; Domier, C.; Dudek, L.; Efthimion, P. C.; Finkenthal, M.; Fredd, E.; Fu, G. Y.; Glasser, A.; Goldston, R. J.; Greenough, N. L.; Grisham, L. R.; Gorelenkov, N.; Guazzotto, L.; Hawryluk, R. J.; Hogan, J.; Houlberg, W.; Humphreys, D.; Jaeger, F.; Kalish, M.; Krasheninnikov, S.; Lao, L. L.; Lawrence, J.; Leuer, J.; Liu, D.; Luhmann, N. C.; Mazzucato, E.; Oliaro, G.; Pacella, D.; Parsells, R.; Schaffer, M.; Semenov, I.; Shaing, K. C.; Shapiro, M. A.; Shinohara, K.; Sichta, P.; Tang, X.; Vero, R.; Walker, D.; Wampler, W.

    2005-10-01

    The major objective of the National Spherical Torus Experiment (NSTX) is to understand basic toroidal confinement physics at low aspect ratio and high βT in order to advance the spherical torus (ST) concept. In order to do this, NSTX utilizes up to 7.5 MW of neutral beam injection, up to 6 MW of high harmonic fast waves (HHFWs), and it operates with plasma currents up to 1.5 MA and elongations of up to 2.6 at a toroidal field up to 0.45 T. New facility, and diagnostic and modeling capabilities developed over the past two years have enabled the NSTX research team to make significant progress towards establishing this physics basis for future ST devices. Improvements in plasma control have led to more routine operation at high elongation and high βT (up to ~40%) lasting for many energy confinement times. βT can be limited by either internal or external modes. The installation of an active error field (EF) correction coil pair has expanded the operating regime at low density and has allowed for initial resonant EF amplification experiments. The determination of the confinement and transport properties of NSTX plasmas has benefited greatly from the implementation of higher spatial resolution kinetic diagnostics. The parametric variation of confinement is similar to that at conventional aspect ratio but with values enhanced relative to those determined from conventional aspect ratio scalings and with a βT dependence. The transport is highly dependent on details of both the flow and magnetic shear. Core turbulence was measured for the first time in an ST through correlation reflectometry. Non-inductive start-up has been explored using PF-only and transient co-axial helicity injection techniques, resulting in up to 140 kA of toroidal current generated by the latter technique. Calculated bootstrap and beam-driven currents have sustained up to 60% of the flat-top plasma current in NBI discharges. Studies of HHFW absorption

  8. Current halo structures in high-current plasma experiments: {theta}-pinch

    SciTech Connect

    Matveev, Yu. V.

    2007-03-15

    Experimental data elucidating mechanisms for halo formation in {theta}-pinch discharges are presented and discussed. The experiments were performed with different gases (H{sub 2}, D{sub 2}, He, and Ar) in a theta-pinch device with a porcelain vacuum chamber and an excitation coil 15 cm in diameter and 30 cm in length. The stored energy, the current in the excitation coil, and the current half-period were W = 10 kJ, I = 400 kA, and T/2 = 14 {mu}s, respectively. It is found that the plasma rings (halos) surrounding the pinch core arise as a result of coaxial pinch stratification due to both the excitation of closed currents (inductons) inside the pinch and the radial convergence of the plasma current sheaths produced after the explosion of T-layers formed near the wall in the initial stage of the discharge. It is concluded that halo structures observed in pinches, tokamaks, and other high-current devices used in controlled fusion research have the same nature.

  9. Connecting Arctic/Antarctic Researchers and Educators (CARE): Supporting Teachers and Researchers Beyond the Research Experience

    NASA Astrophysics Data System (ADS)

    Warburton, J.; Warnick, W. K.; Breen, K.; Fischer, K.; Wiggins, H.

    2007-12-01

    Teacher research experiences (TREs) require long-term sustained support for successful transfer of research experiences into the classroom. Specifically, a support mechanism that facilitates focused discussion and collaboration among teachers and researchers is critical to improve science content and pedagogical approaches in science education. Connecting Arctic/Antarctic Researchers and Educators (CARE) is a professional development network that utilizes online web meetings to support the integration of science research experiences into classroom curriculum. CARE brings together teachers and researchers to discuss field experiences, current science issues, content, technology resources, and pedagogy. CARE is a component of the Arctic Research Consortium of the U.S. (ARCUS) education program PolarTREC--Teachers and Researchers Exploring and Collaborating. PolarTREC is a three-year (2007-2009) teacher professional development program celebrating the International Polar Year (IPY) that advances polar science education by bringing K-12 educators and polar researchers together in hands-on field experiences in the Arctic and Antarctic. Currently in its second year, the program fosters the integration of research and education to produce a legacy of long-term teacher-researcher collaborations, improved teacher content knowledge through experiences in scientific inquiry, and broad public interest and engagement in polar science. The CARE network was established to develop a sustainable learning community through which teachers and researchers will further their work to bring polar research into classrooms. Through CARE, small groups of educators are formed on the basis of grade-level and geographic region; each group also contains a teacher facilitator. Although CARE targets educators with previous polar research experiences, it is also open to those who have not participated in a TRE but who are interested in bringing real-world polar science to the classroom

