WorldWideScience

Sample records for sustained spheromak plasma

  1. Magnetic helicity balance in the Sustained Spheromak Plasma Experiment

    International Nuclear Information System (INIS)

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

    2003-01-01

    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

  2. Sustained spheromak technology

    Energy Technology Data Exchange (ETDEWEB)

    Platts, D.A.; Sherwood, A.R.; Jarboe, T.R.; Linford, R.K.; Hoida, H.W.; Henins, I.

    1984-01-01

    The goal of these experiments is to devise a technique for driving a spheromak using dc-powered electrodes. The reduction or elimination of pulsed power components in the spheromak source would result in more attractive reactors, and simpler, cheaper experiments. This is important as experiments get larger and approach reactor size. According to some concepts, the dc spheromak would operate with plasma injection so that it would clean up any impurities produced during its formation. These features make the investigation of dc-powered spheromaks interesting. The questions that need to be answered in this investigation are: (1) can a spheromak be sustained by a dc source; and (2) can a practical source be designed to produce a hot clean plasma. After summarizing the evidence which suggests an answer to question one, the approach being taken to answer question two is discussed.

  3. Sustained spheromak technology

    International Nuclear Information System (INIS)

    Platts, D.A.; Sherwood, A.R.; Jarboe, T.R.; Linford, R.K.; Hoida, H.W.; Henins, I.

    1984-01-01

    The goal of these experiments is to devise a technique for driving a spheromak using dc-powered electrodes. The reduction or elimination of pulsed power components in the spheromak source would result in more attractive reactors, and simpler, cheaper experiments. This is important as experiments get larger and approach reactor size. According to some concepts, the dc spheromak would operate with plasma injection so that it would clean up any impurities produced during its formation. These features make the investigation of dc-powered spheromaks interesting. The questions that need to be answered in this investigation are: (1) can a spheromak be sustained by a dc source; and (2) can a practical source be designed to produce a hot clean plasma. After summarizing the evidence which suggests an answer to question one, the approach being taken to answer question two is discussed

  4. Sustained spheromak physics experiment

    International Nuclear Information System (INIS)

    Hooper, E.B.; Bulmer, R.H.; Cohen, B.I.

    2001-01-01

    The Sustained Spheromak Physics Experiment, SSPX, will study spheromak physics with particular attention to energy confinement and magnetic fluctuations in a spheromak sustained by electrostatic helicity injection. In order to operate in a low collisionality mode, requiring T e >100 eV, vacuum techniques developed for tokamaks will be applied, and a divertor will be used for the first time in a spheromak. The discharge will operate for pulse lengths of several milliseconds, long compared to the time to establish a steady-state equilibrium but short compared to the L/R time of the flux conserver. The spheromak and helicity injector ('gun') are closely coupled, as shown by an ideal MHD model with force-free injector and edge plasmas. The current from the gun passes along the symmetry axis of the spheromak, and the resulting toroidal magnetic field causes the safety factor, q, to diverge on the separatrix. The q-profile depends on the ratio of the injector current to spheromak current and on the magnetic flux coupling the injector to the spheromak. New diagnostics include magnetic field measurements by a reflectometer operating in combined O- and X-modes and by a transient internal probe (TIP). (author)

  5. Sustained spheromak physics experiment

    International Nuclear Information System (INIS)

    Hooper, E.B.; Bulmer, R.H.; Cohen, B.I.

    1999-01-01

    The Sustained Spheromak Physics Experiment, SSPX, will study spheromak physics with particular attention to energy confinement and magnetic fluctuations in a spheromak sustained by electrostatic helicity injection. In order to operate in a low collisionality mode, requiring T e > 100 eV, vacuum techniques developed for tokamaks will be applied, and a divertor will be used for the first time in a spheromak. The discharge will operate for pulse lengths of several milliseconds, long compared to the time to establish a steady-state equilibrium but short compared to the L/R time of the flux conserver. The spheromak and helicity injector ('gun') are closely coupled, as shown by an ideal MHD model with force-free injector and edge plasmas. The current from the gun passes along the symmetry axis of the spheromak, and the resulting toroidal magnetic field causes the safety factor, q, to diverge on the separatrix. The q-profile depends on the ratio of the injector current to spheromak current and on the magnetic flux coupling the injector to the spheromak. New diagnostics include magnetic field measurements by a reflectometer operating in combined O- and X-modes and by a transient internal probe (TIP). (author)

  6. Sustained Spheromak Physics Experiment, SSPX

    International Nuclear Information System (INIS)

    Hooper, E.B.

    1997-01-01

    The Sustained Spheromak Physics Experiment is proposed for experimental studies of spheromak confinement issues in a controlled way: in steady state relative to the confinement timescale and at low collisionality. Experiments in a flux - conserver will provide data on transport in the presence of resistive modes in shear-stabilized systems and establish operating regimes which pave the way for true steady-state experiments with the equilibrium field supplied by external coils. The proposal is based on analysis of past experiments, including the achievement of T e = 400 eV in a decaying spheromak in CTX. Electrostatic helicity injection from a coaxial ''''gun'''' into a shaped flux conserver will form and sustain the plasma for several milliseconds. The flux conserver minimizes fluxline intersection with the walls and provides MHD stability. Improvements from previous experiments include modem wall conditioning (especially boronization), a divertor for density and impurity control, and a bias magnetic flux for configurational flexibility. The bias flux will provide innovative experimental opportunities, including testing helicity drive on the large-radius plasma boundary. Diagnostics include Thomson scattering for T e measurements and ultra-short pulse reflectrometry to measure density and magnetic field profiles and turbulence. We expect to operate at T e of several hundred eV, allowing improved understanding of energy and current transport due to resistive MHD turbulence during sustained operation. This will provide an exciting advance in spheromak physics and a firm basis for future experiments in the fusion regime

  7. Magnetohydrodynamic simulation of kink instability and plasma flow during sustainment of a coaxial gun spheromak

    International Nuclear Information System (INIS)

    Kanki, Takashi; Nagata, Masayoshi; Kagei, Yasuhiro

    2010-01-01

    Kink instability and the subsequent plasma flow during the sustainment of a coaxial gun spheromak are investigated by three-dimensional nonlinear magnetohydrodynamic simulations. Analysis of the parallel current density λ profile in the central open column revealed that the n = 1 mode structure plays an important role in the relaxation and current drive. The toroidal flow (v t ≈ 37 km/s) is driven by magnetic reconnection occurring as a result of the helical kink distortion of the central open column during repetitive plasmoid ejection and merging. (author)

  8. Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masaaki [Princeton Plasma Physics Laboratory, Princeton University Princeton, New Jersey USA (United States)

    2016-03-25

    This paper briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactor program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.

  9. Spheromak type plasma experiment apparatus

    International Nuclear Information System (INIS)

    Odagiri, Kiyoyuki; Miyauchi, Yasuyuki; Oomura, Hiroshi

    1985-01-01

    The fusion power reactor which is expected to be the most promising energy has been developed for several plasma confinement systems. Under these circumstances, Spheromak configuration has recently attracted attention because of its simple structure and efficient plasma confinement. This apparatus was ordered by the Engineering Department of University of Tokyo for basic studies of the Spheromak plasma confinement technologies. This forms Spheromak plasma according to the induction discharge system which injects this plasma with magnetic energy generated by a toroidal current in the plasma and discharges the current through the electrical feed through. Toroidal current is induced by the poloidal coil in the vessel. We worked together with the researchers of University of Tokyo to conduct experiments and confirmed the formation and confinement of Spheromak plasma in the initial test. (author)

  10. Sustained spheromak experiments in CTX

    International Nuclear Information System (INIS)

    Jarboe, T.R.; Barnes, C.W.; Henins, I.; Hoida, H.W.; Linford, R.K.; Sherwood, A.R.

    1983-01-01

    So far, spheromaks can be sustained as long as the source is injecting helicity. When the injection stops the configuration decays. Spheromks have been sustained for more than 1 ms with total lifetimes of more than 2 ms. The physical properties of the sustained spheromak are under investigation in this paper. Preliminary data indicate that (B) approx. = 2 kG, n approx. = 2 x 10 14 -cm -3 and T /sub e/ approx. = 20-30 eV. An helicity decay rate is determined from the ratio of an estimate of the helicity content of the spheromak and the rate of helicity flow from the source. In the coaxial source geometry a constant value of poloidal flux /PHI/ /sub p/ is placed inside the center electrode. By applying a voltage V between the two electrodes toroidal flux is injected (/PHI/ /sub t/ =V) which links the poloidal flux. The rate of helicity injection is then 2V/PHI/ /sub p/ . The helicity content of the spheromak is estimated by measuring the fields at one point and using the model described above to calculate the profiles. The result is that /TAU/ /sub Hel/ approx. = 200 us. This value is about the same as the /TAU/ /sub B/ 2 of a decaying spheromak with similar parameters. These results indicate that helicity injection is possible and that a large fraction (30-100%) of the injected helicity is absorbed

  11. All plasma spheromak: the plasmak

    International Nuclear Information System (INIS)

    Koloc, P.; Ogden, J.

    1981-01-01

    There has been an evolutionary pattern established in magnetic fusion concepts. The flow in ideas follows three directions. By extrapolating this evolutionary movement, we have anticipated the concept called Spheromak and have predicted the omega of this evolution which is called PLASMAK, or Plasma Spheromak. The evolutionary directions are from open systems to closed systems, from zero or low dimensional compression schemes to three dimensional compression, and finally from plasma configurations without any self confining currents to a plasma configuration which is completely self confined except for the mechanical pressure necessary to maintain the verticle field and hoop stress. Nevertheless, the plasma is imprisoned by heavy poloidal coils and a vacuum wall

  12. Final Report Sustained Spheromak Physics Project FY 1997 - FY 1999

    International Nuclear Information System (INIS)

    Hooper, E.B.; Hill, D.N.

    2000-01-01

    This is the final report on the LDRD SI-funded Sustained Spheromak Physics Project for the years FY1997-FY1999, during which the SSPX spheromak was designed, built, and commissioned for operation at LLNL. The specific LDRD project covered in this report concerns the development, installation, and operation of specialized hardware and diagnostics for use on the SSPX facility in order to study energy confinement in a sustained spheromak plasma configuration. The USDOE Office of Fusion Energy Science funded the construction and routine operation of the SSPX facility. The main distinctive feature of the spheromak is that currents in the plasma itself produce the confining toroidal magnetic field, rather than external coils, which necessarily thread the vacuum vessel. There main objective of the Sustained Spheromak Physics Project was to test whether sufficient energy confinement could be maintained in a spheromak plasma sustained by DC helicity injection. Achieving central electron temperatures of several hundred eV would indicate this. In addition, we set out to determine how the energy confinement scales with T c and to relate the confinement time to the level of internal magnetic turbulence. Energy confinement and its scaling are the central technical issues for the spheromak as a fusion reactor concept. Pending the outcome of energy confinement studies now under way, the spheromak could be the basis for an attractive fusion reactor because of its compact size, simply-connected magnetic geometry, and potential for steady-state current drive

  13. The impedance of energy efficiency of a coaxial magnetized plasma source used for spheromak formation and sustainment

    International Nuclear Information System (INIS)

    Barnes, C.W.; Jarboe, T.R.; Marklin, G.J.; Knox, S.O.; Henins, I.

    1989-01-01

    Electrostatic (dc) helicity injection has previously been shown to successfully sustain the magnetic fields of spheromaks and tokamaks. The magnitude of the injected magnetic helicity balances (within experimental error) the flux lost be resistive decay of the toroidal equilibrium. The problem of optimizing this current drive scheme hence involves maximizing the injected helicity (the voltage-connecting-flux product) while minimizing the current (which multiplied by the voltage represents the energy input and also possible damage to the electrodes). The impedance (voltage-to-current ratio) and energy efficiency of a dc helicity injection experiment are studied on the CTX spheromak. Over several years changes were made in the physical geometry of the coaxial magnetized plasmas source as well as changes in the external electrical circuit. The source could be operated over a wide range of external charging voltage (and hence current), applied axial flux, and source gas flow rate. A database of resulting voltage, helicity injection, efficiency, electron density, and rotation has been created. These experimental results are compared to an ideal magnetohydrodynamic theory of magnetic flux flow. The theory is parameterized by the dimensionless Hall parameter, the ratio of electric to mass current. For a constant Hall parameter the theory explains why the voltage depends quadratically on the current at constant flux. The theory also explains the approximately linear dependence of the impedance-to-current ratio on the current-to-flux ratio of the source. 9 refs., 6 figs

  14. Theory of edge plasma in a spheromak

    International Nuclear Information System (INIS)

    Hooper, E.B.

    1998-01-01

    Properties of the edge plasma in the SSPX spheromak during the plasma formation and sustainment phases are discussed. For the breakdown and formation phase, the main emphasis is on the analysis of possible plasma contamination by impurities from the electrodes of the plasma gun (helicity injector). The issue of an azimuthally uniform breakdown initiation is also discussed. After the plasma settles down in the main vacuum chamber, one has to sustain the current between the electrodes, in order to continuously inject helicity. We discuss properties of the plasma on the field lines intersecting the electrodes. We conclude that the thermal balance of this plasma is maintained by Joule heating competing with parallel heat losses to the electrodes. The resulting plasma temperature is in the range of 15 - 30 eV. Under the expected operational conditions, the ''current'' velocity of the electrons is only slightly below their thermal velocity. Implications of this observation are briefly discussed

  15. Spheromak experiment using separate guns for formation and sustainment

    International Nuclear Information System (INIS)

    Brown, M.R.; Martin, A.

    1996-01-01

    An experiment is described that incorporates the use of separate magnetized plasma guns for formation and sustainment of a spheromak. It is shown that energy coupling efficiency approaches unity if the gun and spheromak are of comparable size. A large gun should be able to operate at lower current and therefore lower voltage. In addition, it is expected that a gun matched to the size of the spheromak will cause less perturbation to the equilibrium. It is proposed to use a smaller gun for spheromak formation and a large, efficient gun for sustainment. The theoretical basis for the experiment is developed, and the details of the experiment are described. A prediction of the equilibrium magnetic flux surfaces using the EFIT code is presented. 28 refs., 3 figs., 1 tab

  16. Magnetic structure in the entrance region of spheromaks sustained by a magnetized coaxial plasma gun under long pulse operation

    International Nuclear Information System (INIS)

    Amemiya, Naoyuki; Takaichi, Kazuaki; Katsurai, Makoto

    1989-01-01

    The magnetic structure in coaxial-gun-sustained spheromaks has been investigated. The plasma gun has been operated with a small axial/radial bias magnetic flux as compared to the azimuthal magnetic flux produced by the discharge current. Stronger magnetic field is observed in the entrance region (ER) than in the flux conserver (FC). In both ER and FC, the magnetic structure is nearly axisymmetric. The axial magnetic field in ER is amplified up to about sixteen times as large as the bias magnetic field. This amplification is limited by the drastic change in the magnetic structure, which occurs when the discharge current becomes very large. The magnetic structure before the drastic change is interpreted with the Bessel function model. The μ estimation shows that the magnetic structure is mainly determined by the boundary geometry, not by the external magnetic flux and current. (author)

  17. Structure of Maryland Spheromak plasmas

    International Nuclear Information System (INIS)

    Hess, R.; Chinfatt, C.; Cote, C.; DeSilva, A.; Filuk, A.; Goldenbaum, G.; Gauvreau, J.; Hwang, Fukwun

    1990-01-01

    Recent efforts on the Maryland Spheromak (MS) have concentrated on detailed measurement of magnetic field structures in order to better understand the formation and evolution of the spheromak configuration. These efforts were prompted by results showing a very rapid decay of the magnetic field under certain conditions. It was not known if this loss was a rapid movement of the plasma to the walls of the vacuum vessel, or by some mechanism causing a rapid decay of a more or less stationary field. To investigate the magnetic field structure in more detail, an array of magnetic probes was built that could be moved from shot to shot so as to acquire a complete map of the three magnetic field components in a plane containing the symmetry axis of the machine. Data taken with these probes in a case where the rapid loss of field occurs is given. Further analysis of the data shows that the instability that forms is a combination of tilt and shift. The initial asymmetry of the magnetic field is possibly due to the non-symmetric configuration of the reversal field coils, or the non-symmetric cabling to the I z electrodes. Future work will concentrate on eliminating the initial plasma asymmetry by eliminating any asymmetries in the machine, and on stopping the tilt/shift instability by different configurations for the passive stabilization coils

  18. New mode of operating a magnetized coaxial plasma gun for injecting magnetic helicity into a spheromak

    International Nuclear Information System (INIS)

    Woodruff, S.; Hill, D.N.; Stallard, B.W.; Bulmer, R.; Cohen, B.; Holcomb, C.T.; Hooper, E.B.; McLean, H.S.; Moller, J.; Wood, R.D.

    2003-01-01

    By operating a magnetized coaxial plasma gun continuously with just sufficient current to enable plasma ejection, large gun-voltage spikes (∼1 kV) are produced, giving the highest sustained voltage ∼500 V and highest sustained helicity injection rate observed in the Sustained Spheromak Physics Experiment. The spheromak magnetic field increases monotonically with time, exhibiting the lowest fluctuation levels observed during formation of any spheromak (B-tilde)/B≥2%). The results suggest an important mechanism for field generation by helicity injection, namely, the merging of helicity-carrying filaments

  19. New mode of operating a magnetized coaxial plasma gun for injecting magnetic helicity into a spheromak.

    Science.gov (United States)

    Woodruff, S; Hill, D N; Stallard, B W; Bulmer, R; Cohen, B; Holcomb, C T; Hooper, E B; McLean, H S; Moller, J; Wood, R D

    2003-03-07

    By operating a magnetized coaxial plasma gun continuously with just sufficient current to enable plasma ejection, large gun-voltage spikes (approximately 1 kV) are produced, giving the highest sustained voltage approximately 500 V and highest sustained helicity injection rate observed in the Sustained Spheromak Physics Experiment. The spheromak magnetic field increases monotonically with time, exhibiting the lowest fluctuation levels observed during formation of any spheromak (B/B>/=2%). The results suggest an important mechanism for field generation by helicity injection, namely, the merging of helicity-carrying filaments.

  20. Visible Spectrometer at the Compact Toroid Injection Experiment, the Sustained Spheromak Plasma Experiment and the Alcator C-Mod Tokamak for Doppler Width and Shift Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A; Howard, S; Horton, R; Hwang, D; May, M; Beiersdorfer, P; McLean, H; Terry, J

    2006-05-15

    A novel Doppler spectrometer is currently being used for ion or neutral velocity and temperature measurements on the Alcator C-Mod Tokamak. The spectrometer has an f/No. of {approx}3.1 and is appropriate for visible light (3500-6700 {angstrom}). The full width at half maximum from a line emitting calibration source has been measured to be as small as 0.4 {angstrom}. The ultimate time resolution is line brightness light limited and on the order of ms. A new photon efficient detector is being used for the setup at C-Mod. Time resolution is achieved by moving the camera during a plasma discharge in a perpendicular direction through the dispersion plane of the spectrometer causing a vertical streaking across the camera face. Initial results from C-Mod as well as previous measurements from the Compact Toroid Injection Experiment (CTIX) and the Sustained Spheromak Plasma Experiment (SSPX) are presented.

  1. Simulation study of stepwise relaxation in a spheromak plasma

    International Nuclear Information System (INIS)

    Horiuchi, Ritoku; Uchida, Masaya; Sato, Tetsuya.

    1991-10-01

    The energy relaxation process of a spheromak plasma in a flux conserver is investigated by means of a three-dimensional magnetohydrodynamic simulation. The resistive decay of an initial force-free profile brings the spheromak plasma to an m = 1/n = 2 ideal kink unstable region. It is found that the energy relaxation takes place in two steps; namely, the relaxation consists of two physically distinguished phases, and there exists an intermediate phase in between, during which the relaxation becomes inactive temporarily. The first relaxation corresponds to the transition from an axially symmetric force-free state to a helically symmetric one with an n = 2 crescent magnetic island structure via the helical kink instability. The n = 2 helical structure is nonlinearly sustained in the intermediate phase. The helical twisting of the flux tube creates a reconnection current in the vicinity of the geometrical axis. The second relaxation is triggered by the rapid growth of the n = 1 mode when the reconnection current exceeds a critical value. The helical twisting relaxes through magnetic reconnection toward an axially symmetric force-free state. It is also found that the poloidal flux reduces during the helical twisting in the first relaxation and the generation of the toroidal flux occurs through the magnetic reconnection process in the second relaxation. (author)

  2. Multi-pulse power injection and spheromak sustainment in SSPX

    Science.gov (United States)

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

    2000-10-01

    Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. Spheromak formation (gun injection phase) and sustainment experiments are now routine in SSPX using a multi-bank power system. Gun voltage, impedance, and power coupling show a clear current threshold dependence on gun flux (I_th~=λ_0φ_gun/μ_0), increasing with current above the threshold, and are compared with CTX results. The characteristic gun inductance, L_gun~=0.6 μH, derived from the gun voltage dependence on di/dt, is larger than expected from Corsica modeling of the spheromak equilibrium. It’s value is consistent with the n=1 ‘doughook’ mode structure reported in SPHEX and believed important for helicity injection and toroidal current drive. Results of helicity and power balance calculations of spheromak poloidal field buildup are compared with experiment and used to project sustainment with a future longer pulse power supply. This work was performed under the auspices of US DOE by the University of California Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

  3. Tearing-mode stability of a forming Spheromak plasma

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Jardin, S.C.; Chance, M.S.

    1981-10-01

    The results of numerical calculations of Δ' for a class of equilibria typical of those encountered during the early formation stage of the S1 Spheromak are presented. The equilibrium plasma is assumed to be cylindrically symmetric and pressureless. It encloses a current carrying perfect conductor (flux core) and is surrounded by a vacuum with zero longitudinal field. Stability boundaries in the space formed by the equilibrium parameters are mapped. The plasma is tearing mode stable provided B/sub z//B/sub theta/ at the flux core is below a certain critical value which depends on the equilibrium parameters. For typical equilibria, this critical value is 0.65

  4. Sustained spheromak coaxial gun operation in the presence of an n=1 magnetic distortion

    International Nuclear Information System (INIS)

    Holcomb, C.T.; Jarboe, T.R.; Hill, D.N.; Woodruff, S.; Wood, R.D.

    2006-01-01

    The Sustained Spheromak Physics Experiment (SSPX) [E. B. Hooper, L. D. Pearlstein, and R. H. Bulmer, Nucl. Fusion 39, 863 (1999)] uses a magnetized coaxial gun to form and sustain spheromaks by helicity injection. Internal probes give the magnetic profile within the gun. An analysis of these data show that a number of commonly applied assumptions are not completely correct, and some previously unrecognized processes may be at work. Specifically, the fraction of the available vacuum flux spanning the gun that is stretched out of the gun is variable and not usually 100%. The n=1 mode that is present during sustained discharges has its largest value of δB/B within the gun, so that instantaneously B within the gun is not axisymmetric. By applying a rigid-rotor model to account for the mode, the instantaneous field and current structure within the gun are determined. The current density is also highly nonaxisymmetric and the local value of λ≡μ 0 j parallel /B is not constant, although the global value λ g ≡μ 0 I g /ψ g closely matches that expected by axisymmetric models. The current distribution near the gun muzzle suggests a cross-field current exists, and this is explained as a line-tying reaction to plasma rotation

  5. Stability of force-free spheromak plasma in spheroidal flux conserver

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Tsutsui, Hiroaki

    1988-01-01

    The Woltjer-Taylor method is applied to spheromak plasmas in spheroidal flux conservers. As models of the flux conserver, both oblate and prolate spheroidal vessels with a center conductor are used. The plasma is not assumed to be nearly spherical, and the Rayleigh-Ritz method and the finite element method are used to evaluate the eigenvalues. The oblate spheromak is shown to be stable irrespective of the shape of the flux conserver. Though the prolate spheromak is unstable if there is no center conductor, it can be stable if the center conductor is installed. (author)

  6. Stability of spheroidal spheromak plasma by use of force-free approximation

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Tsutsui, Hiroaki.

    1987-09-01

    The Woltjer-Taylor method is applied to spheromak plasmas in spheroidal flux conservers. As models of the flux conserver, both oblate and prolate spheroidal vessels with a center conductor are used. The plasma is not assumed to be nearly spherical, and the Rayleigh-Ritz method and the finite element method are used to evaluate the eigenvalues. The oblate spheromak is shown to be stable irrespective of the shape of the flux conserver. Though the prolate spheromak is unstable if there is no center conductor, it can be stable if the center conductor is installed. (author)

  7. Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

    Science.gov (United States)

    García-Martínez, Pablo Luis; Lampugnani, Leandro Gabriel; Farengo, Ricardo

    2014-12-01

    The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.

  8. Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

    Energy Technology Data Exchange (ETDEWEB)

    García-Martínez, Pablo Luis, E-mail: pablogm@cab.cnea.gov.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Sede Andina—Universidad Nacional de Río Negro (UNRN), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina); Lampugnani, Leandro Gabriel; Farengo, Ricardo [Instituto Balseiro and Centro Atómico Bariloche (CAB-CNEA), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina)

    2014-12-15

    The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.

  9. Magnetohydrodynamic stability of spheromak plasma in spheroidal flux conserver

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Kamitani, Atsushi.

    1985-11-01

    The MHD equilibrium configurations of spheromak plasmas in a spheroidal flux conserver are determined by use of a pressure distribution whose derivative dp/dψ vanishes on the magnetic axis, and by use of an optimized distribution. Here p is the pressure and ψ is the flux function. These equilibria are shown to be stable for symmetric modes. The stability for localized modes is investigated by the Mercier criterion. The values of the maximum beta ratio β max are evaluated for both pressure distributions and are shown to become about two times larger by optimization. If the condition, q axis max are found to be less than 30 %. The oblate spheroidal flux conserver is shown to be better than the toroidal conserver with a rectangular cross section from the standpoint of stability. (author)

  10. Fundamental Magnetofluid Physics Studies on the Swarthmore Spheromak Experiment: Reconnection and Sustainment

    International Nuclear Information System (INIS)

    Brown, M.R.

    2001-01-01

    The general goal of the Magnetofluids Laboratory at Swarthmore College is to understand how magnetofluid kinetic energy can be converted to magnetic energy as it is in the core of the earth and sun (the dynamo problem) and to understand how magnetic energy can be rapidly converted back to kinetic energy and heat as it is in solar flares (the magnetic reconnection problem). Magnetic reconnection has been studied using the Swarthmore Spheromak Experiment (SSX) which was designed and built under this Junior Faculty Grant. In SSX we generate and merge two rings of magnetized plasma called spheromaks and study their interaction. The spheromaks have many properties similar to solar flares so this work is directly relevant to basic solar physics. In addition, since the spheromak is a magnetic confinement fusion configuration, issues of formation and stability have direct impact on the fusion program

  11. Three dimensional simulation study of spheromak injection into magnetized plasmas

    International Nuclear Information System (INIS)

    Suzuki, Y.; Watanabe, T.H.; Sato, T.; Hayashi, T.

    2000-01-01

    The three dimensional dynamics of a spheromak-like compact toroid (SCT) plasmoid, which is injected into a magnetized target plasma region, is investigated by using MHD numerical simulations. It is found that the process of SCT penetration into this region is much more complicated than that which has been analysed so far by using a conducting sphere (CS) model. The injected SCT suffers from a tilting instability, which grows with a similar timescale to that of the SCT penetration. The instability is accompanied by magnetic reconnection between the SCT magnetic field and the target magnetic field, which disrupts the magnetic configuration of the SCT. Magnetic reconnection plays a role in supplying the high density plasma, initially confined in the SCT magnetic field, to the target region. The penetration depth of the SCT high density plasma is also examined. It is shown to be shorter than that estimated from the CS model. The SCT high density plasma is decelerated mainly by the Lorentz force of the target magnetic field, which includes not only the magnetic pressure force but also the magnetic tension force. Furthermore, by comparing the SCT plasmoid injection with the bare plasmoid injection, magnetic reconnection is considered to relax the magnetic tension force, i.e. the deceleration of the SCT plasmoid. (author)

  12. Studies on spheromak plasma production by external-flux-core method, (2)

    International Nuclear Information System (INIS)

    Arata, Masanori; Katsurai, Makoto

    1984-01-01

    The spheromak technique, one of magnetic plasma containment techniques, has such arrangement of magnetic fields that the toroidal magnetic field is produced by the poloidal current flowing in plasma, and the poloidal magnetic field is produced by the toroidal current in plasma and the current in external coils. The authors proposed external flux core method as the technique of plasma formation by this spheromak method, in which the toroidal magnetic field is injected by the discharge using electrodes, whereas the poloidal magnetic field is injected by induction discharge without electrode. Its fundamental action was analyzed by computer simulation and confirmed by experiment. In this study, the behavior of the spheromak plasma produced was investigated in detail and summarized. The contents were the measurement of the spheromak configuration produced and the estimation of plasma parameters. The experimental setup, the principle of action, and the experimental results of magnetic field distribution obtained by a magnetic probe, ion current measured by an electrostatic probe, electron temperature by spectroscopic measurement and the behavior of spheromak plasma observed with an image converter camera are reported. (Kako, I.)

  13. Measurement of magnetic properties of confined compact toroid plasma (spheromak)

    International Nuclear Information System (INIS)

    Hwang, Fu-Kwun.

    1991-01-01

    The theoretical aspect of the spheromak is described in this paper. The MS machine hardware will be explored along with the formation scheme and diagnostic systems. The magnetic pickup probes, their calibration procedures and the data analysis methods will be discussed. Observations from the probe measurements and magnetic properties of the MS spheromak are considered. The axisymmetric Grad-Shafranov equilibrium code calculations are presented and compared with the measurements. Magnetic helicity and its correlation with the experimental observations is described

  14. Investigations into the relationship between spheromak, solar, and astrophysical plasmas

    International Nuclear Information System (INIS)

    Bellan, P.M.; Hsu, S.C.; Hansen, J.F.; Tokman, M.; Pracko, S.E.; Romero-Talamas, C.A.

    2003-01-01

    Spheromaks offer the potential for a simple, low cost fusion reactor and involve physics similar to certain solar and astrophysical phenomena. A program to improve understanding of spheromaks by exploiting this relationship is underway using (i) a planar spheromak gun and (ii) a solar prominence simulator. These devices differ in symmetry but both involve spheromak technology whereby high-voltage is applied across electrodes linking a bias magnetic flux created by external coils. The planar spheromak gun consists of a co-planar disk and annulus linked by a poloidal bias field. Application of high voltage across the gap between disk and annulus drives a current along the bias field. If the current to flux ratio exceeds the inverse of the characteristic linear dimension, a spheromak is ejected. A distinct kink forms just below the ejection threshold. The solar simulation gun consists of two adjacent electromagnets which generate a 'horse-shoe' arched bias field. A current is driven along this arched field by a capacitor bank. The current channel first undergoes pinching, then writhes, and finally bulges outwards due to the hoop force. (author)

  15. Theoretical issues in Spheromak research

    International Nuclear Information System (INIS)

    Cohen, R. H.; Hooper, E.B.; LoDestro, L.L.; Mattor, N.; Pearlstein, L.D.; Ryutov, D.D.

    1997-01-01

    This report summarizes the state of theoretical knowledge of several physics issues important to the spheromak. It was prepared as part of the preparation for the Sustained Spheromak Physics Experiment (SSPX), which addresses these goals: energy confinement and the physics which determines it; the physics of transition from a short-pulsed experiment, in which the equilibrium and stability are determined by a conducting wall (''''flux conserver'''') to one in which the equilibrium is supported by external coils. Physics is examined in this report in four important areas. The status of present theoretical understanding is reviewed, physics which needs to be addressed more fully is identified, and tools which are available or require more development are described. Specifically, the topics include: MHD equilibrium and design, review of MHD stability, spheromak dynamo, and edge plasma in spheromaks

  16. Transport and fluctuations in high temperature spheromak plasmas

    International Nuclear Information System (INIS)

    McLean, H.S.; Wood, R.D.; Cohen, B.I.; Hooper, E.B.; Hill, D.N.; Moller, J.M.; Romero-Talamas, C.; Woodruff, S.

    2006-01-01

    Higher electron temperature (T e >350 eV) and reduced electron thermal diffusivity (χ e 2 /s) is achieved in the Sustained Spheromak Physics Experiment (SSPX) by increasing the discharge current=I gun and gun bias flux=ψ gun in a prescribed manner. The internal current and q=safety factor profile derived from equilibrium reconstruction as well as the measured magnetic fluctuation amplitude can be controlled by programming the ratio λ gun =μ 0 I gun /ψ gun . Varying λ gun above and below the minimum energy eigenvalue=λ FC of the flux conserver (∇xB-vector=λ FC B-vector) varies the q profile and produces the m/n=poloidal/toroidal magnetic fluctuation mode spectrum expected from mode-rational surfaces with q=m/n. The highest T e is measured when the gun is driven with λ gun slightly less than λ FC , producing low fluctuation amplitudes ( e as T e increases, differing from Bohm or open field line transport models where χ e increases with T e . Detailed resistive magnetohydrodynamic simulations with the NIMROD code support the analysis of energy confinement in terms of the causal link with the q profile, magnetic fluctuations associated with low-order mode-rational surfaces, and the quality of magnetic surfaces

  17. Spheromak Physics Development

    International Nuclear Information System (INIS)

    Hooper, E.B.

    1997-01-01

    The spheromak is a Magnetic Fusion Energy (MFE) configuration, which is a leading alternative to the tokamak. It has a simple geometry which offers an opportunity to achieve the promise of fusion energy if the physics of confinement, current drive, and pressure holding capability extrapolate favorably to a reactor. Recent changes in the US MFE program, taken in response to budget constraints and programmatic directions from Congress, include a revitalization of an experimental alternative concept effort. Detailed studies of the spheromak were consequently undertaken to examine the major physics issues which need to be resolved to advance it as a fusion plasma, the optimum configuration for an advanced experiment, and its potential as a reactor. As a result of this study, we conclude that it is important to evaluate several physics issues experimentally. Such an experiment might be appropriately be named the Sustained Spheromak Physics Experiment (SSPX). It would address several critical issues, the solution to which will provide the physics basis to enable an advanced experiment. The specific scientific goals of SSPX would be to: * Demonstrate that electron and ion temperatures of a few hundred electron volts can be achieved in a steady-state spheromak plasma sustained by a magnetic dynamo (''helicity injection''). * Relate energy confinement quantitatively to the magnetic turbulence accompanying the dynamo and use this knowledge to optimize performance. * Measure the magnetic field profiles and magnetic turbulence in the plasma and relate these to the science of the magnetic dynamo which drives the current in the plasma. * Examine experimentally the pressure holding capability (''beta limit'') of the spheromak. * Understand the initial phases of the transition of the plasma from an equilibrium supported by a magnetic-flux conserving wall to one supported by external coils

  18. Route to High Temperatures by Current Amplification in the Sustained Spheromak Physics Experiment (SSPX)

    International Nuclear Information System (INIS)

    Woodruff, S.; Holbomb, C. T.; Stallard, B. W.; Hill, D. N.; Hooper, E. B.; McLean, H. S.; Wood, R. D.; Bulmer, R.; Cohen, B.; Sovinec, C.; Pearlstein, L. D.

    2002-01-01

    For the spheromak to be attractive as a reactor concept it would be necessary to sustain the configuration with a low recycling power, reflected in the current amplification factor: A 1 = I tor /I gun , where I tor is the toroidal current and I gun is the gun current. It is understood that A 1 needs to be around 60 for a reactor [1], although the highest obtained so far in the spheromak has been ∼3 [2]. The spheromak is a simply connected toroidal confinement device related to the reversed field pinch in that the q-profile falls at the edge and the first wall is conducting, although the central solenoid is absent. In the spheromak, the paradigm for field generation (and hence current amplification) is the injection of helicity, K = ∫A.BdV = 2ΦΨ where φ and Ψ are linked fluxes. Helicity is additive in the process of electrostatic injection by a coaxial gun [3]: K = 2V gunΨgun , where V gun is the voltage applied between two coaxial electrodes (giving the rate of toroidal flux injection) and Ψ gun is the poloidal vacuum flux connecting them. SSPX [4] is a 1m wide coaxial-gun-driven spheromak with W-coated copper electrodes (FIGURE 1) and a uniquely programmable vacuum field configuration. SSPX was built to assess if confinement can be reasonably preserved during injection, and to address the specific physics of the processes governing helicity injection

  19. Simulation of multi-pulse coaxial helicity injection in the Sustained Spheromak Physics Experiment

    Science.gov (United States)

    O'Bryan, J. B.; Romero-Talamás, C. A.; Woodruff, S.

    2018-03-01

    Nonlinear, numerical computation with the NIMROD code is used to explore magnetic self-organization during multi-pulse coaxial helicity injection in the Sustained Spheromak Physics eXperiment. We describe multiple distinct phases of spheromak evolution, starting from vacuum magnetic fields and the formation of the initial magnetic flux bubble through multiple refluxing pulses and the eventual onset of the column mode instability. Experimental and computational magnetic diagnostics agree on the onset of the column mode instability, which first occurs during the second refluxing pulse of the simulated discharge. Our computations also reproduce the injector voltage traces, despite only specifying the injector current and not explicitly modeling the external capacitor bank circuit. The computations demonstrate that global magnetic evolution is fairly robust to different transport models and, therefore, that a single fluid-temperature model is sufficient for a broader, qualitative assessment of spheromak performance. Although discharges with similar traces of normalized injector current produce similar global spheromak evolution, details of the current distribution during the column mode instability impact the relative degree of poloidal flux amplification and magnetic helicity content.

  20. Magnetic flux conversion and relaxation toward a minimum-energy state in S-1 spheromak plasmas

    International Nuclear Information System (INIS)

    Janos, A.

    1985-09-01

    S-1 Spheromak currents and magnetic fluxes have been measured with Rogowski coils and flux loops external to the plasma. Toroidal plasma currents up to 350 kA and spheromak configuration lifetimes over 1.0 msec have been achieved at moderate power levels. The plasma formation in the S-1 Spheromak device is based on an inductive transfer of poloidal and toroidal magnetic flux from a toroidal ''flux core'' to the plasma. Formation is programmed to guide the configuration into a force-free, minimum-energy Taylor state. Properly detailed programming of the formation process is found not to be essential since plasmas adjust themselves during formation to a final equilibrium near the Taylor state. After formation, if the plasma evolves away from the stable state, then distinct relaxation oscillation events occur which restore the configuration to that stable state. The relaxation process involves reconnection of magnetic field lines, and conversion of poloidal to toroidal magnetic flux (and vice versa) has been observed and documented. The scaling of toroidal plasma current and toroidal magnetic flux in the plasma with externally applied currents is consistent with the establishment of a Taylor state after formation. In addition, the magnetic helicity is proportional to that injected from the flux core, independent of how that helicity is generated

  1. Global magnetic fluctuations in S-1 spheromak plasmas and relaxation toward a minimum-energy state

    International Nuclear Information System (INIS)

    Janos, A.; Hart, G.W.; Yamada, M.

    1986-01-01

    Globally coherent modes have been observed during formation in the S-1 Spheromak plasma. These modes play an important role in flux conversion and plasma relaxation toward a minimum-energy state. A significant finding is the temporal progression through the n = 5, 4, 3, 2; m = 1 mode sequence as q rises through rational fractions m/n. Peak amplitudes of the modes relative to the unperturbed field are typically less than 5%, while amplitudes as high as 20% have been observed

  2. Los Alamos Spheromak Program

    International Nuclear Information System (INIS)

    Knox, S.O.; Barnes, C.W.; Fernandez, J.C.

    1985-01-01

    The Los Alamos Spheromak Program consists of two experimental facilities. The confinement physics of sustained and decaying spheromaks are being studied in CTX, which has an extensive array of diagnostics. Experiments are directed towards extending the physics understanding of the spheromak as a magnetic confinement concept. Electrodes for the production of clean sustained spheromaks are developed on the Electrode Facility, which is more flexible in terms of experimental modifications. Improvements to helicity sources and elecrodes which are proven on the Electrode Facility are then considered for incorporation onto CTX

  3. Energy conversion and concentration in a high-current gaseous discharge: Dense plasma spheromak in plasma focus experiments

    International Nuclear Information System (INIS)

    Kukushkin, A.B.; Rantsev-Kartinov, V.A.; Terentiev, A.R.

    1995-01-01

    Experimental results are presented which verify the possibility of the self-generated transformation of the magnetic field in plasma focus discharges to give a closed, spheromak-like magnetic configuration (SLMC). The energy conversion mechanism suggests a possibility of further concentrating the plasma power density by means of natural compressing the SLMC-trapped plasma by the residual magnetic field of the plasma focus discharge

  4. Two-fluid (plasma-neutral) Extended-MHD simulations of spheromak configurations in the HIT-SI experiment with PSI-Tet

    Science.gov (United States)

    Sutherland, D. A.; Hansen, C. J.; Jarboe, T. R.

    2017-10-01

    A self-consistent, two-fluid (plasma-neutral) dynamic neutral model has been implemented into the 3-D, Extended-MHD code PSI-Tet. A monatomic, hydrogenic neutral fluid reacts with a plasma fluid through elastic scattering collisions and three inelastic collision reactions: electron-impact ionization, radiative recombination, and resonant charge-exchange. Density, momentum, and energy are evolved for both the plasma and neutral species. The implemented plasma-neutral model in PSI-Tet is being used to simulate decaying spheromak configurations in the HIT-SI experimental geometry, which is being compare to two-photon absorption laser induced fluorescence measurements (TALIF) made on the HIT-SI3 experiment. TALIF is used to measure the absolute density and temperature of monatomic deuterium atoms. Neutral densities on the order of 1015 m-3 and neutral temperatures between 0.6-1.7 eV were measured towards the end of decay of spheromak configurations with initial toroidal currents between 10-12 kA. Validation results between TALIF measurements and PSI-Tet simulations with the implemented dynamic neutral model will be presented. Additionally, preliminary dynamic neutral simulations of the HIT-SI/HIT-SI3 spheromak plasmas sustained with inductive helicity injection will be presented. Lastly, potential benefits of an expansion of the two-fluid model into a multi-fluid model that includes multiple neutral species and tracking of charge states will be discussed.

  5. 3-D MHD modeling and stability analysis of jet and spheromak plasmas launched into a magnetized plasma

    Science.gov (United States)

    Fisher, Dustin; Zhang, Yue; Wallace, Ben; Gilmore, Mark; Manchester, Ward; Arge, C. Nick

    2016-10-01

    The Plasma Bubble Expansion Experiment (PBEX) at the University of New Mexico uses a coaxial plasma gun to launch jet and spheromak magnetic plasma configurations into the Helicon-Cathode (HelCat) plasma device. Plasma structures launched from the gun drag frozen-in magnetic flux into the background magnetic field of the chamber providing a rich set of dynamics to study magnetic turbulence, force-free magnetic spheromaks, and shocks. Preliminary modeling is presented using the highly-developed 3-D, MHD, BATS-R-US code developed at the University of Michigan. BATS-R-US employs an adaptive mesh refinement grid that enables the capture and resolution of shock structures and current sheets, and is particularly suited to model the parameter regime under investigation. CCD images and magnetic field data from the experiment suggest the stabilization of an m =1 kink mode trailing a plasma jet launched into a background magnetic field. Results from a linear stability code investigating the effect of shear-flow as a cause of this stabilization from magnetic tension forces on the jet will be presented. Initial analyses of a possible magnetic Rayleigh Taylor instability seen at the interface between launched spheromaks and their entraining background magnetic field will also be presented. Work supported by the Army Research Office Award No. W911NF1510480.

  6. Magnetohydrodynamic equilibrium and stability of spheromak with spheroidal plasma-vacuum interface

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Kamitani, Atsushi; Takimoto, Akio.

    1985-05-01

    The analytic solutions to the Grad-Shafranov equation are obtained for a prolate and an oblate spheroidal plasma by using Hill's vortex model. Effects of a toroidal magnetic field Bsub(phi) on the MHD equilibrium configurations are investigated by using these analytic solutions. When Bsub(phi) is larger than that of the force-free configuration, the spheroidal plasmas in a vacuum magnetic field are shown to be unable in the MHD equilibrium. The several physical quantities on the equilibrium configuration are evaluated. The spheromak plasma is proved to be unstable if dp/d psi not equal 0 and d 2 V/d psi 2 >= 0 on the magnetic axis. Here p is the pressure and V(psi) the volume surrounded by a magnetic surface of psi=const. The equilibrium configurations of the spheroidal plasmas by using Hill's vortex model are shown to satisfy the above conditions, i.e., to be unstable. (author)

  7. Magnetohydrodynamic equilibrium and stability of spheromak with spheroidal plasma-vacuum interface

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Kamitani, Atsushi; Takimoto, Akio

    1985-01-01

    The analytic solutions to the Grad-Shafranov equation are obtained for a prolate and an oblate spheroidal plasma by using Hill's vortex model. Effects of a toroidal magnetic field Bsub(phi) on the MHD equilibrium configurations are investigated by using these analytic solutions. When Bsub(phi) is stronger than that of the force-free configuration, the spheroidal plasmas in a vacuum magnetic field are shown to be unable in the MHD equilibrium. The several physical quantities on the equilibrium configuration are evaluated. The spheromak plasma is proved to be unstable if dp/d psi not equal 0 and d 2 V/d psi 2 >= 0 on the magnetic axis. Here p is the pressure and V(psi) the volume surrounded by a magnetic surface of psi = const. The equilibrium configurations of the spheroidal plasmas by using Hill's vortex model are shown to satisfy the above conditions, i.e., to be unstable. (author)

  8. Spheromak formation studies in SSPX

    International Nuclear Information System (INIS)

    Hill, D.N.; Bulmer, R.H.; Cohen, B.L.; Hooper, E.B.; LoDestro, L.L.; Mattor, N.; McLean, H.S.; Moller, J.; Pearlstein, L.D.; Ryutov, D.D.; Stallard, B.W.; Wood, R.D.; Woodruff, S.; Holcomb, C.T.; Jarboe, T.; Sovinec, C.R.; Wang, Z.; Wurden, G.