  10. Experiment to Study Alfven Wave Propagation in Plasma Loops

    NASA Astrophysics Data System (ADS)

    Kendall, Mark; Bellan, Paul

    2010-11-01

    Arched plasma-filled twisted magnetic flux tubes are generated in the laboratory using pulsed power techniques (J.F. Hansen, S.K.P. Tripathi, P.M. Bellan, 2004). Their structure and time evolution exhibit similarities with both solar coronal loops and spheromaks. We are now developing a method to excite propagating torsional Alfven wave modes in such plasma loops by superposing a ˜10kA, ˜100ns current pulse upon the ˜50kA, 10μs main discharge current that flows along the ˜20cm long, 2cm diameter arched flux tube. To achieve this high power 100ns pulse, a magnetic pulse compression technique based on saturable reactors is employed. A low power prototype has been successfully tested, and design and construction of a full-power device is nearing completion. The full-power device will compress an initial 2μs pulse by a factor of nearly 20; the final stage utilizes a water-filled transmission line with ultra-low inductance to attain the final timescale. This new pulse device will subsequently be used to investigate interactions between Alfven waves and the larger-scale loop evolution; one goal will be to directly image the wave using high-speed photography. Attention will be paid to wave propagation including dispersion and reflection, as well as dissipation mechanisms and possible energetic particle generation.

  11. Experiments on the transportation of a magnetized plasma stream in the GOL-3 facility

    NASA Astrophysics Data System (ADS)

    Postupaev, V. V.; Batkin, V. I.; Burdakov, A. V.; Ivanov, I. A.; Kuklin, K. N.; Mekler, K. I.; Rovenskikh, A. F.

    2016-04-01

    The program of the deep upgrade of the GOL-3 multiple-mirror trap is presented. The upgrade is aimed at creating a new GOL-NB open trap located at the GOL-3 site and intended to directly demonstrate the efficiency of using multiple-mirror magnetic cells to improve longitudinal plasma confinement in a gasdynamic open trap. The GOL-NB device will consist of a new central trap, adjoint cells with a multiple-mirror magnetic field, and end tanks (magnetic flux expanders). Plasma in the central trap will be heated by neutral beam injection with a power of up to 1.5 MW and duration of 1 ms. At present, physical experiments directed at developing plasma technologies that are novel for this facility are being carried out using the 6-m-long autonomous part of the GOL-3 solenoid. The aim of this work was to develop a method for filling the central trap with a low-temperature start plasma. Transportation of a plasma stream from an arc source over a distance of 3 m in a uniform magnetic field with an induction of 0.5-4.5 T is demonstrated. In these experiments, the axial plasma density was (1-4) × 1020 m-3 and the mirror ratio varied from 5 to 60. In general, the experiments confirmed the correctness of the adopted decisions for the start plasma source of the GOL-NB device.

  12. Washer-Gun Plasma Source for Magnetic Reconnection Experiments on VTF

    NASA Astrophysics Data System (ADS)

    Vrublevskis, A.; Egedal, J.; Fox, W.; Katz, N.; Le, A.; Porkolab, M.

    2009-11-01

    We present a recently built electrostatic washer-gun plasma source for the Versatile Toroidal Facility (VTF). The source produces plasmas with estimated densities of ˜10^19 m^- 3 and electron temperatures of ˜5-20 eV. The present plasma source for VTF is microwave-induced electron cyclotron resonant breakdown and requires a strong toroidal magnetic field, which acts as a guide field in reconnection experiments. The gun will allow reconnection experiments with no guide field. The source is based on the design developed by Sterling Scientific [1, 2]. To operate, gas is injected into a channel formed by a stack of alternating molybdenum and boron nitride washers with a molybdenum electrode washer at each end. A capacitor bank is discharged through these electrodes and the gas. The resulting plasma escapes the channel into the main chamber of the experiment. If available, we will present data on argon plasma produced by the gun inside the VTF. [1ex] [1] G. Fiksel, et al., Plasma Sources Sci. Technol., 5, 78 (1996)[0ex] [2] D. Hartog et al., Plasma Sources Sci. Technol., 6, 492 (1997)

  13. Experiments on the transportation of a magnetized plasma stream in the GOL-3 facility

    SciTech Connect

    Postupaev, V. V. Batkin, V. I.; Burdakov, A. V.; Ivanov, I. A.; Kuklin, K. N.; Mekler, K. I.; Rovenskikh, A. F.

    2016-04-15

    The program of the deep upgrade of the GOL-3 multiple-mirror trap is presented. The upgrade is aimed at creating a new GOL-NB open trap located at the GOL-3 site and intended to directly demonstrate the efficiency of using multiple-mirror magnetic cells to improve longitudinal plasma confinement in a gasdynamic open trap. The GOL-NB device will consist of a new central trap, adjoint cells with a multiple-mirror magnetic field, and end tanks (magnetic flux expanders). Plasma in the central trap will be heated by neutral beam injection with a power of up to 1.5 MW and duration of 1 ms. At present, physical experiments directed at developing plasma technologies that are novel for this facility are being carried out using the 6-m-long autonomous part of the GOL-3 solenoid. The aim of this work was to develop a method for filling the central trap with a low-temperature start plasma. Transportation of a plasma stream from an arc source over a distance of 3 m in a uniform magnetic field with an induction of 0.5–4.5 T is demonstrated. In these experiments, the axial plasma density was (1–4) × 10{sup 20} m{sup –3} and the mirror ratio varied from 5 to 60. In general, the experiments confirmed the correctness of the adopted decisions for the start plasma source of the GOL-NB device.

  14. LHCD and ICRF heating experiments in H-mode plasmas on EAST

    SciTech Connect

    Zhang, X. J.; Zhao, Y. P.; Wan, B. N.; Ding, B. J.; Xu, G. S.; Gong, X. Z.; Li, J. G.; Lin, Y.; Wukitch, S.; Taylor, G.; Noterdaeme, J. M.; Braun, F.; Magne, R.; Litaudon, X.; Kumazawa, R.; Kasahara, H.; Collaboration: EAST Team

    2014-02-12

    An ICRF system with power up to 6.0 MW and a LHCD system up to 4MW have been applied for heating and current drive experiments on EAST. Intensive lithium wall coating was intensively used to reduce particle recycling and Hydrogen concentration in Deuterium plasma, which is needed for effective ICRF and LHCD power absorption in high density plasmas. Significant progress has been made with ICRF heating and LHW current drive for realizing the H-mode plasma operation in EAST. In 2010, H-mode was generated and sustained by LHCD alone, where lithium coating and gas puffing launcher mouth were applied to improve the LHCD power coupling and penetration into the core plasmas at high density of H-modes. During the last two experimental campaigns, ICRF Heating experiments were carried out at the fixed frequency of 27MHz, achieving effective ions and electrons heating with the H Minority Heating (H-MH) mode, where electrons are predominantly heated by collisions with high energy minority ions. The H-MH mode gave the best plasma performance, and realized H-mode alone in 2012. Combination of ICRF and LHW power injection generated the H-mode plasmas with various ELMy characteristics. The first successful application of the ICRF Heating in the D (He3) plasma was also achieved. The progress on ICRF heating, LHCD experiments and their application in achieving H-mode operation from last two years will be discussed in this report.

  15. A cesium TELEC experiment at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Britt, E. J.

    1979-01-01

    The thermoelectronic laser energy converter (TELEC), was studied as a method of converting a 10.6 mm CO2 laser beam into electric power. The calculated characteristics of a TELEC seem to be well matched to the requirements of a spacecraft laser energy conversion system. The TELEC is a high power density plasma device which absorbs an intense laser beam by inverse bremsstrahlung with the plasma electrons. In the TELEC process, electromagnetic radiation is absorbed directly in the plasma electrons producing a high electron temperature. The energetic electrons diffuse out of the plasma striking two electrodes which are in contact with the plasma at the boundaries. These two electrodes have different areas: the larger one is designated as the collector, the smaller one is designated as the emitter. The smaller electrode functions as an electron emitter to provide continuity of the current. Waste heat is rejected from the collector electrode. An experiment was carried out with a high power laser using a cesium vapor TELEC cell with 30 cm active length. Laser supported plasma was produced in the TELEC device during a number of laser runs over a period of several days. Electric power from the TELEC was observed with currents in the range of several amperes and output potentials of less than 1 volt. The magnitudes of these electric outputs were smaller than anticipated but consistent with the power levels of the laser during this experiment.