    2000-01-01

    We present results from the Sustained Spheromak Physics Experiment (SSPX) at LLNL, which has been built to study energy confinement in spheromak plasmas sustained for up to 2 ms by coaxial DC helicity injection. Peak toroidal currents as high as 600kA have been obtained in the 1m dia. (0.23m minor radius) device using injection currents between 200-400kA; these currents generate edge poloidal fields in the range of 0.2-0.4T. The internal field and current profiles are inferred from edge field measurements using the CORSICA code. Density and impurity control is obtained using baking, glow discharge cleansing, and titanium gettering, after which long plasma decay times (τ (ge) 1.5ms) are observed and impurity radiation losses are reduced from ∼50% to e (0)∼120eV and β e ∼7%. Edge field measurements show the presence of n=1 modes during the formation phase, as has been observed in other spheromaks. This mode dies away during sustainment and decay so that edge fluctuation levels as low as 1% have been measured. These results are compared with numerical simulations using the NIMROD code

  9. The Spheromak path to fusion energy

    International Nuclear Information System (INIS)

    Hooper, E.B.; Barnes, C.W.; Bellan, P.M.

    1998-01-01

    The spheromak is a simple and robust magnetofluid configuration with several attractive reactor attributes including compact geometry, no material center post, high engineering β, and sustained steady state operation through helicity injection. Spheromak physics was extensively studied in the US program and abroad (especially Japan) in the 1980' s with work continuing into the 1990s in Japan and the UK. Scientific results included demonstration of self-organization at constant helicity, control of the tilt and shift modes by shaped flux conservers, elucidation of the role of magnetic reconnection in the magnetic dynamo, and sustainment of a spheromak by helicity injection. Several groups attained electron temperatures above 100 eV in decaying plasmas, with CTX reaching 400 eV. This experiment had high magnetic field (>l T on the edge and ∼ 3 T near the symmetry axis) and good confinement. More recently, analysis of CTX found the energy confinement in the plasma core to be consistent with Rechester-Rosenbluth transport in a fluctuating magnetic field, potentially scaling to good confinement at higher electron temperatures. The SPHEX group developed an understanding of the dynamo in sustained spheromaks but in a relatively cold device. These and other physics results provide a foundation for a new ''concept exploration'' experiment to study the physics of a hot, sustained spheromak. If successful, this work leads to a next generation, proof-of-principle program. The new SSPX experiment will address the physics of a large-scale sustained spheromak in a national laboratory (LLNL) setting. The key issue in near term spheromak research will be to explore the possibly deleterious effects of sustainment on confinement. Other important issues include exploring the β scaling of confinement, scaling with Lundquist number S, and determining the need for active current-profile control. Collaborators from universities and other national laboratories are contributing

  10. Plasma response to sustainment with imposed-dynamo current drive in HIT-SI and HIT-SI3

    Science.gov (United States)

    Hossack, A. C.; Jarboe, T. R.; Chandra, R. N.; Morgan, K. D.; Sutherland, D. A.; Penna, J. M.; Everson, C. J.; Nelson, B. A.

    2017-07-01

    The helicity injected torus—steady inductive (HIT-SI) program studies efficient, steady-state current drive for magnetic confinement plasmas using a novel experimental method. Stable, high-beta spheromaks have been sustained using steady, inductive current drive. Externally induced loop voltage and magnetic flux are oscillated together so that helicity and power injection are always positive, sustaining the edge plasma current indefinitely. Imposed-dynamo current drive (IDCD) theory further shows that the entire plasma current is sustained. The method is ideal for low aspect ratio, toroidal geometries with closed flux surfaces. Experimental studies of spheromak plasmas sustained with IDCD have shown stable magnetic profiles with evidence of pressure confinement. New measurements show coherent motion of a stable spheromak in response to the imposed perturbations. On the original device two helicity injectors were mounted on either side of the spheromak and the injected mode spectrum was predominantly n  =  1. Coherent, rigid motion indicates that the spheromak is stable and a lack of plasma-generated n  =  1 energy indicates that the maximum q is maintained below 1 during sustainment. Results from the HIT-SI3 device are also presented. Three inductive helicity injectors are mounted on one side of the spheromak flux conserver. Varying the relative injector phasing changes the injected mode spectrum which includes n  =  2, 3, and higher modes.

  11. Progress in the SSPX Spheromak

    International Nuclear Information System (INIS)

    McLean, H S; Woodruff, S; Hill, D N; Bulmer, R H; Cohen, B I; Hooper, E B; Moller, J; Ryutov, D D; Stallard, B W; Wood, R D; Holcomb, C T; Jarboe, T R; Romero-Talamas, C

    2003-01-01

    The spheromak, with its simply connected geometry, holds promise as a less expensive fusion reactor. It has reasonably good plasma beta and can be formed and sustained in steady state with a magnetized coaxial plasma gun. The Sustained Spheromak Physics Experiment (SSPX) shown in Fig. 1 was constructed to investigate the key issues of magnetic field generation and energy confinement. In addition to the coaxial gun, nine magnetic field coils are utilized to shape the vacuum magnetic flux. This flexibility allows operation in many different regimes producing very different plasma characteristics. Pulse length is extended and magnetic field strength is increased. Improved surface conditioning produces plasmas with low impurity content, and higher electron temperature, T e . Electron heat transport within the separatrix is reduced by a factor of 4. The results strongly suggest the existence of closed flux surfaces even though the plasma is connected to the coaxial source. The CORSICA Grad-Shafranov 2-d equilibrium code with data from edge magnetic probes along with T e and electron density ne from Thomson scattering is used to calculate internal profiles: normalized current γ = μ 0 J/B, safety factor = q, ohmic heating, thermal energy density, and thermal diffusivity = ξ e . Ohmic heating is calculated by assuming spatially constant Spitzer resistivity with Z eff =2.3 estimated by VUV spectroscopy

  12. Steady-state spheromak

    International Nuclear Information System (INIS)

    Jarboe, T.R.

    1982-01-01

    A major effort is being made in the national program to make the operation of axisymmetric, toroidal confinement systems steady state by the application of expensive rf current drive. Described here is a method by which such a confinement system, the spheromak, can be refluxed indefinitely through the application of dc power. As a step towards dc sustainment we have operated the present CTX source in the slow source mode with a longer power application time (approx. 0.1 ms) and successfully generated long-lived spheromaks. If the erosion of the electrodes can be controlled as well as it is with MPD arcs then dc operation should be very clean. If only a small fraction (approx. 10% for an experiment) of the poloidal flux of the spheromak connects to the source then the dc sustainment can be very efficient. The amount of connecting flux that is necessary for sustainment needs to be determined experimentally

  13. Interaction of a spheromak-like compact toroid with a high beta spherical tokamak plasma

    International Nuclear Information System (INIS)

    Hwang, D.Q.; McLean, H.S.; Baker, K.L.; Evans, R.W.; Horton, R.D.; Terry, S.D.; Howard, S.; Schmidt, G.L.

    2000-01-01

    Recent experiments using accelerated spheromak-like compact toroids (SCTs) to fuel tokamak plasmas have quantified the penetration mechanism in the low beta regime; i.e. external magnetic field pressure dominates plasma thermal pressure. However, fusion reactor designs require high beta plasma and, more importantly, the proper plasma pressure profile. Here, the effect of the plasma pressure profile on SCT penetration, specifically, the effect of diamagnetism, is addressed. It is estimated that magnetic field pressure dominates penetration even up to 50% local beta. The combination of the diamagnetic effect on the toroidal magnetic field and the strong poloidal field at the outer major radius of a spherical tokamak will result in a diamagnetic well in the total magnetic field. Therefore, the spherical tokamak is a good candidate to test the potential trapping of an SCT in a high beta diamagnetic well. The diamagnetic effects of a high beta spherical tokamak discharge (low aspect ratio) are computed. To test the penetration of an SCT into such a diamagnetic well, experiments have been conducted of SCT injection into a vacuum field structure which simulates the diamagnetic field effect of a high beta tokamak. The diamagnetic field gradient length is substantially shorter than that of the toroidal field of the tokamak, and the results show that it can still improve the penetration of the SCT. Finally, analytic results have been used to estimate the effect of plasma pressure on penetration, and the effect of plasma pressure was found to be small in comparison with the magnetic field pressure. The penetration condition for a vacuum field only is reported. To study the diamagnetic effect in a high beta plasma, additional experiments need to be carried out on a high beta spherical tokamak. (author)

  14. Overview of the HIT-SI3 spheromak experiment

    Science.gov (United States)

    Hossack, A. C.; Jarboe, T. R.; Chandra, R. N.; Morgan, K. D.; Sutherland, D. A.; Everson, C. J.; Penna, J. M.; Nelson, B. A.

    2017-10-01

    The HIT-SI and HIT-SI3 spheromak experiments (a = 23 cm) study efficient, steady-state current drive for magnetic confinement plasmas using a novel method which is ideal for low aspect ratio, toroidal geometries. Sustained spheromaks show coherent, imposed plasma motion and low plasma-generated mode activity, indicating stability. Analysis of surface magnetic fields in HIT-SI indicates large n = 0 and 1 mode amplitudes and little energy in higher modes. Within measurement uncertainties all the n = 1 energy is imposed by the injectors, rather than being plasma-generated. The fluctuating field imposed by the injectors is sufficient to sustain the toroidal current through dynamo action whereas the plasma-generated field is not (Hossack et al., Phys. Plasmas, 2017). Ion Doppler spectroscopy shows coherent, imposed plasma motion inside r 10 cm in HIT-SI and a smaller volume of coherent motion in HIT-SI3. Coherent motion indicates the spheromak is stable and a lack of plasma-generated n = 1 energy indicates the maximum q is maintained below 1 for stability during sustainment. In HIT-SI3, the imposed mode structure is varied to test the plasma response (Hossack et al., Nucl. Fusion, 2017). Imposing n = 2, n = 3, or large, rotating n = 1 perturbations is correlated with transient plasma-generated activity. Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under Award Number DE-FG02-96ER54361.

  15. Confinement requirements for OHMIC-compressive ignition of a Spheromak plasma

    International Nuclear Information System (INIS)

    Olson, R.; Gilligan, J.; Miley, G.

    1980-01-01

    The Moving Plasmoid Reactor (MPR) is an attractive alternative magnetic fusion scheme in which Spheromak plasmoids are envisioned to be formed, compressed, burned, and expanded as the plasmoids translate through a series of linear reactor modules. Although auxiliary heating of the plasmoids may be possible, the MPR scenario would be especially interesting if ohmic decay and compression along were sufficient to heat the plasmoids to an ignition temperature. In the present work, we will study the transport conditions under which a Spheromak plasmoid could be expected to reach ignition via a combination of ohmic and compression heating

  16. Confinement requirements for ohmic-compressive ignition of a Spheromak plasma

    International Nuclear Information System (INIS)

    Olson, R.E.; Miley, G.H.

    1981-01-01

    The Moving Plasmoid Reactor (MPR) is an attractive alternative magnetic fusion scheme in which Spheromak plasmoids are envisioned to be formed, compressed, burned, and expanded as the plasmoids translate through a series of linear reactor modules. Although auxiliary heating of the plasmoids may be possible, the MPR scenario would be especially interesting if ohmic decay and compression alone is sufficient to heat the plasmoids to an ignition temperature. In the present work, we examine the transport conditions under which a Spheromak plasmoid can be expected to reach ignition via a combination of ohmic and compression heating

  17. Field and current amplification in the SSPX spheromak

    International Nuclear Information System (INIS)

    Hill, D.N. . hilld@llnl.gov; Bulmer, R.H.; Cohen, B.I.

    2003-01-01

    Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasmas with Te > 150eV, e >∼4% and core χ e ∼30m 2 /s. Helicity balance for these plasmas suggests that sheath dissipation can be significant, pointing to the importance of maximizing the voltage on the coaxial injector. For most operational modes we find a stiff relationship between peak spheromak field and injector current, and little correlation with plasma temperature, which suggests that other processes than ohmic dissipation may limit field amplification. However, slowing spheromak buildup by limiting the initial current pulse increases the ratio of toroidal current to injected current and points to new operating regimes with more favorable current amplification. (author)

  18. Spheromak Merging Experiments on SSX

    Science.gov (United States)

    Brown, M. R.; Kornack, T. W.; Sollins, P. K.; Luh, W. J.

    1997-11-01

    Spheromak merging experiments are underway at the Swarthmore Spheromak Experiment (SSX) at Swarthmore College. The spheromaks are formed by identical magnetized plasma guns and equilibrium is established in close fitting 0.5 m diameter copper flux conservers. Partial merging is achieved through openings in the back wall. We observe the formation of a reconnection boundary layer at the interface of the two spheromaks using a linear probe array. The characteristic scale of the flux reversal is about 1 cm (consistent with the diffusion scale δ_diff, the ion Larmor radius ρi and the ion inertial length c/ω_pi). Movies of the formation and evolution of the layer will be presented. Correlations between reconnection events and pulses of soft x-rays and energetic particles will be presented if available. Plans for 2D and 3D imaging of the layer will also be discussed.

  19. A new diagnostic for spheromaks

    International Nuclear Information System (INIS)

    Boyd, D.A.

    1986-01-01

    Electron cyclotron emission from a spheromak plasma may be able to provide information about the confining magnetic field of the system. Emission generated in the extraordinary mode wit hits electric vector perpendicular to the local magnetic field at sufficiently high frequency will propagate out of the plasma while retaining the original orientation if its electric vector. Thus, a measurement of the orientation of the emergent electric vector and the emission frequency will allow one to deduce the orientation and strength of the magnetic field at the radiation source. In this paper, simple models of the Maryland spheromak are used to examine the practicality of such a diagnostic

  20. Stellarator-Spheromak

    International Nuclear Information System (INIS)

    Moroz, P.E.

    1997-03-01

    A novel concept for magnetic plasma confinement, Stellarator-Spheromak (SSP), is proposed. Numerical analysis with the classical-stellarator-type outboard stellarator windings demonstrates a number of potential advantages of SSP for controlled nuclear fusion. Among the main ones are: simple and compact magnet coil configuration, absence of material structures (e.g. magnet coils or conducting walls) in the center of the torus, high rotational transform, and a possibility of MHD equilibria with very high β (pressure/magnetic pressure) of the confined plasma

  1. Particle confinement and fueling effects on the Maryland spheromak

    International Nuclear Information System (INIS)

    Filuk, A.B.

    1991-01-01

    The spheromak plasma confinement concept provides the opportunity to study the evolution of a nearly force-free magnetic field configuration. The plasma currents and magnetic fields are produced self-consistently, making this type of device attractive as a possible fusion reactor. At present, spheromaks are observed to have poorer particle and magnetic confinement than expected from simple theory. The purpose of this study is to examine the role of plasma density in the decay of spheromaks produced in the Maryland Spheromak experiment. Density measurements are made with an interferometer and Langmuir probe, and results are correlated with those of other plasma diagnostics to understand the sources of plasma, the spheromak formation effects on the density, and the magnitude of particle loss during the spheromak decay. A power and particle balance computer model is constructed and applied to the spheromaks studied in order to assess the impact of high density and particle loss rate on the spheromak decay. The observations and model indicate that the decay of the spheromaks is at present dominated by impurity radiation loss. The model also predicts that high density and short particle confinement time play a critical role in the spheromak power balance when the impurity levels are reduced

  2. Stellarmak a hybrid stellarator: Spheromak

    International Nuclear Information System (INIS)

    Hartman, C.W.

    1980-01-01

    This paper discusses hybridization of modified Stellarator-like transform windings (T-windings) with a Spheromak or Field-Reversed-Mirror configuration. This configuration, Stellarmak, retains the important topological advantage of the Spheromak or FRM of having no plasma linking conductors or blankets. The T-windings provide rotational transformation in toroidal angle of the outer poloidal field lines, in effect creating a reversed B/sub Toroidal/ Spheromak or adding average B/sub T/ to the FRM producing higher shear, increased limiting β, and possibly greater stability to kinks and tilt. The presence of field ripple in the toroidal direction may be sufficient to inhibit cancellation of directed ion current by electron drag to allow steady state operation with the toroidal as well as poloidal current maintained by neutral beams

  3. Optimization of the Magnetic Field Structure for Sustained Plasma Gun Helicity Injection for Magnetic Turbulence Studies at the Bryn Mawr Plasma Laboratory

    Science.gov (United States)

    Cartagena-Sanchez, C. A.; Schaffner, D. A.; Johnson, H. K.; Fahim, L. E.

    2017-10-01

    A long-pulsed magnetic coaxial plasma gun is being implemented and characterized at the Bryn Mawr Plasma Laboratory (BMPL). A cold cathode discharged between the cylindrical electrodes generates and launches plasma into a 24cm diameter, 2m long chamber. Three separately pulsed magnetic coils are carefully positioned to generate radial magnetic field between the electrodes at the gun edge in order to provide stuffing field. Magnetic helicity is continuously injected into the flux-conserving vacuum chamber in a process akin to sustained slow-formation of spheromaks. The aim of this source, however, is to supply long pulses of turbulent magnetized plasma for measurement rather than for sustained spheromak production. The work shown here details the optimization of the magnetic field structure for this sustained helicity injection.

  4. Theoretical aspects of the use of pulsed reflectometry in a spheromak plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B. J., LLNL

    1998-06-11

    Pulsed reflectometry using both ordinary (O) and extraordinary (X) modes has the potential of providing time and space-resolved measurements of the electron density, the magnitude of the magnetic field, and the magnetic shear as a function of radius. Such a diagnostic also yields the current profile from the curl of the magnetic field. This research addresses theoretical issues associated with the use of reflectometry in the SSPX spheromak experiment at the Lawrence Livermore National Laboratory. We have extended a reflectometry simulation model to accommodate O and X-mode mixed polarization and linear mode conversion between the two polarizations. A Wentzel-Kramers-Brillouin-Jeffreys (WKBJ) formula for linear mode conversion agrees reasonably well with direct numerical solutions of the wave equation, and we have reconstructed the magnetic pitch-angle profile by matching the results of the WKBJ formula with the mode conversion data observed in simulations using a least-squares determination of coefficients in trial functions for the profile. The reflectometry data also yield information on fluctuations. Instrumental issues, e.g., the effects of microwave mixers and filters on model reflectometry pulses, have been examined to optimize the performance of the reflectometry diagnostics.

  5. Development of the STPX Spheromak System

    Science.gov (United States)

    Williams, R. L.; Clark, J.; Weatherford, C. A.

    2015-11-01

    The progress made in starting up the STPX Spheromak system, which is now installed at the Florida A&M University, is reviewed. Experimental, computational and theoretical activities are underway. The control system for firing the magnetized coaxial plasma gun and for collecting data from the diagnostic probes, based on LabView, is being tested and adapted. Preliminary results of testing the installed magnetic field probes, Langmuir triple probes, cylindrical ion probes, and optical diagnostics will be discussed. Progress in modeling this spheromak using simulation codes, such as NIMROD, will be discussed. Progress in investigating the use of algebraic topology to describe this spheromak will be reported.

  6. Spheromak Buildup in SSPX using a Modular Capacitor Bank

    International Nuclear Information System (INIS)

    Wood, R D; McLean, H S; Hill, D N; Hooper, E B; Romero-Talamas, C A

    2006-01-01

    The Sustained Spheromak Physics Experiment (SSPX) [1] was designed to address both magnetic field generation and confinement. The SSPX produces 1.5-3.5msec, spheromak plasmas with a 0.33m major radius and a minor radius of ∼0.23m. DC coaxial helicity injection is used to build and sustain the spheromak plasma within the flux conserver. Optimal operation is obtained by flattening the profile of λ = μ 0 j/B, consistent with reducing the drive for tearing and other MHD modes, and matching of edge current and bias flux to minimize |(delta)B/B| rms . With these optimizations, spheromak plasmas with central T e >350eV and β e ∼ 5% with toroidal fields of 0.6T [3] have been obtained. If a favorable balance between current drive efficiency and energy confinement can be shown, the spheromak has the potential to yield an attractive magnetic fusion concept [4]. The original SSPX power system consists of two lumped-circuit capacitor banks with fixed circuit parameters. This power system is used to produce an initial fast formation current pulse (10kV, 0.5MJ formation bank), followed by a lower current, 3.5ms flattop sustainment pulse (5kV, 1.5MJ sustainment bank). Experimental results indicate that a variety of injected current pulses, such as a longer sustainment flattop [5], higher and longer fast formation [6], and multiple current pulses [7], might further our understanding of magnetic field generation. Although the formation bank can be split into two independent banks capable of producing other injected current waveforms, the variety of current waveforms produced by this power system is limited. Thus, to extend the operating range of the SSPX, a new pulsed-power system has been designed and partially constructed. In this paper, we discuss the design of the programmable bank and present first results from using the bank to increase the magnetic field in SSPX

  7. Review of spheromak research

    International Nuclear Information System (INIS)

    Jarboe, T.R.

    1994-01-01

    Spheromak research from 1979 to the present is reviewed including over 160 references. Emphasis is on understanding and interpretation of results. In addition to summarizing results some new interpretations are presented. An introduction and brief history is followed by a discussion of generalized helicity and its time derivative. Formation and sustainment are discussed including five different methods, flux core, θ-pinch z-pinch, coaxial source, conical θ-pinch, and kinked z-pinch. All methods are helicity injections. Steady-state methods and rules for designing spheromak experiments are covered, followed by equilibrium and stability. Methods of stabilizing the tilt and shift modes are discussed as well as their impact on the reactor designs. Current-driven and pressure-driven instabilities as well as relaxation in general are covered. Energy confinement is discussed in terms of helicity decay time and βs limits. The confinement in high and low open-flux geometries are compared and the reactor implications discussed. (author)

  8. Scaling studies of spheromak formation and equilibrium

    International Nuclear Information System (INIS)

    Geddes, C.G.; Kornack, T.W.; Brown, M.R.

    1998-01-01

    Formation and equilibrium studies have been performed on the Swarthmore Spheromak Experiment (SSX). Spheromaks are formed with a magnetized coaxial plasma gun and equilibrium is established in both small (d small =0.16 m) and large (d large =3d small =0.50 m) copper flux conservers. Using magnetic probe arrays it has been verified that spheromak formation is governed solely by gun physics (in particular the ratio of gun current to flux, μ 0 I gun /Φ gun ) and is independent of the flux conserver dimensions. It has also been verified that equilibrium is well described by the force free condition ∇xB=λB (λ=constant), particularly early in decay. Departures from the force-free state are due to current profile effects described by a quadratic function λ=λ(ψ). Force-free SSX spheromaks will be merged to study magnetic reconnection in simple magnetofluid structures. copyright 1998 American Institute of Physics

  9. The spheromak as a compact fusion reactor

    International Nuclear Information System (INIS)

    Hagenson, R.L.; Krakowski, R.A.

    1987-03-01

    After summarizing the economic and utility-based rationale for compact, higher-power-density fusion reactors, the gun-sustained spheromak concept is explored as one of a number of poloidal-field-dominated confinement configurations that might improve the prospects for economically attractive and operationally simplified fusion power plants. Using a comprehensive physics/engineering/costing model for the spheromak, guided by realistic engineering constraints and physics extrapolation, a range of cost-optimized reactor design points is presented, and the sensitivity of cost to key physics, engineering, and operational variables is reported. The results presented herein provide the basis for conceptual engineering designs of key fusion-power-core (FPC) subsystems and more detailed plasma modeling of this promising, high mass-power-density concept, which stresses single-piece FPC maintenance, steady-state current drive through electrostatic magnetic helicity injection, a simplified co-axial electrode-divertor, and efficient resistive-coal equilibrium-field coils. The optimal FPC size and the cost estimates project a system that competes aggressively with the best offered by alternative energy sources while simplifying considerably the complexity that has generally been associated with most approaches to magnetic fusion energy

  10. The spheromak as a compact fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hagenson, R.L.; Krakowski, R.A.

    1987-03-01

    After summarizing the economic and utility-based rationale for compact, higher-power-density fusion reactors, the gun-sustained spheromak concept is explored as one of a number of poloidal-field-dominated confinement configurations that might improve the prospects for economically attractive and operationally simplified fusion power plants. Using a comprehensive physics/engineering/costing model for the spheromak, guided by realistic engineering constraints and physics extrapolation, a range of cost-optimized reactor design points is presented, and the sensitivity of cost to key physics, engineering, and operational variables is reported. The results presented herein provide the basis for conceptual engineering designs of key fusion-power-core (FPC) subsystems and more detailed plasma modeling of this promising, high mass-power-density concept, which stresses single-piece FPC maintenance, steady-state current drive through electrostatic magnetic helicity injection, a simplified co-axial electrode-divertor, and efficient resistive-coal equilibrium-field coils. The optimal FPC size and the cost estimates project a system that competes aggressively with the best offered by alternative energy sources while simplifying considerably the complexity that has generally been associated with most approaches to magnetic fusion energy.

  11. Computational studies of ohmic heating in the spheromak

    International Nuclear Information System (INIS)

    Olson, R.E.

    1983-01-01

    Time-dependent computational simulations using both single-fluid O-D and two-fluid 1 1/2-D models are developed for and utilized in an investigation of the ohmic heating of a spheromak plasma. The plasma density and composition, the applied magnetic field strength, the plasma size, and the plasma current density profile are considered for their effects on the spheromak heating rate and maximum achievable temperature. The feasibility of ohmic ignition of a reactor-size spheromak plasma is also contemplated

  12. Particle diffusion in a spheromak

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Levinton, F.M.; Yamada, M.

    1988-01-01

    The local carbon particle diffusion coefficient was measured in the Proto S-1/C spheromak using a test particle injection scheme. When the plasma was not in a force-free Taylor state, and when there were pressure gradients in the plasma, the particle diffusion was five times that predicted by Bohm and was consistent with collisional drift wave diffusion. The diffusion appears to be driven by correlations of the fluctuating electric field and density. During the decay phase of the discharge when the plasma was in the Taylor state, the diffusion coefficient of the carbon was classical. 23 refs., 4 figs

  13. Studies of conceptual spheromak fusion reactors

    International Nuclear Information System (INIS)

    Katsurai, M.; Yamada, M.

    1982-01-01

    Preliminary design studies are carried out for a spheromak fusion reactor. Simplified circuit theory is applied to obtain the characteristic relations among various parameters of the spheromak configuration for an aspect ratio of A >or approx. 1.6. These relations are used to calculate the parameters for the conceptual designs of three types of fusion reactor: (1) the DT reactor with two-component-type operation, (2) the ignited DT reactor, and (3) the ignited catalysed-type DD reactor. With a total wall loading of approx. 4 MW.m -2 , it is found that edge magnetic fields of only approx. 4 T (DT) and approx. 9 T (Cat. DD) are required for ignited reactors of 1 m plasma (minor) radius with output powers in the gigawatt range. An assessment of various schemes of generation, compression and translation of spheromak plasmas is presented. (author)

  14. Current drive by spheromak injection into a tokamak

    International Nuclear Information System (INIS)

    Brown, M.R.; Bellan, P.M.

    1990-01-01

    The authors report the first observation of current drive by spheromak injection into a tokamak due to the process of helicity injection. Current drive is observed in Caltech's ENCORE tokamak (30% increase, ΔI > 1 kA) only when both the tokamak and injected spheromak have the same sign of helicity (where helicity is defined as positive if current flows parallel to magnetic field lines and negative if anti-parallel). The initial increase (decrease) in current is accompanied by a sharp decrease (increase) in loop voltage and the increase in tokamak helicity is consistent with the helicity content of the injected spheromak. In addition, the injection of the spheromak raises the tokamak central density by a factor of six. The introduction of cold spheromak plasma causes sudden cooling of the tokamak discharge from 12 eV to 4 eV which results in a gradual decline in tokamak plasma current by a factor of three. In a second experiment, the authors inject spheromaks into the magnetized toroidal vacuum vessel (with no tokamak plasma). An m = 1 magnetic structure forms in the vessel after the spheromak undergoes a double tilt; once in the cylindrical entrance between gun and tokamak, then again in the tokamak vessel. A horizontal shift of the spheromak equilibrium is observed in the direction opposite that of the static toroidal field. In the absence of net toroidal flux, the structure develops a helical pitch as predicted by theory. Experiments with a number of refractory metal coatings have shown that tungsten and chrome coatings provide some improvement in spheromak parameters. They have also designed and will soon construct a larger, higher current spheromak gun with a new accelerator section for injection experiments on the Phaedrus-T tokamak

  15. Magnetic Reconnection Results on the Swarthmore Spheromak Experiment

    Science.gov (United States)

    Kornack, T. W.; Sollins, P. K.; Brown, M. R.

    1997-11-01

    Linear and 2D arrays of magnetic probes are used to study magnetic reconnection in the Swarthmore Spheromak Experiment (SSX). Opposing coaxial plasma guns form two identical spheromaks into adjacent 0.5 m diameter copper flux conservers. The flux conservers have symmetrical openings that allow the spheromaks to merge in a controlled manner. The stable equilibrium of the spheromaks provides a reservoir of magnetic flux for reconnection experiments. Currently, the magnetic configuration of the spheromaks allows the study of counter-helicity reconnection. Preliminary analysis will be presented and may include 2D B field movies of the reconnection region, measurement of the reconnection rate and comparison to the Sweet-Parker and standard Petschek models.

  16. Theory of the evolution of the decaying spheromak

    International Nuclear Information System (INIS)

    Sgro, A.G.; Marklin, G.; Mirin, A.A.

    1986-01-01

    The strongly nonlinear dynamics present in decaying Spheromaks has been studied by various computational methods, demonstrating the tendency of the plasma to oscillate about or approach relaxed states and resulting in new insight into the significance of minimum energy states

  17. Effects of passive coils on spheromak gross MHD instabilities

    International Nuclear Information System (INIS)

    Munson, C.; Janos, A.; Paul, S.; Wysocki, F.; Yamada, M.

    1983-01-01

    The experimental investigation of the effectiveness of figure-8 coils in stabilizing the n=1 tilting mode of spheromak plasmas in Proto S-1 A/B is extended. In addition, another coil configuration, the saddle coil, is examined

  18. Steady-state spheromak reactor studies

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Hagenson, R.L.

    1985-01-01

    After summarizing the essential elements of a gun-sustained spheromak, the potential for a steady-state is explored by means of a comprehensive physics/engineering/costing model. A range of cost-optimized reactor design points is presented, and the sensitivity of cost to key physics, engineering, and operational variables is reported

  19. Design of a spheromak compressor driven by high explosives

    International Nuclear Information System (INIS)

    Henins, I.; Fernandez, J.C.; Jarboe, T.R.; Marsh, S.P.; Marklin, G.J.; Mayo, R.M.; Wysocki, F.J.

    1990-01-01

    High energy density spheromaks can be used to accelerate a thin section of the flux conserver wall to high velocities. The energy density of a spheromak, formed by conventional helicity injection into a flux conserver, can be increased by reducing the flux conserver volume after the spheromak is formed. A method of accomplishing this is by imploding one wall of the flux conserver with high explosives. The authors have embarked on a program to demonstrate that a spheromak can be used as an energy transfer medium, and that a velocity gain over high-explosive driven plate velocities can be achieved. To do this, a plasma gun helicity source that will inject a spheromak with suitable initial energy density and lifetime is needed. Also, an implodable flux conserver that remains intact and clean during the implosion must be developed. The flux conserver problem is probably the more challenging one, because very little experimental work has been done in the past on explosively driven metal plates into a high vacuum, with sizes and travel distances appropriate for their application. There are two necessary practical requirements for an explosive compression of a flux conserver. The first is that the imploding wall does not rupture. The second is that gasses or other debri are not ejected which could penetrate and poison the spheromak plasma, and thus reduce the spheromak lifetime below what is necessary to carry out the spheromak compression and the subsequent acceleration of the flyer plate. The authors have designed and fabricated a plasma gun to be used for injecting the initial spheromak plasma into the collapsible flux conserver

  20. Sustainment dynamo reexamined: nonlocal electrical conductivity of plasma in a stochastic magnetic field

    International Nuclear Information System (INIS)

    Jacobson, A.R.; Moses, R.W.

    1984-01-01

    The plasma dynamo is both an intriguing and a practical concept. The intrigue derives from attempting to explain naturally occurring and man-made plasmas whose strong field-aligned currents j/sub parallel/ apparently disobey the most naive Ohm's law j/sub parallel/ = sigma/sub parallel/E/sub parallel/. The practical importance derives from the dynamo's role both in formation and in sustainment of reversed-field pinch (RFP) and Spheromak fusion plasmas. We will examine certain features of the documented quasi-steady discharges on ZT-40M, and RFP in apparent need of a sustainment dynamo. We will show that the tail electrons (which carry j/sub parallel/) are probably wandering (along stochastic B Vector-field lines) over much of the minor radius in one mean-free-path

  1. Model predictions for auxiliary heating in spheromaks

    International Nuclear Information System (INIS)

    Fauler, T.K.; Khua, D.D.

    1997-01-01

    Calculations are presented of the plasma temperature waited for under auxiliary heating in spheromaks. A model, ensuring good agreement of earlier experiments with joule heating results, is used. The model includes heat losses due to magnetic fluctuations and shows that the plasma temperatures of the kilo-electron-volt order may be achieved in a small device with the radius of 0.3 m only

  2. Simulation of Spheromak Evolution and Energy Confinement

    International Nuclear Information System (INIS)

    Cohen, B; Hooper, E; Cohen, R; Hill, D; McLean, H; Wood, R; Woodruff, S; Sovinec, C; Cone, G

    2004-01-01

    Simulation results are presented that illustrate the formation and decay of a spheromak plasma driven by a coaxial electrostatic plasma gun, and that model the energy confinement of the plasma. The physics of magnetic reconnection during spheromak formation is also illuminated. The simulations are performed with the three-dimensional, time-dependent, resistive magnetohydrodynamic NIMROD code. The simulation results are compared to data from the SSPX spheromak experiment at the Lawrence Livermore National Laboratory. The simulation results are tracking the experiment with increasing fidelity (e.g., improved agreement with measurements of the magnetic field, fluctuation amplitudes, and electron temperature) as the simulation has been improved in its representations of the geometry of the experiment (plasma gun and flux conserver), the magnetic bias coils, and the detailed time dependence of the current source driving the plasma gun, and uses realistic parameters. The simulations are providing a better understanding of the dominant physics in SSPX, including when the flux surfaces close and the mechanisms limiting the efficiency of electrostatic drive

  3. Simulation of Spheromak Evolution and Energy Confinement

    International Nuclear Information System (INIS)

    Cohen, B.; Hooper, E.; Cohen, R.; Hill, D.; McLean, H.; Wood, R.; Woodruff, S.

    2004-01-01

    Simulation results are presented that illustrate the formation and decay of a spheromak plasma driven by a coaxial electrostatic plasma gun, and that model the energy confinement of the plasma. The physics of magnetic reconnection during spheromak formation is also illuminated. The simulations are performed with the three-dimensional, time-dependent, resistive magnetohydrodynamic NIMROD code. The dimensional, simulation results are compared to data from the SSPX spheromak experiment at the Lawrence Livermore National Laboratory. The simulation results are tracking the experiment with increasing fidelity (e.g., improved agreement with measurements of the magnetic field, fluctuation amplitudes, and electron temperature) as the simulation has been improved in its representations of the geometry of the experiment (plasma gun and flux conserver), the magnetic bias coils, and the detailed time dependence of the current source driving the plasma gun, and uses realistic parameters. The simulations are providing a better understanding of the dominant physics in SSPX, including when the flux surfaces close and the mechanisms limiting the efficiency of electrostatic drive

  4. Controlled and spontaneous magnetic field generation in a gun-driven spheromak

    International Nuclear Information System (INIS)

    Woodruff, S.; Cohen, B.I.; Hooper, E.B.; Mclean, H.S.; Stallard, B.W.; Hill, D.N.; Holcomb, C.T.; Romero-Talamas, C.; Wood, R.D.; Cone, G.; Sovinec, C.R.

    2005-01-01

    In the Sustained Spheromak Physics Experiment, SSPX [E. B. Hooper, D. Pearlstein, and D. D. Ryutov, Nucl. Fusion 39, 863 (1999)], progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1 m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations (δB/B∼1% on the midplane edge) yields T e profiles peaked at >200 eV. Trends indicate a limiting beta (β e ∼4%-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with δB/B∼2% and large voltage fluctuations (δV∼1 kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7 T along the geometric axis). By increasing the time between pulses, a quasisteady sustainment is produced (with periodic good confinement), comparing well with resistive magnetohydrodynamic simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  5. Controlled and Spontaneous Magnetic Field Generation in a Gun-Driven Spheromak

    International Nuclear Information System (INIS)

    Woodruff, S; Cohen, B I; Hooper, E B; McLean, H S; Stallard, B W; Hill, D N; Holcomb, C T; Romero-Talamas, C; Wood, R D; Cone, G; Sovinec, C R

    2005-04-01

    In the Sustained Spheromak Physics Experiment, SSPX, progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1-m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations ((delta)B/B∼1% on the midplane edge) yields T e profiles peaked at > 200eV. Trends indicate a limiting beta (β e ∼ 4-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with (delta)B/B ∼2% and large voltage fluctuations ((delta)V ∼ 1kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7T along the geometric axis). By increasing the time between pulses, a quasi-steady sustainment is produced (with periodic good confinement), comparing well with resistive MHD simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  6. Advanced spheromak fusion reactor

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1996-01-01

    The spheromak has no toroidal magnetic field coils or other structure along its geometric axis, and is thus more attractive than the leading magnetic fusion reactor concept, the tokamak. As a consequence of this and other attributes, the spheromak reactor may be compact and produce a power density sufficiently high to warrant consideration of a liquid 'blanket' that breeds tritium, converts neutron kinetic energy to heat, and protects the reactor vessel from severe neutron damage. However, the physics is more complex, so that considerable research is required to learn how to achieve the reactor potential. Critical physics problems and possible ways of solving them are described. The opportunities and issues associated with a possible liquid wall are considered to direct future research

  7. Power balance and characterization of impurities in the Maryland Spheromak

    International Nuclear Information System (INIS)

    Cote, C.

    1993-01-01

    The Maryland Spheromak is a medium size magnetically confined plasma of toroidal shape. Low T e and higher n e than expected contribute to produce a radiation dominated short-lived spheromak configuration. A pyroelectric radiation detector and a VUV spectrometer have been used for space and time-resolved measurements of radiated power and impurity line emission. Results from the bolometry and VUV spectroscopy diagnostics have been combined to give the absolute concentrations of the major impurity species together with the electron temperature. The large amount of oxygen and nitrogen ions in the plasma very early in the discharge is seen to be directly responsible for the abnormally high electron density. The dominant power loss mechanisms are found to be radiation (from impurity line emission) and electron convection to the end walls during the formation phase of the spheromak configuration, and radiation only during the decay phase

  8. Power balance and characterization of impurities in the Maryland Spheromak

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Claude [Univ. of Maryland, College Park, MD (United States)

    1993-01-01

    The Maryland Spheromak is a medium size magnetically confined plasma of toroidal shape. Low Te and higher ne than expected contribute to produce a radiation dominated short-lived spheromak configuration. A pyroelectric radiation detector and a VUV spectrometer have been used for space and time-resolved measurements of radiated power and impurity line emission. Results from the bolometry and VUV spectroscopy diagnostics have been combined to give the absolute concentrations of the major impurity species together with the electron temperature. The large amount of oxygen and nitrogen ions in the plasma very early in the discharge is seen to be directly responsible for the abnormally high electron density. The dominant power loss mechanisms are found to be radiation (from impurity line emission) and electron convection to the end walls during the formation phase of the spheromak configuration, and radiation only during the decay phase.

  9. Critical beta for analytical spheromak equilibria

    International Nuclear Information System (INIS)

    Freire, E.M.; Clemente, R.A.

    1985-01-01

    The Mercier criterion is applied to two analytical spheromak equilibria, one with a spherical separatrix and the other with a cylindrical one of variable elongation. The maximum beta, defined as the ratio between the plasma pressure and the magnetic pressure averaged over the plasma volume, for which the criterion is satisfied on every magnetic surface, has been obtained. In the spherical model the critical beta is 0.003, while in the cylindrical case it is a function of the elongation of the separatrix with a maximum of 0.083. (author)

  10. Re-examination of spheromak experiments and opportunities

    International Nuclear Information System (INIS)

    Hooper, B.E.; Hammer, J.H.; Barnes, C.W.; Fernandez, J.C.; Wysocki, F.J.

    1996-01-01

    The results of spheromak experiments are reexamined in light of the hypothesis that the core energy confinement is considerably better than the global confinement and that it extrapolates favorably with magnetic Reynolds number S. The data in decaying spheromaks are found to be consistent with the hypothesis and with magnetic fluctuations scaling as S -1/2 and determining the electron thermal conductivity. No conclusion is drawn from the data for sustained spheromaks, indicating the importance of a new experiment to determine core energy confinement while helicity is injected. The characteristics of such an experiment are discussed, including the importance of using modern vacuum and wall-conditioning techniques and of minimizing magnetic field errors. 44 refs., 7 figs., 1 tab

  11. Progress with energy confinement time in the CTX spheromak

    International Nuclear Information System (INIS)

    Jarboe, T.R.; Fernandez, J.C.; Wysocki, F.J.; Barnes, C.W.; Henins, I.; Knox, S.O.; Marklin, G.J.

    1990-01-01

    The 0.67 m radius mesh flux conserver (MFC) in CTX was replaced by a solid flux conserver (SFC), resulting in greatly reduced field errors. Decreased spheromak open flux led to vastly improved decaying discharged, including increased global energy confinement times, τ E (from 20 to 180 μs), and corresponding magnetic energy decay times, τ B 2 (from 0.7 to 2 ms). Improved confinement allowed the observation of the pressure-driven instability (predicted by Mercier) which ejects plasma from the spheromak interior to the wall

  12. Ohmic heating of a spheromak to 100 eV

    Energy Technology Data Exchange (ETDEWEB)

    Jarboe, T.R.; Barnes, C.W.; Henins, I.; Hoida, H.W.; Knox, S.O.; Linford, R.K.; Sherwood, A.R.

    1984-01-01

    The first spheromaks with Thomson-scattering-measured electron temperatures of over 100 eV are described. The spheromak is generated by a magnetized coaxial plasma source in a background gas of 30 mTorr of H/sub 2/, and it is stably confined in an oblate 80 cm diam copper mesh flux conserver. The open mesh design allows rapid impurity transport out of the spheromak. The peak temperature, measured using multipoint Thomson scattering, is observed to rise from approximately 25 eV to over 100 eV in about 0.2 msec due to Ohmic heating from the decaying magnetic fields. Density (approx.5 x 10/sup 13/ cm/sup -3/) and magnetic fields (approximately 2 kG) are measured using interferometry and magnetic probes.

  13. Ohmic heating of a spheromak to 100 eV

    International Nuclear Information System (INIS)

    Jarboe, T.R.; Barnes, C.W.; Henins, I.; Hoida, H.W.; Knox, S.O.; Linford, R.K.; Sherwood, A.R.

    1984-01-01

    The first spheromaks with Thomson-scattering-measured electron temperatures of over 100 eV are described. The spheromak is generated by a magnetized coaxial plasma source in a background gas of 30 mTorr of H 2 , and it is stably confined in an oblate 80 cm diam copper mesh flux conserver. The open mesh design allows rapid impurity transport out of the spheromak. The peak temperature, measured using multipoint Thomson scattering, is observed to rise from approximately 25 eV to over 100 eV in about 0.2 msec due to Ohmic heating from the decaying magnetic fields. Density (approx.5 x 10 13 cm -3 ) and magnetic fields (approximately 2 kG) are measured using interferometry and magnetic probes

  14. Equilibrium and stability of the Los Alamos spheromak

    International Nuclear Information System (INIS)

    Marklin, G.

    1984-01-01

    The open mesh flux conserver (MFC) on the Los Alamos spheromak (CTX) has been equipped with a large number of Rogowski loops measuring the current in the individual segments of the MFC, providing a complete picture of the surface current pattern induced by the equilibrium and oscillations of the confined plasma. An analysis was made of the data from these Rogowski loops

  15. Steady-state operation of spheromaks by inductive techniques

    International Nuclear Information System (INIS)

    Janos, A.

    1984-04-01

    A method to maintain a steady-state spheromak configuration inductively using the S-1 Spheromak device is described. The S-1 Spheromak formation apparatus can be utilized to inject magnetic helicity continuously (C.W., not pulsed or D.C.) into the spheromak configuration after equilibrium is achieved in the linked mode of operation. Oscillation of both poloidal- and toroidal-field currents in the flux core (psi-phi Pumping), with proper phasing, injects a net time-averaged helicity into the plasma. Steady-state maintenance relies on flux conversion, which has been earlier identified. Relevant experimental data from the operation of S-1 are described. Helicity flow has been measured and the proposed injection scheme simulated. In a reasonable time practical voltages and frequencies can inject an amount of helicity comparable to that in the initial plasma. Plasma currents can be maintained or increased. This pumping technique is similar to F-THETA Pumping of a Reversed-Field-Pinch but is applied to this inverse-pinch formation

  16. Pressure effect on equilibrium configuration of CTCC-2 spheromak

    International Nuclear Information System (INIS)

    Nishikawa, M.; Kato, Y.; Satomi, N.; Watanabe, K.

    1990-01-01

    In CTCC-2 experiment, the initial plasma is produced by a magnetized gun and ejected into a metallic aluminum flux conserver (FC) with thickness of 15 mm. The spheromak is formed in the FC during a life time of 1.5 ms, in which the plasma is isolated from any external feeder. A choking-field-generating coil is equipped on the entrance of the spheroidal FC. The choking field is suppressing some leakage of spheromak field along the entrance duct, which is made of thin stainless steel plate (0.8 mm) for rapid penetration of the choking magnetic field. This resistive part acts as an effective plasma current limiter, which produces stable currentless region (flux hole). The flux hole increases magnetic shear without inserting a central conducting pole along the symmetric axis and is controlled to decrease with the choking field strength. Thus, in CTCC-2 spheromak, a stable oblate spheroidal boundary is rigidly fixed by the metal wall of FC and the entrance hole of FC is effectively closed by choking magnetic field, so that it is suitable to investigate precisely a fine structure of configuration. In spheromak configuration whose aspect ratio is near one, the ratio of the magnetic strength at the inner part to that at the outer part on equi-flux surface (mirror ratio) becomes very large in comparison with that of a large aspect ratio. This extreme configuration with a high mirror ratio may be associated with an anisotropic pressure effect even in collisional state like as our experimental condition. They have investigated the pressure effect on spheromak configuration in more detail. The obtained equilibrium profile is grossly explained by a theoretical profile on assuming low beta limit until now. However, the authors observe a systematic discrepancy between a measured poloidal profile and a theoretical one as mentioned

  17. Ion temperature measurements in the Maryland Spheromak

    International Nuclear Information System (INIS)

    Gauvreau, J.L.

    1992-01-01

    Initial spectroscopic data from MS showed evidence of ion heating as deduced from the line widths of different ion species. Detailed measurements of OIV spectral emission line profiles in space and time revealed that heating takes place at early time, before spheromak formation and is occurring within the current discharge. The measured ion temperature is several times the electron temperature and cannot be explained by classical (Spitzer) resistivity. Classically, ions are expected to have lower temperatures than the electrons and therefore, lower temperatures than observed. High ion temperatures have been observed in different RFP's and Spheromaks but are usually associated with relaxation to the Taylor state and occur in the sustainment phase. During formation, the current delivered to start the discharge is not axisymmetric and as a consequence, X-points appear in the magnetic flux. A two dimensional analysis predicts that magnetic reconnection occurring at an X-point can give rise to high ion heating rates. A simple 0-dimensional calculation showed that within the first 20 μs, a conversion of mass flow kinetic energy into ion temperature could take place due to viscosity

  18. Spheromak Impedance and Current Amplification

    International Nuclear Information System (INIS)

    Fowler, T K; Hua, D D; Stallard, B W

    2002-01-01

    It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, τ REC , which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI TOR 2 /dt ∼ I 2 /τ REC - I TOR 2 /τ closed where I is the gun current, I TOR is the spheromak toroidal current and τ CLOSED is the ohmic decay time of the spheromak. Achieving high current amplification, I TOR >> I, requires τ REC CLOSED . For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that τ REC actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B ∝ I, or I TOR ∼ I. Program implications are discussed

  19. On the jets, kinks, and spheromaks formed by a planar magnetized coaxial gun

    International Nuclear Information System (INIS)

    Hsu, S.C.; Bellan, P.M.

    2005-01-01

    Measurements of the various plasma configurations produced by a planar magnetized coaxial gun provide insight into the magnetic topology evolution resulting from magnetic helicity injection. Important features of the experiments are a very simple coaxial gun design so that all observed geometrical complexity is due to the intrinsic physical dynamics rather than the source shape and use of a fast multiple-frame digital camera which provides direct imaging of topologically complex shapes and dynamics. Three key experimental findings were obtained: (1) formation of an axial collimated jet [Hsu and Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002)] that is consistent with a magnetohydrodynamic description of astrophysical jets (2) identification of the kink instability when this jet satisfies the Kruskal-Shafranov limit, and (3) the nonlinear properties of the kink instability providing a conversion of toroidal to poloidal flux as required for spheromak formation by a coaxial magnetized source [Hsu and Bellan, Phys. Rev. Lett. 90, 215002 (2003)]. An interpretation is proposed for how the n=1 central column instability provides flux amplification during spheromak formation and sustainment, and it is shown that jet collimation can occur within one rotation of the background poloidal field

  20. Relaxation phenomena in the high temperature S-1 spheromak

    International Nuclear Information System (INIS)

    Ono, Y.; Ellis, R.A. Jr.; Janos, A.C.; Levinton, F.M.; Mayo, R.M.; Motley, R.W.; Ueda, Y.; Yamada, M.

    1988-06-01

    Operation of the S-1 device in a high current density (j/n/sub e/ ≥ 2 /times/ 10 -14 A/center dot/m) regime has created high electron temperature spheromaks (50eV ≤ T/sub e/ ≤ 130eV). The mechanisms and causes of the periodic relaxation events often observed in these hotter spheromak plasmas were made clear. Also, a relationship between the MHD relaxation cycle and confinement characteristics was revealed for the first time. Resistive loss at the outer edge of the plasma causes a departure from the initial force-free minimum-energy Taylor state to a MHD profile unstable to low-n ideal MHD modes; a relaxation event then returns the configuration to nearly a Taylor state. 11 refs., 5 figs

  1. Prospects for spheromak fusion reactors

    International Nuclear Information System (INIS)

    Fowler, T.K.; Hua, D.D.

    1995-01-01

    The reactor study of Hagenson and Krakowski demonstrated the attractiveness of the spheromak as a compact fusion reactor, based on physics principles confirmed in CTX experiments in many respects. Most uncertain was the energy confinement time and the role of magnetic turbulence inherent in the concept. In this paper, a one-dimensional model of heat confinement, calibrated by CTX, predicts negligible heat loss by magnetic turbulence at reactor scale

  2. High aspect ratio spheromak experiments

    International Nuclear Information System (INIS)

    Robertson, S.; Schmid, P.

    1987-05-01

    The Reversatron RFP (R/a = 50cm/8cm) has been operated as an ohmically heated spheromak of high aspect ratio. We find that the dynamo can drive the toroidal field upward at rates as high as 10 6 G/sec. Discharges can be initiated and ramped upward from seed fields as low as 50 G. Small toroidal bias fields of either polarity (-0.2 < F < 0.2) do not significantly affect operation. 5 refs., 3 figs

  3. MHD stability analysis of axisymmetric surface current model tokamaks close to the spheromak regime

    International Nuclear Information System (INIS)

    Honma, Toshihisa; Kaji, Ikuo; Fukai, Ichiro; Kito, Masafumi.

    1984-01-01

    In the toroidal coordinates, a stability analysis is presented for very low-aspect-ratio tokamaks with circular cross section which is described by a surface current model (SCM) of axisymmetric equilibria. The energy principle determining the stability of plasma is treated without any expansion of aspect ratio. Numerical results show that, owing to the occurrence of the non-axisymmetric (n=1) unstable modes, there exists no MHD-stable ideal SCM spheromak characterized by zero external toroidal vacuum field. Instead, a stable spheromak-type plasma which comes to the ideal SCM spheromak is provided by the configuration with a very weak external toroidal field. Close to the spheromak regime (1.0 1 aspect ratio< = 1.1), the minimum safety factor and the critical β-values increase mo notonically with aspect ratio decreasing from a large value, and curves of βsub(p) versus β in the marginal stability approach to an ideal SCM spheromak line βsub(p)=β. (author)

  4. Plasma chemistry for concept of sustainable development

    International Nuclear Information System (INIS)

    Chernyak, V.Yu.; Nedybaliuk, O.A.; Tsymbaliuk, O.M.; Fedirchuk, I.I.; Chunikhina, K.I.; Martysh, E.V.; Iukhimenko, V.V.; Veremii, Iu.P.; Prisyazhnevych, I.V.; Prysiazhna, O.V.

    2016-01-01

    This work is devoted to the exploration of the compatibility of the hybrid plasma-catalytic conversion of liquid hydrocarbons into syngas with the concept of sustainable development. The results of the experimental investigations indicate the high efficiency of plasma-catalytic conversion of ethanol to syngas and the small amount of waste (a few percent of feedstock weight). The results of the simulation of the kinetics using ZDPlasKin code for traditional thermochemical and hybrid plasma-catalytic conversions indicate some differences in their mechanisms, which lead to the significant changes in the syngas ratio.

  5. Properties of spheromaks generated by a magnetized coaxial source

    International Nuclear Information System (INIS)

    Hoida, H.W.; Henins, I.; Jarboe, T.R.; Linford, R.K.; Lipson, J.; Marshall, J.; Platts, D.A.; Sherwood, A.R.; Tuszewski, M.

    1981-01-01

    In gun-generated spheromaks impurity contamination plays an important role in determining the energy loss. Metallic impurities can be reduced by an appropriate change of source parameters. The reduction of the level of metal impurities results in a spectrum showing a preponderance of oxygen and carbon lines and OIV radiation is observed to increase indicating a warmer plasma. However, the plasma lifetime is not changed. Discharge cleaning techniques appear to be necessary. It is still possible that electron heat conduction during the reconnection processs will be found to be important once the impurities are reduced

  6. Properties of spheromaks generated by a magnetized coaxial source

    Energy Technology Data Exchange (ETDEWEB)

    Hoida, H.W.; Henins, I.; Jarboe, T.R.; Linford, R.K.; Lipson, J.; Marshall, J.; Platts, D.A.; Sherwood, A.R.; Tuszewski, M.

    1981-01-01

    In gun-generated spheromaks impurity contamination plays an important role in determining the energy loss. Metallic impurities can be reduced by an appropriate change of source parameters. The reduction of the level of metal impurities results in a spectrum showing a preponderance of oxygen and carbon lines and OIV radiation is observed to increase indicating a warmer plasma. However, the plasma lifetime is not changed. Discharge cleaning techniques appear to be necessary. It is still possible that electron heat conduction during the reconnection processs will be found to be important once the impurities are reduced.

  7. Formation of a field-reversed configuration by coalescence of spheromaks

    International Nuclear Information System (INIS)

    Dasgupta, B.; Sato, Tetsuya; Hayashi, Takaya; Watanabe, Kunihiko; Watanabe, Tomohiko

    1995-01-01

    We present a numerical simulation of the slow formation of FRC by the merging of two spheromaks with opposite toroidal fluxes. A rather important feature of such a method of formation of FRC should be made explicit. A spheromak is basically a Taylor minimum energy state. On the other hand the FRC with its single component poloidal magnetic field and high plasma beta is decidedly far away from a Taylor state. So a numerical simulation of this process, besides demonstrating the feasibility of such FRC formation, is expected to show the traits in the process of transition from a Taylor state to a non-Taylor state. 5 refs., 2 figs., 1 tab

  8. Spheromak tilting and its stability control

    International Nuclear Information System (INIS)

    Hayashi, T.; Sato, T.

    1983-01-01

    Spheromak tilting instability was studied. A numerical technique to create a rather arbitrarily-shaped spheromak like the one with a flux hole was investigated. The dynamics governing the tilting instability, namely, the influence of the magnetic index, the toroidal current (q-profile) and the resistivity upon the tilting growth rate, and the roles of magnetc reconnection upon the nonlinear development were studied. The best way to control the tilting instability was invented. The stabilizing effects of the vertical wall, the isolated conducting cylindrical belt, and the horizontal wall were studied. Central pole stabilization was also investigated. The influence of the wall condition, namely, whether the wall acted as a flux conserver in the spheromak creation stage or not is discussed. The present study has shown that the three- dimensional simulation is indeed useful and practical in not only studying the underlying physics but also finding a stabilization technique of spheromaks. (Kato, T.)

  9. The University of Maryland spheromak fusion experiment: Final report

    International Nuclear Information System (INIS)

    Antoniades, J.A.; Chin-Fatt, C.; DeSilva, A.W.; Goldenbaum, G.C.; Hess, R.A.; Shaw, R.S.

    1986-01-01

    The spheromak is a magnetic plasma confinement configuration that features a simple magnetic structure free of coils that link the plasma torus. It offers the possibility of a simple and efficient confinement system for a fusion plasma. Design of the experimental apparatus occupied the first 15 months of the contract period. At the same time, computer studies of the formation of the spheromak plasma, using a two-dimensional MHD code were performed. After the first 12 months of the contract period, subcontracts were let for major components of the system, particularly for the liquid nitrogen cooled bias magnetic coils, the associated power supplies, and the capacitors for the reversal bank. When the design work was complete, the machining contract for the vacuum vessel was placed. At about this time, work on the operating system for the control computer was begun. The necessary hardware items for the data acquisition computer were decided upon and ordered at the end of the second year. The capacitor bank for the Z-directed current (I/sub z/ bank) was rebuilt from existing parts here, and construction of this bank and of the parts for the reversal bank was accomplished while the outside fabrication of other major parts was in progress. Switching hardware for the two capacitor banks was fabricated in house to reduce costs. As capacitors for the reversal bank were delivered, they were incorporated into the bank modules. A full description of the MS experimental hardware is described in this paper. 2 refs., 9 figs., 1 tab

  10. Recent results from the Los Alamos CTX spheromak

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, C.W.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; Knox, S.O.; Linford, R.K.; Platts, D.A.; Sherwood, A.R.

    1982-01-01

    Continued discharge cleaning, improved vacuum practices, and optimized plasma formation operation have resulted in the Los Alamos CTX spheromak experiment achieving 1 millisecond plasma lifetimes with average temperatures of 20 to 40 eV. Impurity radiation power loss has been reduced significantly and the plasma behavior appears to be dominated by pressure-driven instabilities causing increased particle loss. The major advance in operation has been the use of a constant, uniform background of 5 to 20 mTorr of H/sub 2/ filling the vacuum tank, flux conserver, and plasma source. This fill operation directly reduces the impurities generated in the plasma source, allows operation of the source at parameters resulting in fewer impurities, and provides a neutral source to maintain the density for long lifetimes. In this paper we present data on the improved operation of CTX, and present evidence for its ..beta..-limited operation.

  11. Recent results from the Los Alamos CTX spheromak

    International Nuclear Information System (INIS)

    Barnes, C.W.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; Knox, S.O.; Linford, R.K.; Platts, D.A.; Sherwood, A.R.

    1982-01-01

    Continued discharge cleaning, improved vacuum practices, and optimized plasma formation operation have resulted in the Los Alamos CTX spheromak experiment achieving 1 millisecond plasma lifetimes with average temperatures of 20 to 40 eV. Impurity radiation power loss has been reduced significantly and the plasma behavior appears to be dominated by pressure-driven instabilities causing increased particle loss. The major advance in operation has been the use of a constant, uniform background of 5 to 20 mTorr of H 2 filling the vacuum tank, flux conserver, and plasma source. This fill operation directly reduces the impurities generated in the plasma source, allows operation of the source at parameters resulting in fewer impurities, and provides a neutral source to maintain the density for long lifetimes. In this paper we present data on the improved operation of CTX, and present evidence for its β-limited operation

  12. Control of the Helicity Content of a Gun-Generated Spheromak by Incorporating a Conducting Shell into a Magnetized Coaxial Plasma Gun

    Science.gov (United States)

    Matsumoto, Tadafumi; Sekiguchi, Jun'ichi; Asai, Tomohiko

    In the formation of magnetized plasmoid by a magnetized coaxial plasma gun (MCPG), the magnetic helicity content of the generated plasmoid is one of the critical parameters. Typically, the bias coil to generate a poloidal flux is mounted either on the outer electrode or inside the inner electrode. However, most of the flux generated in the conventional method spreads even radially outside of the formation region. Thus, only a fraction of the total magnetic flux is actually exploited for helicity generation in the plasmoid. In the proposed system, the plasma gun incorporates a copper shell mounted on the outer electrode. By changing the rise time of the discharge bias coil current and the geometrical structure of the shell, the magnetic field structure and its time evolution can be controlled. The effect of the copper shell has been numerically simulated for the actual gun structure, and experimentally confirmed. This may increase the magnetic helicity content results, through increased poloidal magnetic field.

  13. Current driven instabilities of the kinetic shear Alfven wave: application to reversed field pinches and spheromaks

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Perkins, F.W.

    1984-04-01

    The kinetic Alfven wave is studied in a cylindrical force-free plasma with self-consistent magnetic fields. This equilibrium represents a reversed field pinch or a spheromak. The stability of the wave is found to depend on the ratio of the electron drift velocity to the Alfven velocity. This ratio varies inversely with the square root of the plasma line density. The critical line density using the Spitzer-Harm electron distribution function is found for reversed field pinches with deuterium plasmas to be approximately 2 x 10 18 m -1 and is 5 x 10 17 m -1 in spheromaks with hydrogen plasmas. The critical line density is in reasonable agreement with experimental data for reversed field pinches

  14. Field-Reversed Configuration Formation Scheme Utilizing a Spheromak and Solenoid Induction

    International Nuclear Information System (INIS)

    Gerhardt, S.P.; Belova, E.V.; Yamada, M.; Ji, H.; Ren, Y.; McGeehan, B.; Inomoto, M.

    2008-01-01

    A new field-reversed configuration (FRC) formation technique is described, where a spheromak transitions to a FRC with inductive current drive. The transition is accomplished only in argon and krypton plasmas, where low-n kink modes are suppressed; spheromaks with a lighter majority species, such as neon and helium, either display a terminal tilt-mode, or an n=2 kink instability, both resulting in discharge termination. The stability of argon and krypton plasmas through the transition is attributed to the rapid magnetic diffusion of the currents that drive the kink-instability. The decay of helicity during the transition is consistent with that expected from resistivity. This observation indicates a new scheme to form a FRC plasma, provided stability to low-n modes is maintained, as well as a unique situation where the FRC is a preferred state

  15. 0-D study of the compression of low temperature spheromaks

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Hulse, R.A.; Zweibel, E.G.

    1985-09-01

    Compression of low temperature spheromak plasmas has been studied with the aid of a O-D two-fluid computer code. It is found that in a plasma which is radiation dominated, the electron temperature can be increased by up to a factor of seven for a compression of a factor of two, provided the temperature is above some critical value (approx.25eV) and the electron density particle confinement time product n/sub e/tau/sub p/ greater than or equal to 1 x 10 9 s/cm 3 . If the energy balance is dominated by particle confinement losses rather than radiation losses, the effect of compression is to raise the temperature as T/sub e/ approx.C/sup 6/5/, for constant tau/sub p/

  16. Confinement and power balance in the S-1 spheromak

    Energy Technology Data Exchange (ETDEWEB)

    Levinton, F.M.; Meyerhofer, D.D.; Mayo, R.M.; Janos, A.C.; Ono, Y.; Ueda, Y.; Yamada, M.

    1989-07-01

    The confinement and scaling features of the S-1 spheromak have been investigated using magnetic, spectroscopic, and Thomson scattering data in conjunction with numerical modeling. Results from the multipoint Thomson scattering diagnostic shows that the central beta remains constant (/beta//sub to/ /approximately/ 5%) as the plasma current density increases from 0.68--2.1 MA/m/sup 2/. The density is observed to increase slowly over this range, while the central electron temperature increases much more rapidly. Analysis of the global plasma parameters shows a decrease in the volume average beta and energy confinement as the total current is increased. The power balance has been modeled numerically with a 0-D non-equilibrium time-dependent coronal model and is consistent with the experimental observations. 20 refs., 12 figs., 2 tabs.

  17. Confinement and power balance in the S-1 spheromak

    International Nuclear Information System (INIS)

    Levinton, F.M.; Meyerhofer, D.D.; Mayo, R.M.; Janos, A.C.; Ono, Y.; Ueda, Y.; Yamada, M.; Rochester Univ., NY; Los Alamos National Lab., NM; Princeton Univ., NJ

    1989-07-01

    The confinement and scaling features of the S-1 spheromak have been investigated using magnetic, spectroscopic, and Thomson scattering data in conjunction with numerical modeling. Results from the multipoint Thomson scattering diagnostic shows that the central beta remains constant (β to ∼ 5%) as the plasma current density increases from 0.68--2.1 MA/m 2 . The density is observed to increase slowly over this range, while the central electron temperature increases much more rapidly. Analysis of the global plasma parameters shows a decrease in the volume average beta and energy confinement as the total current is increased. The power balance has been modeled numerically with a 0-D non-equilibrium time-dependent coronal model and is consistent with the experimental observations. 20 refs., 12 figs., 2 tabs

  18. Instantaneous current and field structure of a gun-driven spheromak for two gun polarities

    International Nuclear Information System (INIS)

    Woodruff, S; Nagata, M

    2002-01-01

    The instantaneous plasma structure of the SPHEX spheromak is determined here by numerically processing data from insertable Rogowski and magnetic field probes. Data is presented and compared for two modes of gun operation: with the central electrode biased positively and negatively. It is found that while the mean-, or even instantaneous-, field structure would give the impression of a roughly axisymmetric spheromak, the instantaneous current structure does not. Hundred per cent variations in J measured at the magnetic axis can be explained by the rotation of a current filament that has a width equal to half of the radius of the flux-conserving first wall. In positive gun operation, current leaves the filament in the confinement region leading to high wall current there. In negative gun operation, wall current remains low as all injected current returns to the gun through the plasma. The plasma, in either instance, is strongly asymmetric. We discuss evidence for the existence of the current filament in other gun-driven spheromaks and coaxial plasma thrusters

  19. Experiments of spheromak and reversed field configuration in 2m theta pinch

    International Nuclear Information System (INIS)

    Nogi, Y.; Shimamura, S.; Ogura, H.; Osanai, Y.; Saito, K.; Shiina, S.; Yoshimura, H.

    1981-01-01

    Since the z-current produces the paramagnetic field near the electrodes, the spheromak formation is more difficult in the straight bias field. In order to help the reconnection at the coil ends, the cusp bias coils are added to both ends of the straight coil. Then the spheromak configuration is formed and the plasma is confined for 5 to 10 μs. On the other hand, the RFC continues for about 30 μs in case of the straight bias field. The confinement time is limited by the rotational instability. Although the start time of the instability is not clear, the elongation of the plasma is detected in 15 to 20 μs after the RFC is formed. The period of the rotation is slightly different every shot. Detailed study of the instability is being pursued

  20. Axisymmetric force-free states and relaxation of a spheroidal spheromak

    International Nuclear Information System (INIS)

    Throumoulopoulos, G.N.; Pantis, G.

    1990-01-01

    Axisymmetric force-free equilibrium eigenstates for a prolate as well as an oblate spheroidal Spheromak with arbitrary elongation are obtained. In the framework of the Woltjer-Taylor relaxation theory the relaxed states are also identified. A simple hypothesis for the relaxation process is introduced, which implies that the plasma relaxes from multitoroidal formations to a singly toroidal configuration, in qualitative agreement with experimental results. (author)

  1. Axisymmetric force-free states and relaxation of a spheroidal spheromak

    International Nuclear Information System (INIS)

    Throumoulopoulos, G.N.; Pantis, G.

    1990-01-01

    Axisymmetric force-free equilibrium eigenstates for a prolate as well as an oblate spheroidal spheromak with arbitrary elongation are obtained. In the framework of the Woltjer-Taylor relaxation theory the relaxed states are also identified. A simple hypothesis for the relaxation process is introduced which implies that the plasma relaxes from multitoroidal formations to a singly toroidal configuration in qualitative agreement with experimental results. (Author)

  2. Verification of the Taylor (minimum energy) state in the S-1 Spheromak

    International Nuclear Information System (INIS)

    Hart, G.W.; Janos, A.; Meyerhofer, D.D.; Yamada, M.

    1985-09-01

    Experimental measurements of the equilibrium in the S-1 Spheromak by use of magnetic probes inside the plasma show that the final magnetic equilibrium is one which has relaxed close to the Taylor (minimum-energy) state, even though the plasma is far from that state during formation. The comparison is made by calculating the two-dimensional μ profile of the plasma from the probe data, where μ is defined as μ 0 j/sub parallel//B. Measurements using a triple Langmuir probe provide evidence to support the conclusion that the pressure gradients in the relaxed state are confined to the edge region of the plasma

  3. Selective decay in a helicity-injected spheromak

    International Nuclear Information System (INIS)

    MartInez, P L Garcia; Farengo, R

    2009-01-01

    The non-linear evolution of several unstable equilibria, representative of helicity-injected spheromak configurations inside a cylindrical flux conserver, is studied by means of three dimensional resistive MHD simulations. These equilibria are force-free (∇ x B = λ(ψ)B) but do not correspond to minimum energy states, having linear λ(ψ) profiles with negative slope. Several aspects of this process are studied (magnetic energy relaxation, selective helicity decay, relaxed profiles) for different initial A slopes. The stability threshold predicted by linear theory is recovered. The results show that complete plasma relaxation leading to a uniform A, is achieved only if the initial profile is hollow enough. The evolution for cases just above the stability threshold is more gentle and does not end in a Taylor state. The final state in these cases has a linear λ(ψ) profile, as the initial condition, but with a smaller slope.

  4. Experimental Identification of the Kink Instability as a Poloidal Flux Amplification Mechanism for Coaxial Gun Spheromak Formation

    OpenAIRE

    Hsu, S. C.; Bellan, P. M.

    2003-01-01

    The magnetohydrodynamic kink instability is observed and identified experimentally as a poloidal flux amplification mechanism for coaxial gun spheromak formation. Plasmas in this experiment fall into three distinct regimes which depend on the peak gun current to magnetic flux ratio, with (I) low values resulting in a straight plasma column with helical magnetic field, (II) intermediate values leading to kinking of the column axis, and (III) high values leading immediately to a detached plasma...

  5. Increased particle confinement with the use of external dc bias field in the CTX spheromak

    International Nuclear Information System (INIS)

    Barnes, C.W.; Hoida, H.W.; Henins, I.; Fernandez, J.C.; Jarboe, T.R.; Marklin, G.J.

    1985-01-01

    Spheromaks are formed in a mesh flux conserver in the presence of an external dc bias field. The spheromaks remain stable to tilt instabilities with ratios of bias-to-spheromak flux of up to 47 +- 7%. Normally applied bias flux puts the spheromak separatrix inside the metal mesh and improves the particle confinement

  6. Current-driven instabilities of the kinetic shear Alfven wave: Application to reversed field pinches and spheromaks

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Perkins, F.W.

    1984-01-01

    The kinetic Alfven wave is studied in a cylindrical force-free plasma with self-consistent magnetic fields. This equilibrium represents a reversed field pinch or a spheromak. The stability of the wave is found to depend on the ratio of the electron drift velocity to the Alfven velocity. This ratio varies inversely with the square root of the plasma line density. The critical line density using the Spitzer--Harm electron distribution function is found for reversed field pinches with deuterium plasmas to be approximately 2 x 10 18 and is 5 x 10 17 m -1 in spheromaks with hydrogen plasmas. The critical line density is in reasonable agreement with experimental data for reversed field pinches

  7. Generation conditions of CW Diode Laser Sustained Plasma

    Science.gov (United States)

    Nishimoto, Koji; Matsui, Makoto; Ono, Takahiro

    2016-09-01

    Laser sustained plasma was generated using 1 kW class continuous wave diode laser. The laser beam was focused on the seed plasma generated by arc discharge in 1 MPa xenon lamp. The diode laser has advantages of high energy conversion efficiency of 80%, ease of maintenance, compact size and availability of conventional quartz based optics. Therefore, it has a prospect of further development compared with conventional CO2 laser. In this study, variation of the plasma shape caused by laser power is observed and also temperature distribution in the direction of plasma radius is measured by optical emission spectroscopy.

  8. Tilt and shift mode stability in a spheromak with a flux core

    Energy Technology Data Exchange (ETDEWEB)

    Finn, J.M.; Jardin, S.C.

    1984-07-01

    The stability of spheromak equilibria with a flux core, or reversal coil, is studied by means of an ideal MHD code. Results depend critically upon whether the flux hole region (the current free area just inside the separatrix) is treated as perfectly conducting plasma or as vacuum. This indicates that the tilt and shift modes persist as resistive instabilities if they are stable in ideal MHD. Specifically, for nonoptimally shaped equilibria, the flux core must nearly touch the current channel if the flux hole is vacuum, whereas the core may be slightly outside the separatrix if the flux hole has conducting plasma. A larger margin exists for optimally shaped equilibria.

  9. Heat loss by helicity injection in spheromaks

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1994-01-01

    A model is presented for spheromak buildup and decay including thermal diffusivity associated with magnetic turbulence during helicity injection. It is shown that heat loss by magnetic turbulence scales more favorably than gyroBohm transport. Thus gyroBohm scaling for the proposed ignition experiment would be the conservative choice, though present experiments may be dominated by magnetic turbulence. Because of a change in boundary conditions when the gun is turned off, the model may account for the observed increase in electron temperature in CTX after turnoff

  10. Experimental identification of the kink instability as a poloidal flux amplification mechanism for coaxial gun spheromak formation.

    Science.gov (United States)

    Hsu, S C; Bellan, P M

    2003-05-30

    The magnetohydrodynamic kink instability is observed and identified experimentally as a poloidal flux amplification mechanism for coaxial gun spheromak formation. Plasmas in this experiment fall into three distinct regimes which depend on the peak gun current to magnetic flux ratio, with (I) low values resulting in a straight plasma column with helical magnetic field, (II) intermediate values leading to kinking of the column axis, and (III) high values leading immediately to a detached plasma. Onset of column kinking agrees quantitatively with the Kruskal-Shafranov limit, and the kink acts as a dynamo which converts toroidal to poloidal flux. Regime II clearly leads to both poloidal flux amplification and the development of a spheromak configuration.

  11. Experimental identification of the kink instability as a poloidal flux amplification mechanism for coaxial gun spheromak formation

    International Nuclear Information System (INIS)

    Hsu, S.C.; Bellan, P.M.

    2003-01-01

    The magnetohydrodynamic kink instability is observed and identified experimentally as a poloidal flux amplification mechanism for coaxial gun spheromak formation. Plasmas in this experiment fall into three distinct regimes which depend on the peak gun current to magnetic flux ratio, with (I) low values resulting in a straight plasma column with helical magnetic field, (II) intermediate values leading to kinking of the column axis, and (III) high values leading immediately to a detached plasma. Onset of column kinking agrees quantitatively with the Kruskal-Shafranov limit, and the kink acts as a dynamo which converts toroidal to poloidal flux. Regime II clearly leads to both poloidal flux amplification and the development of a spheromak configuration

  12. Amplification of S-1 Spheromak current by an inductive current transformer

    International Nuclear Information System (INIS)

    Jardin, S.C.; Janos, A.; Yamada, M.

    1985-11-01

    We attempt to predict the consequences of adding an inductive current transformer (OH Transformer) to the present S-1 Spheromak experiment. Axisymmetric modeling with only classical dissipation shows an increase of toroidal current and a shrinking and hollowing of the current channel, conserving toroidal flux. These unstable profiles will undergo helical reconnection, conserving helicity K = ∫ A-vector x B-vector d tau while increasing the toroidal flux and decreasing the poloidal flux so that the plasma relaxes toward the Taylor state. This flux rearrangement is modeled by a new current viscosity term in the mean-field Ohm's law which conserves helicity and dissipates energy

  13. Relaxation and particle diffusion in the Proto S-1/C spheromak

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.

    1987-01-01

    The relationship between relaxation and particle diffusion in the Proto S-1C spheromak has been studied. The plasma was formed in a magnetic configuration which was not the minimum-energy Taylor state, and went through a period of relaxation before its magnetic configuration was that of the Taylor state. Early in the relaxation phase, the internal and external magnetic fluctuations were correlated and it was found that, at the time of peak amplitude, they had a radial structure of a tearing mode. After the reconnection of these modes, the plasma continued to evolve towards the Taylor state with only small magnetic fluctuations at the center of plasma. The local particle diffusion coefficient was measured in these Proto S-1C discharges, the technique used was to inject a delta-function source of impurities into the plasma and observe the motion of the impurities relative to the flux surface. It was found that, during the decay phase of the spheromak discharge, when the plasma was in a Taylor state, the carbon diffusion coefficient was explained classically. While the plasma was relaxing towards the Taylor state, the diffusion coefficient was 2 ∼ 4a times larger than classical. At this time, the plasma was not yet force-free. This nonclassical diffusion appears to have been caused by v/sub ExB/ velocities due to correlations between the fluctuating electric field and density. Because the v/sub ExB/ velocity acts on all of the plasma species similarly, the anomalous hydrogen-particle diffusion coefficient should have been as large as that of carbon

  14. Plasma heating and hot ion sustaining in mirror based hybrids

    International Nuclear Information System (INIS)

    Moiseenko, V. E.; Ågren, O.

    2012-01-01

    Possibilities of plasma heating and sloshing ion sustaining in mirror based hybrids are briefly reviewed. Sloshing ions, i.e. energetic ions with a velocity distribution concentrated to a certain pitch-angle, play an important role in plasma confinement and generation of fusion neutrons in mirror machines. Neutral beam injection (NBI) is first discussed as a method to generate sloshing ions. Numerical results of NBI modeling for a stellarator-mirror hybrid are analyzed. The sloshing ions could alternatively be sustained by RF heating. Fast wave heating schemes, i.e. magnetic beach, minority and second harmonic heating, are addressed and their similarities and differences are described. Characteristic features of wave propagation in mirror hybrid devices including both fundamental harmonic minority and second harmonic heating are examined. Minority heating is efficient for a wide range of minority concentration and plasma densities; it allows one to place the antenna aside from the hot ion location. A simple-design strap antenna suitable for this has good performance. However, this scenario is appropriate only for light minority ions. The second harmonic heating can be applied for the heavy ion component. Arrangements are similar for minority and second harmonic heating. The efficiency of second harmonic heating is influenced by a weaker wave damping than for minority heating. Numerical calculations show that in a hybrid reactor scaled mirror machine the deuterium sloshing ions could be heated within the minority heating scheme, while the tritium ions could be sustained by second harmonic heating.

  15. Local drift parameter, j/n/sub e/ and resistivity anomaly measurements in CTX spheromaks

    International Nuclear Information System (INIS)

    Hoida, H.W.; Barnes, C.W.; Henins, I.; Jarboe, T.R.; Marklin, G.; Buchenauer, C.J.; Knox, S.O.

    1985-01-01

    In a spheromak, the magnetic fields confining the plasma are generated primarily by internal currents rather than external coils. In order to provide information on the possible existence of current-driven microinstabilities, localized measurements of the ratio of the drift velocity of the electrons generating the internal current to their thermal velocity, V/sub d//V/sub th/ proportional to j/n/sub e/√T/sub e/ (known as the drift or streaming parameter), and j/n/sub e/ (proportional to V/sub d/) are needed. These microinstabilities are in some theories associated with an increase in the resistivity anomaly factor (eta/eta/sub Spitzer/). We present results on local measurements (at the magnetic axis) of the values of V/sub d//V/sub th/ and eta/eta/sub Spitzer/ by combining data from the spatially-resolved diagnostics employed on the CTX spheromak experiment, coupled with current density profile information from equilibrium measurements. The values of V/sub d//V/sub th/ and j/n/sub e/ appear to be correlated with local variations in eta/eta/sub Spitzer/, and can be changed by varying the plasma density. Data sets are presented for three values of n/sub e/

  16. Resistive stability of the cylindrical spheromak

    International Nuclear Information System (INIS)

    DeLucia, J.; Jardin, S.C.; Glasser, A.H.

    1983-11-01

    The growth rates for resistive instabilities in a straight circular cylinder with spheromak profiles are computed by using two complementary methods. The first method employs boundary layer analysis and asymptotic matching, most valid for values of the magnetic Reynolds number S greater than or equal to 10 5 . The second method solved the full linearized resistive MHD equations as an initial value problem, utilizing zone packing around the mode rational surface. Resolution requirements limit this to S less than or equal to 10 7 . The results from these two methods agree to better than 1 in 10 3 in the overlap region 10 7 greater than or equal to S greater than or equal to 10 5 . A scan of parameter space reveals that for parabolic q-profiles, the least unstable configurations have q 0 R/a approx. 0.67. The Hall term in Ohm's Law is easily incorporated into both methods. Recalculating the resistive MHD growth rates in the presence of this term shows that the resistive interchange mode is completely stabilized for a large enough value of the ion cyclotron time

  17. Conditions for sustaining low-pressure plasma columns by travelling electromagnetic UHF waves

    International Nuclear Information System (INIS)

    Benova, E.; Zhelyazkov, I.

    1997-01-01

    The paper considers the conditions for sustaining low-pressure plasma columns by travelling electromagnetic waves in symmetric and dipolar modes, respectively. The treatment is fully electrodynamic. It is shown that the wave energy flux along the plasma column determines the conditions for sustaining the discharge. In particular as the plasma is sustained by a symmetric wave whose flux depends mainly on the radial distribution of the wave electric field whilst for a dipolar wave sustained plasma the flux is specified by the magnitude of the axial wave field component at the plasma-dielectric interface. (orig.)

  18. The S-1 Spheromak Control System

    International Nuclear Information System (INIS)

    Mathe, P.; Mika, R.; Oliaro, G.

    1983-01-01

    The use of a CAMAC based DEC LSI-11/23 microcomputer to perform all control functions for the S-1 Spheromak is described. The system monitors and controls the three coil systems, Toroidal, Poloidal, and Equilibrium field coils and their associated power sources, the water cooling system, the personnel and machine safety system, the machine and diagnostic timing system and the control room display and operator interface. Future requirements include control of the vacuum system, the gas injection system and interface to the PPPL Data Acquisition System DEC10. The computer is connected to five remotely located CAMAC crates by a fiber-optic serial highway operating at five megahertz. These crates contain interface modules required to control the S-1 experiment. These modules include: D/A and A/D converters, fast transient digitizers, timing modules, temperature sensing modules, CRT alphanumeric display drivers, watchdog timers, and relay and TTL parallel I/O ports. The computer itself resides in crate number0 and consists of an LSI-11/23 with hardware floating post processor, memory management, 256K bytes of memory, four RS-232 serial ports and a 30 megabyte hard disk with a one megabyte floppy disk backup. The majority of software is written in FORTRAN with a few speed critical programs written in PDP-11 MACRO assembly language. The software simulates a sequential state machine which allows easily changeable logic since all logic is represented by standard Boolean Fortran statements. The RSX-11/m operating system allows multiple tasks to be active simultaneously. This provides computing time for operator interactions, editing of critical machine parameters, data analysis and transmission of data to other computers while still maintaining the scan activity which constantly monitors machine parameters

  19. Self-sustained oscillations in the divertor plasma

    International Nuclear Information System (INIS)

    Krasheninnikov, S.I.; Kukushkin, A.S.; Pistunovich, V.I.; Pozharov, V.A.

    1985-01-01

    A simple analytical model of the edge plasma with high recycling, which relays on the presence of a small parameter - the ratio of the particle flows crossing the magnetic field to those impinging onto the divertor target, is proposed. A concept of the one-dimensional steady state (OSS) is introduced as the zero approximation in the small parameter. The mean number density N-tilde of the particles - ions plus neutrals - in the magnetic flux tube is choosen as the most representative and convenient parameter of the problem. The OSS are shown to be ambiguous in some N-tilde range for sufficiently high values of the energy flow entering the scrape-off layer from the bulk plasma. An equation, that describes a quasi-steady variations in OSS, is derived and a mechanism of exciting the self-sustained oscillations is developed. Results of simulation of the edge plasma oscillations are found to be in a good agreement with this mechanism, which could be responsible for the H-mode oscillations observed in the divertor experiments

  20. Sustained high βN plasmas on EAST tokamak

    Science.gov (United States)

    Gao, Xiang; the EAST team

    2018-05-01

    Sustained high normalized beta (βN ∼ 1.9) plasmas with an ITER-like tungsten divertor have been achieved on EAST tokamak recently. The high power NBI heating system of 4.8 MW and the 4.6 GHz lower hybrid wave of 1 MW were developed and applied to produce edge and internal transport barriers in high βN discharges. The central flat q profile with q (ρ) ∼ 1 at ρ safety factor q95 = 4.7 is identified by the multi-channel far-infrared laser polarimeter and the EFIT code. The fraction of non-inductive current is about 40%. The relation between fishbone activity and ITB formation is observed and discussed.

  1. Theory of self-sustained turbulence in confined plasmas

    International Nuclear Information System (INIS)

    Itoh, K.; Itoh, S.-I.; Fukuyama, A.; Yagi, M.

    1996-01-01

    This article reviews some aspects of recent theoretical activities in Japan on the problem of turbulent transport in confined plasmas. The method of self-sustained turbulence is discussed. The process of the renormalization is shown and the turbulent Prandtl number is introduced. Nonlinear destabilization by the electron momentum diffusion is explained. The nonlinear eigenmode equation is derived for the dressed-test-mode for the inhomogeneous plasma in the shear magnetic field. The eigenvalue equation is solved, and the least stable mode determines the anomalous transport coefficient. The formula of the thermal conductivity is presented for the system of bad average magnetic curvature (current diffusive interchange mode (CDIM) turbulence) and that for the average good magnetic curvature (current diffusive ballooning mode (CDBM) turbulence). The transport coefficient, scale length of fluctuations and fluctuation level are shown to be an increasing function of the pressure gradient. Verification by use of the nonlinear simulation is shown. The bifurcation of the electric field and improved confinement are addressed, in order to explain the H-mode physics. The improved confinement and dynamics such as ELMs are explained. Application to the transport analysis of tokamaks is also presented, including explanations of the L-mode confinement, internal transport barrier, and the role of the current profile control

  2. HIFLUX: OBLATE FRCS, DOUBLE HELICES,SPHEROMAKS AND RFPS IN ONE SYSTEM

    International Nuclear Information System (INIS)

    SCHAFFER, M.J.; BOEDO, J.A.

    2003-01-01

    OAK-B135 High magnetic flux is required for thermonuclear FRC reactors and, more immediately, to advance the FRC experimental program in general. Oblate FRCs are of special interest because they are predicted to have certain improved MHD stability over elongated FRCs, and oblate FRCs may yield the most compact, magnetically confined fusion reactors. Neither oblate nor high-flux FRCs have been investigated experimentally to date. Our presently proposed technique is to make two high-flux, oppositely-handed plasmas by a pair of large, external, reversed-field pinch (RFP) sources. The plasmas would propagate as two Taylor-relaxed double-helix plasmas, to an oblate main plasma chamber, where they would relax further to a counter-helicity pair of spheromaks, which would finally merge into a single high-flux FRC. A concept for a new experimental facility, HIFLUX, to make and study high-magnetic-flux oblate Field-Reversed Configuration (FRC) plasmas, is described. Similar principles might also enable high flux non-inductive startup of other plasma devices

  3. Properties of plasma flames sustained by microwaves and burning hydrocarbon fuels

    International Nuclear Information System (INIS)

    Hong, Yong Cheol; Uhm, Han Sup

    2006-01-01

    Plasma flames made of atmospheric microwave plasma and a fuel-burning flame were presented and their properties were investigated experimentally. The plasma flame generator consists of a fuel injector and a plasma flame exit connected in series to a microwave plasma torch. The plasma flames are sustained by injecting hydrocarbon fuels into a microwave plasma torch in air discharge. The microwave plasma torch in the plasma flame system can burn a hydrocarbon fuel by high-temperature plasma and high atomic oxygen density, decomposing the hydrogen and carbon containing fuel. We present the visual observations of the sustained plasma flames and measure the gas temperature using a thermocouple device in terms of the gas-fuel mixture and flow rate. The plasma flame volume of the hydrocarbon fuel burners was more than approximately 30-50 times that of the torch plasma. While the temperature of the torch plasma flame was only 868 K at a measurement point, that of the diesel microwave plasma flame with the addition of 0.019 lpm diesel and 30 lpm oxygen increased drastically to about 2280 K. Preliminary experiments for methane plasma flame were also carried out, measuring the temperature profiles of flames along the radial and axial directions. Finally, we investigated the influence of the microwave plasma on combustion flame by observing and comparing OH molecular spectra for the methane plasma flame and methane flame only

  4. Theoretical investigation of field-line quality in a driven spheromak

    International Nuclear Information System (INIS)

    Cohen, R.H.; Cohen, B.I.; Berk, H.L.

    2003-01-01

    Theoretical studies aimed at predicting and diagnosing field-line quality in a spheromak are described. These include nonlinear 3-D MHD simulations, stability studies, analyses of confinement in spheromaks dominated by either open (stochastic) field lines or approximate flux surfaces, and a theory of fast electrons as a probe of field-line length. (author)

  5. Configuration of gun-generated spheromak in effectively closed metal flux conserver

    International Nuclear Information System (INIS)

    Kato, Yushi; Nishikawa, Masahiro; Honda, Yoshihide; Satomi, Norio; Watanabe, Kenji

    1988-01-01

    In the CTCC-II spheromak experiment, the gun-generated plasma is confined in a spheroidal aluminum flux conserver (FC) with a choking coil. This coil produces the additional magnetic field to close perfectly all magnetic surfaces into the FC, i.e. the entrance hole for plasma injection is enable to be closed by magnetic field. Hence the plasma is confined in the effectively closed metal FC. In this experiment the average life time is 1.2 msec, and electron density and temperature are n e = 2 x 10 13 /cc, T e = 30 eV, respectively. The configuration with a flux hole region in which the toroidal magnetic field vanishes around the geometrical axis has been observed in the FC. The radius of the flux hole depends on the condition how the external choking field is applied. The flux hole enhances the magnetic shear near the plasma surfaces and, therefore, has a stabilizing effect even without inserting the central conducting pole. (author)

  6. Effects of the current boundary conditions at the plasma-gun gap on density in SSPX

    Science.gov (United States)

    Kolesnikov, Roman; Lodestro, L. L.; Meyer, W. H.