  16. D-alpha Probe Investigation on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    Karama, Jackson; James, Royce; Sherman, Justin; Page, Eric; Schlank, Carter; Stutzman, Brook; Duke-Tenson, Omar; Coast Guard Academy Plasma Laboratory Team

    2013-10-01

    Now that reproducible plasmas have been created on HPX at the Coast Guard Academy Plasma Laboratory (CGAPL) we are starting to set up a spectral probes to help verify plasma mode transitions to the W-mode. These optical probes will utilize movable filters, ccd cameras and diodes, to gather data at selected spectral frequency bands. Data collected will be used to investigate the plasma's structure and behavior during experiments. The spectral probes will take advantage of HPX's magnetic fields to define and measure the plasma's radiation temp as a function of time. A d-alpha filter will allow for the collection of neutral density fluctuations for different plasma behaviors. In d-alpha mode, the probe may also provide some information on the internal plasma structure and perhaps reveal some global plasma interactions. The spectral probe will add to HPX's data collection capabilities and be used in conjunction with the particle probes, and Thomson Scattering device to create a robust picture of the internal and external plasma parameters on HPX. Progress on the construction of the probe will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY12.

  17. Laboratory Experiments on Propagating Plasma Bubbles into Vacuum, Vacuum Magnetic Field, and Background Plasmas

    NASA Astrophysics Data System (ADS)

    Lynn, Alan G.; Zhang, Yue; Gilmore, Mark; Hsu, Scott

    2014-10-01

    We discuss the dynamics of plasma ``bubbles'' as they propagate through a variety of background media. These bubbles are formed by a pulsed coaxial gun with an externally applied magnetic field. Bubble parameters are typically ne ~1020 m-3, Te ~ 5 - 10 eV, and Ti ~ 10 - 15 eV. The structure of the bubbles can range from unmagnetized jet-like structures to spheromak-like structures with complex magnetic flux surfaces. Some of the background media the bubbles interact with are vacuum, vacuum with magnetic field, and other magnetized plasmas. These bubbles exhibit different qualitative behavior depending on coaxial gun parameters such as gas species, gun current, and gun bias magnetic field. Their behavior also depends on the parameters of the background they propagate through. Multi-frame fast camera imaging and magnetic probe data are used to characterize the bubble evolution under various conditions.

  18. A table top experiment to study plasma confined by a dipole magnet

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Sudeep; Baitha, Anuj Ram

    2016-10-01

    There has been a long quest to understand charged particle generation, confinement and underlying complex processes in a plasma confined by a dipole magnet. Our earth's magnetosphere is an example of such a naturally occurring system. A few laboratory experiments have been designed for such investigations, such as the Levitated Dipole Experiment (LDX) at MIT, the Terella experiment at Columbia university, and the Ring Trap-1 (RT-1) experiment at the University of Tokyo. However, these are large scale experiments, where the dipole magnetic field is created with superconducting coils, thereby, necessitating power supplies and stringent cryogenic requirements. We report a table top experiment to investigate important physical processes in a dipole plasma. A strong cylindrical permanent magnet, is employed to create the dipole field inside a vacuum chamber. The magnet is suspended and cooled by circulating chilled water. The plasma is heated by electromagnetic waves of 2.45 GHz and a second frequency in the range 6 - 11 GHz. Some of the initial results of measurements and numerical simulation of magnetic field, visual observations of the first plasma, and spatial measurements of plasma parameters will be presented.

  19. Medical School Research Pipeline: Medical Student Research Experience in Psychiatry

    ERIC Educational Resources Information Center

    Balon, Richard; Heninger, George; Belitsky, Richard

    2006-01-01

    Objective: The authors discuss the importance of introducing research training in psychiatry and neurosciences to medical students. Methods: A review of existing models of research training in psychiatry with focus on those providing research training to medical students is presented. Results: Two research-training models for medical students that…

  20. Medical School Research Pipeline: Medical Student Research Experience in Psychiatry

    ERIC Educational Resources Information Center

    Balon, Richard; Heninger, George; Belitsky, Richard

    2006-01-01

    Objective: The authors discuss the importance of introducing research training in psychiatry and neurosciences to medical students. Methods: A review of existing models of research training in psychiatry with focus on those providing research training to medical students is presented. Results: Two research-training models for medical students that…