    2012-10-01

    The Sustained Spheromak Physics Experiment (SSPX) was a toroidal magnetic-confinement device without toroidal magnetic-field coils or a central transformer but which generated core-plasma currents by dynamo processes driven by coaxial plasma-gun injection into a flux-conserving vessel. Record electron temperatures in a spheromak (Te˜500eV) were achieved, and final results of the SSPX program were reported in [1]. Plasma density, which depended strongly on wall conditions, was an important parameter in SSPX. It was observed that density rises with Igun and that confinement improved as the density was lowered. Shortly after the last experiments, a new feature was added to the Corsica code's solver used to reconstruct SSPX equilibria. Motivated by n=0 fields observed in NIMROD simulations of SSPX, an insulating boundary condition was implemented at the plasma-gun gap. Using this option we will perform new reconstructions of SSPX equilibria and look for correlations between the location of the separatrix (which moves up the gun wall and onto the insulating gap as Igun increases) and plasma density and magnetic-flux amplification [2].[4pt] [1] H. S. McLean, APS, DPP, Dallas, TX, 2008.[0pt] [2] E. B. Hooper et al., Nucl. Fusion 47, 1064 (2007).

  7. Sustainability of a public system for plasma collection, contract fractionation and plasma-derived medicinal product manufacturing.

    Science.gov (United States)

    Grazzini, Giuliano; Ceccarelli, Anna; Calteri, Deanna; Catalano, Liviana; Calizzani, Gabriele; Cicchetti, Americo

    2013-09-01

    In Italy, the financial reimbursement for labile blood components exchanged between Regions is regulated by national tariffs defined in 1991 and updated in 1993-2003. Over the last five years, the need for establishing standard costs of healthcare services has arisen critically. In this perspective, the present study is aimed at defining both the costs of production of blood components and the related prices, as well as the prices of plasma-derived medicinal products obtained by national plasma, to be used for interregional financial reimbursement. In order to analyse the costs of production of blood components, 12 out 318 blood establishments were selected in 8 Italian Regions. For each step of the production process, driving costs were identified and production costs were. To define the costs of plasma-derived medicinal products obtained by national plasma, industrial costs currently sustained by National Health Service for contract fractionation were taken into account. The production costs of plasma-derived medicinal products obtained from national plasma showed a huge variability among blood establishments, which was much lower after standardization. The new suggested plasma tariffs were quite similar to those currently in force. Comparing the overall costs theoretically sustained by the National Health Service for plasma-derived medicinal products obtained from national plasma to current commercial costs, demonstrates that the national blood system could gain a 10% cost saving if it were able to produce plasma for fractionation within the standard costs defined in this study. Achieving national self-sufficiency through the production of plasma-derived medicinal products from national plasma, is a strategic goal of the National Health Service which must comply not only with quality, safety and availability requirements but also with the increasingly pressing need for economic sustainability.

  8. D-T plasma of self-sustained burning under high performance

    International Nuclear Information System (INIS)

    Gong Xueyu

    2003-01-01

    By adopting a Bohm-type thermal diffusion coefficient related to the energy confinement enhancement factor H within the conventional magnetic shear regime, and a mixed Bohm-gyro-Bohm thermal diffusion coefficient related to the shear within the negative central magnetic shear regime, considering the effect of the α particle anomalous diffusion and the dynamic feedback heating, and starting from energy transport of electrons and ions, we have studied the high performance self-sustaining burning deuterium-tritium plasma under a given plasma density profile for the two different kinds of magnetic shear regimes. Some conclusions are obtained: under the conventional shear, only when H≥3, the D-T burning can produce a large power output, and when H is larger than a certain value (H≅4), D-T plasma self-sustained burning can be maintained without the dynamic feedback heating; under the negative central shear, the plasmas have a higher plasma performance and a larger power output than that under conventional shear, and D-T plasma self-sustained burning can be maintained without the dynamic feedback heating power, the suitable alpha particle diffusion is advantage ous to D-T plasma burning under the conventional shear, and D-T self-sustained burning cannot be maintained under a large α particle anomalous diffusion for the negative central shear. The dynamic feedback heating power is important for sustaining D-T plasma burning under the conventional shear

  9. Radiation characteristics of input power from surface wave sustained plasma antenna

    Energy Technology Data Exchange (ETDEWEB)

    Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

    2016-09-15

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  10. Radiation characteristics of input power from surface wave sustained plasma antenna

    International Nuclear Information System (INIS)

    Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

    2016-01-01

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  11. Local carbon diffusion coefficient measurement in the S-1 spheromak

    International Nuclear Information System (INIS)

    Mayo, R.M.; Levinton, F.M.; Meyerhofer, D.D.; Chu, T.K.; Paul, S.F.; Yamada, M.

    1988-10-01

    The local carbon diffusion coefficient was measured in the S - 1 spheromak by detecting the radial spread of injected carbon impurity. The radial impurity density profile is determined by the balance of ionization and diffusion. Using measured local electron temperature T/sub e/ and density n/sub e/, the ionization rate is determined from which the particle diffusion coefficient is inferred. The results found in this work are consistent with Bohm diffusion. The absolute magnitude of D/sub /perpendicular// was determined to be (4/approximately/6) /times/ D/sub Bohm/. 25 refs., 13 figs., 2 tabs

  12. Steady equilibrium of a cylindrically symmetric plasma sustained by fueling

    International Nuclear Information System (INIS)

    Tomita, Yukihiro; Momota, Hiromu

    1993-01-01

    By introducing a novel and natural method to obtain a steady equilibrium, it is shown that a pressure gradient produced by the particle injection or resultant diamagnetic current can sustain only an equilibrium of a diffused linear pinch. For an extremely elongated FRC where magnetic field vanishes at a certain point, a seed current is needed to sustain configuration in a steady state equilibrium. A directed flow of fusion produced protons forms a seed current and consequently it sustains a steady FRC equilibrium by fueling only once D- 3 He burning takes place. Effects of anomalous transports on the sustainment are discussed. (author)

  13. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    NARCIS (Netherlands)

    Vries, de N.; Palomares, J.M.; Iordanova, E.I.; Veldhuizen, van E.M.; Mullen, van der J.J.A.M.

    2008-01-01

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined

  14. Formation and sustainment of a low aspect ratio tokamak by a series of plasma injections

    International Nuclear Information System (INIS)

    Shimamura, Shin; Taniguchi, Makoto; Takahashi, Tsutomu; Nogi, Yasuyuki

    1995-01-01

    A low aspect ratio tokamak plasma was generated and sustained by injecting a series of plasmas from a magnetized coaxial gun into a flux conserver with toroidal field. The magnetized coaxial gun was supplied by an oscillating current with a d.c. component. The first few current pulses injected plasma and helicity into the flux conserver. This pulse helicity injection method worked effectively to maintain the low aspect ratio tokamak. 8 refs., 5 figs

  15. Stable sustainment of plasmas with electron internal transport barrier by ECH in the LHD

    Science.gov (United States)

    Yoshimura, Y.; Kasahara, H.; Tokitani, M.; Sakamoto, R.; Ueda, Y.; Marushchenko, N. B.; Seki, R.; Kubo, S.; Shimozuma, T.; Igami, H.; Takahashi, H.; Tsujimura, T. I.; Makino, R.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Okada, K.; Akiyama, T.; Tanaka, K.; Tokuzawa, T.; Yamada, I.; Yamada, H.; Mutoh, T.; Takeiri, Y.; the LHD Experiment Group

    2018-02-01

    The long pulse experiments in the Large Helical Device has made progress in sustainment of improved confinement states. It was found that steady-state sustainment of the plasmas with improved confinement at the core region, that is, electron internal transport barrier (e-ITB), was achieved with no significant difficulty. Sustainment of a plasma having e-ITB with the line average electron density n e_ave of 1.1 × 1019 m-3 and the central electron temperature T e0 of ˜3.5 keV for longer than 5 min only with 340 kW ECH power was successfully demonstrated.

  16. Recent Progress on the magnetic turbulence experiment at the Bryn Mawr Plasma Laboratory

    Science.gov (United States)

    Schaffner, D. A.; Cartagena-Sanchez, C. A.; Johnson, H. K.; Fahim, L. E.; Fiedler-Kawaguchi, C.; Douglas-Mann, E.

    2017-10-01

    Recent progress is reported on the construction, implementation and testing of the magnetic turbulence experiment at the Bryn Mawr Plasma Laboratory (BMPL). The experiment at the BMPL consists of an ( 300 μs) long coaxial plasma gun discharge that injects magnetic helicity into a flux-conserving chamber in a process akin to sustained slow-formation of spheromaks. A 24cm by 2m cylindrical chamber has been constructed with a high density axial port array to enable detailed simultaneous spatial measurements of magnetic and plasma fluctuations. Careful positioning of the magnetic structure produced by the three separately pulsed coils (one internal, two external) are preformed to optimize for continuous injection of turbulent magnetized plasma. High frequency calibration of magnetic probes is also underway using a power amplifier.

  17. Sustainment of spherical tokamak by means of repetitive injection of compact torus plasma

    International Nuclear Information System (INIS)

    Shimamura, Shin; Matsura, Ken; Takahashi, Tsutomu; Nogi, Yasuyuki

    2000-01-01

    Sustainment of spherical tokamak (S.T.) has been studied. A compact torus (C.T.) plasma was injected into confinement region by magnetized coaxial gun. For start-up and sustainment of large main spherical tokamak, single pulsed injection of small C.T. is not sufficient in many cases. C.T.plasma injection of high repetition rate is required. For this purpose magnetized coaxial gun was driven with high repetition rate current. The first injected C.T. plasma could start-up S.T. without other help. The repetitive C.T. injection grew and sustained the S.T. plasma. A CCD camera with fast gated image intensifier took a cross sectional view of S.T. during the repetitive C.T. injection. (author)

  18. Proteomics reveals the effects of sustained weight loss on the human plasma proteome

    DEFF Research Database (Denmark)

    Geyer, Philipp E; Wewer Albrechtsen, Nicolai J; Tyanova, Stefka

    2016-01-01

    Sustained weight loss is a preferred intervention in a wide range of metabolic conditions, but the effects on an individual's health state remain ill-defined. Here, we investigate the plasma proteomes of a cohort of 43 obese individuals that had undergone 8 weeks of 12% body weight loss followed...... by a year of weight maintenance. Using mass spectrometry-based plasma proteome profiling, we measured 1,294 plasma proteomes. Longitudinal monitoring of the cohort revealed individual-specific protein levels with wide-ranging effects of losing weight on the plasma proteome reflected in 93 significantly...

  19. Dynamics of spheromak-like compact toroids in a drift tube

    International Nuclear Information System (INIS)

    Suzuki, Y.; Kishimoto, Y.; Hayashi, T.

    2001-01-01

    In order to supply plasma fuel confined in spheromak-like compact toroids (SCTs) to a fusion device, the SCTs must be successfully guided through a drift tube region, in which they might be influenced by the magnetic field leaking from the fusion device. To reveal the SCT dynamics in a drift tube, MHD numerical simulations, where the SCTs are accelerated in a co-axial perfectly conducting cylinder with an external magnetic field, are carried out. In addition, the effect of an extended central electrode is examined by changing the length of the inner conducting cylinder. It is revealed that the SCT penetration depth is shorter than that estimated from the conventional conducting sphere model and that the SCTs are further decelerated by extending the inner conducting cylinder. These results are consistent with the results of the compact toroid injection experiment performed on the TEXT Upgrade tokamak. Finally, the deceleration mechanism of the SCTs is discussed by comparing the simulation result with the proposed theoretical model. (author)

  20. Generation and Sustainment of Plasma Rotation by ICRF Heating

    Science.gov (United States)

    Perkins, F. W.

    2000-10-01

    When tokamak plasmas are heated by the fundamental minority ion-cyclotron process, they are observed to rotate toroidally, even though this heating process introduces negligable angular momentum. This work proposes and evaluates a physics mechanism which resolves this apparent conflict. The argument has two elements. First, it is assumed that angular momentum transport is governed by a diffusion equation with a v_tor = 0 boundary condition at the plasma surface and a torque-density source. When the source consists of separated regions of positive and negative torque density, a finite central rotation velocity results, even though the volume integrated torque density - the angular momentum input - vanishes. Secondly, ions energized by the ICRF process can generate separated regions of positive and negative torque density. Heating increases their banana widths which leads to radial energetic-particle transport that must be balanced by neutralizing radial currents and a j_rB_pR torque density in the bulk plasma. Additional, comparable torque density results from collisional transfer of mechanical angular momentum from energetic particles to the bulk plasma and particle loss through banana particles impacting the wall. Monte-Carlo calculations utilizing the ORBIT code evaluate all sources of torque density and rigorously assure that no net angular momentum is introduced. Two models of ICRF heating, diffusive and instantaneous, give similar results. When the resonance location is on the LFS, the calculated rotation has the magnitude, profile, and co-current sense of Alcator C-Mod observations. For HFS resonance locations, the model predicts counter-current rotation. Scans of rotational profiles vs. resonance location, initial energy, particle loss, pitch, and qm will be presented as will the location of the velocity shear layer its scaling to a reactor.

  1. Radiofrequency initiation and radiofrequency sustainment of laser initiated seeded high pressure plasma

    International Nuclear Information System (INIS)

    Paller, Eric S.; Scharer, John E.; Akhtar, Kamran; Kelly, Kurt; Ding, Guowen

    2001-01-01

    We examine radiofrequency initiation of high pressure(1-70 Torr) inductive plasma discharges in argon, nitrogen, air and organic seed gas mixtures. Millimeter wave interferometry, optical emission and antenna wave impedance measurements for double half-turn helix and helical inductive antennas are used to interpret the rf/plasma coupling, measure the densities in the range of 10 12 cm -3 and analyze the ionization and excited states of the gas mixtures. We have also carried out 193 nm excimer laser initiation of an organic gas seed plasma which is sustained at higher pressures(150 Torr) by radiofrequency coupling at 2.8 kW power levels

  2. Proteomics reveals the effects of sustained weight loss on the human plasma proteome

    DEFF Research Database (Denmark)

    Geyer, Philipp E; Wewer Albrechtsen, Nicolai J; Tyanova, Stefka

    2016-01-01

    Sustained weight loss is a preferred intervention in a wide range of metabolic conditions, but the effects on an individual's health state remain ill-defined. Here, we investigate the plasma proteomes of a cohort of 43 obese individuals that had undergone 8 weeks of 12% body weight loss followed ...

  3. Rise of plasma ghrelin with weight loss is not sustained during weight maintenance

    Science.gov (United States)

    Ghrelin is postulated to be an orexigenic signal that promotes weight regain after weight loss (WL). However, it is not known whether this putative effect of ghrelin is sustained after weight stabilization. The objective of this study was to investigate the relationship of plasma ghrelin concentrati...

  4. Modelling of microwave sustained capillary plasma columns at atmospheric pressure

    International Nuclear Information System (INIS)

    Pencheva, M; Petrova, Ts; Benova, E; Zhelyazkov, I

    2006-01-01

    In this work we present a model of argon microwave sustained discharge at high pressure (1 atm), which includes two self-consistently linked parts - electrodynamic and kinetic ones. The model is based on a steady-state Boltzmann equation in an effective field approximation coupled with a collisional-radiative model for high-pressure argon discharge numerically solved together with Maxwell's equation for an azimuthally symmetric TM surface wave and wave energy balance equation. It is applied for the purpose of theoretical description of the discharge in a stationary state. The phase diagram, the electron energy distribution function as well as the dependences of the electron and heavy particles densities and the mean input power per electron on the electron number density and wave number are presented

  5. Increasing the magnetic helicity content of a plasma by pulsing a magnetized source.

    Science.gov (United States)

    Woodruff, S; Stallard, B W; McLean, H S; Hooper, E B; Bulmer, R; Cohen, B I; Hill, D N; Holcomb, C T; Moller, J; Wood, R D

    2004-11-12

    By operating a magnetized coaxial gun in a pulsed mode it is possible to produce large voltage pulses of duration approximately 500 mus while reaching a few kV, giving a discrete input of helicity into a spheromak. In the sustained spheromak physics experiment (SSPX), it is observed that pulsing serves to nearly double the stored magnetic energy and double the temperature. We discuss these results by comparison with 3D MHD simulations of the same phenomenon.

  6. Profile formation and sustainment of autonomous tokamak plasma with current hole configuration

    International Nuclear Information System (INIS)

    Hayashi, N.; Takizuka, T.; Ozeki, T.

    2005-01-01

    We have investigated the profile formation and sustainment of tokamak plasmas with the current hole (CH) configuration by using 1.5D time-dependent transport simulations. A model of the current limit inside the CH on the basis of the Axisymmetric Tri-Magnetic-Islands equilibrium is introduced into the transport simulation. We found that a transport model with the sharp reduction of anomalous transport in the reversed-shear (RS) region can reproduce the time evolution of profiles observed in JT-60U experiments. The transport becomes neoclassical-level in the RS region, which results in the formation of profiles with internal transport barrier (ITB) and CH. The CH plasma has an autonomous property because of the strong interaction between a pressure profile and a current profile through the large bootstrap current fraction. The ITB width determined by the neoclassical-level transport agrees well with that measured in JT-60U. The energy confinement inside the ITB agrees with the scaling based on the JT-60U data. The scaling means the autonomous limitation of energy confinement in the CH plasma. The plasma with the large CH is sustained with the full current drive by the bootstrap current. The plasma with the small CH and the small bootstrap current fraction shrinks due to the penetration of inductive current. This shrink is prevented and the CH size can be controlled by the appropriate external current drive (CD). The CH plasma is found to respond autonomically to the external CD. (author)

  7. Generation and sustainment of plasma rotation by ICRF heating

    International Nuclear Information System (INIS)

    Perkins, F.W.; White, R.; Bonoli, P.T.; Chan, V.S.

    2001-01-01

    A mechanism is proposed and evaluated for driving rotation in tokamak plasmas by minority ion-cyclotron heating, even though this process introduces negligible angular momentum. The mechanism has two elements: First, angular momentum transport is governed by a diffusion equation with a non-slip boundary condition at the separatrix. Second, Monte-Carlo calculations show that energized particles will provide a torque density source which has a zero volume integral but separated positive and negative regions. With such a source, a solution of the diffusion equation predicts the on-axis rotation frequency Ω to be Ω=(4q max WJ*)eBR 3 a 2 n e (2π) 2 ) -1 (τ M /τ E ) where vertical bar J* vertical bar ∼ 5-10 is a non-dimensional rotation frequency calculated by the Monte-Carlo ORBIT code. Overall, agreement with experiment is good, when the resonance is on the low-field-side of the magnetic axis. The rotation becomes more counter-current and reverses sign on the high field side for a no-slip boundary. The velocity shear layer position is controllable and of sufficient magnitude to affect microinstabilities. (author)

  8. Production of O2(1Δ) in flowing plasmas using spiker-sustainer excitation

    International Nuclear Information System (INIS)

    Babaeva, Natalia Y.; Arakoni, Ramesh A.; Kushner, Mark J.

    2006-01-01

    In chemical oxygen iodine lasers (COILs), oscillation at 1.315 μm in atomic iodine ( 2 P 1/2 → 2 P 3/2 ) is produced by collisional excitation transfer of O 2 ( 1 Δ) to I 2 and I. Plasma production of O 2 ( 1 Δ) in electrical COILs (eCOILs) eliminates liquid phase generators. For the flowing plasmas used for eCOILs (He/O 2 , a few to tens of torr), self-sustaining electron temperatures, T e , are 2-3 eV whereas excitation of O 2 ( 1 Δ) optimizes with T e =1-1.5 eV. One method to increase O 2 ( 1 Δ) production is by lowering the average value of T e using spiker-sustainer (SS) excitation where a high power pulse (spiker) is followed by a lower power period (sustainer). Excess ionization produced by the spiker enables the sustainer to operate with a lower T e . Previous investigations suggested that SS techniques can significantly raise yields of O 2 ( 1 Δ). In this paper, we report on the results from a two-dimensional computational investigation of radio frequency (rf) excited flowing He/O 2 plasmas with emphasis on SS excitation. We found that the efficiency of SS methods generally increase with increasing frequency by producing a higher electron density, lower T e , and, as a consequence, a more efficient production of O 2 ( 1 Δ)

  9. Energy efficiency of the CTX magnetized coaxial plasma source

    International Nuclear Information System (INIS)

    Fernandez, J.C.; Barnes, C.W.; Jarboe, T.R.; Knox, S.O.; Platts, D.A.; McKenna, K.F.

    1985-01-01

    The energy efficiency of the CTX coaxial plasma source in creating spheromaks is determined experimentally to be in agreement with the theoretical prediction of lambda/sub sp//lambda/sub g/, where del x B = lambda/sub sp/ B in the spheromak, and lambda/sub g/ identical with μ 0 I/sub g//phi/sub g/ with I/sub g/ the source current and phi/sub g/ the magnetic flux through either source electrode. This is shown to be equivalent to magnetic helicity conservation. The spheromak impurity radiation was measured using an absolutely calibrated single chord bolometer system. The theoretical efficiency is within the experimental uncertainty of the ratio of spheromak radiated energy to source input energy in a group of ''dirty'' discharges. But the radiation measurement uncertainty is too large to determine whether a substantial part of the excess source energy not used in the production of spheromak magnetic energy is radiated from the spheromak volume

  10. Sustainability.

    Science.gov (United States)

    Chang, Chein-Chi; DiGiovanni, Kimberly; Mei, Ying; Wei, Li

    2016-10-01

    This review on Sustainability covers selected 2015 publications on the focus of Sustainability. It is divided into the following sections : • Sustainable water and wastewater utilities • Sustainable water resources management • Stormwater and green infrastructure • Sustainability in wastewater treatment • Life cycle assessment (LCA) applications • Sustainability and energy in wastewater industry, • Sustainability and asset management.

  11. Computational study of plasma sustainability in radio frequency micro-discharges

    International Nuclear Information System (INIS)

    Zhang, Y.; Jiang, W.; Zhang, Q. Z.; Bogaerts, A.

    2014-01-01

    We apply an implicit particle-in-cell Monte-Carlo (PIC-MC) method to study a radio-frequency argon microdischarge at steady state in the glow discharge limit, in which the microdischarge is sustained by secondary electron emission from the electrodes. The plasma density, electron energy distribution function (EEDF), and electron temperature are calculated in a wide range of operating conditions, including driving voltage, microdischarge gap, and pressure. Also, the effect of gap size scaling (in the range of 50-1000 μm) on the plasma sustaining voltage and peak electron density at atmospheric pressure is examined, which has not been explored before. In our simulations, three different EEDFs, i.e., a so-called three temperature hybrid mode, a two temperature α mode, and a two temperature γ mode distribution, are identified at different gaps and voltages. The maximum sustaining voltage to avoid a transition from the glow mode to an arc is predicted, as well as the minimum sustaining voltage for a steady glow discharge. Our calculations elucidate that secondary electrons play an essential role in sustaining the discharge, and as a result the relationship between breakdown voltage and gap spacing is far away from the Paschen law at atmospheric pressure

  12. The spheromak as a prototype for ultra-high-field superconducting magnets

    International Nuclear Information System (INIS)

    Furth, H.P.; Jardin, S.C.

    1987-08-01

    In view of current progress in the development of superconductor materials, the ultimate high-field limit of superconducting magnets is likely to be set by mechanical stress problems. Maximum field strength should be attainable by means of approximately force-free magnet windings having favorable ''MHD'' stability properties (so that small winding errors will not grow). Since a low-beta finite-flux-hole spheromak configuration qualifies as a suitable prototype, the theoretical and experimental spheromak research effort of the past decade has served to create a substantial technical basis for the design of ultra-high-field superconducting coils. 11 refs

  13. Sustainment of high confinement in JT-60U reversed shear plasmas

    International Nuclear Information System (INIS)

    Fujita, T.; Kamada, Y.; Ide, S.; Takeji, S.; Sakamoto, Y.; Isayama, A.; Suzuki, T.; Oikawa, T.; Fukuda, T.

    2001-01-01

    confinement is achieved owing to strong internal transport barriers (ITBs), are reported. In a high current plasma with an L-mode edge, deuterium-tritium-equivalent fusion power gain, Q DT eq =0.5 was sustained for 0.8 s (∼ energy confinement time) by adjusting plasma beta precisely using feedback control of stored energy. In a high triangularity plasma with an ELMy H-mode edge, the shrinkage of reversed shear region was suppressed and quasi steady sustainment of high confinement was achieved by raising the poloidal beta and enhancing the bootstrap current peaked at the ITB layer. High bootstrap current fraction (∼80%) was obtained in a high q regime (q 95 ∼9), which leaded to full non-inductive current drive condition. The normalized beta (β N ) of ∼ 2 and H-factor of H 89 ∼3.5 (HH 98y2 ∼2.2) were sustained for 2.7 s (∼ 6 times energy confinement time). (author)

  14. Product surface hardening in non-self-sustained glow discharge plasma before synthesis of superhard coatings

    International Nuclear Information System (INIS)

    Krasnov, P S; Metel, A S; Nay, H A

    2017-01-01

    Before the synthesis of superhard coating, the product surface is hardened by means of plasma nitriding, which prevents the surface deformations and the coating brittle rupture. The product heating by ions accelerated from plasma by applied to the product bias voltage leads to overheating and blunting of the product sharp edges. To prevent the blunting, it is proposed to heat the products with a broad beam of fast nitrogen molecules. The beam injection into a working vacuum chamber results in filling of the chamber with quite homogeneous plasma suitable for nitriding. Immersion in the plasma of the electrode and heightening of its potential up to 50–100 V initiate a non-self-sustained glow discharge between the electrode and the chamber. It enhances the plasma density by an order of magnitude and reduces its spatial nonuniformity down to 5–10%. When a cutting tool is isolated from the chamber, it is bombarded by plasma ions with an energy corresponding to its floating potential, which is lower than the sputtering threshold. Hence, the sharp edges are sputtered only by fast nitrogen molecules with the same rate as other parts of the tool surface. This leads to sharpening of the cutting tools instead of blunting. (paper)

  15. Princeton Plasma Physics Laboratory:

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, C.A. (ed.)

    1986-01-01

    This paper discusses progress on experiments at the Princeton Plasma Physics Laboratory. The projects and areas discussed are: Principal Parameters Achieved in Experimental Devices, Tokamak Fusion Test Reactor, Princeton Large Torus, Princeton Beta Experiment, S-1 Spheromak, Current-Drive Experiment, X-ray Laser Studies, Theoretical Division, Tokamak Modeling, Spacecraft Glow Experiment, Compact Ignition Tokamak, Engineering Department, Project Planning and Safety Office, Quality Assurance and Reliability, and Administrative Operations.

  16. Princeton Plasma Physics Laboratory:

    International Nuclear Information System (INIS)

    Phillips, C.A.

    1986-01-01

    This paper discusses progress on experiments at the Princeton Plasma Physics Laboratory. The projects and areas discussed are: Principal Parameters Achieved in Experimental Devices, Tokamak Fusion Test Reactor, Princeton Large Torus, Princeton Beta Experiment, S-1 Spheromak, Current-Drive Experiment, X-ray Laser Studies, Theoretical Division, Tokamak Modeling, Spacecraft Glow Experiment, Compact Ignition Tokamak, Engineering Department, Project Planning and Safety Office, Quality Assurance and Reliability, and Administrative Operations

  17. Nonlinear saturation of non-resonant internal instabilities in a straight spheromak

    International Nuclear Information System (INIS)

    Park, W.; Jardin, S.C.

    1982-04-01

    An initial value numerical solution of the time dependent nonlinear ideal magnetohydrodynamic equations demonstrates that spheromak equilibria which are linearly unstable to nonresonant helical internal perturbations saturate at low amplitude without developing singularities. These instabilities thus represent the transition from an axisymmetric to a non-axisymmetric equilibrium state, caused by a peaking of the current density

  18. Self-sustained turbulence and L-mode confinement in toroidal plasmas

    International Nuclear Information System (INIS)

    Itoh, K.; Itoh, S.; Fukuyama, A.; Yagi, M.; Azumi, M.

    1993-04-01

    Theory of the L-mode confinement in toroidal plasmas is developed. The quantitative effect of the anomalous transport, which is caused by microscopic fluctuations, on the pressure-gradient- driven modes is analyzed. The ExB nonlinearity is renormalized in a form of the transport coefficient such as the thermal diffusivity, the ion viscosity and the current diffusivity. The destabilization by the current-diffusivity and the stabilization by the thermal transport and ion viscosity are analyzed. By use of the mean-field approximations, the nonlinear dispersion relation is solved. Growth rate and stability condition are expressed in terms of the renormalized transport coefficients. The transport coefficients in the steady state are obtained by the marginal stability condition for the least stable mode. This method is applied to the microscopic ballooning mode for the toroidal plasma with the magnetic well (such as tokamak). The comparison with experimental observations are made. A good agreement is found in a various aspects of the L-mode plasmas; The typical wavenumber and level of the fluctuations for the self-sustained turbulence is also obtained. The analysis is also made for the plasma with magnetic hill and shear (such as torsatron/Heliotron devices). This method is applied to the interchange modes. Formula of the anomalous transport is obtained. Also investigated is the case of the magnetic well and low magnetic shear (conventional stellarator). The roles of the pressure gradient and the collisionless skin depth in determining the anomalous transport are found to be generic in toroidal plasmas. The difference in the magnetic configuration affects the transport coefficient. These formula explain major experimental observations. (J.P.N.)

  19. Application of a magnetized coaxial plasma gun for formation of a high-beta field-reversed configuration

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Kiguchi, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Asai, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)]. E-mail: asai@phys.cst.nihon-u.ac.jp; Takahashi, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Matsuzawa, Y. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Okano, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Nogi, Y. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)

    2006-11-15

    We have tested a field-reversed configuration (FRC) formation with a spheromak injection for the first time. In this method, initial pre-ionized plasma is injected as a magnetized spheromak-like plasmoid into the discharge chamber prior to main field reversal. The FRC plasma with an electron density of 1.3 x 10{sup 21} m{sup -3}, a separatrix radius of 0.04 m and a plasma length of 0.8 m was produced successfully in initial background plasma of about 1.6 x 10{sup 19} m{sup -3} by spheromak injection. The density is about one third of the conventional formed by the z-ionized method.

  20. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    International Nuclear Information System (INIS)

    Vries, N de; Iordanova, E I; Van Veldhuizen, E M; Mullen, J J A M van der; Palomares, J M

    2008-01-01

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined more precisely. The electron density, n e , is determined with Thomson scattering (TS), absolute continuum measurements, Stark broadening and an extrapolation of the atomic state distribution function (ASDF). The electron temperature, T e , is obtained using TS and absolute line intensity (ALI) measurements combined with a collisional-radiative (CR) model for argon. At an argon pressure of 15 mbar, the n e values obtained with TS and Stark broadening agree with each other within the error bars and are equal to (4 ± 0.5) x 10 19 m -3 , whereas the n e value (2 ± 0.5) x 10 19 m -3 obtained from the continuum is about 30% lower. This suggests that the used formula and cross-section values for the continuum method have to be reconsidered. The electron density determined by means of extrapolation of the ASDF to the continuum is too high (∼10 20 m -3 ). This is most probably related to the fact that the plasma is strongly ionizing so that the extrapolation method is not justified. At 15 mbar, the T e values obtained with TS are equal to 13 400 ± 1100 K while the ALI/CR-model yields an electron temperature that is about 10% lower. It can be concluded that the passive results are in good or fair agreement with the active results. Therefore, the calibrated passive methods can be applied to other plasmas in a similar regime for which active diagnostic techniques cannot be used.

  1. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vries, N de; Iordanova, E I; Van Veldhuizen, E M; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Palomares, J M [Departamento de Fisica, Universidad de Cordoba, Campus de Rabanales, ed. C-2, 14071 Cordoba (Spain)], E-mail: j.j.a.m.v.d.Mullen@tue.nl

    2008-10-21

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined more precisely. The electron density, n{sub e}, is determined with Thomson scattering (TS), absolute continuum measurements, Stark broadening and an extrapolation of the atomic state distribution function (ASDF). The electron temperature, T{sub e}, is obtained using TS and absolute line intensity (ALI) measurements combined with a collisional-radiative (CR) model for argon. At an argon pressure of 15 mbar, the n{sub e} values obtained with TS and Stark broadening agree with each other within the error bars and are equal to (4 {+-} 0.5) x 10{sup 19} m{sup -3}, whereas the n{sub e} value (2 {+-} 0.5) x 10{sup 19} m{sup -3} obtained from the continuum is about 30% lower. This suggests that the used formula and cross-section values for the continuum method have to be reconsidered. The electron density determined by means of extrapolation of the ASDF to the continuum is too high ({approx}10{sup 20} m{sup -3}). This is most probably related to the fact that the plasma is strongly ionizing so that the extrapolation method is not justified. At 15 mbar, the T{sub e} values obtained with TS are equal to 13 400 {+-} 1100 K while the ALI/CR-model yields an electron temperature that is about 10% lower. It can be concluded that the passive results are in good or fair agreement with the active results. Therefore, the calibrated passive methods can be applied to other plasmas in a similar regime for which active diagnostic techniques cannot be used.

  2. Spectroscopic Investigations of Highly Charged Tungsten Ions - Atomic Spectroscopy and Fusion Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Clementson, Joel [Lund Univ. (Sweden)

    2010-05-01

    The spectra of highly charged tungsten ions have been investigated using x-ray and extreme ultraviolet spectroscopy. These heavy ions are of interest in relativistic atomic structure theory, where high-precision wavelength measurements benchmark theoretical approaches, and in magnetic fusion research, where the ions may serve to diagnose high-temperature plasmas. The work details spectroscopic investigations of highly charged tungsten ions measured at the Livermore electron beam ion trap (EBIT) facility. Here, the EBIT-I and SuperEBIT electron beam ion traps have been employed to create, trap, and excite tungsten ions of M- and L-shell charge states. The emitted spectra have been studied in high resolution using crystal, grating, and x-ray calorimeter spectrometers. In particular, wavelengths of n = 0 M-shell transitions in K-like W55+ through Ne-like W64+, and intershell transitions in Zn-like W44+ through Co-like W47+ have been measured. Special attention is given to the Ni-like W46+ ion, which has two strong electric-dipole forbidden transitions that are of interest for plasma diagnostics. The EBIT measurements are complemented by spectral modeling using the Flexible Atomic Code (FAC), and predictions for tokamak spectra are presented. The L-shell tungsten ions have been studied at electron-beam energies of up to 122 keV and transition energies measured in Ne-like W64+ through Li-like W71+. These spectra constitute the physics basis in the design of the ion-temperature crystal spectrometer for the ITER tokamak. Tungsten particles have furthermore been introduced into the Sustained Spheromak Physics Experiment (SSPX) spheromak in Livermore in order to investigate diagnostic possibilities of extreme ultraviolet tungsten spectra for the ITER divertor. The spheromak measurement and spectral modeling using FAC suggest that tungsten ions in charge states around Er-like W6+ could be useful for

  3. Absorption kinetics and steady-state plasma concentrations of theophylline following therapeutic doses of two sustained-release preparations

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, M K; Eriksen, P B

    1983-01-01

    Ten healthy volunteers received two sustained-release preparations as a single and multiple dose regimen in an open crossover study. Plasma theophylline concentrations were measured by an enzyme immunoassay. The limited fluctuation of the theophylline levels at steady state, with twice daily...... formulation, whereas this was not the case for the other (r = 0.27 and 0.49). The daily dose necessary to keep the plasma concentration within the therapeutic range of 55-110 mumole/liter varied from 7.9 to 22.9 mg/kg. Only mild side effects were recorded, but they were not correlated to the plasma...... theophylline concentration....

  4. The role of plasma radius as a condition for sustaining a coaxial discharge at various wave modes

    International Nuclear Information System (INIS)

    Ivanov, K; Bogdanov, T; Benova, E

    2012-01-01

    A gas discharge can be produced and sustained by travelling electromagnetic waves in various geometries: planar, spherical, cylindrical and coaxial. An electromagnetic wave travelling along a dielectric tube can produce plasma outside the tube when a metal rod is placed along the tube axis, which is the typical arrangement of a coaxial surface-wave-sustained discharge (CSWD). The CSWD has been studied intensively both theoretically and experimentally since 1998. In the case of a SWD in cylindrical geometry, plasma is mainly produced and sustained by the azimuthally symmetric waves. In coaxial geometry, there are both experimental and theoretical indications showing that higher wave modes may also produce and sustain plasma under certain conditions. In order to find out these conditions theoretically, we developed a one-dimensional fluid model. The purpose of this work is to investigate theoretically the behavior of wave phase diagrams under various discharge conditions and to find the discharge conditions under which plasma can be produced, as well as those conditions when this is not possible.

  5. Compact toroidal plasmas: Simulations and theory

    International Nuclear Information System (INIS)

    Harned, D.S.; Hewett, D.W.; Lilliequist, C.G.

    1983-01-01

    Realistic FRC equilibria are calculated and their stability to the n=1 tilting mode is studied. Excluding kinetic effects, configurations ranging from elliptical to racetrack are unstable. Particle simulations of FRCs show that particle loss on open field lines can cause sufficient plasma rotation to drive the n=2 rotational instability. The allowed frequencies of the shear Alfven wave are calculated for use in heating of spheromaks. An expanded spheromak is introduced and its stability properties are studied. Transport calculations of CTs are described. A power balance model shows that many features of gun-generated CT plasmas can be explained by the dominance of impurity radiation. It is shown how the Taylor relaxation theory, applied to gun-generated CT plasmas, leads to the possibility of steady-state current drive. Lastly, applications of accelerated CTs are considered. (author)

  6. A self-organized plasma with induction, reconnection, and injection techniques: the SPIRIT concept for field reversed configuration research

    International Nuclear Information System (INIS)

    Yamada, Masaaki; JI, Hantao; Gerhardt, Stefan P.; Belova, Elena V.; Davidson, Ronald C.; Mikkelsen, David R.

    2007-01-01

    A comprehensive research concept, known as SPIRIT, is described for the investigation of the formation, stability, and sustainment of oblate field reversed configurations (FRCs). This concept, whose name stands for Self-organized Plasma with Induction, Reconnection, and Injection Techniques (SPIRIT), allows for the study of FRC stability properties on time scales much longer than the energy confinement time. Counter-helicity merging of inductively formed spheromaks is utilized to form large-flux FRCs. These FRCs are sustained by neutral beam injection with the initial aid of compact ohmic solenoids. Stability to n=1 tilt/shift modes is provided by plasma shaping and conducting shells. Stability to n ≥ 2 co-interchange modes is achieved by a distribution of high-energy non-thermal ions provided by the neutral beam. The combination of plasma shaping, conducting shells, current sustainment, and the non-thermal beam component are expected to lead to a configuration with stability to all global MHD modes, a regime recently discovered through hybrid-MHD simulation using the HYM code. An experimental test of the concept, utilizing the existing Magnetic Reconnection Experiment (MRX) facility, is described. Initial experiments in MRX have confirmed the viability of the SPIRIT concept, and calculations indicate that the confinement of high-energy ions in MRX should be sufficient to test the SPIRIT concept. (author)

  7. Current results from the Los Alamos CTX spheromak

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, C.W.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; Knox, S.O.; Linford, R.K.; Platts, D.A.; Sherwood, A.R.

    1982-01-01

    Continued discharge cleaning, improved vacuum practices, and optimized plasma formation operation have resulted in the CTX experiment achieving 1-ms plasma lifetimes with average temperatures of 20 to 40 eV. The major advance in operation has been the use of 5 to 20 mTorr H/sub 2/ gas fill. A multipoint Thomson scattering diagnostic with 12 radial positions yields radial profiles of temperature and densities, an example of which is shown. Local ..beta..'s can be determined from the measured pressure profile, and average values are typically 15 to 20%. In clean, long-lived discharges the density decreases at a more rapid rate than the magnetic field, until it reaches a value around 2 to 4 x 10/sup 13/ cm/sup -3/ where it remains constant. This is in contrast to the colder, radiation-dominated behavior, and is taken as evidence that the plasma ..beta.. is a limit to current operation in CTX.

  8. Internal oscillating current-sustained RF plasmas: Parameters, stability, and potential for surface engineering

    DEFF Research Database (Denmark)

    Ostrikov, K.; Tsakadze, E.L.; Tsakadze, Z.L.

    2005-01-01

    . Moreover, under certain conditions, the plasma becomes unstable due to spontaneous transitions between low-density (electrostatic, E) and high-density (electromagnetic, H) operating modes. Excellent uniformity of high-density plasmas makes the plasma reactor promising for various plasma processing...... applications and surface engineering. (c) 2005 Elsevier B.V. All rights reserved....

  9. Design of spheromak injector using conical accelerator for large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, J.; Yamada, H.; Yasui, K.; Kato, S. [National Inst. for Fusion Science, Toki, Gifu (Japan); Fukumoto, N.; Nagata, M.; Uyama, T. [Himeji Inst. of Tech., Hyogo (Japan)

    1999-11-01

    Optimization of CT injector for LHD has been carried out and conical electrode for adiabatic CT compression is adopted in the design. Point-model of CT acceleration in a co-axial electrode is solved to optimize the electrode geometry and the power supplies. Large acceleration efficiency of 34% is to be obtained with 3.2 m long conical accelerator and 40 kV - 42 kJ power supply. The operation scenario of a CT injector named SPICA mk. I (SPheromak Injector using Conical Accelerator) consisting of 0.8 m conical accelerator is discussed based on this design. (author)

  10. A laboratory plasma experiment for studying magnetic dynamics of accretion discs and jets

    OpenAIRE

    Hsu, S. C.; Bellan, P. M.

    2002-01-01

    This work describes a laboratory plasma experiment and initial results which should give insight into the magnetic dynamics of accretion discs and jets. A high-speed multiple-frame CCD camera reveals images of the formation and helical instability of a collimated plasma, similar to MHD models of disc jets, and also plasma detachment associated with spheromak formation, which may have relevance to disc winds and flares. The plasmas are produced by a planar magnetized coaxial gun. The resulting...

  11. Experimental investigation of coaxial-gun-formed plasmas injected into a background transverse magnetic field or plasma

    Science.gov (United States)

    Zhang, Yue; Fisher, Dustin M.; Gilmore, Mark; Hsu, Scott C.; Lynn, Alan G.

    2018-05-01

    Injection of coaxial-gun-formed magnetized plasmas into a background transverse vacuum magnetic field or into a background magnetized plasma has been studied in the helicon-cathode (HelCat) linear plasma device at the University of New Mexico [M. Gilmore et al., J. Plasma Phys. 81, 345810104 (2015)]. A magnetized plasma jet launched into a background transverse magnetic field shows emergent kink stabilization of the jet due to the formation of a sheared flow in the jet above the kink stabilization threshold 0.1kVA [Y. Zhang et al., Phys. Plasmas 24, 110702 (2017)]. Injection of a spheromak-like plasma into a transverse background magnetic field led to the observation of finger-like structures on the side with a stronger magnetic field null between the spheromak and the background field. The finger-like structures are consistent with magneto-Rayleigh-Taylor instability. Jets or spheromaks launched into a background, low-β magnetized plasma show similar behavior as above, respectively, in both cases.

  12. A sustained increase in plasma NEFA upregulates the Toll-like receptor network in human muscle.

    Science.gov (United States)

    Hussey, Sophie E; Lum, Helen; Alvarez, Andrea; Cipriani, Yolanda; Garduño-Garcia, Jesús; Anaya, Luis; Dube, John; Musi, Nicolas

    2014-03-01

    Insulin-sensitive tissues (muscle, liver) of individuals with obesity and type 2 diabetes mellitus are in a state of low-grade inflammation, characterised by increased Toll-like receptor (TLR) expression and TLR-driven signalling. However, the cause of this mild inflammatory state is unclear. We tested the hypothesis that a prolonged mild increase in plasma NEFA will increase TLR expression and TLR-driven signalling (nuclear factor κB [NFκB] and mitogen-activated kinase [MAPK]) and impair insulin action in muscle of lean healthy individuals. Twelve lean, normal-glucose-tolerant participants were randomised to receive a 48 h infusion (30 ml/h) of saline or Intralipid followed by a euglycaemic-hyperinsulinaemic clamp. Vastus lateralis muscle biopsies were performed before and during the clamp. Lipid infusion impaired insulin-stimulated IRS-1 tyrosine phosphorylation and reduced peripheral insulin sensitivity (p < 0.01). The elevation in circulating NEFA increased expression of TLR3, TLR4 and TLR5, and several MAPK (MAPK8, MAP4K4, MAP2K3) and inhibitor of κB kinase-NFκB (CHUK [IKKA], c-REL [REL] and p65 [RELA, NFKB3, p65]) signalling genes (p < 0.05). The lipid infusion also increased extracellular signal-regulated kinase (ERK) phosphorylation (p < 0.05) and tended to reduce the content of inhibitor of kappa Bα (p = 0.09). The muscle content of most diacylglycerol, ceramide and acylcarnitine species was unaffected. In summary, insulin resistance induced by prolonged low-dose lipid infusion occurs together with increased TLR-driven inflammatory signalling and impaired insulin-stimulated IRS-1 tyrosine phosphorylation. A sustained, mild elevation in plasma NEFA is sufficient to increase TLR expression and TLR-driven signalling (NFκB and MAPK) in lean individuals. The activation of this pathway by NEFA may be involved in the pathogenesis of insulin resistance in humans. ClinicalTrials.gov NCT01740817.

  13. Review of recent experiments on magnetic reconnection in laboratory plasmas

    International Nuclear Information System (INIS)

    Yamada, M.

    1995-02-01

    The present paper reviews recent laboratory experiments on magnetic reconnection. Examples will be drawn from electron current sheet experiments, merging spheromaks, and from high temperature tokamak plasmas with the Lundquist numbers exceeding 10 7 . These recent laboratory experiments create an environment which satisfies the criteria for MHD plasma and in which the global boundary conditions can be controlled externally. Experiments with fully three dimensional reconnection are now possible. In the most recent TFTR tokamak discharges, Motional Stark effect (MSE) data have verified the existence of a partial reconnection. In the experiment of spheromak merging, a new plasma acceleration parallel to the neutral line has been indicated. Together with the relationship of these observations to the analysis of magnetic reconnection in space and in solar flares, important physics issues such as global boundary conditions, local plasma parameters, merging angle of the field lines, and the 3-D aspects of the reconnection are discussed

  14. A spheromak ignition experiment reusing Mirror Fusion Test Facility (MFTF) equipment

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1993-01-01

    Based on available experimental results and theory, a scenario is presented to achieve ohmic ignition in a spheromak by slow (∼ 10 sec.) helicity injection using power from the Mirror Fusion Test Facility (MFTF) substation. Some of the other parts needed (vacuum vessel, coils, power supplies, pumps, shielded building space) might also be obtained from MFTF or other salvage, as well as some components needed for intermediate experiments for additional verification of the concept (especially confinement scaling). The proposed ignition experiment would serve as proof-of-principle for the spheromak DT fusion reactor design published by Hagenson and Krakowski, with a nuclear island cost about ten times less than a tokamak of comparable power. Designs at even higher power density and lower cost might be possible using Christofilos' concept of a liquid lithium blanket. Since all structures would be protected from neutrons by the lithium blanket and the tritium inventory can be reduced by continuous removal from the liquid blanket, environmental and safety characteristics appear to be favorable

  15. Control of energy and matter at nanoscales: challenges and opportunities for plasma nanoscience in a sustainability age

    International Nuclear Information System (INIS)

    Ostrikov, Kostya

    2011-01-01

    Plasma nanoscience is an emerging multidisciplinary research field at the cutting edge of a large number of disciplines including but not limited to physics and chemistry of plasmas and gas discharges, materials science, surface science, nanoscience and nanotechnology, solid-state physics, space physics and astrophysics, photonics, optics, plasmonics, spintronics, quantum information, physical chemistry, biomedical sciences and related engineering subjects. This paper examines the origin, progress and future perspectives of this research field driven by the global scientific and societal challenges. The future potential of plasma nanoscience to remain a highly topical area in the global research and technological agenda in the age of fundamental-level control for a sustainable future is assessed using a framework of the five Grand Challenges for Basic Energy Sciences recently mapped by the US Department of Energy. It is concluded that the ongoing research is very relevant and is expected to substantially expand to competitively contribute to the solution of all of these Grand Challenges. The approach to controlling energy and matter at nano- and subnanoscales is based on identifying the prevailing carriers and transfer mechanisms of the energy and matter at the spatial and temporal scales that are most relevant to any particular nanofabrication process. Strong accent is made on the competitive edge of the plasma-based nanotechnology in applications related to the major socio-economic issues (energy, food, water, health and environment) that are crucial for a sustainable development of humankind. Several important emerging topics, opportunities and multidisciplinary synergies for plasma nanoscience are highlighted. The main nanosafety issues are also discussed and the environment- and human health-friendly features of plasma-based nanotech are emphasized.

  16. Control of energy and matter at nanoscales: challenges and opportunities for plasma nanoscience in a sustainability age

    Science.gov (United States)

    (Ken Ostrikov, Kostya

    2011-05-01

    Plasma nanoscience is an emerging multidisciplinary research field at the cutting edge of a large number of disciplines including but not limited to physics and chemistry of plasmas and gas discharges, materials science, surface science, nanoscience and nanotechnology, solid-state physics, space physics and astrophysics, photonics, optics, plasmonics, spintronics, quantum information, physical chemistry, biomedical sciences and related engineering subjects. This paper examines the origin, progress and future perspectives of this research field driven by the global scientific and societal challenges. The future potential of plasma nanoscience to remain a highly topical area in the global research and technological agenda in the age of fundamental-level control for a sustainable future is assessed using a framework of the five Grand Challenges for Basic Energy Sciences recently mapped by the US Department of Energy. It is concluded that the ongoing research is very relevant and is expected to substantially expand to competitively contribute to the solution of all of these Grand Challenges. The approach to controlling energy and matter at nano- and subnanoscales is based on identifying the prevailing carriers and transfer mechanisms of the energy and matter at the spatial and temporal scales that are most relevant to any particular nanofabrication process. Strong accent is made on the competitive edge of the plasma-based nanotechnology in applications related to the major socio-economic issues (energy, food, water, health and environment) that are crucial for a sustainable development of humankind. Several important emerging topics, opportunities and multidisciplinary synergies for plasma nanoscience are highlighted. The main nanosafety issues are also discussed and the environment- and human health-friendly features of plasma-based nanotech are emphasized.

  17. Parallel-beam correlation technique for measuring density fluctuations in plasmas with strong magnetic shear

    International Nuclear Information System (INIS)

    Jacobson, A.R.

    1981-04-01

    A laser diagnostic scheme is described which facilitates localization of density fluctuations along the line of sight. The method exploits both the generally observed anisotropy of density fluctuations in low-beta plasmas, as well as the twisting of the magnetic field which occurs across the minor diameter of reversed-field pinches, spheromaks, etc. Both interferometric and schlieren variations are discussed

  18. Theoretical plasma physics: Progress report, January 1, 1987-December 31, 1987

    International Nuclear Information System (INIS)

    Boozer, A.H.; Vahala, G.; Tracy, E.R.

    1987-09-01

    During the past year, research has been carried out on current drive in tokamaks and in spheromaks, fast integration techniques for magnetic field lines, alpha particle diagnostics that use CO 2 laser scattering, and plasma turbulence. This paper discusses this research

  19. Reduction of plasma density in the Helicity Injected Torus with Steady Inductance experiment by using a helicon pre-ionization source

    International Nuclear Information System (INIS)

    Hossack, Aaron C.; Jarboe, Thomas R.; Victor, Brian S.; Firman, Taylor; Prager, James R.; Ziemba, Timothy; Wrobel, Jonathan S.

    2013-01-01

    A helicon based pre-ionization source has been developed and installed on the Helicity Injected Torus with Steady Inductance (HIT-SI) spheromak. The source initiates plasma breakdown by injecting impurity-free, unmagnetized plasma into the HIT-SI confinement volume. Typical helium spheromaks have electron density reduced from (2–3) × 10 19 m −3 to 1 × 10 19 m −3 . Deuterium spheromak formation is possible with density as low as 2 × 10 18 m −3 . The source also enables HIT-SI to be operated with only one helicity injector at injector frequencies above 14.5 kHz. A theory explaining the physical mechanism driving the reduction of breakdown density is presented

  20. Reduction of plasma density in the Helicity Injected Torus with Steady Inductance experiment by using a helicon pre-ionization source

    Energy Technology Data Exchange (ETDEWEB)

    Hossack, Aaron C.; Jarboe, Thomas R.; Victor, Brian S. [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States); Firman, Taylor; Prager, James R.; Ziemba, Timothy [Eagle Harbor Technologies, Inc., 119 W. Denny Way, Suite 210, Seattle, Washington 98119 (United States); Wrobel, Jonathan S. [979B West Moorhead Circle, Boulder, Colorado 80305 (United States)

    2013-10-15

    A helicon based pre-ionization source has been developed and installed on the Helicity Injected Torus with Steady Inductance (HIT-SI) spheromak. The source initiates plasma breakdown by injecting impurity-free, unmagnetized plasma into the HIT-SI confinement volume. Typical helium spheromaks have electron density reduced from (2–3) × 10{sup 19} m{sup −3} to 1 × 10{sup 19} m{sup −3}. Deuterium spheromak formation is possible with density as low as 2 × 10{sup 18} m{sup −3}. The source also enables HIT-SI to be operated with only one helicity injector at injector frequencies above 14.5 kHz. A theory explaining the physical mechanism driving the reduction of breakdown density is presented.

  1. Effects of internal structure on equilibrium of field-reversed configuration plasma sustained by rotating magnetic field

    International Nuclear Information System (INIS)

    Yambe, Kiyoyuki; Inomoto, Michiaki; Okada, Shigefumi; Kobayashi, Yuka; Asai, Tomohiko

    2008-01-01

    The effects of an internal structure on the equilibrium of a field-reversed configuration (FRC) plasma sustained by rotating magnetic field is investigated by using detailed electrostatic probe measurements in the FRC Injection Experiment apparatus [S. Okada, et al., Nucl. Fusion. 45, 1094 (2005)]. An internal structure installed axially on the geometrical axis, which simulates Ohmic transformer or external toroidal field coils on the FRC device, brings about substantial changes in plasma density profile. The internal structure generates steep density-gradients not only on the inner side but on the outer side of the torus. The radial electric field is observed to sustain the ion thermal pressure-gradient in the FRC without the internal structure; however, the radial electric field is not sufficient to sustain the increased ion thermal pressure-gradient in the FRC with the internal structure. Spontaneously driven azimuthal ion flow will be accountable for the imbalance of the radial pressure which is modified by the internal structure.

  2. The Potential of Cold Plasma for Safe and Sustainable Food Production.

    Science.gov (United States)

    Bourke, Paula; Ziuzina, Dana; Boehm, Daniela; Cullen, Patrick J; Keener, Kevin

    2018-06-01

    Cold plasma science and technology is increasingly investigated for translation to a plethora of issues in the agriculture and food sectors. The diversity of the mechanisms of action of cold plasma, and the flexibility as a standalone technology or one that can integrate with other technologies, provide a rich resource for driving innovative solutions. The emerging understanding of the longer-term role of cold plasma reactive species and follow-on effects across a range of systems will suggest how cold plasma may be optimally applied to biological systems in the agricultural and food sectors. Here we present the current status, emerging issues, regulatory context, and opportunities of cold plasma with respect to the broad stages of primary and secondary food production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Magnetohydrodynamic stability of spheromak plasma in toroidal flux conserver with rectangular cross section, 2

    International Nuclear Information System (INIS)

    Kaneko, Shobu; Tsutsui, Hiroaki; Miyazaki, Takeshi; Taguchi, Masayoshi.

    1985-08-01

    The magnetohydrodynamic equilibrium states by Hill's vortex model and by the Coulomb-wave-function model are proved to be unstable. New MHD equilibrium configurations are determined by using another model for which dp/dψ = 0 on the magnetic axis. Here p is the pressure and ψ is the flux function. The values of the safety factor on the magnetic axis, q axis , are evaluated for these configurations. The MHD stability of these equilibrium states is investigated by the Mercier criterion. The values of the maximum beta ratio β max are evaluated for this model. The optimized pressure distributions are determined by use of the Mercier criterion and the values of β max are also evaluated for these pressure distributions. The values of β max are shown to be at most 12 %, if the condition q axis < 1 is required. (author)

  4. Comparative study of the electron density profiles in the compact torus plasma merging experiments

    International Nuclear Information System (INIS)

    Hayashiya, Hitoshi; Asaka, Takeo; Katsurai, Makoto

    2003-01-01

    Following two previous papers on the comparative studies of the electron density distributions for a single compact torus (CT) and a spherical tokamak (ST), and for the a single ST and a merged ST, a comparative study on the dynamics of the electron density profile and after the CT and ST plasma merging process was performed. The sharpness of the peak in the electron density profile around the mid-plane just after the merging of CT with a low safety factor (q value) such as RFP or spheromak is found to be related to the speed of the magnetic axis during the plasma merging process. It is also found that the electron density gradient near the plasma edge in a high q ST is larger than that of a low q CT. High q ST is found to be provided with the magnetic structure which is able to sustain a large thermal pressure by a strong j x B force. Despite these differences in the electron density profile between CT and ST during merging, the confinement characteristics evaluated from the number of electrons confined within the magnetic separatrix after the completion of the merging is almost similar between in the merging CT and in the merging ST. For all configurations, the electron density profiles after the completion of the merging are analogous to those of the corresponding single configuration produced without the merging process. (author)

  5. Modelling of a plasma column sustained by a travelling circularly polarized electromagnetic wave (m=1 mode) in the presence of a constant axial magnetic field

    International Nuclear Information System (INIS)

    Benova, E.; Staikov, P.; Zhelyazkov, I.

    1992-01-01

    A set of equations modelling a low-pressure plasma column sustained by a travelling electromagnetic wave in the dipolar mode in the presence of a constant external magnetic field is presented. It is shown that, from a practical point of view, only the m = 1 mode (the right-hand-polarized wave) can sustain plasma columns in a wide region of gas-discharge conditions: plasma radius R, wave frequency ω, magnetic field B 0 and low pressures, irrespective of the nature of the gas. The main result of this study is that the magnetic field makes it possible to sustain a plasma column for values of σ smaller than σ cr = 0.3726, below which, in the absence of a magnetic field, the dipolar wave cannot produce a plasma. Moreover, at a fixed wave power, the magnetic field - in contrast with the case of plasma columns sustained by azimuthally symmetric waves - increases the plasma density and its axial gradient. The limit of an infinite external magnetic field (Ω → ∞) is also considered. A three-dimensional wave structure is obtained, and it indicates that the wave can be a generalized surface mode, a pure surface or a pseudosurface one. (author)

  6. Current sustaining by RF travelling field in a collisional toroidal plasma

    International Nuclear Information System (INIS)

    Fukuda, Masaji; Matsuura, Kiyokata.

    1977-06-01

    The relation between the current generation by RF travelling field and the accompanied power absorption is studied in a collisional toroidal plasma, parameters being phase velocity and filling gas pressure or electron collision frequency. It is observed at a low magnetic field that the current is proportional to the plasma conductivity and an effective electromotive force, which is a new concept introduced on the basis of fluid model; the electromotive force is proportional to the absorbed RF power and inversely proportional to the plasma density and the phase velocity of the travelling field. (auth.)

  7. Current sustaining by RF travelling field in a collisional toroidal plasma

    International Nuclear Information System (INIS)

    Fukuda, Masaji; Matsuura, Kiyokata

    1978-01-01

    The relation between the current generated by RF travelling field and the absorbed power is studied in a collisional toroidal plasma, parameters being phase velocity and filling gap pressure or electron collision frequency. It is observed at a low magnetic field that the current is proportional to the plasma conductivity and an effective electromotive force, which is a new concept introduced on the basis of fluid model; the electromotive force is proportional to the absorbed RF power and inversely proportional to the plasma density and the phase velocity of the travelling field. (author)

  8. Plasma current sustainment after iron core saturation in the STOR-M tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Mitarai, O., E-mail: omitarai@ktmail.tokai-u.jp [Kumamoto Liberal Arts Education Center, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto 862-8652 (Japan); Ding, Y.; Hubeny, M.; Lu, Y.; Onchi, T.; McColl, D.; Xiao, C.; Hirose, A. [Plasma Physics Laboratory, University of Saskatchewan, 116 Science Place, Saskatoon, SK S7N 5E2 (Canada)

    2014-10-15

    Highlights: • Plasma current can be started up by small iron core without central solenoid. • Iron core removes central solenoid. • Plasma current can be maintained after iron core saturation. • Hysteresis curve shows the partial core saturation. • Image field from iron core is estimated during discharge. • Spherical tokamak reactor without CS is proposed using the small iron core. - Abstract: We propose to use of a small iron core transformer to start up the plasma current in a spherical tokamak (ST) reactor without central solenoid (CS). Taking advantage of the high aspect ratio of the STOR-M iron core tokamak, we have demonstrated that the plasma current up to 10–15 kA can be started up using the outer Ohmic heating (OH) coils without CS, and that the plasma current can be maintained further by increasing the outer OH coil current during iron core saturation phase. When the magnetizing current reaches 1.2 kA and the iron core becomes saturated, the third capacitor bank connected to the outer OH coils is discharged to maintain the plasma current. The plasma current is slightly increased and maintained for additional 5 ms as expected from numerical calculations. Core saturation has been clearly observed on the hysteresis curve. This is the first experimental demonstration of the feasibility of slow transition from the iron core to air core transformer phase without CS. The results implies that a plasma current can be initiated by a small iron core and could be ramped up by additional heating and vertical field after iron core saturation in future STs without CS.

  9. Plasma current sustained by fusion charged particles in a field reversed configuration

    International Nuclear Information System (INIS)

    Berk, H.L.; Momota, H.; Tajima, T.

    1987-04-01

    The distribution of energetic charged particles generated by thermonuclear fusion reactions in a field reversed configuration (FRC) are studied analytically and numerically. A fraction of the charged fusion products escapes directly while the others are trapped to form a directed particle flow parallel to the plasma current. It is shown that the resultant current density produced by these fusion charged particles can be comparable to background plasma current density that produces the original field reversed configuration in a D- 3 He reactor. Self-consistent equilibria arising from the currents of the background plasma and proton fusion products are constructed where the Larmor radius of the fusion product is of arbitrary size. Reactor relevant parameters are examined, such as how the fusion reactivity rate varies as a result of supporting the pressure associated with the fusion products. We also model the synchrotron emission from various pressure profiles and quantitatively show how synchrotron losses vary with different pressure profiles in an FRC configuration

  10. Computations of the Power to Sustain Plasma in Air with Relevance to Aerospace Technology

    National Research Council Canada - National Science Library

    Vidmar, Robert

    2004-01-01

    ... level to 300,000 ft. An air chemistry code was upgraded and optimized for air-plasma research with key reactions that are functions of the reduced electric field, E/N, with a maximum value of 2E-15 V-sq cm...

  11. Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

    2014-10-28

    We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

  12. EMAPS: An Efficient Multiscale Approach to Plasma Systems with Non-MHD Scale Effects

    Energy Technology Data Exchange (ETDEWEB)

    Omelchenko, Yuri A. [SciberQuest, Inc., Del Mar, CA (United States); Karimabadi, Homa [SciberQuest, Inc., Del Mar, CA (United States)

    2014-10-14

    Using Discrete-Event Simulation (DES) as a novel paradigm for time integration of large-scale physics-driven systems, we have achieved significant breakthroughs in simulations of multi-dimensional magnetized plasmas where ion kinetic and finite Larmor radius (FLR) and Hall effects play a crucial role. For these purposes we apply a unique asynchronous simulation tool: a parallel, electromagnetic Particle-in-Cell (PIC) code, HYPERS (Hybrid Particle Event-Resolved Simulator), which treats plasma electrons as a charge neutralizing fluid and solves a self-consistent set of non-radiative Maxwell, electron fluid equations and ion particle equations on a structured computational grid. HYPERS enables adaptive local time steps for particles, fluid elements and electromagnetic fields. This ensures robustness (stability) and efficiency (speed) of highly dynamic and nonlinear simulations of compact plasma systems such spheromaks, FRCs, ion beams and edge plasmas. HYPERS is a unique asynchronous code that has been designed to serve as a test bed for developing multi-physics applications not only for laboratory plasma devices but generally across a number of plasma physics fields, including astrophysics, space physics and electronic devices. We have made significant improvements to the HYPERS core: (1) implemented a new asynchronous magnetic field integration scheme that preserves local divB=0 to within round-off errors; (2) Improved staggered-grid discretizations of electric and magnetic fields. These modifications have significantly enhanced the accuracy and robustness of 3D simulations. We have conducted first-ever end-to-end 3D simulations of merging spheromak plasmas. The preliminary results show: (1) tilt-driven relaxation of a freely expanding spheromak to an m=1 Taylor helix configuration and (2) possibility of formation of a tilt-stable field-reversed configuration via merging and magnetic reconnection of two double-sided spheromaks with opposite helicities.

  13. Development of a real-time simulation tool towards self-consistent scenario of plasma start-up and sustainment on helical fusion reactor FFHR-d1

    Science.gov (United States)

    Goto, T.; Miyazawa, J.; Sakamoto, R.; Suzuki, Y.; Suzuki, C.; Seki, R.; Satake, S.; Huang, B.; Nunami, M.; Yokoyama, M.; Sagara, A.; the FFHR Design Group

    2017-06-01

    This study closely investigates the plasma operation scenario for the LHD-type helical reactor FFHR-d1 in view of MHD equilibrium/stability, neoclassical transport, alpha energy loss and impurity effect. In 1D calculation code that reproduces the typical pellet discharges in LHD experiments, we identify a self-consistent solution of the plasma operation scenario which achieves steady-state sustainment of the burning plasma with a fusion gain of Q ~ 10 was found within the operation regime that has been already confirmed in LHD experiment. The developed calculation tool enables systematic analysis of the operation regime in real time.

  14. Plasma characteristics in an electrically asymmetric capacitive discharge sustained by multiple harmonics: operating in the very high frequency regime

    Science.gov (United States)

    Zhang, Yu-Ru; Hu, Yan-Ting; Gao, Fei; Song, Yuan-Hong; Wang, You-Nian

    2018-05-01

    A novel method, the so-called electrical asymmetry effect (EAE), is gaining increasing interest for realizing the separate control of the ion flux and ion energy. In this paper, a two-dimensional fluid model combined with the full set of Maxwell equations is used to investigate the plasma properties in an electrically asymmetric capacitive discharge sustained by multiple consecutive harmonics operating in the very high frequency regime. The results indicate that by increasing the total number of consecutive harmonics k, the modulation of the dc self-bias induced by changing {θ }1 (the relative phase of the fundamental frequency) becomes different, especially for k ≤slant 6. In a discharge driven by eight consecutive harmonics, the dc self-bias varies with a period 2π, and the most positive value appears at {θ }1 = 3π/2. In addition, with the electromagnetic effects taken into account, the plasma density shifts from edge-high to uniform when {θ }1 increases from 0 to π, and the maximum moves again towards the radial wall at {θ }1 = 3π/2. Moreover, the transient behavior of electrodynamics is also important for a better understanding of the EAE. Within a period, three positive peaks of {P}z are observed, which cause substantial ionization at similar places. {P}r is characterized by a pronounced peak at the end of the period, and the lowest peak value appears at {θ }1 = π. The results obtained in this work are important for improving the plasma processes by utilizing the EAE, especially when the higher order harmonics are included.

  15. Departure from Local Thermodynamic Equilibrium in argon plasmas sustained in a Torche à Injection Axiale sur Guide d'Ondes

    International Nuclear Information System (INIS)

    Rincón, R.; Muñoz, J.; Calzada, M.D.

    2015-01-01

    Plasma torches are suitable plasma sources for a wide range of applications. The capability of these discharges to produce processes like sample excitation or decomposition of molecules inside them depends on the density of the plasma species and their energies (temperatures). The relation between these parameters determines the specific state of thermodynamic equilibrium in the discharge. Thus, the understanding of plasma possibilities for application purposes is related to the knowledge of the plasma thermodynamic equilibrium degree. In this paper a discussion about the equilibrium state for Ar plasmas generated by using a Torche à Injection Axiale sur Guide d'Ondes, TIAGO device, is presented. Emission spectroscopy techniques were used to measure gas temperature and electron density at the exit of the nozzle torch and along the dart. Boltzmann-plots as well as b p parameters were calculated to characterize the type and degree of departure from partial Local Saha Equilibrium (pLSE). This study indicates that the closer situation to Local Thermodynamic Equilibrium (LTE) of the plasma corresponds to larger Ar flows which highlights the importance of the nitrogen (atmosphere surrounding the plasma) in the kinetics of Ar-TIAGO discharges. - Highlights: • Discharges sustained in Ar using a TIAGO Torch show a significant departure from Local Thermodynamic Equilibrium. • Nitrogen entrance from surrounding air highly influences Thermodynamic Equilibrium. • Departure from LTE has been studied by means of Boltzmann plots and b p parameters. • The discharge is ionizing at the nozzle exit plasma, while along the dart it becomes recombining

  16. Singlet oxygen in the low-temperature plasma of an electron-beam-sustained discharge

    International Nuclear Information System (INIS)

    Vagin, N. P.; Ionin, A. A.; Klimachev, Yu. M.; Kotkov, A. A.; Kochetov, I. V.; Napartovich, A. P.; Podmar'kov, Yu. P.; Rulev, O. A.; Seleznev, L. V.; Sinitsyn, D. V.; Frolov, M. P.; Yuryshev, N. N.

    2006-01-01

    Results are presented from experimental and theoretical studies of the production of singlet delta oxygen in a pulsed electron-beam-sustained discharge ignited in a large (∼18-1) volume at a total gas mixture pressure of up to 210 Torr. The measured yield of singlet oxygen reaches 10.5%. It is found that varying the reduced electric field from ∼2 to ∼11 kV/(cm atm) slightly affects singlet oxygen production. It is shown experimentally that an increase in the gas mixture pressure or the specific input energy reduces the duration of singlet oxygen luminescence. The calculated time evolution of the singlet oxygen concentration is compared with experimental results

  17. Atmospheric plasma assisted PLA/microfibrillated cellulose (MFC) multilayer biocomposite for sustainable barrier application

    DEFF Research Database (Denmark)

    Meriçer, Çağlar; Minelli, Matteo; Angelis, Maria G De

    2016-01-01

    Fully bio-based and biodegradable materials, such as polylactic acid (PLA) and microfibrillated cellulose (MFC), are considered in order to produce a completely renewable packaging solution for oxygen barrier applications, even at medium-high relative humidity (R.H.). Thin layers of MFC were coated...... on different PLA substrates by activating film surface with an atmospheric plasma treatment, leading to the fabrication of robust and transparent multilayer composite films, which were then characterized by different experimental techniques. UV transmission measurements confirmed the transparency of multilayer...... films (60% of UV transmission rate), while SEM micrographs showed the presence of a continuous, dense and defect free layer of MFC on PLA surface. Concerning the mechanical behavior of the samples, tensile tests revealed that the multilayer films significantly improved the stress at break value of neat...

  18. Discharge characteristics of He-Ne-Xe gas mixture with varying Xe contents and at varying sustain electrode gap lengths in the plasma display panel

    International Nuclear Information System (INIS)

    Kwon, Ohyung; Whang, Ki-Woong; Bae, Hyun Sook

    2009-01-01

    The discharge characteristics of He-Ne-Xe gas mixture in the plasma display panel were investigated using a two-dimensional numerical simulation to understand the effects of adding He and varying the Xe contents in the gas mixture, and also varying sustain electrode gap. With 5% Xe content and 60 μm sustain electrode gap, decreased ionization led to the improvement of the vacuum ultraviolet (vuv) efficacy at increasing He mixing ratios. However, at 20% Xe content and 60 μm sustain electrode gap, increased electron heating improved the vuv efficacy until the He mixing ratio reached 0.7, but the efficacy decreased beyond the ratio of 0.7 due to the increased ionization of Xe atoms. At 5% Xe content and 200 μm sustain electrode gap, the vuv efficacy increased as a result of increased electron heating at the gap space at increasing He mixing ratios.

  19. Proceeding of A3 foresight program seminar on critical physics issues specific to steady state sustainment of high-performance plasmas 2014

    International Nuclear Information System (INIS)

    Morita, Shigeru; Hu Liqun; Oh, Yeong-Kook

    2014-10-01

    The A3 Foresight Program titled by 'Critical Physics Issues Specific to Steady State Sustainment of High-Performance Plasmas', based on the scientific collaboration among China, Japan and Korea in the field of plasma physics, has been started from August 2012 under the auspice of the Japan Society for the Promotion of Science (JSPS, Japan), the National Research Foundation of Korea (NRF, Korea) and the National Natural Science Foundation of China (NSFC, China). The main purpose of this project is to enhance joint experiments on three Asian advanced fully superconducting fusion devices (EAST in China, LHD in Japan and KSTAR in Korea) and other magnetic confinement devices to several key physics issues on steady state sustainment of high-performance plasmas. The fourth seminar on the A3 collaboration, as the fifth meeting of A3 program, took place in Kagoshima, Japan, 23-26 June 2014, which was hosted by National Institute for Fusion Science, to discuss achievement during past two years and to summarize intermediate report. New collaborative research was also encouraged as well as participation of young scientists. The topics include steady state sustainment of magnetic configuration, edge and divertor plasma control and confinement of alpha particles. This issue is the collection of 41 papers presented at the entitled meeting. All the 41 of the presented papers are indexed individually. (J.P.N.)

  20. A comparison between characteristics of atmospheric-pressure plasma jets sustained by nanosecond- and microsecond-pulse generators in helium

    International Nuclear Information System (INIS)

    Zhang, Cheng; Shao, Tao; Wang, Ruixue; Yan, Ping; Zhou, Zhongsheng; Zhou, Yixiao

    2014-01-01

    Power source is an important parameter that can affect the characteristics of atmospheric-pressure plasma jets (APPJs), because it can play a key role on the discharge characteristics and ionization process of APPJs. In this paper, the characteristics of helium APPJs sustained by both nanosecond-pulse and microsecond-pulse generators are compared from the aspects of plume length, discharge current, consumption power, energy, and optical emission spectrum. Experimental results showed that the pulsed APPJ was initiated near the high-voltage electrode with a small curvature radius, and then the stable helium APPJ could be observed when the applied voltage increased. Moreover, the discharge current of the nanosecond-pulse APPJ was larger than that of the microsecond-pulse APPJ. Furthermore, although the nanosecond-pulse generator consumed less energy than the microsecond-pulse generator, longer plume length, larger instantaneous power per pulse and stronger spectral line intensity could be obtained in the nanosecond-pulse excitation case. In addition, some discussion indicated that the rise time of the applied voltage could play a prominent role on the generation of APPJs

  1. Self-sustaining thin films as a means of reducing first wall erosion and plasma impurity influx

    International Nuclear Information System (INIS)

    Krauss, A.R.; Gruen, D.M.

    1982-01-01

    Neutral impurities ejected from Tokamak wall and limiter surfaces may travel several cm before being ionized very quickly upon entering the plasma edge. The influence of the unipolar sheath potential is exerted only within a very short distance of the surface and has no effect on neutral impurity atoms within a very short distance of the surface and has no effect on neutral impurity atoms which are subsequently ionized by charge-exchange collisions or electron impact ionization. However, secondary ions emanating from the limiter surfaces with kinetic energies less than the sheath potential will have essentially zero probability of traveling more than a few Debye lengths before being redeposited. Similarly, secondary ions originating at the first wall are redeposited as a result of the deflection produced by the magnetic field. Impurity influx resulting from sputtering would therefore be substantially reduced for surfaces which produce a very high ion/neutral ratio when sputtered. It has been previously shown that the high secondary ion yield associated with the alkali metal potassium does not apply to the bulk metal but pertains to ionic compounds and thin (mono-layer) films. Two processes are discussed as a means of producing these films in a self-sustaining manner compatible with the fusion reactor environment. (orig.)

  2. The dynomak: An advanced spheromak reactor concept with imposed-dynamo current drive and next-generation nuclear power technologies

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, D.A., E-mail: das1990@uw.edu; Jarboe, T.R.; Morgan, K.D.; Pfaff, M.; Lavine, E.S.; Kamikawa, Y.; Hughes, M.; Andrist, P.; Marklin, G.; Nelson, B.A.

    2014-04-15

    A high-β spheromak reactor concept has been formulated with an estimated overnight capital cost that is competitive with conventional power sources. This reactor concept utilizes recently discovered imposed-dynamo current drive (IDCD) and a molten salt (FLiBe) blanket system for first wall cooling, neutron moderation and tritium breeding. Currently available materials and ITER-developed cryogenic pumping systems were implemented in this concept from the basis of technological feasibility. A tritium breeding ratio (TBR) of greater than 1.1 has been calculated using a Monte Carlo N-Particle (MCNP5) neutron transport simulation. High temperature superconducting tapes (YBCO) were used for the equilibrium coil set, substantially reducing the recirculating power fraction when compared to previous spheromak reactor studies. Using zirconium hydride for neutron shielding, a limiting equilibrium coil lifetime of at least thirty full-power years has been achieved. The primary FLiBe loop was coupled to a supercritical carbon dioxide Brayton cycle due to attractive economics and high thermal efficiencies. With these advancements, an electrical output of 1000 MW from a thermal output of 2486 MW was achieved, yielding an overall plant efficiency of approximately 40%.

  3. Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

  4. The roles of electric field shear and Shafranov shift in sustaining high confinement in enhanced reversed shear plasmas on the TFTR tokamak

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Beer, M.A.

    1997-02-01

    The relaxation of core transport barriers in TFTR Enhanced Reversed Shear plasmas has been studied by varying the radial electric field using different applied torques from neutral beam injection. Transport rates and fluctuations remain low over a wide range of radial electric field shear, but increase when the local E x B shearing rates are driven below a threshold comparable to the fastest linear growth rates of the dominant instabilities. Shafranov-shift-induced stabilization alone is not able to sustain enhanced confinement

  5. Theory and application of maximum magnetic energy in toroidal plasmas

    International Nuclear Information System (INIS)

    Chu, T.K.

    1992-02-01

    The magnetic energy in an inductively driven steady-state toroidal plasma is a maximum for a given rate of dissipation of energy (Poynting flux). A purely resistive steady state of the piecewise force-free configuration, however, cannot exist, as the periodic removal of the excess poloidal flux and pressure, due to heating, ruptures the static equilibrium of the partitioning rational surfaces intermittently. The rupture necessitates a plasma with a negative q'/q (as in reverse field pinches and spheromaks) to have the same α in all its force-free regions and with a positive q'/q (as in tokamaks) to have centrally peaked α's

  6. Generation of uniform low-temperature plasma in a pulsed non-self-sustained glow discharge with a large-area hollow cathode

    Energy Technology Data Exchange (ETDEWEB)

    Akhmadeev, Yu. H.; Denisov, V. V., E-mail: volodyadenisov@yandex.ru; Koval, N. N.; Kovalsky, S. S.; Lopatin, I. V.; Schanin, P. M.; Yakovlev, V. V. [Russian Academy of Sciences, Institute of High-Current Electronics, Siberian Branch (Russian Federation)

    2017-01-15

    Generation of plasma in a pulsed non-self-sustained glow discharge with a hollow cathode with an area of ≥2 m{sup 2} at gas pressures of 0.4–1 Pa was studied experimentally. At an auxiliary arc-discharge current of 100 A and a main discharge voltage of 240 V, a pulse-periodic glow discharge with a current amplitude of 370 A, pulse duration of 340 μs, and repetition rate of 1 kHz was obtained. The possibility of creating a uniform gas-discharge plasma with a density of up to 10{sup 12} cm{sup −3} and an electron temperature of 1 eV in a volume of >0.2 m{sup 3} was demonstrated. Such plasma can be efficiently used to treat material surfaces and generate pulsed ion beams with a current density of up to 15 mA/cm{sup 2}.

  7. Plasmas in saline solutions sustained using rectified ac voltages: polarity and frequency effects on the discharge behaviour

    International Nuclear Information System (INIS)

    Chang Hungwen; Hsu Chengche

    2012-01-01

    In this work, three major problems, namely severe electrode damage, poor plasma stability and excess power consumption, arising in ac-driven plasmas in saline solutions are solved using a rectified power source. Diagnostic studies on the effects of power source polarity and frequency on the plasma behaviour are performed. Examination of I-V characteristics and temporally resolved light emission shows that the polarity significantly influences the current amplitude when the plasma exists, while the frequency alters the bubble dynamics, which in turn affects the plasma ignition voltage. When the plasma is driven by a rectified ac power source, the electrode erosion is reduced substantially. With a low frequency, moderate applied voltage and positively rectified ac power source (e.g. 100 Hz and 350 V), a stable plasma is ignited in nearly every power cycle. (paper)

  8. Proceedings of A3 foresight program seminar on critical physics issues specific to steady state sustainment of high-performance plasmas

    International Nuclear Information System (INIS)

    Morita, Shigeru; Hu Liqun; Oh, Yeong-Kook

    2013-06-01

    The A3 Foresight Program titled by 'Critical Physics Issues Specific to Steady State Sustainment of High-Performance Plasmas', based on the scientific collaboration among China, Japan and Korea in the field of plasma physics, has been newly started from August 2012 under the auspice of the Japan Society for the Promotion of Science (JSPS, Japan), the National Research Foundation of Korea (NRF, Korea) and the National Natural Science Foundation of China (NSFC, China). A seminar on the A3 collaboration took place in Hotel Gozensui, Kushiro, Japan, 22-25 January 2013. This seminar was organized by National Institute for Fusion Science. One special talk and 36 oral talks were presented in the seminar including 13 Chinese, 14 Japanese and 9 Korean attendees. Steady state sustainment of high-performance plasmas is a crucial issue for realizing a nuclear fusion reactor. This seminar was motivated along the issues. Results on fusion experiments and theory obtained through A3 foresight program during recent two years were discussed and summarized. Possible direction of future collaboration and further encouragement of scientific activity of younger scientists were also discussed in this seminar with future experimental plans in three countries. This issue is the collection of 29 papers presented at the entitled meeting. All the 29 of the presented papers are indexed individually. (J.P.N.)

  9. Progress In Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Francis Y. C.; Kirkpatrick, Ronald C.; Knapp, Charles E.; Cassibry, Jason; Eskridge, Richard; Lee, Michael; Smith, James; Martin, Adam; Wu, S. T.; Schmidt, George; hide

    2001-01-01

    Magnetized target fusion (MTF) attempts to combine the favorable attributes of magnetic confinement fusion (MCF) for energy confinement with the attributes of inertial confinement fusion (ICF) for efficient compression heating and wall-free containment of the fusing plasma. It uses a material liner to compress and contain a magnetized plasma. For practical applications, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC).

  10. Sustained high plasma mannose less sensitive to fluctuating blood glucose in glycogen storage disease type Ia children

    NARCIS (Netherlands)

    Nagasaka, Hironori; Yorifuji, Tohru; Bandsma, Robert H. J.; Takatani, Tomozumi; Asano, Hisaki; Mochizuki, Hiroshi; Takuwa, Mayuko; Tsukahara, Hirokazu; Inui, Ayano; Tsunoda, Tomoyuki; Komatsu, Haruki; Hiejima, Eitaro; Fujisawa, Tomoo; Hirano, Ken-ichi; Miida, Takashi; Ohtake, Akira; Taguchi, Tadao; Miwa, Ichitomo

    Plasma mannose is suggested to be largely generated from liver glycogen-oriented glucose-6-phosphate. This study examined plasma mannose in glycogen storage disease type Ia (GSD Ia) lacking conversion of glucose-6-phosphate to glucose in the liver. We initially examined fasting-and postprandial 2

  11. Angiogenic properties of sustained release platelet-rich plasma: characterization in-vitro and in the ischemic hind limb of the mouse.

    Science.gov (United States)

    Bir, Shyamal Chandra; Esaki, Jiro; Marui, Akira; Yamahara, Kenichi; Tsubota, Hideki; Ikeda, Tadashi; Sakata, Ryuzo

    2009-10-01

    While single growth factor has limitation to induce optimal neovascularization, platelet-rich plasma (PRP) is an autologous reserver of various growth factors. However, little is known about the mechanism of PRP-related neovascularization.The objective of this investigation was to characterize the angiogenic and growth factor content of PRP and to determine, in vitro, its effect on endothelial cell proliferation. Additionally, this experiment sought to determine the effectiveness of different compositions of PRP (solution versus sustained release) on perfusion and neovascularization in a murine model of hind limb ischemia. Different growth factors were measured by enzyme-linked immunosorbent assay (ELISA). In vivo study, we used gelatin hydrogel as a sustained release carrier for growth factors in PRP. We induced hind limb ischemia by excising right femoral artery in wild type C57BL6 mice. After surgery, mice were randomly assigned to four experimental groups; control (C), 100 muL of sustained release form of platelet-poor plasma (PPP), 100 muL of solution form of PRP (PRP-sol), 100 muL of sustained release form of PRP (PRP-sr); each formulation was administered via an intramuscular injection to the ischemic hind limb. Endpoint evaluations were blood perfusion by laser Doppler perfusion image, vascular density by anti Von Willebrand factor (vWF), and mature vessel density by anti smooth muscle actin (SMA) antibody. Green fluorescent protein (GFP+) transgenic mice were generated by transplantation of bone marrow derived mononuclear cells to wild type C57BL6 mice, and finally CD34+ cell in the ischemic site of transgenic mice was detected by staining with anti-CD34 antibody. In vitro study showed that PRP containing different growth factors induces endothelial cell proliferation and capillary tube formation. In vivo study demonstrated that sustained release of PRP increased perfusion of ischemic tissue as measured by laser Doppler perfusion imaging (LDPI) (57 +/- 12

  12. Continuous, edge localized ion heating during non-solenoidal plasma startup and sustainment in a low aspect ratio tokamak

    Science.gov (United States)

    Burke, M. G.; Barr, J. L.; Bongard, M. W.; Fonck, R. J.; Hinson, E. T.; Perry, J. M.; Reusch, J. A.; Schlossberg, D. J.

    2017-07-01

    Plasmas in the Pegasus spherical tokamak are initiated and grown by the non-solenoidal local helicity injection (LHI) current drive technique. The LHI system consists of three adjacent electron current sources that inject multiple helical current filaments that can reconnect with each other. Anomalously high impurity ion temperatures are observed during LHI with T i,OV  ⩽  650 eV, which is in contrast to T i,OV  ⩽  70 eV from Ohmic heating alone. Spatial profiles of T i,OV indicate an edge localized heating source, with T i,OV ~ 650 eV near the outboard major radius of the injectors and dropping to ~150 eV near the plasma magnetic axis. Experiments without a background tokamak plasma indicate the ion heating results from magnetic reconnection between adjacent injected current filaments. In these experiments, the HeII T i perpendicular to the magnetic field is found to scale with the reconnecting field strength, local density, and guide field, while {{T}\\text{i,\\parallel}} experiences little change, in agreement with two-fluid reconnection theory. This ion heating is not expected to significantly impact the LHI plasma performance in Pegasus, as it does not contribute significantly to the electron heating. However, estimates of the power transfer to the bulk ion are quite large, and thus LHI current drive provides an auxiliary ion heating mechanism to the tokamak plasma.

  13. Proceedings of the third meeting for A3 foresight program workshop on critical physics issues specific to steady state sustainment of high-performance plasmas

    International Nuclear Information System (INIS)

    Hu Liqun; Morita, Shigeru; Oh, Yeong-Kook

    2013-12-01

    To enhance close collaborations among scientists in three Asian countries (China, Japan and Korea), A3 foresight program on Plasma Physics was newly started from August 2012 under the auspice of JSPS (Japan), NRF (Korea) and NSFC (China). The main purpose of this project is to solve several key physics issues through joint experiments on three Asian advanced fully superconducting fusion devices (EAST in China, LHD in Japan and KSTAR in Korea) and other magnetic confinement devices to carry out multi-faceted and complementary physics researches. To summarize the progress and achievement in the first academic year under this A3 foresight program, this workshop was hosted by Institute of Plasma Physics, Chinese Academy of Sciences and held in Beijing during 19-24 May, 2013. Collaborated research and communication with other A3 programs and bilateral programs, as well as participation of young scientists were encouraged in this workshop. The topics include steady state sustainment of magnetic configurations, edge and divertor plasma control and confinement of alpha particles. This issue is the collection of 40 papers presented at the entitled meeting. All the 40 of the presented papers are indexed individually. (J.P.N.)

  14. Proceeding of A3 foresight program seminar on critical physics issues specific to steady state sustainment of high-performance plasmas 2015

    International Nuclear Information System (INIS)

    Hu Liqun; Morita, Shigeru; Oh, Yeong-Kook

    2015-12-01

    To enhance close collaborations among scientists in three Asian countries (China, Japan and Korea), A3 foresight program on Plasma Physics was launched from August 2012 under the auspice of JSPS (Japan), NRF (Korea) and NSFC (China). The main purpose of this project is to solve several key physics issues through joint experiments on three Asian advanced fully superconducting fusion devices (EAST in China, LHD in Japan and KSTAR in Korea) and other magnetic confinement devices to carry out multi-faceted and complementary physics researches. To summarize the progress and achievement in the second academic year under this A3 foresight program, the 6th workshop hosted by Institute of Plasma Physics, Chinese Academy of Sciences was held in Nanning during 6-9 January, 2015. The research collaboration carried out by young scientists was also encouraged with participation of graduated students. The three topics of steady state sustainment of magnetic configurations, edge and divertor plasma control and confinement of alpha particles are mainly discussed in addition to relevant studies in small devices. This issue is the collection of 41 papers presented at the entitled meeting. The 39 of the presented papers are indexed individually. (J.P.N.)

  15. A simple data acquisition system based on arduino platform for non-self-sustained gas discharge plasma diagnostics

    International Nuclear Information System (INIS)

    Misiruk, I.O.; Garkusha, I.E.; Timoshenko, O.I.; Taran, V.S.

    2016-01-01

    A simple data acquisition system based on Arduino Nano platform is developed. Bluetooth wireless protocol is used for data transmission. Android OS application for data visualization and recording is developed. The system was success-fully applied for acquiring data of Langmuir probe measurements in the non-self-sustained discharge with a hollow anode.

  16. Large density amplification measured on jets ejected from a magnetized plasma gun

    OpenAIRE

    Yun, Gunsu S.; You, Setthivoine; Bellan, Paul M.

    2007-01-01

    Observation of a large density amplification in the collimating plasma jet ejected from a coplanar coaxial plasma gun is reported. The jet velocity is ~30 km s^-1 and the electron density increases from ~10^20 to 10^(22–23) m^-3. In previous spheromak experiments, electron density of the order 10^(19–21) m^-3 had been measured in the flux conserver region, but no density measurement had been reported for the source gun region. The coplanar geometry of our electrodes permits direct observation...

  17. Sustained availability of trimethoprim in drinking water to achieve higher plasma sulphonamide-trimethoprim antibacterial activity in broilers.

    Science.gov (United States)

    Sumano, H; Hernandez, L; Gutierrez, L; Bernad-Bernad, M J

    2005-02-01

    (1) In order to make trimethoprim (TMP) available to broilers throughout the day, a sustained release formulation (SRF) of the drug in the form of granules was added to the water tank that supplies drinking water. (2) Broilers were initially dosed with sulphachloropiridazine-TMP (SCP-TMP 5:1) and then further medicated throughout the day, achieving in the end a dose of 30 mg/kg each of SCP and TMP (group A). Group B received a preparation with the same dose of SCP and TMP (1:1) as group A, but administered as a single dose without the SRF of TMP. Group C received the customary SCP-TMP 5:1 preparation (30 and 6 mg/kg, respectively). Water tanks were completely consumed in 3 to 4 h. (3) Broilers were bled at different times and concentration of antibacterial activity in serum determined by correlating the composite antibacterial activity of SCP and TMP with actual concentrations of these drugs by means of a microbiological agar diffusion assay. (4) Time vs serum concentrations of activity were higher in group B; the increments in the maximum serum concentration for group B over groups A and C being 39 and 67%, respectively. (5) However, the sustained concentration of activity over time, measured as the area under the cu)rve, was highest in group A. Group B had higher values for area under the curve than group C. (6) An additional dose of TMP to achieve 30 mg/kg of both SCP and TMP improves the serum concentration of this combination over the customary 5:1 proportion. The best values for sustaining antibacterial activity were obtained using a 1:1 ratio as in group A. The use of a SRF as in group A may translate into better clinical results.

  18. On the jets, kinks, and spheromaks formed by a planar magnetized coaxial gun

    OpenAIRE

    Hsu, S. C.; Bellan, P. M.

    2005-01-01

    Measurements of the various plasma configurations produced by a planar magnetized coaxial gun provide insight into the magnetic topology evolution resulting from magnetic helicity injection. Important features of the experiments are a very simple coaxial gun design so that all observed geometrical complexity is due to the intrinsic physical dynamics rather than the source shape and use of a fast multiple-frame digital camera which provides direct imaging of topologically complex shapes and dy...

  19. Sustained High Levels of Both Total and High Molecular Weight Adiponectin in Plasma during the Convalescent Phase of Haemorrhagic Fever with Renal Syndrome Are Associated with Disease Severity

    Directory of Open Access Journals (Sweden)

    Kang Tang

    2017-01-01

    Full Text Available Haemorrhagic fever with renal syndrome (HFRS is characterised by an uncontrolled immune response that causes vascular leakage. Adiponectin (APN is an adipocytokine involved in prorevascularisation and immunomodulation. To investigate the possible effects of APN in the pathogenesis of HFRS, total and high molecular weight (HMW APN levels in the plasma of patients with HFRS were quantified using enzyme-linked immunosorbent assay (ELISA. Compared with those in healthy controls, the plasma total and HMW APN levels in patients were elevated to different degrees from the fever onset and remained high at the convalescent phase. Consistent with these results, western blot analysis additionally showed that low molecular weight (LMW, middle molecular weight (MMW, and HMW APN levels were all elevated and contributed to the elevation of the total APN level. Importantly, sustained high levels of total and HMW APN at the convalescent phase were significantly higher in patients with critical disease than those in patients with mild or moderate disease. Moreover, total and HMW APN levels negatively correlated with white blood cell count and positively correlated with platelet count and serum albumin level. These results may provide insights into understanding the roles of total and HMW APN in the pathogenesis of HFRS.

  20. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    Energy Technology Data Exchange (ETDEWEB)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2006-10-07

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10{sup 14} and 6 x 10{sup 15} m{sup -3}. Using the estimated values for the electron density, between 2 x 10{sup 19} and 3 x 10{sup 19} m{sup -3}, the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%.

  1. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    International Nuclear Information System (INIS)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der

    2006-01-01

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10 14 and 6 x 10 15 m -3 . Using the estimated values for the electron density, between 2 x 10 19 and 3 x 10 19 m -3 , the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%

  2. Laboratory Experiments on Propagating Plasma Bubbles into Vacuum, Vacuum Magnetic Field, and Background Plasmas

    Science.gov (United States)

    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.

  3. New approach for sustaining energetic, efficient and scalable non-equilibrium plasma in water vapours at atmospheric pressure

    International Nuclear Information System (INIS)

    Malik, Muhammad Arif; Schoenbach, Karl H

    2012-01-01

    Energetic and scalable non-equilibrium plasma was formed in pure water vapour at atmospheric pressure between wire-to-strip electrodes on a dielectric surface with one of the electrodes extended forming a conductive plane on the back side of the dielectric surface. The energy deposition increased by an order of magnitude compared with the conventional pulsed corona discharges under the same conditions. The scalability was demonstrated by operating two electrode assemblies with a common conductive plane between two dielectric layers. The energy yields for hydrogen and hydrogen peroxide generation were measured as ∼1.2 g H 2 /kWh and ∼4 g H 2 O 2 /kWh. (fast track communication)

  4. Hybrid simulation of electron energy distributions and plasma characteristics in pulsed RF CCP sustained in Ar and SiH4/Ar discharges

    Science.gov (United States)

    Wang, Xi-Feng; Jia, Wen-Zhu; Song, Yuan-Hong; Zhang, Ying-Ying; Dai, Zhong-Ling; Wang, You-Nian

    2017-11-01

    Pulsed-discharge plasmas offer great advantages in deposition of silicon-based films due to the fact that they can suppress cluster agglomeration, moderate the energy of bombarding ions, and prolong the species' diffusion time on the substrate. In this work, a one-dimensional fluid/Monte-Carlo hybrid model is applied to study pulse modulated radio-frequency (RF) plasmas sustained in capacitively coupled Ar and SiH4/Ar discharges. First, the electron energy distributions in pulsed Ar and SiH4/Ar plasmas have been investigated and compared under identical discharge-circuit conditions. The electron energy distribution function (EEDF) in Ar discharge exhibits a familiar bi-Maxwellian shape during the power-on phase of the pulse, while a more complex (resembling a multi-Maxwellian) distribution with extra inflection points at lower energies is observed in the case of the SiH4/Ar mixture. These features become more prominent with the increasing fraction of SiH4 in the gas mixture. The difference in the shape of the EEDF (which is pronounced inside the plasma but not in the RF sheath where electron heating occurs) is mainly attributed to the electron-impact excitations of SiH4. During the power-off phase of the pulse, the EEDFs in both Ar and SiH4/Ar discharges evolve into bi-Maxwellian shapes, with shrinking high energy tails. Furthermore, the parameter of ion species in the case of SiH4/Ar discharge is strongly modulated by pulsing. For positive ions, such as SiH3+ and Si2H4+ , the particle fluxes overshoot at the beginning of the power-on interval. Meanwhile, for negative ions such as SiH2- and SiH3- , density profiles observed between the electrodes are saddle-shaped due to the repulsion by the self-bias electric field as it builds up. During the power-off phase, the wall fluxes of SiH2- and SiH3- gradually increase, leading to a significant decrease in the net surface charge density on the driven electrode. Compared with ions, the density of SiH3 is poorly modulated

  5. Relationship between Sustained Reductions in Plasma Lipid and Lipoprotein Concentrations with Apheresis and Plasma Levels and mRNA Expression of PTX3 and Plasma Levels of hsCRP in Patients with HyperLp(a)lipoproteinemia

    Science.gov (United States)

    Stefanutti, Claudia; Mazza, Fabio; Steiner, Michael; Watts, Gerald F.; De Nève, Joel; Pasqualetti, Daniela; Paal, Juergen

    2016-01-01

    The effect of lipoprotein apheresis (Direct Adsorption of Lipids, DALI) (LA) on plasma levels of pentraxin 3 (PTX3), an inflammatory marker that reflects coronary plaque vulnerability, and expression of PTX3 mRNA was evaluated in patients with hyperLp(a)lipoproteinemia and angiographically defined atherosclerosis/coronary artery disease. Eleven patients, aged 55 ± 9.3 years (mean ± SD), were enrolled in the study. PTX3 soluble protein levels in plasma were unchanged by 2 sessions of LA; however, a downregulation of mRNA expression for PTX3 was observed, starting with the first session of LA (p < 0.001). The observed reduction was progressively increased in the interval between the first and second LA sessions to achieve a maximum decrease by the end of the second session. A statistically significantly greater treatment-effect correlation was observed in patients undergoing weekly treatments, compared with those undergoing treatment every 15 days. A progressive reduction in plasma levels of C-reactive protein was also seen from the first session of LA, with a statistically significant linear correlation for treatment-effect in the change in plasma levels of this established inflammatory marker (R 2 = 0.99; p < 0.001). Our findings suggest that LA has anti-inflammatory and endothelium protective effects beyond its well-established efficacy in lowering apoB100-containing lipoproteins. PMID:26903710

  6. Relationship between Sustained Reductions in Plasma Lipid and Lipoprotein Concentrations with Apheresis and Plasma Levels and mRNA Expression of PTX3 and Plasma Levels of hsCRP in Patients with HyperLp(alipoproteinemia

    Directory of Open Access Journals (Sweden)

    Claudia Stefanutti

    2016-01-01

    Full Text Available The effect of lipoprotein apheresis (Direct Adsorption of Lipids, DALI (LA on plasma levels of pentraxin 3 (PTX3, an inflammatory marker that reflects coronary plaque vulnerability, and expression of PTX3 mRNA was evaluated in patients with hyperLp(alipoproteinemia and angiographically defined atherosclerosis/coronary artery disease. Eleven patients, aged 55±9.3 years (mean ± SD, were enrolled in the study. PTX3 soluble protein levels in plasma were unchanged by 2 sessions of LA; however, a downregulation of mRNA expression for PTX3 was observed, starting with the first session of LA (p<0.001. The observed reduction was progressively increased in the interval between the first and second LA sessions to achieve a maximum decrease by the end of the second session. A statistically significantly greater treatment-effect correlation was observed in patients undergoing weekly treatments, compared with those undergoing treatment every 15 days. A progressive reduction in plasma levels of C-reactive protein was also seen from the first session of LA, with a statistically significant linear correlation for treatment-effect in the change in plasma levels of this established inflammatory marker (R2=0.99; p<0.001. Our findings suggest that LA has anti-inflammatory and endothelium protective effects beyond its well-established efficacy in lowering apoB100-containing lipoproteins.

  7. A mechanism for the formation and sustainment of the self-organized global profile and E   ×   B staircase in tokamak plasmas

    Science.gov (United States)

    Wang, W.; Kishimoto, Y.; Imadera, K.; Li, J. Q.; Wang, Z. X.

    2018-05-01

    The mechanism for the formation and sustainment of a self-organized global profile and the ‘ E   ×   B staircase’ are investigated through simulations of a flux-driven ion temperature gradient (ITG) turbulence based on GKNET, a 5D global gyrokinetic code. The staircase is found to be initiated from the radially extended ITG mode structures with nearly up-down symmetry during the saturation phase, and is established as it evolves into a quasi-steady turbulence, leading to a self-organized global temperature profile and to meso-scale isomorphic profiles of the radial electric field and the temperature gradient. It is found that the quasi-regular E   ×   B shear flow pattern is primarily originated from an even-symmetrical zonal flow produced by the extended ITG mode, which flow pattern exhibits an in-phase relation with the mean flow variation induced by the temperature relaxation. Consequently, the staircase is initiated through the profiles of total electric field and temperature gradient with a self-organized manner. Since the sign of E   ×   B shear flow at the central part are opposite to that at both edges, it disintegrates the ITG mode into smaller scale eddies. Meanwhile, smaller scale eddies tend to be aligned radially by spontaneous phase matching, which can provide the growth of mode amplitude and the formation of radially extended mode structures, leading to the bursty heat transport. This process is repeated quasi-periodically, sustaining self-organized structures and the E   ×   B staircase. Moreover, the equilibrium mean field is found to be of specific importance in causing the structures and dynamics from meso- to macro scales in toroidal plasmas.

  8. Magnetic vortex growth in the transition layer of a mildly relativistic plasma shock

    International Nuclear Information System (INIS)

    Murphy, G. C.; Dieckmann, M. E.; Drury, L. O'C.

    2010-01-01

    A two-dimensional particle simulation models the collision of two electron-ion plasma clouds along a quasiparallel magnetic field. The collision speed is 0.9c and the density ratio, 10. A current sheet forms at the front of the dense cloud, in which the electrons and the magnetic field reach energy equipartition with the ions. A structure composed of a solenoidal and a toroidal magnetic field grows in this sheet. It resembles the cross-section of the torus of a spheromak, which may provide the coherent magnetic fields in gamma-ray burst jets needed for their prompt emissions.

  9. Sustaining Effect of Intensive Nutritional Intervention Combined with Health Education on Dietary Behavior and Plasma Glucose in Type 2 Diabetes Mellitus Patients.

    Science.gov (United States)

    Fan, Rui; Xu, Meihong; Wang, Junbo; Zhang, Zhaofeng; Chen, Qihe; Li, Ye; Gu, Jiaojiao; Cai, Xiaxia; Guo, Qianying; Bao, Lei; Li, Yong

    2016-09-13

    Diabetes mellitus is very common in elderly Chinese individuals. Although nutritional intervention can provide a balanced diet, the sustaining effect on at-home dietary behavior and long-term plasma glucose control is not clear. Consequently, we conducted a long-term survey following one month of experiential nutritional intervention combined with health education. Based on the Dietary Guidelines for a Chinese Resident, we found that the food items met the recommended values, the percentages of energy provided from fat, protein, and carbohydrate were more reasonable after one year. The newly formed dietary patterns were "Healthy", "Monotonous", "Vegetarian", "Japanese", "Low energy", and "Traditional" diets. The 2h-PG of female participants as well as those favoring the "Japanese diet" decreased above 12 mmol/L. Participants who selected "Japanese" and "Healthy" diets showed an obvious reduction in FPG while the FPG of participants from Group A declined slightly. "Japanese" and "Healthy" diets also obtained the highest DDP scores, and thus can be considered suitable for T2DM treatment in China. The results of the newly formed dietary patterns, "Japanese" and "Healthy" diets, confirmed the profound efficacy of nutritional intervention combined with health education for improving dietary behavior and glycemic control although health education played a more important role. The present study is encouraging with regard to further exploration of comprehensive diabetes care.

  10. Sustaining Effect of Intensive Nutritional Intervention Combined with Health Education on Dietary Behavior and Plasma Glucose in Type 2 Diabetes Mellitus Patients

    Directory of Open Access Journals (Sweden)

    Rui Fan

    2016-09-01

    Full Text Available Diabetes mellitus is very common in elderly Chinese individuals. Although nutritional intervention can provide a balanced diet, the sustaining effect on at-home dietary behavior and long-term plasma glucose control is not clear. Consequently, we conducted a long-term survey following one month of experiential nutritional intervention combined with health education. Based on the Dietary Guidelines for a Chinese Resident, we found that the food items met the recommended values, the percentages of energy provided from fat, protein, and carbohydrate were more reasonable after one year. The newly formed dietary patterns were “Healthy”, “Monotonous”, “Vegetarian”, “Japanese”, “Low energy”, and “Traditional” diets. The 2h-PG of female participants as well as those favoring the “Japanese diet” decreased above 12 mmol/L. Participants who selected “Japanese” and “Healthy” diets showed an obvious reduction in FPG while the FPG of participants from Group A declined slightly. “Japanese” and “Healthy” diets also obtained the highest DDP scores, and thus can be considered suitable for T2DM treatment in China. The results of the newly formed dietary patterns, “Japanese” and “Healthy” diets, confirmed the profound efficacy of nutritional intervention combined with health education for improving dietary behavior and glycemic control although health education played a more important role. The present study is encouraging with regard to further exploration of comprehensive diabetes care.

  11. Observations and modeling of magnetized plasma jets and bubbles launched into a transverse B-field

    Science.gov (United States)

    Fisher, Dustin M.; Zhang, Yue; Wallace, Ben; Gilmore, Mark; Manchester, Ward B., IV; van der Holst, Bart; Rogers, Barrett N.; Hsu, Scott C.

    2017-10-01

    Hot, dense, plasma structures launched from a coaxial plasma gun on the HelCat dual-source plasma device at the University of New Mexico drag frozen-in magnetic flux into the chamber's background magnetic field providing a rich set of dynamics to study magnetic turbulence, force-free magnetic spheromaks, shocks, as well as CME-like dynamics possibly relevant to the solar corona. Vector magnetic field data from an eleven-tipped B-dot rake probe and images from an ultra-fast camera will be presented in comparison with ongoing MHD modeling using the 3-D MHD BATS-R-US code developed at the University of Michigan. BATS-R-US employs an adaptive mesh refinement grid (AMR) that enables the capture and resolution of shock structures and current sheets and is uniquely suited for flux-rope expansion modeling. Recent experiments show a possible magnetic Rayleigh-Taylor (MRT) instability that appears asymmetrically at the interface between launched spheromaks (bubbles) and their entraining background magnetic field. Efforts to understand this instability using in situ measurements, new chamber boundary conditions, and ultra-fast camera data will be presented. Work supported by the Army Research Office Award No. W911NF1510480.

  12. Magnetic reconnection and self-organized plasma systems

    International Nuclear Information System (INIS)

    Yamada, Masaaki; Ji, Hantao

    2000-01-01

    In this paper the recent results from the Magnetic Reconnection Experiment (MRX) at PPPL are discussed along with their relationship to observations from solar flares, the magnetosphere, and current carrying pinch discharges such as tokamaks, reversed field pinches, spheromaks and field reversed configurations. It is found that the reconnection speed decreases as the angle of merging field lines decreases, consistent with the well-established observation in the dayside magnetosphere. This observation can also provide a qualitative interpretation of a generally observed trend in pinch plasmas, namely that magnetic field diffuses (or reconnects) faster when magnetic shear is larger. A recently conceived research project, SPIRIT (Self-organized Plasma with Induction, Reconnection, and Injection Techniques), will also be discussed. (author)

  13. Measurement of the local particle diffusion coefficient in a magnetized plasma

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Levinton, F.M.

    1987-02-01

    Local impurity particle diffusion coefficients have been measured in a low temperature plasma by the injection of test particles at the center of the plasma. The injection is accomplished by a high voltage discharge between two small graphite electrodes on a probe. The probe can be located anywhere in the plasma. The diffusion is observed spectroscopically. An analysis of the spatial and temporal evolution of the CII radiation from the carbon discharge can determine the parallel and perpendicular diffusion of the impurity ions. Results with the diagnostic have been obtained in the Proto S-1/C spheromak. The measured value of the diffusion coefficient in the afterglow plasma is in good agreement with classical predictions

  14. Dynamics of Magnetized Plasma Jets and Bubbles Launched into a Background Magnetized Plasma

    Science.gov (United States)

    Wallace, B.; Zhang, Y.; Fisher, D. M.; Gilmore, M.

    2016-10-01

    The propagation of dense magnetized plasma, either collimated with mainly azimuthal B-field (jet) or toroidal with closed B-field (bubble), in a background plasma occurs in a number of solar and astrophysical cases. Such cases include coronal mass ejections moving in the background solar wind and extragalactic radio lobes expanding into the extragalactic medium. Understanding the detailed MHD behavior is crucial for correctly modeling these events. In order to further the understanding of such systems, we are investigating the injection of dense magnetized jets and bubbles into a lower density background magnetized plasma using a coaxial plasma gun and a background helicon or cathode plasma. In both jet and bubble cases, the MHD dynamics are found to be very different when launched into background plasma or magnetic field, as compared to vacuum. In the jet case, it is found that the inherent kink instability is stabilized by velocity shear developed due to added magnetic tension from the background field. In the bubble case, rather than directly relaxing to a minimum energy Taylor state (spheromak) as in vacuum, there is an expansion asymmetry and the bubble becomes Rayleigh-Taylor unstable on one side. Recent results will be presented. Work supported by the Army Research Office Award No. W911NF1510480.

  15. A mechanism for the dynamo terms to sustain closed-flux current, including helicity balance, by driving current which crosses the magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Jarboe, T. R.; Nelson, B. A.; Sutherland, D. A. [University of Washington, Seattle, Washington 98195 (United States)

    2015-07-15

    An analysis of imposed dynamo current drive (IDCD) [T.R. Jarboe et al., Nucl. Fusion 52 083017 (2012)] reveals: (a) current drive on closed flux surfaces seems possible without relaxation, reconnection, or other flux-surface-breaking large events; (b) the scale size of the key physics may be smaller than is often computationally resolved; (c) helicity can be sustained across closed flux; and (d) IDCD current drive is parallel to the current which crosses the magnetic field to produce the current driving force. In addition to agreeing with spheromak data, IDCD agrees with selected tokamak data.

  16. Identification of Y-shaped and O-shaped diffusion regions during magnetic reconnection in a laboratory plasma

    International Nuclear Information System (INIS)

    Yamada, Masaaki; Ji, H.; Hsu, S.; Carter, T.; Kulsrud, R.; Ono, Yasushi; Perkins, F.

    1997-01-01

    Two strikingly different shapes of diffusion regions are identified during magnetic reconnection in a magnetohydrodynamic laboratory plasma. The shapes depend on the third vector component of the reconnecting magnetic fields. Without the third component (anti-parallel or null-helicity reconnection), a thin double-Y shaped diffusion region is identified. In this case, the neutral sheet current profile is accurately measured to be as narrow as the order of the ion gyro-radius. In the presence of an appreciable third component (co-helicity reconnection), an O-shaped diffusion region appears and grows into a spheromak configuration

  17. Plasma-based accelerator structures

    International Nuclear Information System (INIS)

    Schroeder, Carl B.

    1999-01-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  18. Grassland Sustainability

    Science.gov (United States)

    Deborah U. Potter; Paulette L. Ford

    2004-01-01

    In this chapter we discuss grassland sustainability in the Southwest, grassland management for sustainability, national and local criteria and indicators of sustainable grassland ecosystems, and monitoring for sustainability at various scales. Ecological sustainability is defined as: [T]he maintenance or restoration of the composition, structure, and processes of...

  19. Investigation of MHD Instabilities in Jets and Bubbles Using a Compact Coaxial Plasma Gun in a Background Magnetized Plasma

    Science.gov (United States)

    Zhang, Y.; Fisher, D. M.; Wallace, B.; Gilmore, M.; Hsu, S. C.

    2016-10-01

    A compact coaxial plasma gun is employed for experimental investigation of launching plasma into a lower density background magnetized plasma. Experiments are being conducted in the linear device HelCat at UNM. Four distinct operational regimes with qualitatively different dynamics are identified by fast CCD camera images. For regime I plasma jet formation, a global helical magnetic configuration is determined by a B-dot probe array data. Also the m =1 kink instability is observed and verified. Furthermore, when the jet is propagating into background magnetic field, a longer length and lifetime jet is formed. Axial shear flow caused by the background magnetic tension force contributes to the increased stability of the jet body. In regime II, a spheromak-like plasma bubble formation is identified when the gun plasma is injected into vacuum. In contrast, when the bubble propagates into a background magnetic field, the closed magnetic field configuration does not hold anymore and a lateral side, Reilgh-Taylor instability develops. Detailed experimental data and analysis will be presented for these cases.

  20. Concurrent Training Promoted Sustained Anti-Atherogenic Benefits In The Fasting Plasma Triacylglycerolemia Of Postmenopausal Women At 1-Year Follow-Up.

    Science.gov (United States)

    Rossi, Fabrício E; Diniz, Tiego A; Fortaleza, Ana Claudia S; Neves, Lucas M; Picolo, Malena R; Monteiro, Paula A; Buonani, Camila; Lira, Fábio S; Freitas, Ismael F

    2016-11-16

    The aim of this study was to compare the effects of aerobic and concurrent training (aerobic plus strength training) on the lipid profiles of normotriacylglycerolemic and hypertriacylglycerolemic postmenopausal women and to verify whether the benefits of aerobic and concurrent training were sustained after 1 year. Total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), Triacylglycerol (TAG) and glucose were assessed in 46 normotriacylglycerolemic (TAGbenefits are sustained at the 1-year follow-up among the hypertriacylglycerolemic subjects.

  1. Validation of single-fluid and two-fluid magnetohydrodynamic models of the helicity injected torus spheromak experiment with the NIMROD code

    International Nuclear Information System (INIS)

    Akcay, Cihan; Victor, Brian S.; Jarboe, Thomas R.; Kim, Charlson C.

    2013-01-01

    We present a comparison study of 3-D pressureless resistive MHD (rMHD) and 3-D presureless two-fluid MHD models of the Helicity Injected Torus with Steady Inductive helicity injection (HIT-SI). HIT-SI is a current drive experiment that uses two geometrically asymmetric helicity injectors to generate and sustain toroidal plasmas. The comparable size of the collisionless ion skin depth d i to the resistive skin depth predicates the importance of the Hall term for HIT-SI. The simulations are run with NIMROD, an initial-value, 3-D extended MHD code. The modeled plasma density and temperature are assumed uniform and constant. The helicity injectors are modeled as oscillating normal magnetic and parallel electric field boundary conditions. The simulations use parameters that closely match those of the experiment. The simulation output is compared to the formation time, plasma current, and internal and surface magnetic fields. Results of the study indicate 2fl-MHD shows quantitative agreement with the experiment while rMHD only captures the qualitative features. The validity of each model is assessed based on how accurately it reproduces the global quantities as well as the temporal and spatial dependence of the measured magnetic fields. 2fl-MHD produces the current amplification (I tor /I inj ) and formation time τ f demonstrated by HIT-SI with similar internal magnetic fields. rMHD underestimates (I tor /I inj ) and exhibits much a longer τ f . Biorthogonal decomposition (BD), a powerful mathematical tool for reducing large data sets, is employed to quantify how well the simulations reproduce the measured surface magnetic fields without resorting to a probe-by-probe comparison. BD shows that 2fl-MHD captures the dominant surface magnetic structures and the temporal behavior of these features better than rMHD

  2. CTR plasma engineering studies. Annual progress report, 1 December 1984-30 November 1985

    International Nuclear Information System (INIS)

    Miley, G.H.

    1985-01-01

    Work under this project is focused on plasma engineering developments in support of fusion reactor studies. The work described in this annual progress report covers a variety of topics ranging from plasma transport modelling for compact tori to radiation heating of the first wall in a fusion device. Sections 2 and 3 decribe computer codes developed for use with field-reversed configurations such as spheromaks and field-reversed mirrors. Section 4 presents an evaluation of the feasibility of heating a RFP-type reactor to ignition with ohmic current input alone. Sections 5 and 6 describe new work that has been initiated on optimal control theory for fusion reactors. Sections 7 to 9 discuss recent results on alpha-particle transport, instabilities, and diagnostics. In the final section, methods for analysis of the poloidal variation in the thermal wall loading of a tokamak reactor are discussed and some typical results are presented

  3. Sustainable Food & Sustainable Economics

    OpenAIRE

    Alvarez, Mavis Dora

    2012-01-01

    Cuba today is immersed in a very intense process of perfecting its agricultural production structures with the goal of making them more efficient and sustainable in their economic administration and in their social and environmental management. Agricultural cooperatives in Cuba have the responsibility of producing on 73% of the country's farmland. Their contributions are decisive to developing agricultural production and to ensuring more and better food for the population, in addition to redu...

  4. Effect of a sustained reduction in plasma free fatty acid concentration on insulin signalling and inflammation in skeletal muscle from human subjects.

    Science.gov (United States)

    Liang, Hanyu; Tantiwong, Puntip; Sriwijitkamol, Apiradee; Shanmugasundaram, Karthigayan; Mohan, Sumathy; Espinoza, Sara; Defronzo, Ralph A; Dubé, John J; Musi, Nicolas

    2013-06-01

    Free fatty acids (FFAs) have been implicated in the pathogenesis of insulin resistance. Reducing plasma FFA concentration in obese and type 2 diabetic (T2DM) subjects improves insulin sensitivity. However, the molecular mechanism by which FFA reduction improves insulin sensitivity in human subjects is not fully understood. In the present study, we tested the hypothesis that pharmacological FFA reduction enhances insulin action by reducing local (muscle) inflammation, leading to improved insulin signalling. Insulin-stimulated total glucose disposal (TGD), plasma FFA species, muscle insulin signalling, IBα protein, c-Jun phosphorylation, inflammatory gene (toll-like receptor 4 and monocyte chemotactic protein 1) expression, and ceramide and diacylglycerol (DAG) content were measured in muscle from a group of obese and T2DM subjects before and after administration of the antilipolytic drug acipimox for 7 days, and the results were compared to lean individuals. We found that obese and T2DM subjects had elevated saturated and unsaturated FFAs in plasma, and acipimox reduced all FFA species. Acipimox-induced reductions in plasma FFAs improved TGD and insulin signalling in obese and T2DM subjects. Acipimox increased IBα protein (an indication of decreased IB kinase-nuclear factor B signalling) in both obese and T2DM subjects, but did not affect c-Jun phosphorylation in any group. Acipimox also decreased inflammatory gene expression, although this reduction only occurred in T2DM subjects. Ceramide and DAG content did not change. To summarize, pharmacological FFA reduction improves insulin signalling in muscle from insulin-resistant subjects. This beneficial effect on insulin action could be related to a decrease in local inflammation. Notably, the improvements in insulin action were more pronounced in T2DM, indicating that these subjects are more susceptible to the toxic effect of FFAs.

  5. Plasma processing: Technologies and applications

    International Nuclear Information System (INIS)

    Naddaf, M.; Saloum, S.

    2005-01-01

    This study aims to present the fundamentals of physics of plasmas, methods of generation, diagnostics, and applications for processing of materials. The first chapter defines plasma in general as well as its main parameters, the most important differential equations in plasma physics, and classifies the types of plasmas. the various methods and techniques to create and sustain plasma are presented in the second chapter. Chapter 3 focuses on plasma diagnostic methods and tools. While chapter 4 deals with applications of plasma processing such as; surface modification of materials, plasma ashing and etching, plasma cutting, and the environmental applications of plasma. Plasma polymerization and its various applications have been presented in more details in the last chapter. (Author)

  6. Sustainable Marketing

    NARCIS (Netherlands)

    Dam, van Y.K.

    2017-01-01

    In this article, three different conceptions of sustainable marketing are discussed and compared. These different conceptions are referred to as social, green, and critical sustainable marketing. Social sustainable marketing follows the logic of demand-driven marketing management and places the

  7. Dynamics of Plasma Jets and Bubbles Launched into a Transverse Background Magnetic Field

    Science.gov (United States)

    Zhang, Yue

    2017-10-01

    A coaxial magnetized plasma gun has been utilized to launch both plasma jets (open B-field) and plasma bubbles (closed B-field) into a transverse background magnetic field in the HelCat (Helicon-Cathode) linear device at the University of New Mexico. These situations may have bearing on fusion plasmas (e.g. plasma injection for tokamak fueling, ELM pacing, or disruption mitigation) and astrophysical settings (e.g. astrophysical jet stability, coronal mass ejections, etc.). The magnetic Reynolds number of the gun plasma is 100 , so that magnetic advection dominates over magnetic diffusion. The gun plasma ram pressure, ρjetVjet2 >B02 / 2μ0 , the background magnetic pressure, so that the jet or bubble can easily penetrate the background B-field, B0. When the gun axial B-field is weak compared to the gun azimuthal field, a current-driven jet is formed with a global helical magnetic configuration. Applying the transverse background magnetic field, it is observed that the n = 1 kink mode is stabilized, while magnetic probe measurements show contrarily that the safety factor q(a) drops below unity. At the same time, a sheared axial jet velocity is measured. We conclude that the tension force arising from increasing curvature of the background magnetic field induces the measured sheared flow gradient above the theoretical kink-stabilization threshold, resulting in the emergent kink stabilization of the injected plasma jet. In the case of injected bubbles, spheromak-like plasma formation is verified. However, when the spheromak plasma propagates into the transverse background magnetic field, the typical self-closed global symmetry magnetic configuration does not hold any more. In the region where the bubble toroidal field opposed the background B-field, the magneto-Rayleigh-Taylor (MRT) instability has been observed. Details of the experiment setup, diagnostics, experimental results and theoretical analysis will be presented. Supported by the National Science Foundation

  8. Exploiting Laboratory and Heliophysics Plasma Synergies

    Directory of Open Access Journals (Sweden)

    Jill Dahlburg

    2010-05-01

    provides direct experimental observation of reconnection dynamics; and the Swarthmore Spheromak Experiment, which provides well-diagnosed data on three-dimensional (3D null-point magnetic reconnection that is also applicable to solar active regions embedded in pre-existing coronal fields. New computer capabilities highlighted include: HYPERION, a fully compressible 3D magnetohydrodynamics (MHD code with radiation transport and thermal conduction; ORBIT-RF, a 4D Monte-Carlo code for the study of wave interactions with fast ions embedded in background MHD plasmas; the 3D implicit multi-fluid MHD spectral element code, HiFi; and, the 3D Hall MHD code VooDoo. Research synergies for these new tools are primarily in the areas of magnetic reconnection, plasma charged particle acceleration, plasma wave propagation and turbulence in a diverging magnetic field, plasma atomic processes, and magnetic dynamo behavior.

  9. Agglomeration processes sustained by dust density waves in Ar/C2H2 plasma: From C2H2 injection to the formation of an organized structure

    International Nuclear Information System (INIS)

    Dap, Simon; Hugon, Robert; Poucques, Ludovic de; Briancon, Jean-Luc; Bougdira, Jamal; Lacroix, David

    2013-01-01

    In this paper, an experimental investigation of dust particle agglomeration in a capacitively coupled RF discharge is reported. Carbonaceous particles are produced in an argon plasma using acetylene. As soon as the particle density becomes sufficient, dust density waves (DDWs) are spontaneously excited within the cathode sheath. Recently, it was proven that DDWs can significantly enhance the agglomeration rate between particles by transferring them a significant kinetic energy. Thus, it helps them to overcome Coulomb repulsion. The influence of this mechanism is studied from acetylene injection to the formation of very large agglomerates forming an organized structure after a few dozens of seconds. For this purpose, three diagnostic tools are used: extinction measurements to probe nanometer-sized particles, fast imaging for large agglomerates and a dust extraction technique developed for ex-situ analysis.

  10. GATO: an MHD stability code for axisymmetric plasmas with internal separatrices

    International Nuclear Information System (INIS)

    Bernard, L.C.; Helton, F.J.; Moore, R.W.

    1981-07-01

    The GATO code computes the growth rate of ideal magnetohydrodynamic instabilities in axisymmetric geometries with internal separatrices such as doublet and expanded spheromak. The basic method, which uses a variational principle and a Galerkin procedure to obtain a matrix eigenvalue problem, is common to the ERATO and PEST codes. A new coordinate system has been developed to handle the internal separatrix. Efficient algorithms have been developed to solve the matrix eigenvalue problem for matrices of rank as large as 40,000. Further improvement is expected using graph theoretical techniques to reorder the matrices. Using judicious mesh repartition, the marginal point can be determined with great precision. The code has been extensively used to optimize doublet and general tokamak plasmas

  11. GATO: An MHD stability code for axisymmetric plasmas with internal separatrices

    International Nuclear Information System (INIS)

    Bernard, L.C.; Helton, F.J.; Moore, R.W.

    1981-01-01

    The GATO code computes the growth rate of ideal magnetohydrodynamic instabilities in axisymmetric geometries with internal separatrices such as doublet and expanded spheromak. The basic method, which uses a variational principle and a Galerkin procedure to obtain a matrix eigenvalue problem, is common to the ERATO and PEST codes. A new coordinate system has been developed to handle the internal separatrix. Efficient algorithms have been developed to solve the matrix eigenvalue problem for matrices of rank as large as 40 000. Further improvement is expected using graph theoretical techniques to reorder the matrices. Using judicious mesh repartition, the marginal point can be determined with great precision. The code has been extensively used to optimize doublet and general tokamak plasmas. (orig.)

  12. Sustainable Disruptions

    DEFF Research Database (Denmark)

    Friis, Silje Alberthe Kamille; Kjær, Lykke Bloch

    2016-01-01

    Since 2012 the Sustainable Disruptions (SD) project at the Laboratory for Sustainability at Design School Kolding (DK) has developed and tested a set of design thinking tools, specifically targeting the barriers to economically, socially, and environmentally sustainable business development....... The tools have been applied in practice in collaboration with 11 small and medium sized companies (SMEs). The study investigates these approaches to further understand how design thinking can contribute to sustainable transition in a business context. The study and the findings are relevant to organizations...... invested in the issue of sustainable business development, in particular the leaders and employees of SMEs, but also to design education seeking new ways to consciously handle and teach the complexity inherent in sustainable transformation. Findings indicate that the SD design thinking approach contributes...

  13. Computational sustainability

    CERN Document Server

    Kersting, Kristian; Morik, Katharina

    2016-01-01

    The book at hand gives an overview of the state of the art research in Computational Sustainability as well as case studies of different application scenarios. This covers topics such as renewable energy supply, energy storage and e-mobility, efficiency in data centers and networks, sustainable food and water supply, sustainable health, industrial production and quality, etc. The book describes computational methods and possible application scenarios.

  14. Sustainable Universities

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2011-01-01

    Declarations on Sustainability in Higher Education (SHE) can be viewed as a piece of international regulation. Over the past 30 years research at universities has produced convincing data to warn about deterioration of the environment, resource scarcity and the need for sustainability. This in turn....... Declarations tend to have impact on three trends. Firstly, there is emerging international consensus on the university’s role and function in relation to sustainable development; secondly, the emergence of national legislation, and thirdly, an emerging international competition to be leader in sustainable...

  15. Physics issues of a proposed program, SPIRIT

    International Nuclear Information System (INIS)

    Ji, Hantao; Yamada, Masaaki

    2000-01-01

    Physics issues of the proposed program, SPIRIT (Self-organized Plasma with Induction, Reconnection, and Induction Techniques) are discussed. The main purpose of this program is to explore the physics of global stability and sustainment of compact toroids, including FRC (field reversed configuration) as well as low-aspect-ratio RFP (reversed field pinch), spheromak and spherical torus. (author)

  16. Progress towards internal transport barriers at high plasma density sustained by pure electron heating and current drive in the FTU tokamak

    International Nuclear Information System (INIS)

    Pericoli Ridolfini, V.; Barbato, E.; Buratti, P.

    2003-01-01

    Strong electron Internal Transport Barriers (ITBs) are obtained in FTU by the combined injection of Lower Hybrid (LH, up to 1.9 MW) and Electron Cyclotron (EC up to 0.8 MW) radio frequency waves. ITBs occur during either the current plateau or the ramp up phase, and both in full and partial current drive (CD) regimes, up to peak densities n e0 >1.2·10 20 m -3 , relevant to ITER operation. Central electron temperatures T e0 >11 keV, at n e0 ∼0.8·10 20 m -3 are sustained longer than 6 confinement times. The ITB extends over a region where a slightly reversed magnetic shear is established by off-axis LHCD and can be as wide as r/a=0.5. The EC power, instead, is used either to benefit from this improved confinement by heating inside the ITB, or to enhance the peripheral LH power deposition and CD with off axis resonance. Collisional ion heating is also observed, but thermal equilibrium with the electrons cannot be attained since the e-i equipartition time is always 4-5 times longer than the energy confinement time. The transport analysis performed with both ASTRA and JETTO codes shows a very good relation between the foot of the barrier and the weak/reversed shear region, which in turn depends on the LH deposition profile. The Bohm-gyroBohm model accounts for the electron transport until T e0 <6 keV, but is pessimistic at higher temperatures, where often also a reduction in the ion thermal conductivity is observed, provided any magneto hydrodynamic activity is suppressed. (author)

  17. Sustainable Transition

    DEFF Research Database (Denmark)

    Hansen, Ole Erik; Søndergård, Bent

    2014-01-01

    of agendas/vision, technologies, actors and institutions in the emergent design of an urban mobility system based on an electric car sharing system. Why. Designing for sustainability is a fundamental challenge for future design practices; designers have to obtain an ability to contribute to sustainable...

  18. Sustainable transformation

    DEFF Research Database (Denmark)

    Andersen, Nicolai Bo

    This paper is about sustainable transformation with a particular focus on listed buildings. It is based on the notion that sustainability is not just a question of energy conditions, but also about the building being robust. Robust architecture means that the building can be maintained and rebuil...

  19. Sustainability Labeling

    NARCIS (Netherlands)

    Dam, van Y.K.

    2017-01-01

    Sustainability labeling originated from a need to protect the identity of alternative systems of food production and to increase market transparency. From the 1980s onwards sustainability labeling has changed into a policy instrument replacing direct government regulation of the food market, and a

  20. Afterschool Sustainability

    Directory of Open Access Journals (Sweden)

    Hilary D. Joyce

    2014-12-01

    Full Text Available Youth participation in quality extended learning opportunities (ELOs results in positive academic, physical, mental health, and social/emotional outcomes. Funding is essential to implementing and sustaining quality ELOs; however multiple funding barriers and challenges exist. Understanding the types of funds available for ELOs and the factors that influence sustainability is critical. Through surveys and telephone interviews of ELO providers, this descriptive study identified and examined ELO funding streams, the ways ELO providers use these funding streams, and the barriers and challenges to sustainability. ELO programs often relied on one major funding stream coupled with nutrition supports as well as in-kind resources. Barriers to sustainability included year-to-year funding, transportation costs, reducing community partnerships, and difficulty in diversifying funds. Recommendations to enhance ELO sustainability are offered, particularly in relation to overcoming the challenges to diversification of funding resources and establishing mutually supportive partnerships and collaboration.

  1. Field-reversing electron and ion rings for the confinement and heating of plasmas. Annual progress report, September 1, 1980-August 31, 1981

    International Nuclear Information System (INIS)

    Fleischmann, H.H.

    1981-09-01

    Our experimental work on the RECE-Christa device during the present period concentrated on obtaining conditions for first measurements of plasma confinement and on the generation of mixed-CT configurations. The most important results in these areas included the generation of rings with plasma currents significantly larger than originally hoped for, and - on the other hand - a failure to propagate rings efficiently in background gas densities below 1 mTorr. In addition, a digital data management system has been acquired and the respective software is being completed. Finally, theoretical work was performed on calculating banana drift orbits in Spheromak-type configurations and on developing a semi-analytic model for the equilibrium of ion rings which could be used for estimating the ring behavior during the slow-down of the ions

  2. Sustainable Cities

    DEFF Research Database (Denmark)

    Georg, Susse; Garza de Linde, Gabriela Lucía

    Judging from the number of communities and cities striving or claiming to be sustainable and how often eco-development is invoked as the means for urban regeneration, it appears that sustainable and eco-development have become “the leading paradigm within urban development” (Whitehead 2003....../assessment tool. The context for our study is urban regeneration in one Danish city, which had been suffering from industrial decline and which is currently investing in establishing a “sustainable city”. Based on this case study we explore how the insights and inspiration evoked in working with the tool...

  3. MHD simulation study of compact toroid injection into magnetized plasmas

    International Nuclear Information System (INIS)

    Suzuki, Yoshio; Kishimoto, Yasuaki

    2000-01-01

    To understand the fuelling process in a fusion device by a compact toroid (CT) plasmoid injection method, we have carried out MHD numerical simulations where a spheromak-like CT (SCT) is injected into a magnetized target plasma region. So far, we revealed that the penetration depth of the SCT plasma becomes shorter than that estimated from the conducting sphere (CS) model, because in the simulation the Lorentz force of the target magnetic field sequentially decelerates the injected SCT while in the CS model only the magnetic pressure force acts as the deceleration mechanism. In this study, we represent the new theoretical model where the injected SCT is decelerated by both the magnetic pressure force and the magnetic tension force (we call it the non-slipping sphere (NS) model) and investigate in detail the deceleration mechanism of the SCT by comparison with simulation results. As a result, it is found that the decrease of the SCT kinetic energy in the simulation coincides with that in the NS model more than in the CS model. It means that not only the magnetic pressure force but also the magnetic tension force acts as the deceleration mechanism of the SCT. Furthermore, it is revealed that magnetic reconnection between the SCT magnetic field and the target magnetic field plays a role to relax the SCT deceleration. (author)

  4. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts...... that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  5. Agriculture: Sustainability

    Science.gov (United States)

    Sustainability creates and maintains the conditions under which humans and nature can exist in productive harmony, that permit fulfilling the food, feed, and fiber needs of our country and the social, economic and other requirements.

  6. Sustainable consumption

    DEFF Research Database (Denmark)

    Prothero, Andrea; Dobscha, Susan; Freund, Jim

    2011-01-01

    This essay explores sustainable consumption and considers possible roles for marketing and consumer researchers and public policy makers in addressing the many sustainability challenges that pervade our planet. Future research approaches to this interdisciplinary topic need to be comprehensive...... and systematic and will benefit from a variety of different perspectives. There are a number of opportunities for future research, and three areas are explored in detail. First, the essay considers the inconsistency between the attitudes and behaviors of consumers with respect to sustainability; next, the agenda...... is broadened to explore the role of individual citizens in society; and finally, a macro institutional approach to fostering sustainability is explored. Each of these areas is examined in detail and possible research avenues and public policy initiatives are considered within each of these separate...

  7. Sustainable Futures

    Science.gov (United States)

    Sustainable Futures is a voluntary program that encourages industry to use predictive models to screen new chemicals early in the development process and offers incentives to companies subject to TSCA section 5.

  8. Sustainability reporting

    NARCIS (Netherlands)

    Kolk, A.

    2005-01-01

    This article gives an overview of developments in sustainability (also sometimes labelled corporate social responsibility) reporting. The article will first briefly indicate how accountability on social and environmental issues started, already in the 1970s when social reports were published.

  9. Sustainable transformation

    DEFF Research Database (Denmark)

    Andersen, Nicolai Bo

    This paper is about sustainable transformation with a particular focus on listed buildings. It is based on the notion that sustainability is not just a question of energy conditions, but also about the building being robust. Robust architecture means that the building can be maintained and rebuilt......, that it can be adapted to changing functional needs, and that it has an architectural and cultural value. A specific proposal for a transformation that enhances the architectural qualities and building heritage values of an existing building forms the empirical material, which is discussed using different...... theoretical lenses. It is proposed that three parameters concerning the ꞌtransformabilityꞌ of the building can contribute to a more nuanced understanding of sustainable transformation: technical aspects, programmatic requirements and narrative value. It is proposed that the concept of ꞌsustainable...

  10. Sustainable Consumption

    DEFF Research Database (Denmark)

    Røpke, Inge

    2015-01-01

    The intention of this chapter is to explore the role of consumption and consumers in relation to sustainability transition processes and wider systemic transformations. In contrast to the individualistic focus in much research on sustainable consumption, the embeddedness of consumption activities...... in wider social, economic and technological frameworks is emphasised. In particular, the chapter is inspired by practice theory and transition theory. First, various trends in consumption are outlined to highlight some of the challenges for sustainability transitions. Then, it is discussed how consumption...... patterns are shaped over time and what should be considered in sustainability strategies. While discussions on consumption often take their point of departure in the perspective of the individual and then zoom to the wider context, the present approach is the opposite. The outline starts with the basic...

  11. Stabilizing Sustainability

    DEFF Research Database (Denmark)

    Reitan Andersen, Kirsti

    The publication of the Brundtland Report in 1987 put the topic of sustainable development on the political and corporate agenda. Defining sustainable development as “a development that meets the needs of the future without compromising the ability of future generations to meet their own needs......” (WCED, 1987, p. 43), the Report also put a positive spin on the issue of sustainability by upholding capitalist beliefs in the possibility of infinite growth in a world of finite resources. While growth has delivered benefits, however, it has done so unequally and unsustainably. This thesis focuses...... on the textile and fashion industry, one of the world’s most polluting industries and an industry to some degree notorious for leading the ‘race to the bottom’ in global labour standards. Despite being faced with increasing demands to practise sustainability, most textile and fashion companies continue to fail...

  12. Seeking Sustainability

    OpenAIRE

    Clive L. Spash

    2014-01-01

    What does sustainability research do to help the environment? One might well wonder when observing the annual conference season with various academics and professors in sustainability science, ecological economics or environmental ethics driving to the airport to fly off to international meetings to discuss how bad things are getting, what should been done about it, and how time is running out for action. In fact, singling out a few academic groups is highly unfair because the link between pr...

  13. Local Sustainability

    International Nuclear Information System (INIS)

    Carrizosa Umana, Julio

    1998-01-01

    The current polemic about the possibilities of sustainable development has led to a renovated interest for the topic of the sustainability of the communities and the local sustainability. In front of the global sustainability whose conditions have been exposed by systemic ecologists and for macro economists, the sustainability of specific places arises in the planet whose conditions are object of study of the ecology of landscapes, of the ecological economy, of the cultural anthropology, of the environmental sociology and naturally, of the integral environmentalism. In this discussion the Colombian case charges unusual interest to be one of the few countries of Latin America, where a very dense net of municipalities exists, each one with its urban helmet and with a position and some functions defined by the political constitution of the nation. This net of municipalities and of urban helmets it also constitutes net of alternative to the current macro-cephalic situation. As well as Bogota grew, in a hundred years, of less than a hundred thousand inhabitants to six million inhabitants, each one of these municipalities contains a potential of growth that depends on the characteristics of its ecological, social, economic and politic sustainability

  14. Sustainable markets for sustainable energy

    Energy Technology Data Exchange (ETDEWEB)

    Millan, J.; Smyser, C.

    1997-12-01

    The author discusses how the Inter-American Development Bank (IDB) is involved in sustainable energy development. It presently has 50 loans and grants for non conventional renewable energy projects and ten grants for efficiency programs for $600 and $17 million respectively, representing 100 MW of power. The IDB is concerned with how to create a sustainable market for sustainable energy projects. The IDB is trying to work with government, private sector, NGOs, trading allies, credit sources, and regulators to find proper roles for such projects. He discusses how the IDB is working to expand its vision and objectives in renewable energy projects in Central and South America.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  17. Roundtabling Sustainability

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2014-01-01

    councils’ and ‘sustainability roundtables’ and have been designed around a set of institutional features seeking to establish legitimacy, fend off possible criticism, and ‘sell’ certifications to potential users. The concept of ‘roundtabling’ emphasizes the fitting a variety of commodity...... and procedures to meet ‘good practice’ in standard setting and management. This is opening space for competing initiatives that are less democratic, quicker, and more aligned with industry interests to establish substantial presence in the market for sustainability certifications. These tend to more easily...

  18. Sustainable finance

    NARCIS (Netherlands)

    Boersma-de Jong, Margreet F.

    2012-01-01

    Presentation for Springschool of Strategy, University of Groningen, 10 October 2012. The role of CSR is to stimulate ethical behaviour, and as a result, mutual trust in society. Advantage of CSR for the company and the evolution of CSR. From CSR to Sustainable Finance: how does CSR influence

  19. Sustainable Procurement

    DEFF Research Database (Denmark)

    Telles, Pedro; Ølykke, Grith Skovgaard

    2017-01-01

    and within it how sustainable requirements have increased the level of compliance required, particularly regulatory compliance. Compliance was already present in previous EU public procurement frameworks, but its extent on Directive 2014/24/EU leads the authors to consider the current legal framework...

  20. Exergy sustainability.

    Energy Technology Data Exchange (ETDEWEB)

    Robinett, Rush D. III (.; ); Wilson, David Gerald; Reed, Alfred W.

    2006-05-01

    Exergy is the elixir of life. Exergy is that portion of energy available to do work. Elixir is defined as a substance held capable of prolonging life indefinitely, which implies sustainability of life. In terms of mathematics and engineering, exergy sustainability is defined as the continuous compensation of irreversible entropy production in an open system with an impedance and capacity-matched persistent exergy source. Irreversible and nonequilibrium thermodynamic concepts are combined with self-organizing systems theories as well as nonlinear control and stability analyses to explain this definition. In particular, this paper provides a missing link in the analysis of self-organizing systems: a tie between irreversible thermodynamics and Hamiltonian systems. As a result of this work, the concept of ''on the edge of chaos'' is formulated as a set of necessary and sufficient conditions for stability and performance of sustainable systems. This interplay between exergy rate and irreversible entropy production rate can be described as Yin and Yang control: the dialectic synthesis of opposing power flows. In addition, exergy is shown to be a fundamental driver and necessary input for sustainable systems, since exergy input in the form of power is a single point of failure for self-organizing, adaptable systems.

  1. Sustainable Buildings

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Elle, Morten

    The scientific community agrees that: all countries must drastically and rapidly reduce their CO2 emissions and that energy efficient houses play a decisive role in this. The general attitude at the workshop on Sustainable Buildings was that we face large and serious climate change problems...

  2. Sustainable Entrepreneurship

    DEFF Research Database (Denmark)

    Schaltegger, Stefan; Beckmann, Markus; Hockerts, Kai

    2018-01-01

    . We also explore the transformation path of the case company, which starts with simple use and then moves to the feedback to core business pattern. By drawing on insights from lead user theory in innovation management and sustainable entrepreneurship, we ground the new concept in extant literature...

  3. Sustainable machining

    CERN Document Server

    2017-01-01

    This book provides an overview on current sustainable machining. Its chapters cover the concept in economic, social and environmental dimensions. It provides the reader with proper ways to handle several pollutants produced during the machining process. The book is useful on both undergraduate and postgraduate levels and it is of interest to all those working with manufacturing and machining technology.

  4. Sustainable processing

    DEFF Research Database (Denmark)

    Kristensen, Niels Heine

    2004-01-01

    Kristensen_NH and_Beck A: Sustainable processing. In Otto Schmid, Alexander Beck and Ursula Kretzschmar (Editors) (2004): Underlying Principles in Organic and "Low-Input Food" Processing - Literature Survey. Research Institute of Organic Agriculture FiBL, CH-5070 Frick, Switzerland. ISBN 3-906081-58-3...

  5. Architecture Sustainability

    NARCIS (Netherlands)

    Avgeriou, Paris; Stal, Michael; Hilliard, Rich

    2013-01-01

    Software architecture is the foundation of software system development, encompassing a system's architects' and stakeholders' strategic decisions. A special issue of IEEE Software is intended to raise awareness of architecture sustainability issues and increase interest and work in the area. The

  6. Sustainable development

    International Nuclear Information System (INIS)

    Boiteux, M.

    2004-01-01

    Marcel Boiteux evokes the results of the work on the sustainable development by the Academie des Sciences Morales et Politiques. This is a vast political programme with the goal of allowing all humanity to live well in growing unity while protecting the environment and favouring economic growth. (author)

  7. Sustainable Development

    African Journals Online (AJOL)

    Tsegai Berhane Ghebretekle

    Ethiopia is selected as a case study in light of its pace in economic growth ... Interrogating the Economy-First Paradigm in 'Sustainable Development' … 65 .... agreement, since such effective global cooperation on climate change ultimately ..... and foster innovation; reduce inequality within and among countries; make cities.

  8. Sustainable Soesterkwartier

    NARCIS (Netherlands)

    Abrahams, H.; Goosen, H.; Jong, de F.; Sickmann, J.; Prins, D.

    2010-01-01

    The municipality of Amersfoort wants to construct an endurable and sustainable eco-town in the Soesterkwartier neighbourhood, by taking future climate change into account. The impact of climate change at the location of the proposed eco-town was studied by a literature review.

  9. Sustainable Sizing.

    Science.gov (United States)

    Robinette, Kathleen M; Veitch, Daisy

    2016-08-01

    To provide a review of sustainable sizing practices that reduce waste, increase sales, and simultaneously produce safer, better fitting, accommodating products. Sustainable sizing involves a set of methods good for both the environment (sustainable environment) and business (sustainable business). Sustainable sizing methods reduce (1) materials used, (2) the number of sizes or adjustments, and (3) the amount of product unsold or marked down for sale. This reduces waste and cost. The methods can also increase sales by fitting more people in the target market and produce happier, loyal customers with better fitting products. This is a mini-review of methods that result in more sustainable sizing practices. It also reviews and contrasts current statistical and modeling practices that lead to poor fit and sizing. Fit-mapping and the use of cases are two excellent methods suited for creating sustainable sizing, when real people (vs. virtual people) are used. These methods are described and reviewed. Evidence presented supports the view that virtual fitting with simulated people and products is not yet effective. Fit-mapping and cases with real people and actual products result in good design and products that are fit for person, fit for purpose, with good accommodation and comfortable, optimized sizing. While virtual models have been shown to be ineffective for predicting or representing fit, there is an opportunity to improve them by adding fit-mapping data to the models. This will require saving fit data, product data, anthropometry, and demographics in a standardized manner. For this success to extend to the wider design community, the development of a standardized method of data collection for fit-mapping with a globally shared fit-map database is needed. It will enable the world community to build knowledge of fit and accommodation and generate effective virtual fitting for the future. A standardized method of data collection that tests products' fit methodically

  10. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates

  11. The influence of nitrogen entrainment on argon plasmas created by the 'Torche à Injection Axiale' (TIA)

    NARCIS (Netherlands)

    Jonkers, J.; Hartgers, A.; Selen, L.J.M.; Mullen, van der J.J.A.M.; Schram, D.C.

    1999-01-01

    When a plasma is sustained in the open air, nitrogen will diffuse into the plasma. Especially for plasmas sustained by the `Torche à Injection Axiale' (TIA) this appears to be the case, since this turbulent jet draws gases from the surroundings. In the argon plasma the entrained nitrogen is probably

  12. Plasma physics aspects of ETF/INTOR

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Rutherford, P.R.; Schmidt, J.A.; Cohn, D.R.; Miller, R.L.

    1980-01-01

    In order to achieve their principle technical objectives, the Engineering Test Facility (ETF) and the International Tokomak Reactor (INTOR) will require an ignited (or near ignited) plasma, sustained for pulse lengths of at least 100 secs at a high enough plasma pressure to provide a neutron wall loading of at least 1.3 MW/m 2 . The ignited plasma will have to be substantially free of impurities. Our current understanding of major plasma physics characters is summarized

  13. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  14. Dynamic mode decomposition for plasma diagnostics and validation

    Science.gov (United States)

    Taylor, Roy; Kutz, J. Nathan; Morgan, Kyle; Nelson, Brian A.

    2018-05-01

    We demonstrate the application of the Dynamic Mode Decomposition (DMD) for the diagnostic analysis of the nonlinear dynamics of a magnetized plasma in resistive magnetohydrodynamics. The DMD method is an ideal spatio-temporal matrix decomposition that correlates spatial features of computational or experimental data while simultaneously associating the spatial activity with periodic temporal behavior. DMD can produce low-rank, reduced order surrogate models that can be used to reconstruct the state of the system with high fidelity. This allows for a reduction in the computational cost and, at the same time, accurate approximations of the problem, even if the data are sparsely sampled. We demonstrate the use of the method on both numerical and experimental data, showing that it is a successful mathematical architecture for characterizing the helicity injected torus with steady inductive (HIT-SI) magnetohydrodynamics. Importantly, the DMD produces interpretable, dominant mode structures, including a stationary mode consistent with our understanding of a HIT-SI spheromak accompanied by a pair of injector-driven modes. In combination, the 3-mode DMD model produces excellent dynamic reconstructions across the domain of analyzed data.

  15. Study of driven magnetic reconnection in a laboratory plasma

    International Nuclear Information System (INIS)

    Yamada, Masaaki; Ji, H.; Hsu, S.; Carter, T.; Kulsrud, R.; Bretz, N.; Jobes, F.; Ono, Yasushi; Perkins, F.

    1998-01-01

    The Magnetic Reconnection Experiment (MRX) has been constructed to investigate the fundamental physics of magnetic reconnection in a well controlled laboratory setting. This device creates an environment satisfying the criteria for a magnetohydrodynamic (MHD) plasma (S much-gt 1, ρ i much-lt L). The boundary conditions can be controlled externally, and experiments with fully three-dimensional reconnection are now possible. In the initial experiments, the effects of the third vector component of reconnecting fields have been studied. Two distinctively different shapes of neutral sheet current layers, depending on the third component, are identified during driven magnetic reconnection. Without the third component (anti-parallel or null-helicity reconnection), a thin double-Y shaped diffusion region is identified. A neutral sheet current profile is measured accurately to be as narrow as order ion gyro-radius. In the presence of an appreciable third component (co-helicity reconnection), an O-shaped diffusion region appears and grows into a spheromak configuration

  16. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  17. Princeton Plasma Physics Laboratory annual report, October 1, 1982-September 30, 1983

    International Nuclear Information System (INIS)

    Phillips, C.A.

    1983-01-01

    The Tokamak Fusion Test Reactor (TFTR) achieved first plasma at 3:05 a.m. on December 24, 1982. During the course of the year, the plasma current was raised to a maximum of 1 MA, and extensive confinement studies were carried out with ohmic-heated plasmas. The most important finding was that tokamak energy confinement time increases as the cube of the plasma size. The Princeton Large Torus (PLT) carried out a number of high-powered plasma-heating experiments in the ion cyclotron frequency range, and also demonstrated for the first time that a 100-kA tokamak discharge can be built up by means of rf-waves in the lower hybrid range, without any need for inductive current drive by the conventional tokamak transformer system. The Poloidal Divertor Experiment (PDX) demonstrated that substantial improvements in plasma confinement during intense neutral-beam heating can be obtained by means of either a magnetic divertor or a mechanical scoop limiter. The S-1 spheromak experiment has come into operation, with first plasma in January 1983, and machine completion in August. The soft X-ray laser development experiment continues to make strong progress towards the demonstration of laser amplification. Thus far, a single-pass gain of 3.5 has been achieved, using the 182 A line of CVI. Theoretical MHD-stability studies have shed new light on the nature of the energetic-ion-driven ''fishbone instability,'' and the utilization of the bean-shaping technique to reach higher beta values in the tokamak

  18. Princeton Plasma Physics Laboratory annual report, October 1, 1982-September 30, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, C.A. (ed.)

    1983-01-01

    The Tokamak Fusion Test Reactor (TFTR) achieved first plasma at 3:05 a.m. on December 24, 1982. During the course of the year, the plasma current was raised to a maximum of 1 MA, and extensive confinement studies were carried out with ohmic-heated plasmas. The most important finding was that tokamak energy confinement time increases as the cube of the plasma size. The Princeton Large Torus (PLT) carried out a number of high-powered plasma-heating experiments in the ion cyclotron frequency range, and also demonstrated for the first time that a 100-kA tokamak discharge can be built up by means of rf-waves in the lower hybrid range, without any need for inductive current drive by the conventional tokamak transformer system. The Poloidal Divertor Experiment (PDX) demonstrated that substantial improvements in plasma confinement during intense neutral-beam heating can be obtained by means of either a magnetic divertor or a mechanical scoop limiter. The S-1 spheromak experiment has come into operation, with first plasma in January 1983, and machine completion in August. The soft X-ray laser development experiment continues to make strong progress towards the demonstration of laser amplification. Thus far, a single-pass gain of 3.5 has been achieved, using the 182 A line of CVI. Theoretical MHD-stability studies have shed new light on the nature of the energetic-ion-driven ''fishbone instability,'' and the utilization of the bean-shaping technique to reach higher beta values in the tokamak.

  19. Building sustainability

    CSIR Research Space (South Africa)

    Mass Media

    2007-11-01

    Full Text Available particu- lar social environment also being awarded. If a building can be used by the community after hours, it should be awarded extra points.” School sports facilities or meeting halls in corporate buildings, are some example. Multi-purpose use..., architect and senior researcher for the CSIR’s Built Environment Unit, the integra- tion of sustainability in building design cannot begin soon enough before it is too late. He says: “Unfortunately nothing is in place in South Africa. For a start...

  20. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described for electron beam heating of a high-density plasma to drive a fast liner. An annular or solid relativistic electron beam is used to heat a plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the plasma then converges on a fast liner to explosively or ablatively drive the liner to implosion. (U.K.)

  1. Travelling-wave-sustained discharges

    International Nuclear Information System (INIS)

    Schlueter, Hans; Shivarova, Antonia

    2007-01-01

    This review is on discharges maintained by travelling waves: new plasma sources, discovered in 1974 and considered as a prototype of the gas discharges according to their definition as nonlinear systems which unify in a self-consistent manner plasmas and fields. In the presentation here of the fluid-plasma models of the diffusion-controlled regime of the travelling-wave-sustained discharges (TWSDs), the basic features of the discharge maintenance-the discharge self-consistency and the electron heating in the high-frequency field-are stressed. Operation of stationary and pulsed discharges, discharge maintenance without and in external magnetic fields as well as discharge production in different gases (argon, helium, helium-argon gas mixtures and hydrogen) are covered. Modulation instability of diffusion-controlled discharges and discharge filamentation at higher gas pressures are also included in the review. Experimental findings which motivate aspects of the reported modelling are pointed out

  2. Plasma Modes

    Science.gov (United States)

    Dubin, D. H. E.

    This chapter explores several aspects of the linear electrostatic normal modes of oscillation for a single-species non-neutral plasma in a Penning trap. Linearized fluid equations of motion are developed, assuming the plasma is cold but collisionless, which allow derivation of the cold plasma dielectric tensor and the electrostatic wave equation. Upper hybrid and magnetized plasma waves in an infinite uniform plasma are described. The effect of the plasma surface in a bounded plasma system is considered, and the properties of surface plasma waves are characterized. The normal modes of a cylindrical plasma column are discussed, and finally, modes of spheroidal plasmas, and finite temperature effects on the modes, are briefly described.

  3. Interdependences between sustainable development and sustainable economy

    OpenAIRE

    Emilia Mioara CÂMPEANU; Carmen Valentina RĂDULESCU

    2014-01-01

    Sustainable development and sustainable economy are mostly used concepts. Understanding clearly their meaning allows their use in an appropriate context and, therefore, their boundaries in terms of theoretical and practical approaches on which occasion it can be given their interdependencies. The paper aim is to analyze the interdependences between sustainable development and sustainable economy.

  4. EDITORIAL: Plasma jets and plasma bullets Plasma jets and plasma bullets

    Science.gov (United States)

    Kong, M. G.; Ganguly, B. N.; Hicks, R. F.

    2012-06-01

    to 1990 with only 31 papers per year on average, and a total of some 1300 papers, precedes a considerable growth of some 35-50% in research activity every five years, over the last 20 years or so. As shown in the table, the annual dissemination of the field is more than 1600 papers and the total number of papers is in excess of 20000. This upwards trajectory is typical of a strong and growing subject area in physical science, with considerable capacity in both fundamental science and applications. PeriodNumber of papersPapers per annum 1948-1990130031 1991-19952279456 1996-20003447689 2001-20054571914 2006-201066401328 2011 1658 In many of the dense plasma jets discussed above, strong physical forces generated by the plasma are often desired and this favours plasma generation at elevated gas pressure, including atmospheric pressure, which favours a high level of gas ionization. Historically it has been challenging to reduce and control the strong physical forces in high-pressure plasmas for applications where these are unwanted, for example, surface modification of polymeric sheets [5]. Indeed, there is a real need for a vast range of material processing applications at temperatures below 100oC (or below 400 K) and this favours atmospheric-pressure plasma jets sustained far from thermal equilibrium with the dissipated electrical energy largely used not in heat generation but in unleashing non-equilibrium chemical reactions. The long-standing difficulty of effectively controlling the level of gas ionization at atmospheric pressure was overcome by the technological breakthrough of achieving atmospheric-pressure glow discharges in the late 1980s [6]. A related challenge stemming from high collisionality of atmospheric-pressure plasmas (v >> ω0) means that large-area plasmas sustained between parallel-plate electrodes are very susceptible to strong plasma instabilities when molecular gases are introduced for processing applications. This led to an effective

  5. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  6. Sustainability; Sustentabilidade

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    This chapter analyses the production chain of ethanol, considering the impacts on the quality of the air, water supplies, soil occupation and biodiversity, and the efforts for the soil preservation. It is pointed out the activities of the production cycle and use of bio ethanol due to great uncertainties as far the environmental impacts is concerning and that will deserve more attention in future evaluations. At same time, the chapter highlights another activities where the present acknowledge is sufficient to assure the control and/or prediction of consequences of the desired intervention on the environment media to accommodate the sugar and ethanol production expansion. The consideration is not conservative but to promote the sustainable development.

  7. Role of Plasma Temperature and Residence Time in Stagnation Plasma Synthesis of c-BN Nanopowders

    Science.gov (United States)

    2013-01-01

    7 A plasma ion source creates the ions, which are then separated by magnetic mass separation to guide the separate beams into a deposition...generator is the soul contributor to sustaining the plasma. Figure 3.3 Plasma synthesis setup. Solid powder-form precursors are sublimated and...operation frequency gives the proper magnetic field skin depth to match the overall plasma torch diameter. The magnetic field skin depth is inversely

  8. Sustainability Science Needs Sustainable Data!

    Science.gov (United States)

    Downs, R. R.; Chen, R. S.

    2013-12-01

    Sustainability science (SS) is an 'emerging field of research dealing with the interactions between natural and social systems, and with how those interactions affect the challenge of sustainability: meeting the needs of present and future generations while substantially reducing poverty and conserving the planet's life support systems' (Kates, 2011; Clark, 2007). Bettencourt & Kaur (2011) identified more than 20,000 scientific papers published on SS topics since the 1980s with more than 35,000 distinct authors. They estimated that the field is currently growing exponentially, with the number of authors doubling approximately every 8 years. These scholars are undoubtedly using and generating a vast quantity and variety of data and information for both SS research and applications. Unfortunately we know little about what data the SS community is actually using, and whether or not the data that SS scholars generate are being preserved for future use. Moreover, since much SS research is conducted by cross-disciplinary, multi-institutional teams, often scattered around the world, there could well be increased risks of data loss, reduced data quality, inadequate documentation, and poor long-term access and usability. Capabilities and processes therefore need to be established today to support continual, reliable, and efficient preservation of and access to SS data in the future, especially so that they can be reused in conjunction with future data and for new studies not conceived in the original data collection activities. Today's long-term data stewardship challenges include establishing sustainable data governance to facilitate continuing management, selecting data to ensure that limited resources are focused on high priority SS data holdings, securing sufficient rights to allow unforeseen uses, and preparing data to enable use by future communities whose specific research and information needs are not yet known. Adopting sustainable models for archival

  9. Plasma centrifuges

    International Nuclear Information System (INIS)

    Karchevskij, A.I.; Potanin, E.P.

    2000-01-01

    The review of the most important studies on the isotope separation processes in the rotating plasma is presented. The device is described and the characteristics of operation of the pulse plasma centrifuges with weakly and strongly ionized plasma as well as the stationary plasma centrifuges with the medium weak ionization and devices, applying the stationary vacuum arc with the high ionization rate and the stationary beam-plasma discharge with complete ionization, are presented. The possible mechanisms of the isotope separation in plasma centrifuges are considered. The specific energy consumption for isotope separation in these devices is discussed [ru

  10. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  11. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  12. Influence of external toroidal flux on low-aspect-ratio toroidal plasma

    International Nuclear Information System (INIS)

    Ikuno, S.; Natori, M.; Kamitani, A.

    1999-01-01

    In the HIST device, the external flux is generated by two kinds of currents: the current I s flowing along the symmetry axis and the bias coil current I D . The influence of the external flux on the MHD equilibrium and stability of the low-aspect-ratio toroidal plasma in the HIST device is investigated numerically. Equilibrium configurations of the low-aspect-ratio toroidal plasma in the HIST device are numerically determined by means of the combination of FDM and BEM. The influence of I s and I D on their stability is also investigated by using the Mercier criterion. The results of computations show that the Mercier limit decreases to zero with increasing I s and with decreasing I D . Moreover, either a further increase in I s or a further decrease in I D raises the Mercier limit considerably. Besides, the equilibrium configuration in the HIST device changes its state from spheromak through ultra-low q to tokamak with increasing I s and with decreasing I D . (author)

  13. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  14. Sustainable NREL - Site Sustainability Plan FY 2015

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-01-01

    NREL's Site Sustainability Plan FY 2015 reports on sustainability plans for the lab for the year 2015 based on Executive Order Goals and provides the status on planned actions cited in the FY 2014 report.

  15. Sustainability : Politics and governance

    NARCIS (Netherlands)

    Heinrichs, Harald; Biermann, Frank

    2016-01-01

    he article gives an overview of global sustainability policy and politics. It is shown how international policy making on sustainable development has progressed from environmental policy toward recent approaches of Earth system governance. Key challenges of international sustainability politics are

  16. Sustainability in Transport Planning

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Greve, Carsten

    Contribution to session J: Joint University Sustainability Initiatives. This session will provide an inspiring overview of interdisciplinary research and teaching activities on sustainability bridging DTU, KU, and CBS, and introduce the joint collaboration Copenhagen Sustainability Initiative (COSI...

  17. Textiles and clothing sustainability sustainable technologies

    CERN Document Server

    2017-01-01

    This is the first book to deal with the innovative technologies in the field of textiles and clothing sustainability. It details a number of sustainable and innovative technologies and highlights their implications in the clothing sector. There are currently various measures to achieve sustainability in the textiles and the clothing industry, including innovations in the manufacturing stage, which is the crux of this book.

  18. Sustainable diets within sustainable food systems.

    Science.gov (United States)

    Meybeck, Alexandre; Gitz, Vincent

    2017-02-01

    Sustainable diets and sustainable food systems are increasingly explored by diverse scientific disciplines. They are also recognised by the international community and called upon to orient action towards the eradication of hunger and malnutrition and the fulfilment of sustainable development goals. The aim of the present paper is to briefly consider some of the links between these two notions in order to facilitate the operationalisation of the concept of sustainable diet. The concept of sustainable diet was defined in 2010 combining two totally different perspectives: a nutrition perspective, focused on individuals, and a global sustainability perspective, in all its dimensions: environmental, economic and social. The nutrition perspective can be easily related to health outcomes. The global sustainability perspective is more difficult to analyse directly. We propose that it be measured as the contribution of a diet to the sustainability of food systems. Such an approach, covering the three dimensions of sustainability, enables identification of interactions and interrelations between food systems and diets. It provides opportunities to find levers of change towards sustainability. Diets are both the results and the drivers of food systems. The drivers of change for those variously involved, consumers and private individuals, are different, and can be triggered by different dimensions (heath, environment, social and cultural). Combining different dimensions and reasons for change can help facilitate the transition to sustainable diets, recognising the food system's specificities. The adoption of sustainable diets can be facilitated and enabled by food systems, and by appropriate policies and incentives.

  19. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  20. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  1. Plasma particle accelerators

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1988-01-01

    The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs

  2. Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta

    International Nuclear Information System (INIS)

    Schlossberg, David J.; Bodner, Grant M.; Bongard, Michael W.; Burke, Marcus G.; Fonck, Raymond J.

    2017-01-01

    Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β t ), low internal inductance, high elongation, and nonsolenoidal current drive is a central goal of present tokamak plasma research. Stable access to this desirable parameter space is demonstrated in plasmas with ultralow aspect ratio and high elongation. Local helicity injection provides nonsolenoidal sustainment, low internal inductance, and ion heating. Equilibrium analyses indicate β t up to ~100% with a minimum |B| well spanning up to ~50% of the plasma volume.

  3. Assessing sustainable remediation frameworks using sustainability principles.

    Science.gov (United States)

    Ridsdale, D Reanne; Noble, Bram F

    2016-12-15

    The remediation industry has grown exponentially in recent decades. International organizations of practitioners and remediation experts have developed several frameworks for integrating sustainability into remediation projects; however, there has been limited attention to how sustainability is approached and operationalized in sustainable remediation frameworks and practices - or whether sustainability plays any meaningful role at all in sustainable remediation. This paper examines how sustainability is represented in remediation frameworks and the guidance provided for practical application. Seven broad sustainability principles and review criteria are proposed and applied to a sample of six international remediation frameworks. Not all review criteria were equally satisfied and none of the frameworks fully met all criteria; however, the best performing frameworks were those identified as sustainability remediation frameworks. Intra-generational equity was addressed by all frameworks. Integrating social, economic and biophysical components beyond triple-bottom-line indicators was explicitly addressed only by the sustainable remediation frameworks. No frameworks provided principle- or rule-based guidance for dealing with trade-offs in sustainability decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Technology and sustainability

    NARCIS (Netherlands)

    Kroeze, C.; Boersema, J.J.; Tellegen, E.; Cremers, A.

    2011-01-01

    In ten essays, this book addresses a broad range of issues related to the interplay of sustainability and technology. How do population growth and technology relate to sustainable development? Can globalization be reconciled with sustainable development? Is sustainability a subjective or an

  5. Sustainable consumption and marketing

    NARCIS (Netherlands)

    Dam, van Y.K.

    2016-01-01

    Sustainable development in global food markets is hindered by the discrepancy between positive consumer attitudes towards sustainable development or sustainability and the lack of corresponding sustainable consumption by a majority of consumers. Apparently for many (light user) consumers the

  6. Comparison of hollow cathode discharge plasma configurations

    International Nuclear Information System (INIS)

    Farnell, Casey C; Farnell, Cody C; Williams, John D

    2011-01-01

    Hollow cathodes used in plasma contactor and electric propulsion devices provide electrons for sustaining plasma discharges and enabling plasma bridge neutralization. Life tests show erosion on hollow cathodes exposed to the plasma environment produced in the region downstream of these devices. To explain the observed erosion, plasma flow field measurements are presented for hollow cathode generated plasmas using both directly immersed probes and remotely located plasma diagnostics. Measurements on two cathode discharge configurations are presented: (1) an open, no magnetic field configuration and (2) a setup simulating the discharge chamber environment of an ion thruster. In the open cathode configuration, large amplitude plasma potential oscillations, ranging from 20 to 85 V within a 34 V discharge, were observed using a fast response emissive probe. These oscillations were observed over a dc potential profile that included a well-defined potential hill structure. A remotely located electrostatic analyzer (ESA) was used to measure the energy of ions produced within the plasma, and energies were detected that met, and in some cases exceeded, the peak oscillatory plasma potentials detected by the emissive probe. In the ion thruster discharge chamber configuration, plasma potentials from the emissive probe again agreed with ion energies recorded by the remotely located ESA; however, much lower ion energies were detected compared with the open configuration. A simplified ion-transit model that uses temporal and spatial plasma property measurements is presented and used to predict far-field plasma streaming properties. Comparisons between the model and remote measurements are presented.

  7. Plasma physics

    CERN Document Server

    Drummond, James E

    1961-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  8. Plasma generator

    International Nuclear Information System (INIS)

    Omichi, Takeo; Yamanaka, Toshiyuki.

    1976-01-01

    Object: To recycle a coolant in a sealed hollow portion formed interiorly of a plasma limiter itself to thereby to cause direct contact between the coolant and the plasma limiter and increase of contact area therebetween to cool the plasma limiter. Structure: The heat resulting from plasma generated during operation and applied to the body of the plasma limiter is transmitted to the coolant, which recycles through an inlet and outlet pipe, an inlet and outlet nozzle and a hollow portion to hold the plasma limiter at a level less than a predetermined temperature. On the other hand, the heater wire is, at the time of emergency operation, energized to heat the plasma limiter, but this heat is transmitted to the limiter body to increase the temperature thereof. However, the coolant recycling the hollow portion comes into direct contact with the limiter body, and since the plasma limiter surround the hollow portion, the heat amount transmitted from the limiter body to the coolant increases to sufficiently cool the plasma limiter. (Yoshihara, H.)

  9. Generalized helicity and its time derivative

    International Nuclear Information System (INIS)

    Jarboe, T.R.; Marklin, G.J.

    1985-01-01

    Spheromaks can be sustained against resistive decay by helicity injection because they tend to obey the minimum energy principle. This principle states that a plasma-laden magnetic configuration will relax to a state of minimum energy subject to the constraint that the magnetic helicity is conserved. Use of helicity as a constraint on the minimization of energy was first proposed by Woltjer in connection with astrophysical phenomena. Helicity does decay on the resistive diffusion time. However, if helicity is created and made to flow continuoiusly into a confinement geometry, these additional linked fluxes can relax and sustain the configuration indefinitely against the resistive decay. In this paper we will present an extension of the definition of helicity to include systems where B vector can penetrate the boundary and the penetration can be varying in time. We then discuss the sustainment of RFPs and spheromaks in terms of helicity injection

  10. Externality or sustainability economics?

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2010-01-01

    In an effort to develop 'sustainability economics' Baumgaertner and Quaas (2010) neglect the central concept of environmental economics-'environmental externality'. This note proposes a possible connection between the concepts of environmental externality and sustainability. In addition, attention is asked for other aspects of 'sustainability economics', namely the distinction weak/strong sustainability, spatial sustainability and sustainable trade, distinctive sustainability policy, and the ideas of early 'sustainability economists'. I argue that both sustainability and externalities reflect a systems perspective and propose that effective sustainability solutions require that more attention is given to system feedbacks, notably other-regarding preferences and social interactions, and energy and environmental rebound. The case of climate change and policy is used to illustrate particular statements. As a conclusion, a list of 20 insights and suggestions for research is offered. (author)

  11. Engineering Sustainability: A Technical Approach to Sustainability

    OpenAIRE

    Rosen, Marc A.

    2012-01-01

    Sustainability is a critically important goal for human activity and development. Sustainability in the area of engineering is of great importance to any plans for overall sustainability given 1) the pervasiveness of engineering activities in societies, 2) their importance in economic development and living standards, and 3) the significant impacts that engineering processes and systems have had, and continue to have, on the environment. Many factors that need to be considered and appropriate...

  12. Bridge between fusion plasma and plasma processing

    International Nuclear Information System (INIS)

    Ohno, Noriyasu; Takamura, Shuichi

    2008-01-01

    In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

  13. Plasma waves

    National Research Council Canada - National Science Library

    Swanson, D. G

    1989-01-01

    ... Swanson, D.G. (Donald Gary), D a t e - Plasma waves. Bibliography: p. Includes index. 1. Plasma waves. QC718.5.W3S43 1989 ISBN 0-12-678955-X I. Title. 530.4'4 88-34388 Printed in the United Sta...

  14. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1991-06-01

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  15. Plasma container

    International Nuclear Information System (INIS)

    Ebisawa, Katsuyuki.

    1985-01-01

    Purpose: To enable to easily detect that the thickness of material to be abraded is reduced to an allowable limit from the outerside of the plasma container even during usual operation in a plasma vessel for a thermonuclear device. Constitution: A labelled material is disposed to the inside or rear face of constituent members of a plasma container undergoing the irradiation of plasma particles. A limiter plate to be abraded in the plasma container is composed of an armour member and heat removing plate, in which the armour member is made of graphite and heat-removing plate is made of copper. If the armour member is continuously abraded under the effect of sputtering due to plasma particles, silicon nitride embedded so far in the graphite at last appears on the surface of the limiter plate to undergo the impact shocks of the plasma particles. Accordingly, abrasion of the limiter material can be detected by a detector comprising gas chromatography and it can easily be detected from the outside of the plasma content even during normal operation. (Horiuchi, T.)

  16. Atomic and molecular processes in fusion plasmas

    International Nuclear Information System (INIS)

    Kato, Daiji; Nakamura, Nobuyuki

    2013-01-01

    One of important issues concerning steady state sustainment of magnetically confined plasmas (MCPs) is distribution of impurity ions in the MCPs and radiation powers by the ions. Since tungsten divertors will be used in ITER, the primary element of heavy impurity ions would be tungsten. Tungsten cannot be fully ionized even in core plasmas of ITER. Line radiations by bound electrons of the tungsten ions following electron impact excitations decrease temperatures of the core plasmas. Thus, it is required to keep tungsten concentration in the core plasmas as small as possible. (J.P.N.)

  17. Cosmic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Alfven, H [California Univ., San Diego, La Jolla (USA)

    1981-01-01

    The properties of space plasmas are analyzed, based on laboratory results and data obtained by in situ measurements in the magnetosphere (including the heliosphere). Attention is given to the question of how much knowledge can be gained by a systematic comparison of different regions of plasma, and plasmas are considered with linear dimensions varying from laboratory size up to the Hubble distance. The traditional magnetic field description of plasmas is supplemented by an electric current description and it is demonstrated that many problems are easier to understand with a dualistic approach. Using the general plasma properties obtained, the origin and evolution of the solar system is summarized and the evolution and present structure of the universe (cosmology) is discussed.

  18. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A relativistic electron beam generator or accelerator produces a high-voltage electron beam which is modulated to initiate electron bunching within the beam which is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10 17 to 10 20 electrons per cubic centimeter. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target. The high-temperature plasma can be used to heat a high Z material to generate radiation. Alternatively, a tunable radiation source is produced by using a moderate Z gas or a mixture of high Z and low Z gas as the target plasma. (author)

  19. Superconducting plasmas

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro; Ohno, J.

    1994-01-01

    Superconducting (SC) plasmas are proposed and investigated. The SC plasmas are not yet familiar and have not yet been studied. However, the existence and the importance of SC plasmas are stressed in this report. The existence of SC plasmas are found as follows. There is a fundamental property of Meissner effect in superconductors, which shows a repulsive effect of magnetic fields. Even in that case, in a microscopic view, there is a region of magnetic penetration. The penetration length λ is well-known as London's penetration depth, which is expressed as δ = (m s /μ 0 n s q s 2 ) 1/2 where m s , n s , q s and μ o show the mass, the density, the charge of SC electron and the permeability in free space, respectively. Because this expression is very simple, no one had tried it into more simple and meaningful form. Recently, one of the authors (T.O.) has found that the length can be expressed into more simple and understandable fundamental form as λ = c/ω ps where c = (ε 0 μ 0 ) -1/2 and ω ps = (n s q s 2 /m s ε 0 ) 1/2 are the light velocity and the superconducting plasma frequency. From this simple expression, the penetration depth of the magnetic field to SC is found as a SC plasma skin depth, that is, the fundamental property of SC can be expressed by the SC plasmas. This discovery indicates an importance of the studies of superconducting plasmas. From these points, several properties (propagating modes et al) of SC plasmas, which consist of SC electrons, normal electrons and lattice ions, are investigated in this report. Observations of SC plasma frequency is also reported with a use of Terahertz electromagnet-optical waves

  20. Sustainability in Business

    DEFF Research Database (Denmark)

    Tollin, Karin; Vej, Jesper

    2012-01-01

    How do companies integrate sustainability into their strategy and practices, and what factors explain their approach? In this paper a typology of sustainability strategies is presented as well as a conceptual framework relating sustainability at the company level to the functional level of market...... managers' mindsets, a framework addressing sustainability from four organisational learning schools was designed and followed......How do companies integrate sustainability into their strategy and practices, and what factors explain their approach? In this paper a typology of sustainability strategies is presented as well as a conceptual framework relating sustainability at the company level to the functional level...... of marketing. The central contribution of the typology is a strategic and managerial view on sustainability. Furthermore, the typology shows that sustainability in business is enacted from different areas of competences and fields in the literature (e.g. supply chain management, corporate branding, value...

  1. Sustainable Table | Welcome to Sustainable Table

    Science.gov (United States)

    Sustainable Seafood Industrial Agriculture Industrial Livestock Production Antibiotics Hormones rBGH Animal , safeguarding animal welfare and supporting local communities. Questions to Ask Asking questions is the best way Livestock Husbandry Sustainable Crop Production Innovative Agriculture New Farmers Organic Agriculture Local

  2. Education for sustainable development

    DEFF Research Database (Denmark)

    Breiting, Søren

    2009-01-01

     An introduction to the idea of sustainable development (SD) and education for sustainable development (ESD) with reference to the international Decade for Education for Sustainable Development . The chapter includes a focus on conflicting interests between present and future generations related ...... to the use of natural resources and other matters, and how that kind of issues can be dealt with in education as ESD....... An introduction to the idea of sustainable development (SD) and education for sustainable development (ESD) with reference to the international Decade for Education for Sustainable Development . The chapter includes a focus on conflicting interests between present and future generations related...

  3. Towards fusion energy as a sustainable energy source: Activities at DTU Physics

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Christensen, Alexander Simon; Dam, Magnus

    2014-01-01

    a fusion plasma) and to confine it within magnetic fields. Learning how such plasmas behave and can be controlled is a crucial step towards realizing fusion as a sustainable energy source.At the Plasma Physics and Fusion Energy (PPFE) section at DTU Physics, we are exploring these issues,focusing on areas...

  4. Smart Sustainable Islands VS Smart Sustainable Cities

    Science.gov (United States)

    Pantazis, D. N.; Moussas, V. C.; Murgante, B.; Daverona, A. C.; Stratakis, P.; Vlissidis, N.; Kavadias, A.; Economou, D.; Santimpantakis, K.; Karathanasis, B.; Kyriakopoulou, V.; Gadolou, E.

    2017-09-01

    This paper has several aims: a) the presentation of a critical analysis of the terms "smart sustainable cities" and "smart sustainable islands" b) the presentation of a number of principles towards to the development methodological framework of concepts and actions, in a form of a manual and actions guide, for the smartification and sustainability of islands. This kind of master plan is divided in thematic sectors (key factors) which concern the insular municipalities c) the creation of an island's smartification and sustainability index d) the first steps towards the creation of a portal for the presentation of our smartification actions manual, together with relative resources, smart applications examples, and, in the near future the first results of our index application in a number of Greek islands and e) the presentation of some proposals of possible actions towards their sustainable development and smartification for the municipalities - islands of Paros and Antiparos in Greece, as case studies.

  5. Plasma universe

    International Nuclear Information System (INIS)

    Alfven, H.

    1986-04-01

    Traditionally the views in our cosmic environment have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasma. Such a medium may also emit synchrotron radiation which is observable in the radio region. If we try to base a model of the universe on the plasma phenomena mentioned we find that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasma. This approach is possible because it is likely that the basic properties of plasma are the same everywhere. In order to test the usefulness of the plasma universe model we apply it to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4-5 bilions years ago with an accuracy of better than 1 percent

  6. Prandtl number of toroidal plasmas

    International Nuclear Information System (INIS)

    Itoh, K.; Itoh, S.; Fukuyama, A.; Yagi, M.; Azumi, M.

    1993-06-01

    Theory of the L-mode confinement in toroidal plasmas is developed. The Prandtl number, the ratio between the ion viscosity and the thermal conductivity is obtained for the anomalous transport process which is caused by the self-sustained turbulence in the toroidal plasma. It is found that the Prandtl number is of order unity both for the ballooning mode turbulence in tokamaks and for the interchange mode turbulence in helical system. The influence on the anomalous transport and fluctuation level is evaluated. Hartmann number and magnetic Prandtl number are also discussed. (author)

  7. Super-high magnetic fields in spatially inhomogeneous plasma

    International Nuclear Information System (INIS)

    Nastoyashchiy, Anatoly F.

    2012-01-01

    The new phenomenon of a spontaneous magnetic field in spatially inhomogeneous plasma is found. The criteria for instability are determined, and both the linear and nonlinear stages of the magnetic field growth are considered; it is shown that the magnetic field can reach a considerable magnitude, namely, its pressure can be comparable with the plasma pressure. Especially large magnetic fields can arise in hot plasma with a high electron density, for example, in laser-heated plasma. In steady-state plasma, the magnetic field can be self-sustaining. The considered magnetic fields may play an important role in thermal insulation of the plasma. (author)

  8. Conceptualising sustainability assessment

    International Nuclear Information System (INIS)

    Pope, Jenny; Annandale, David; Morrison-Saunders, Angus

    2004-01-01

    Sustainability assessment is being increasingly viewed as an important tool to aid in the shift towards sustainability. However, this is a new and evolving concept and there remain very few examples of effective sustainability assessment processes implemented anywhere in the world. Sustainability assessment is often described as a process by which the implications of an initiative on sustainability are evaluated, where the initiative can be a proposed or existing policy, plan, programme, project, piece of legislation, or a current practice or activity. However, this generic definition covers a broad range of different processes, many of which have been described in the literature as 'sustainability assessment'. This article seeks to provide some clarification by reflecting on the different approaches described in the literature as being forms of sustainability assessment, and evaluating them in terms of their potential contributions to sustainability. Many of these are actually examples of 'integrated assessment', derived from environmental impact assessment (EIA) and strategic environmental assessment (SEA), but which have been extended to incorporate social and economic considerations as well as environmental ones, reflecting a 'triple bottom line' (TBL) approach to sustainability. These integrated assessment processes typically either seek to minimise 'unsustainability', or to achieve TBL objectives. Both aims may, or may not, result in sustainable practice. We present an alternative conception of sustainability assessment, with the more ambitious aim of seeking to determine whether or not an initiative is actually sustainable. We term such processes 'assessment for sustainability'. 'Assessment for sustainability' firstly requires that the concept of sustainability be well-defined. The article compares TBL approaches and principles-based approaches to developing such sustainability criteria, concluding that the latter are more appropriate, since they avoid many

  9. Plasma physics

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  10. Plasma centrifuge

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Mase, Hiroshi

    1998-01-01

    The plasma centrifuge is one of statistical isotope separation processes which uses the centrifugal force of a J x B driven rotating plasma in a magnetic field to give rise to the mass-dependent radial transport of isotopic ions. The system has been developed as an alternative to the gas centrifuge because a much higher rotational velocity and separation factor have been achieved. In this review, the physical aspects of the plasma centrifuge followed by the recent experimental achievements are described, especially in comparison with the gas centrifuge. (author)

  11. Handbook of sustainable engineering

    CERN Document Server

    Lee, Kun-Mo

    2013-01-01

    "The efficient utilization of energy, sustainable use of natural resources, and large-scale adoption of sustainable technologies is the key to a sustainable future. The Handbook of Sustainable Engineering provides tools that will help us achieve these goals". Nobel Prize Winner Dr. R.K. Pauchauri, Chairman, UN Intergovernmental Panel on Climate Change As global society confronts the challenges of diminishing resources, ecological degradation, and climate change, engineers play a crucial role designing and building technologies and products that fulfil our needs for utility and sustainability. The Handbook of Sustainable Engineering equips readers with the context and the best practices derived from both academic research and practical examples of successful implementations of sustainable technical solutions. The handbook’s content revolves around the two themes, new ways of thinking and new business models, including sustainable production, products, service systems and consumption while addressing key asse...

  12. Sustainable Water Infrastructure

    Science.gov (United States)

    Resources for state and local environmental and public health officials, and water, infrastructure and utility professionals to learn about sustainable water infrastructure, sustainable water and energy practices, and their role.

  13. Sustainable development. First part

    International Nuclear Information System (INIS)

    Colombo, U.; Lanzavecchia, G.; Berrini, M; Zambrini, M.; Bologna, G.; Carraro, C.; Hinterberger, F.; Mastino, G.; Federico, A.; Gaudioso, D.; Luise, A.; Mauro, F.; Padovani, L.; Federico, A.

    1998-01-01

    This paper summarizes a collective effort and represents the second edition of: Environment, energy, economy: a sustainable future. In this work are reported various interventions on sustainable development problem [it

  14. Sustainable Public Bids

    Directory of Open Access Journals (Sweden)

    Gil César Costa de Paula

    2016-06-01

    Full Text Available In this article we will discuss the issue of sustainability in public procurement, given that the government in Brazil is constituted as a great promoter of economic development and needs to adapt its acquisitions worldwide sustainability agenda.

  15. Neighbourhood facilities for sustainability

    CSIR Research Space (South Africa)

    Gibberd, Jeremy T

    2013-01-01

    Full Text Available . In this paper these are referred to as ‘Neighbourhood Facilities for Sustainability’. Neighbourhood Facilities for Sustainability (NFS) are initiatives undertaken by individuals and communities to build local sustainable systems which not only improve...

  16. FORUM: Is Ecotourism Sustainable?

    Science.gov (United States)

    Wall

    1997-07-01

    / It is legitimate to ask whether and in what form tourism might contribute to sustainable development. This is not the same as sustainable tourism which, as a single-sector approach to development, may overlook important linkages with other sectors. If tourism is to contribute to sustainable development, then it must be economically viable, ecologically sensitive and culturally appropriate. Ecotourism is often advocated as being a sustainable form of tourism but imprecision in terminology clouds basic issues and there are strong economic, ecological, and cultural reasons for believing that, even in its purest forms, ecotourism is likely to present substantial challenges to destination areas, particularly if it competes for scarce resources and displaces existing uses and users. Sustainable tourism and ecotourism are not synonyms, many forms of ecotourism may not be sustainable, and if ecotourism is to contribute to sustainable development, then careful planning and management will be required.KEY WORDS: Ecotourism; Sustainable development; Development; Tourism

  17. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  18. Laser Plasmas

    Indian Academy of Sciences (India)

    -focusing in a plasma ... Center for Energy Studies, Indian Institute of Technology, New Delhi 110 016, India; Tata Consultancy Services, Gurgaon, India; Ideal Institute of Technology, Ghaziabad, India; Center for Research in Cognitive, ...

  19. Plasma will…

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg

    2016-01-01

    Roč. 174, č. 3 (2016), s. 486-487 ISSN 0007-0963 Institutional support: RVO:68378271 Keywords : plasma * ionized gas Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 4.706, year: 2016

  20. Plasma technology

    International Nuclear Information System (INIS)

    Drouet, M.G.

    1984-03-01

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  1. Eigenvalues of relaxed toroidal plasmas of arbitrary sharp edged cross sections. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Sh M [Plasma Physics and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    Relaxed (force-free) toroidal plasmas described by the equations cur 1 B={mu}B, and grad {mu}=O (B is the magnetic field) induces interest in nuclear fusion. Its solution is perceived to describe the gross of the reversed field pinch (RFP), spheromak configuration, current limitation in toroidal plasmas, and others. The parameter {mu} plays an important roll in relaxed states. It cannot exceed the smallest eigenvalue {mu} (min), and that for a toroidal discharge there is a maximum toroidal current which is connected to this value. The values of{mu} were calculated numerically, using the methods of collocation points, for toroids of arbitrary aspect ratio {alpha} ({alpha} = R/a, ratio of major/minor radii of tokamak) and arbitrary curved cross-sections (circle, ellipse, cassini, and D-shaped). The aim of present work is to prove the applicability of the numerical methods for calculating the eigenvalues for toroidal plasmas having sharp edged cross sections and arbitrary aspect ratio. The lowest eigenvalue {mu} (min), satisfy the boundary condition {beta} .n = O (or RB. = O) for which the toroidal flux are calculated. These are the zero field eigenvalues of the equation cur 1 b={mu}B. The poloidal magnetic field lines corresponding to different cross sections are shown by plotting the boundary condition B.n=O. The plots showed good fulfillment of the boundary condition along the whole boundaries of different cross sections. Dependence of eigenvalues {mu}a on aspect ratio {alpha} is also obtained. Several runs of the programme with various wave numbers K showed that {mu}a is very insensitive to the choice of K. 8 figs.

  2. Plasma metallization

    International Nuclear Information System (INIS)

    Crowther, J.M.

    1997-09-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of surface contamination of the films due to plasma treatment was observed but was easily removed by argon ion cleaning. Hydrogen plasma reduction of glass supported silver(l) nitrate and palladium(ll) acetate films reveals that this metallization technique is applicable to a wide variety of metal salts and supports, and has also shown the ability of plasma reduction to retain the complex 'fern-like' structures seen for spin coated silver(l) nitrate layers. Some metal salts are susceptible to decomposition by X-rays. The reduction of Nylon 66 supported gold(lll) chloride films by soft X-rays to produce nanoscopic gold particles has been studied. The spontaneous reduction of these X-ray irradiated support gold(lll) chloride films on exposure to the atmosphere to produce gold rich metallic films has also been reported. (author)

  3. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  4. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  5. Sustainability Statement and Policy

    Science.gov (United States)

    Journal of Education for Sustainable Development, 2009

    2009-01-01

    This article presents nine resources that focus on environmental education and sustainability. These include: (1) "Sustainability Statement and Policy," Dalhousie University, Nova Scotia, Canada, 2009, which is available at http://office.sustainability.dal.ca/Governance; (2) "Climate Literacy: The Essential Principles of Climate…

  6. The sustainable development

    International Nuclear Information System (INIS)

    2004-01-01

    In the framework of the sustainable development week (june 2003), Actu Environnement published a complete document on the sustainable development to inform the public, recall the main steps of this notion (Rio conference and the following conferences) and the possible employments. It presents also the main organizations acting in the sustainable development domain. (A.L.B.)

  7. Toward sustainable logistics

    NARCIS (Netherlands)

    Soysal, Mehmet; Bloemhof-Ruwaard, Jacqueline M.

    2017-01-01

    The fast evolution of sustainability leads to the development of a new fast-growing concept called sustainable logistics management. This research addresses recent business trends and challenges in logistics and their implications for sustainable logistics management. Additionally, we discuss policy

  8. ORNL Annual Sustainability Report

    Energy Technology Data Exchange (ETDEWEB)

    Lapsa, Melissa Voss [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nichols, Teresa A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-02-01

    As described in this report, we have made substantial progress across the 25 roadmaps of the Sustainable Campus Initiative. The report also outlines our plans to continue integrating sustainable practices into the planning, execution, and evaluation of all ORNL activities. We appreciate your interest in our journey to sustainability, and we welcome your comments, questions, and suggestions.

  9. Toward sustainable logistics

    NARCIS (Netherlands)

    Soysal, Mehmet; Bloemhof-Ruwaard, Jacqueline M.

    2018-01-01

    The fast evolution of sustainability leads to the development of a new fast-growing concept called sustainable logistics management. This research addresses recent business trends and challenges in logistics and their implications for sustainable logistics management. Additionally, we discuss policy

  10. Sustainable Learning Organizations

    Science.gov (United States)

    Velazquez, Luis E.; Esquer, Javier; Munguia, Nora E.; Moure-Eraso, Rafael

    2011-01-01

    Purpose: The purpose of this paper is to debate how companies may better become a sustainable learning organization by offering the most used and insightful concepts of sustainability. Design/methodology/approach: Through literature review, learning organization and sustainability perspectives are explored and compared. Findings: Learning…

  11. Sustainability Annual Report 2013

    OpenAIRE

    2013-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  12. Sustainability Annual Report 2014

    OpenAIRE

    2014-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  13. Sustainability Annual Report 2017

    OpenAIRE

    2017-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  14. Sustainability Annual Report 2011

    OpenAIRE

    2011-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  15. Sustainability Annual Report 2012

    OpenAIRE

    2012-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  16. Sustainability Annual Report 2015

    OpenAIRE

    2015-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  17. Sustainability Annual Report 2016

    OpenAIRE

    2016-01-01

    Every year, Virginia Tech releases a sustainability annual report to show the university’s progress in meeting the sustainability goals. The key sustainability metrics these reports cover include: greenhouse gas (GHG) emissions, energy use intensity, alternative transportation use, recycling, and water consumption.

  18. Mirror fusion test facility plasma diagnostics system

    International Nuclear Information System (INIS)

    Thomas, S.R. Jr.; Coffield, F.E.; Davis, G.E.; Felker, B.

    1979-01-01

    During the past 25 years, experiments with several magnetic mirror machines were performed as part of the Magnetic Fusion Energy (MFE) Program at LLL. The latest MFE experiment, the Mirror Fusion Test Facility (MFTF), builds on the advances of earlier machines in initiating, stabilizing, heating, and sustaining plasmas formed with deuterium. The goals of this machine are to increase ion and electron temperatures and show a corresponding increase in containment time, to test theoretical scaling laws of plasma instabilities with increased physical dimensions, and to sustain high-beta plasmas for times that are long compared to the energy containment time. This paper describes the diagnostic system being developed to characterize these plasma parameters

  19. Life Cycle Sustainability Dashboard

    DEFF Research Database (Denmark)

    Traverso, Marzia; Finkbeiner, Matthias; Jørgensen, Andreas

    2012-01-01

    One method to assess the sustainability performance of products is life cycle sustainability assessment (LCSA), which assesses product performance considering the environmental,economic, and social dimensions of the life cycle. The results of LCSA can be used to compare different products...... of sustainability is the communicability of the results by means of a graphical representation (a cartogram), characterized by a suitable chromatic scale and ranking score. The integration of LCSA and the dashboard of sustainability into a so-called Life Cycle Sustainability Dashboard (LCSD) is described here...

  20. LCA and Sustainability

    DEFF Research Database (Denmark)

    Moltesen, Andreas; Bjørn, Anders

    2018-01-01

    LCA is often presented as a sustainability assessment tool. This chapter analyses the relationship between LCA and sustainability. This is done by first outlining the history of the sustainability concept, which gained momentum with the Brundtland Commission’s report ‘Our Common Future report...... is then demonstrated, and the strategy of LCA to achieving environmental protection, namely to guide the reduction of environmental impacts per delivery of a function, is explained. The attempt to broaden the scope of LCA, beyond environmental protection, by so-called life cycle sustainability assessment (LCSA......) is outlined. Finally, the limitations of LCA in guiding a sustainable development are discussed....

  1. Fur and Sustainability

    DEFF Research Database (Denmark)

    Skjold, Else; Csaba, Fabian

    2016-01-01

    This paper explores the notion of deeper luxury, which insists that 'real' luxury should involve sustainable practices in the production and consumption of luxury goods. It traces historical and recent developments in the field of fur, to understand the implications, uncertainties and ambiguities...... of luxury’s confrontation with sustainability. Considering fur in relation to future standards for luxury products, we raise questions about moral problematisation and justification of luxury in terms of sustainability. We first examine the encounter of luxury with sustainability and explain...... the significance of the notion of ‘deeper luxury’. After taking stock of the impact of sustainability on luxury and various directions in which sustainable luxury is evolving, we discuss concepts of sustainable development in relation to the history of moral problematisation of luxury. This leads to the case...

  2. Sustainability index for Taipei

    International Nuclear Information System (INIS)

    Lee, Y.-J.; Huang Chingming

    2007-01-01

    Sustainability indicators are an effective means of determining whether a city is moving towards sustainable development (SD). After considering the characteristics of Taipei, Taiwan, discussions with experts, scholars and government departments and an exhaustive literature review, this study selected 51 sustainability indicators corresponding to the socio-economic characteristic of Taipei City. Such indicators should be regarded as a basis for assessing SD in Taipei City. The 51 indicators are classified into economic, social, environmental and institutional dimensions. Furthermore, statistical data is adopted to identify the trend of SD from 1994 to 2004. Moreover, the sustainability index is calculated for the four dimensions and for Taipei as a whole. Analysis results demonstrate that social and environmental indicators are moving towards SD, while economic and institutional dimensions are performing relatively poorly. However, since 2002, the economic sustainability index has gradually moved towards SD. Overall, the Taipei sustainability index indicates a gradual trend towards sustainable development during the past 11 years

  3. Sustainability and Entrepreneurial Action

    DEFF Research Database (Denmark)

    Korsgaard, Steffen T.; Anderson, Alistair

    Abstract Objectives - This paper explores how entrepreneurial action can lead to environmental sustainability. It builds on the assumption that the creation of sustainble practices is one of the most important challenges facing the global society, and that entrepreneurial action is a vital......: resource oriented sustainable entrepreneurial action.  Approach - The paper uses a case study approach to build deeper theoretical knowledge of environmentally sustainable entrepreneurship.  Results - The paper identifies and analyses a distinct form of sustainable entrepreneurship -  resource oriented...... entrepreneurship - which uses bricolage in various ways to create sustainable solutions. Implications and value - The concept of resource oriented sustainable entrepreneurship contributes to the theoretical understanding of how entrepreneurial action can support sustainability, Furthermore the case study has...

  4. Self-sustained detachment in the Large Helical Device

    International Nuclear Information System (INIS)

    Miyazawa, J.; Masuzaki, S.; Sakamoto, R.; Arimoto, H.; Kondo, K.; Tamura, N.; Shoji, M.; Nishiura, M.; Murakami, S.; Funaba, H.; Peterson, B.J.; Sakakibara, S.; Kobayashi, M.; Tanaka, K.; Narihara, K.; Yamada, I.; Morita, S.; Goto, M.; Osakabe, M.; Ashikawa, N.; Morisaki, T.; Nishimura, K.; Yamada, H.; Ohyabu, N.; Komori, A.; Motojima, O.

    2006-01-01

    Self-sustained detachment has been obtained in the Large Helical Device (LHD). Strong hydrogen gas puffing of ∼200 Pa m 3 s -1 after a density feedback phase detaches the plasma from the divertor plates with high reproducibility. High electron density of over 1 x 10 20 m -3 is sustained without gas puffing until the heating beam stops and a high-density flat top for 2 s has been demonstrated. Throughout the self-sustained detachment phase, the minor radius of the hot plasma column shrinks to ∼90% of the last-closed-flux-surface, which corresponds to the ι-bar ι/2π = 1/q =1 rational surface. This new state has been named the 'Serpens mode', for self-regulated plasma edge 'neath the last-closed-flux-surface. Global energy confinement of the Serpens mode is compared with the international stellarator scaling 1995 (ISS95) and the recently established scaling for high-density LHD plasmas (HD scaling), where shrinking confinement volume and shallow penetration of the heating beams are taken into account. Although the energy confinement of the Serpens mode seems deteriorated compared with ISS95, as in the case of high-density attached plasmas, it is consistent with the HD scaling. This suggests that the energy confinement properties of detached plasmas in LHD are similar to those in high-density attached plasmas

  5. Health and sustainability.

    Science.gov (United States)

    Kjӕrgård, Bente; Land, Birgit; Bransholm Pedersen, Kirsten

    2014-09-01

    In the present article, we explore how sustainable development strategies and health promotion strategies can be bridged. The concept of the 'duality of structure' is taken as our starting point for understanding the linkages between health promotion and sustainable development, and for uncovering the structural properties or conditions which either enable or constrain sustainable public health initiatives. We argue that strategies towards health promotion are not sufficiently integrated with strategies for sustainable development, and thus political strategies aimed at solving health problems or sustainability problems may cause new, undesired and unforeseen environmental or health problems. First, we explore how the relation between health and sustainability is articulated in international policy documents. Next, we develop a model for understanding the relation between health promotion and sustainability. Third, we use examples from agriculture and food production to illustrate that health and sustainability are mutually enabling and constraining. We conclude that while the renewed focus on food security and food inequalities has brought the health and sustainability dimensions of the food system onto the political agenda, the conceptualization of duality between health and sustainability could be a new platform for a critical and theoretical stance towards the market-oriented food system strategy. Thinking along the lines of duality means that the integration of health promotion strategies and sustainable development strategies cannot be based on an approach to integration in which either health or sustainability is given precedence over the other. From a duality perspective, integration means conceiving sustainability from a health perspective and health from a sustainability perspective. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Micro-column plasma emission liquid chromatograph. [Patent application

    Science.gov (United States)

    Gay, D.D.

    1982-08-12

    In a direct current plasma emission spectrometer for use in combination with a microcolumn liquid chromatograph, an improved plasma source unit is claimed. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

  7. Cold plasmas

    International Nuclear Information System (INIS)

    Franz, G.

    1990-01-01

    This textbook discusses the following topics: Phenomenological description of a direct current glow discharge; the plasma (temperature distribution and measurement, potential variation, electron energy distribution function, charge neutralization, wall potentials, plasma oscillations); Production of charge carriers (ions, electrons, ionization in the cathode zone, negative glowing zone, Faraday dark space, positive column, anode zone, hollow cathode discharges); RF-discharges (charge carrier production, RF-Shields, scattering mechanisms); Sputtering (ion-surface interaction, kinetics, sputtering yield and energy distribution, systems and conditions, film formation and stresses, contamination, bias techniques, multicomponent film deposition, cohesion, magnetrons, triode systems, plasma enhanced chemical vapor deposition); Dry etching (sputter etching, reactive etching, topography, process control, quantitative investigations); Etching mechanisms (etching of Si and SiO 2 with CF 4 , of III/V-compound-semiconductors, combination of isotrope and anisotrope etching methods, surface cleaning); ion beam systems (applications, etching); Dyclotron-resonance-systems (electron cyclotron resonance systems, whistler-sources and 'resonant inductive plasma etching'); Appendix (electron energy distribution functions, Bohm's transition zone, plasma oscillations, scattering cross sections and mean free path, metastable states, Child-Langmuir-Schottky equation, loss mechanisms, charge carrier distribution in the positive column, breakdown at high frequencies, motion in a magnetic field, skin depth of an electric field for a HF-discharge, whistler waves, dispersion relations for plane wave propagation). (orig.) With 138 figs

  8. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

    Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

  9. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  10. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1989-08-01

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  11. Electron plasma waves and plasma resonances

    International Nuclear Information System (INIS)

    Franklin, R N; Braithwaite, N St J

    2009-01-01

    In 1929 Tonks and Langmuir predicted of the existence of electron plasma waves in an infinite, uniform plasma. The more realistic laboratory environment of non-uniform and bounded plasmas frustrated early experiments. Meanwhile Landau predicted that electron plasma waves in a uniform collisionless plasma would appear to be damped. Subsequent experimental work verified this and revealed the curious phenomenon of plasma wave echoes. Electron plasma wave theory, extended to finite plasmas, has been confirmed by various experiments. Nonlinear phenomena, such as particle trapping, emerge at large amplitude. The use of electron plasma waves to determine electron density and electron temperature has not proved as convenient as other methods.

  12. ''Dusty plasmas''

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bingham, R.; Angelis, U. de

    1989-09-01

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  13. SMART SUSTAINABLE ISLANDS VS SMART SUSTAINABLE CITIES

    Directory of Open Access Journals (Sweden)

    D. N. Pantazis

    2017-09-01

    Full Text Available This paper has several aims: a the presentation of a critical analysis of the terms “smart sustainable cities” and “smart sustainable islands” b the presentation of a number of principles towards to the development methodological framework of concepts and actions, in a form of a manual and actions guide, for the smartification and sustainability of islands. This kind of master plan is divided in thematic sectors (key factors which concern the insular municipalities c the creation of an island’s smartification and sustainability index d the first steps towards the creation of a portal for the presentation of our smartification actions manual, together with relative resources, smart applications examples, and, in the near future the first results of our index application in a number of Greek islands and e the presentation of some proposals of possible actions towards their sustainable development and smartification for the municipalities - islands of Paros and Antiparos in Greece, as case studies.

  14. Plasma physics and engineering

    CERN Document Server

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  15. Health and Sustainability

    DEFF Research Database (Denmark)

    Land, Birgit; Pedersen, Kirsten Bransholm; Kjærgård, Bente

    2014-01-01

    In the present article, we explore how sustainable development strategies and health promotion strategies can be bridged. The concept of the ‘duality of structure’ is taken as our starting point for understanding the linkages between health promotion and sustainable development, and for uncovering...... the structural properties or conditions which either enable or constrain sustainable public health initiatives. We argue that strategies towards health promotion are not sufficiently integrated with strategies for sustainable development, and thus political strategies aimed at solving health problems...... or sustainability problems may cause new, undesired and unforeseen environmental or health problems. First, we explore how the relation between health and sustainability is articulated in international policy documents. Next, we develop a model for understanding the relation between health promotion...

  16. ICT innovations for sustainability

    CERN Document Server

    Aebischer, Bernard

    2015-01-01

    ICT Innovations for Sustainability is an investigation of how information and communication technology can contribute to sustainable development. It presents clear definitions of sustainability, suggesting conceptual frameworks for the positive and negative effects of ICT on sustainable development. It reviews methods of assessing the direct and indirect impact of ICT systems on energy and materials demand, and examines the results of such assessments. In addition, it investigates ICT-based approaches to supporting sustainable patterns of production and consumption, analyzing them at various levels of abstraction – from end-user devices, Internet infrastructure, user behavior, and social practices to macro-economic indicators.   Combining approaches from Computer Science, Information Systems, Human-Computer Interaction, Economics, and Environmental Sciences, the book presents a new, holistic perspective on ICT for Sustainability (ICT4S). It is an indispensable resource for anyone working in the area of ICT...

  17. Engineering students' sustainability approaches

    Science.gov (United States)

    Haase, S.

    2014-05-01

    Sustainability issues are increasingly important in engineering work all over the world. This article explores systematic differences in self-assessed competencies, interests, importance, engagement and practices of newly enrolled engineering students in Denmark in relation to environmental and non-environmental sustainability issues. The empirical base of the article is a nation-wide, web-based survey sent to all newly enrolled engineering students in Denmark commencing their education in the fall term 2010. The response rate was 46%. The survey focused on a variety of different aspects of what can be conceived as sustainability. By means of cluster analysis, three engineering student approaches to sustainability are identified and described. The article provides knowledge on the different prerequisites of engineering students in relation to the role of sustainability in engineering. This information is important input to educators trying to target new engineering students and contribute to the provision of engineers equipped to meet sustainability challenges.

  18. Sustainable Concrete Technology

    Directory of Open Access Journals (Sweden)

    Sim J.

    2015-12-01

    Full Text Available The growing concern over global warming and significant ecological changes requires sustainable development in all fields of science and technology. Concrete not only consumes huge amount of energy and natural sources, but also emits large amount of CO2, mainly due to the production of cement. It is evident that such large amount of concrete production has put significant impact on the energy, resource, environment, and ecology of the society. Hence, how to develop the concrete technology in a sustainable way has become a significant issue. In this paper, some of Korean researches for sustainable development of concrete are presented. These are sustainable strengthening for deteriorated concrete structure, sustainable reinforcement of new concrete structure, sustainable concrete using recycled aggregate and supplementary cementing materials and finally application of each technique to precast concrete.

  19. Sustainable Housing Design

    DEFF Research Database (Denmark)

    Lauring, Gert Michael

    2016-01-01

    Sustainable Housing Design. Integrating technical and housing quality aspects of sustainable architecture in civil engineering education. Summary An integrated design approach to sustainable architecture is outlined that combines concerns for zero energy building, good indoor climate and adequate...... phases. The outcome shows that integrated design further solutions where sustainable urban forms of settlement can be highly energy efficient while also attractive from a user perspective. Key words: Sustainable architecture, integrated design, zero-energy-housing, dense urban living. 1. Introduction...... When designing sustainable housing, energy optimization and satisfactory indoor climates are central issues that need to be incorporated from early design phases if to reach a coherent design. It might also be argued that the energy consumption of contemporary buildings only plays a rela-tively minor...

  20. Is Mass Customization Sustainable?

    DEFF Research Database (Denmark)

    Petersen, Thomas Ditlev; Jørgensen, Kaj Asbjørn; Nielsen, Kjeld

    2011-01-01

    Mass customizers are like other companies currently experiencing an increasing customer demand for environmentally sustainable products as well as an increasingly strict legislation regarding environmental sustainability. This paper addresses the issue whether the concepts mass customization...... and sustainability are fundamentally compatible by asking the question: can a mass customized product be sustainable? Several factors could indicate that mass customized products are less sustainable than standardized products; however other factors suggest the opposite. This paper explores these factors during...... three life cycle phases for a product: Production, Use and End of Life. It is concluded that there is not an unambiguous causal relationship between mass customization and sustainability; however several factors unique to mass customized products are essential to consider during product and process...

  1. Laser-heating of hydrogen plasma

    International Nuclear Information System (INIS)

    Foeldes, I.B.; Ignacz, P.N.; Kocsis, G.

    1990-10-01

    The possibility of creating a fully ionized hydrogen plasma to investigate the capture of slow antiprotons is discussed. Laser heating of the initially discharge-created arc or Z-pinch plasma is proposed. Within the framework of a simple 1-dimensional model based on the energy balance equation alone it is shown that plasma equilibrium can be sustained for 10 μs. A simple pulsed CO 2 laser with this pulse duration and an energy of about 10-30 J is sufficient for heating. (author) 16 refs.; 3 figs

  2. Motivations Behind Sustainable Purchasing

    OpenAIRE

    Vörösmarty, Gyöngyi; Dobos, Imre; Tátrai, Tünde

    2011-01-01

    Sustainability issues in purchasing are receiving greater attention. Literature is rapidly growing, with several research programs being initiated to investigate the topic. This study presents the results of a research project which aims to reveal and structure the motivating forces leading companies to make efforts in sustainability purchasing and the means used to attain achievements in some fields of sustainability. Results presented in the literature are scattered in terms of ...

  3. Monitor Sustainable Netherlands 2011

    International Nuclear Information System (INIS)

    2011-09-01

    The Monitor provides an image of the sustainability of the Dutch society. It shows which areas are successful and what the 'concerns for tomorrow' are from the point of view of sustainability. An analysis is conducted of how the Netherlands are doing in the fields of climate change, biodiversity, health, knowledge, graying and social cohesion. These and many other topics are discussed in this monitor by means of a number of sustainability indicators and detail analyses [mk]. [nl

  4. Monitor Sustainable Netherlands 2009

    International Nuclear Information System (INIS)

    2009-02-01

    The Monitor provides an image of the sustainability of the Dutch society. It shows which areas are successful and what the 'concerns for tomorrow' are from the point of view of sustainability. An analysis is conducted of how the Netherlands are doing in the fields of climate change, biodiversity, health, knowledge, graying and social cohesion. These and many other topics are discussed in this monitor by means of a number of sustainability indicators and detail analyses [mk] [nl

  5. Managing Supplier Sustainability Risk

    OpenAIRE

    Harilainen, Hanna-Riitta

    2014-01-01

    Supply chains are increasingly global, often reaching to developing regions. The media pressure brand owners to be responsible, but a product is only as sustainable as the practices of all the companies involved in manufacturing it are. It’s not enough that the brand owner acts responsibly; sustainable practices have to reach component and raw material suppliers upstream. Image risk has often been recognized as reason for investing in sustainability. In the supply chain context, supplier m...

  6. Sustainability and Organizational Change

    OpenAIRE

    Sitnikov, Catălina

    2012-01-01

    The relevant and, above all, remarkable feature of sustainability is due to its "duality": on the one hand, it is an indispensable element within the companies even if, on the other hand, it increases the costs of many activities and processes. Facing the challenge of sustainability will determine and create, in the coming years, emerging organizational forms. If ten years ago, many managers clearly expressed their doubts regarding the financial feasibility of sustainability, today, they admi...

  7. Towards a Sustainable Architecture

    OpenAIRE

    Patuel Chust, Pascual

    2014-01-01

    The growing awareness of the importance of ecology in the last decades has led many architects to rethink their construction proposals to make them more respectful of the environment and sustainability. The present article analyzes the legislation, conferences and international declarations (Earth Summit, Declaration of Interdependence for a Sustainable Future, Introduction to Sustainable Design) that have advocated the practice of a more ecological architecture. Also examined ...

  8. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years...

  9. Burning plasmas

    International Nuclear Information System (INIS)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J.

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R ampersand D areas that need to be addressed on the way to a fusion power demonstration

  10. Sustainable Management of Food

    Science.gov (United States)

    To provide information to organizations to help them implement sustainable food management, including joining the Food Recovery Challenge. To provide education and information to communities and concerned citizens.

  11. Sustainable wireless networks

    CERN Document Server

    Zheng, Zhongming; Xuemin

    2013-01-01

    This brief focuses on network planning and resource allocation by jointly considering cost and energy sustainability in wireless networks with sustainable energy. The characteristics of green energy and investigating existing energy-efficient green approaches for wireless networks with sustainable energy is covered in the first part of this brief. The book then addresses the random availability and capacity of the energy supply. The authors explore how to maximize the energy sustainability of the network and minimize the failure probability that the mesh access points (APs) could deplete their

  12. Action Research for Sustainability

    DEFF Research Database (Denmark)

    Egmose, Jonas

    on urban sustainability the need to move towards sustainability at societal level is conceptualised as a democratic challenge questioning the way we live on planet earth. By understanding sustainability as an immanent and emergent ability of ecological and social life, continuously to renew itself without...... with a greater say in the future of urban sustainability research, the work shows how action research can make important methodological contributions to processes of social learning between citizens and scientists by enabling free spaces in peoples everyday life and within academia, where aspects...

  13. Action Research for Sustainability

    DEFF Research Database (Denmark)

    Egmose, Jonas

    by analysing processes of social learning. The book addresses the need to move towards sustainability at societal level as a democratic challenge questioning the way we live on planet earth. By conceptualising sustain-ability as an immanent and emergent ability of ecological and social life, continuously...... to provide local citizens with a greater say in the future of urban sustainability research, this book shows how action research can make important methodological contributions to processes of social learning between citizens and scientists by enabling free spaces in peoples everyday life and within academia...

  14. Interchange Instability and Transport in Matter-Antimatter Plasmas

    Science.gov (United States)

    Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

    2017-06-01

    Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

  15. Theory of electromagnetic fluctuations for magnetized multi-species plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Roberto E., E-mail: roberto.navarro@ug.uchile.cl; Muñoz, Víctor [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Concepción 4070386 (Chile); Moya, Pablo S. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Department of Physics, Catholic University of America, Washington, D. C. 20064 (United States); Viñas, Adolfo F. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Valdivia, Juan A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Centro de Estudios Interdisciplinarios Básicos y Aplicados en Complejidad, CEIBA complejidad, Bogotá (Colombia)

    2014-09-15

    Analysis of electromagnetic fluctuations in plasma provides relevant information about the plasma state and its macroscopic properties. In particular, the solar wind persistently sustains a small but detectable level of magnetic fluctuation power even near thermal equilibrium. These fluctuations may be related to spontaneous electromagnetic fluctuations arising from the discreteness of charged particles. Here, we derive general expressions for the plasma fluctuations in a multi-species plasma following arbitrary distribution functions. This formalism, which generalizes and includes previous works on the subject, is then applied to the generation of electromagnetic fluctuations propagating along a background magnetic field in a plasma of two proton populations described by drifting bi-Maxwellians.

  16. Interchange Instability and Transport in Matter-Antimatter Plasmas.

    Science.gov (United States)

    Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

    2017-06-09

    Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

  17. Safety assessment for the S-1 Spheromak

    International Nuclear Information System (INIS)

    Ellis, R. Jr.; Stencel, J.R.

    1984-02-01

    The S-1 machine is part of the Magnetic Fusion Program. The goal of the Magnetic Fusion Program is to develop and demonstrate the practical application of fusion. S-1 is an experimental device which will provide an essential link in the research effort aiming at the realization of fusion power

  18. Plasma-based EUV light source

    Science.gov (United States)

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

    2010-11-02

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

  19. Operation and control of ITER plasmas

    International Nuclear Information System (INIS)

    2001-01-01

    Features incorporated in the design of the International Thermonuclear Experimental Reactor (ITER) tokamak and its ancillary and plasma diagnostic systems that will facilitate operation and control of ignited and/or high-Q DT plasmas are presented. Control methods based upon straight-forward extrapolation of techniques employed in the present generation of tokamaks are found to be adequate and effective for DT plasma control with burn durations of ≥1000 s. Examples of simulations of key plasma control functions including magnetic configuration control and fusion burn (power) control are given. The prospects for the creation and control of steady-state plasmas sustained by non-inductive current drive are also discussed. (author)

  20. Operation and control of ITER plasmas

    International Nuclear Information System (INIS)

    1999-01-01

    Features incorporated in the design of the International Thermonuclear Experimental Reactor (ITER) tokamak and its ancillary and plasma diagnostic systems that will facilitate operation and control of ignited and/or high-Q DT plasmas are presented. Control methods based upon straight-forward extrapolation of techniques employed in the present generation of tokamaks are found to be adequate and effective for DT plasma control with burn durations of ≥1000 s. Examples of simulations of key plasma control functions including magnetic configuration control and fusion burn (power) control are given. The prospects for the creation and control of steady-state plasmas sustained by non-inductive current drive are also discussed. (author)

  1. Magnetoresistive waves in plasmas

    International Nuclear Information System (INIS)

    Felber, F.S.; Hunter, R.O. Jr.; Pereira, N.R.; Tajima, T.

    1982-01-01

    The self-generated magnetic field of a current diffusing into a plasma between conductors can magnetically insulate the plasma. Propagation of magnetoresistive waves in plasmas is analyzed. Applications to plasma opening switches are discussed

  2. Pharmacokinetics of Sustained-Release Analgesics in Mice

    Science.gov (United States)

    Kendall, Lon V; Hansen, Ryan J; Dorsey, Kathryn; Kang, Sooah; Lunghofer, Paul J; Gustafson, Daniel L

    2014-01-01

    Buprenorphine and carprofen, 2 of the most commonly used analgesics in mice, must be administered every 8 to 12 h to provide sustained analgesia. Sustained-release (SR) formulations of analgesics maintain plasma levels that should be sufficient to provide sustained analgesia yet require less frequent dosing and thus less handling of and stress to the animals. The pharmacokinetics of SR formulations of buprenorphine (Bup-SR), butorphanol (Butp-SR), fentanyl (Fent-SR), carprofen (Carp-SR), and meloxicam (Melox-SR) were evaluated in mice over 72 h and compared with those of traditional, nonSR formulations. Bup-SR provided plasma drug levels greater than the therapeutic level for the first 24 to 48 h after administration, but plasma levels of Bup-HCl fell below the therapeutic level by 4 h. Fent-SR maintained plasma levels greater than reported therapeutic levels for 12 h. Therapeutic levels of the remaining drugs are unknown, but Carp-SR provided plasma drug levels similar to those of Carp for the first 24 h after administration, whereas Melox-SR had greater plasma levels than did Melox for the first 8 h. Butp-SR provided detectable plasma drug levels for the first 24 h, with a dramatic decrease over the first 4 h. These results indicate that Bup-SR provides a stable plasma drug level adequate for analgesia for 24 to 48 h after administration, whereas Carp-SR, Melox-SR, Fent-SR, and Butp-SR would require additional doses to provide analgesic plasma levels beyond 24 h in mice. PMID:25255070

  3. Sustainable building organisation

    NARCIS (Netherlands)

    Schmid, P.

    1998-01-01

    Sustainable Development and Sustainable Building is mainly a question of (human) environmentally-conscious Organisation and Management Criteria are needed in order to capture the best practices in the field. Therefore we developed modells and methods, which help to choose the most adequate

  4. At Home with Sustainability

    DEFF Research Database (Denmark)

    Hale, Lara

    2018-01-01

    of default rules in subconscious decision-making, this research finds that, ultimately, awareness drives the demand necessary for the creation of sustainable consumption. Whereas direct appeal to individuals has a disappointing level of influence on sustainability choices, it is understood that green...

  5. Predicting Sustainable Work Behavior

    DEFF Research Database (Denmark)

    Hald, Kim Sundtoft

    2013-01-01

    Sustainable work behavior is an important issue for operations managers – it has implications for most outcomes of OM. This research explores the antecedents of sustainable work behavior. It revisits and extends the sociotechnical model developed by Brown et al. (2000) on predicting safe behavior...

  6. Sustainability in Software Engineering

    NARCIS (Netherlands)

    Wolfram, N.J.E.; Lago, P.; Osborne, Francesco

    2017-01-01

    The intersection between software engineering research and issues related to sustainability and green IT has been the subject of increasing attention. In spite of that, we observe that sustainability is still not clearly defined, or understood, in the field of software engineering. This lack of

  7. Sustainable Agriculture: Cover Cropping

    Science.gov (United States)

    Webster, Megan

    2018-01-01

    Sustainable agriculture practices are increasingly being used by farmers to maintain soil quality, increase biodiversity, and promote production of food that is environmentally safe. There are several types of sustainable agriculture practices such as organic farming, crop rotation, and aquaculture. This lesson plan focuses on the sustainable…

  8. Sustaining Urban Forests

    Science.gov (United States)

    John F. Dwyer; David J. Nowak

    2003-01-01

    The significance of the urban forest resource and the powerful forces for change in the urban environment make sustainability a critical issue in urban forest management. The diversity, connectedness, and dynamics of the urban forest establish the context for management that will determine the sustainability of forest structure, health, functions, and benefits. A...

  9. Engineering Students' Sustainability Approaches

    Science.gov (United States)

    Haase, S.

    2014-01-01

    Sustainability issues are increasingly important in engineering work all over the world. This article explores systematic differences in self-assessed competencies, interests, importance, engagement and practices of newly enrolled engineering students in Denmark in relation to environmental and non-environmental sustainability issues. The…

  10. Thermodynamics and sustainable development

    NARCIS (Netherlands)

    Cornelissen, Rene

    1997-01-01

    It is the objective of this thesis to demonstrate exergy analysis as a powerful instrument to obtain sustainable development. An important aspect of sustainable development is the minimisation of irreversibilities caused by the use of non-renewables. In order to limit the scope of this thesis

  11. Sustainability at BPA 2012

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-01

    BPA’s Sustainability Action Plan is grounded in our commitment to environmental stewardship and Executive Order 13514 that calls on the federal agencies to “lead by example” by setting a 2020 greenhouse gas emissions target, increasing energy efficiency; reducing fleet petroleum consumption; conserving water; reducing waste; supporting sustainable communities; and leveraging federal purchasing power to promoting environmentally responsible products and technologies.

  12. Gut microbiota sustains hematopoiesis

    DEFF Research Database (Denmark)

    Theilgaard-Mönch, Kim

    2017-01-01

    In this issue of Blood, Josefsdottir et al provide substantial evidence that commensal gut microbes regulate and sustain normal steady-state hematopoiesis.1......In this issue of Blood, Josefsdottir et al provide substantial evidence that commensal gut microbes regulate and sustain normal steady-state hematopoiesis.1...

  13. Sustainable economic structures

    NARCIS (Netherlands)

    Dellink, R.B.; Bennis, M.; Verbruggen, H.

    1999-01-01

    The paper introduces four scenarios for sustainable economic structures in the Netherlands for 2030. The aim of this paper is to provide possible answers to what a sustainable future might look like in terms of alternative economic structures. To this end, an empirical economy-ecology model is

  14. Measurement in Sustainable Building

    DEFF Research Database (Denmark)

    Hale, Lara

    2018-01-01

    Measurement is a necessary aspect of planning and constructing buildings. However, recent attempts to integrate the social dimension of sustainable building into building design and specifications demand measurement of non-technical qualities, such as well-being. The Active House Alliance, in lieu...... and continued provision of sustainable buildings to market demand....

  15. Leading Sustainability in Schools

    Science.gov (United States)

    Carr, Katie

    2016-01-01

    What is the role of schools, and more specifically school leadership, in the transition to a sustainable future for humankind? What different forms of leadership are needed to enable this role? The challenges are huge and complex and for those of us engaged in promoting sustainability learning, it is clear that the issue has never been more…

  16. Aesthetics of sustainable architecture

    NARCIS (Netherlands)

    Lee, S.; Hill, G.; Sauerbruch, M.; Hutton, L.; Knowles, R.; Bothwell, K.; Brennan, J.; Jauslin, D.; Holzheu, H.; AlSayyad, N.; Arboleda, G.; Bharne, V.; Røstvik, H.; Kuma, K.; Sunikka-Blank, M.; Glaser, M.; Pero, E.; Sjkonsberg, M.; Teuffel, P.; Mangone, G.; Finocchiaro, L.; Hestnes, A.; Briggs, D.; Frampton, K.; Lee, S.

    2011-01-01

    The purpose of this book is to reveal, explore and further the debate on the aesthetic potentials of sustainable architecture and its practice. This book opens a new area of scholarship and discourse in the design and production of sustainable architecture, one that is based in aesthetics. The

  17. Sustaining the wild equals sustaining the world.

    Science.gov (United States)

    Nelson, G

    1994-01-01

    Sustainable development and carrying capacity are concepts that denote meeting society's needs without compromising the survival of future generations. The United States and other industrialized countries are pursuing a self-destructive course when fueling their economies by consuming their capital and degrading and depleting their resource base. Maximum exploitation of all resources has been the guiding ethic without paying respect to the environmental consequences. A sustainable society is still possible if strong political leadership and an ecologically literate society with an environmental ethic evolves. In the 1990s the world's population is calculated to increase to 6.3 billion people, the population of the United States already exceeds its carrying capacity and neither of these population increases are sustainable in the long run. In 1916 the US had 98 million people, and in 1994 it had about 260 million and it is still growing. The consequences are already obvious: the National Park System had just 358,000 visitors in 1916, 33 million in 1950, 172 million in 1970, and over 270 million in 1993. Often economists are an impediment to a sustainable economy because they fail to factor in the accumulated environmental deficit or annual cost of environmental deterioration when measuring annual economic output. Fortunately, in the US a conservation ethic is beginning to develop that will eventually become a strong social, political, and economic force. For instance, Wisconsin has mandated environmental education in every school from kindergarten through 12th grade. Such a program will provide the moral and political support to move the country to a sustainable economy. Even losing nations have recovered from World War II, but there is no recovery from destroyed ecosystems.

  18. Sustainable nuclear energy dilemma

    Directory of Open Access Journals (Sweden)

    Afgan Naim H.

    2013-01-01

    Full Text Available Sustainable energy development implies the need for the emerging potential energy sources which are not producing adverse effect to the environment. In this respect nuclear energy has gained the complimentary favor to be considered as the potential energy source without degradation of the environment. The sustainability evaluation of the nuclear energy systems has required the special attention to the criteria for the assessment of nuclear energy system before we can make firm justification of the sustainability of nuclear energy systems. In order to demonstrate the sustainability assessment of nuclear energy system this exercise has been devoted to the potential options of nuclear energy development, namely: short term option, medium term option, long term option and classical thermal system option. Criteria with following indicators are introduced in this analysis: nuclear indicator, economic indicator, environment indicator, social indicator... The Sustainability Index is used as the merit for the priority assessment among options under consideration.

  19. Sustaining Participatory Design Initiatives

    DEFF Research Database (Denmark)

    Iversen, Ole Sejer; Dindler, Christian

    2014-01-01

    While many participatory design (PD) projects succeed in establishing new organisational initiatives or creating technology that is attuned to the people affected, the issue of how such results are sustained after the project ends remains an important challenge. We explore the challenge...... these various forms of sustainability may be pursued in PD practice and how they can become a resource in reflecting on PD activities. Finally, we discuss implications for PD practice, suggesting that a nuanced conception of sustainability and how it may relate to PD practice are useful resources for designers...... of sustaining PD initiatives beyond the individual project and discuss implications for PD practice. First, based on current PD literature, we distinguish between four ideal typical forms of sustainability: maintaining, scaling, replicating and evolving. Second, we demonstrate from a case study how...

  20. The challenge of sustainability

    International Nuclear Information System (INIS)

    Orr, D.W.

    1993-01-01

    This paper discusses sustainability in a world that has changed rapidly. The author suggests that ecological assumptions embedded in communism and capitalism are badly flawed, but the flaws were not apparent when there were fewer than a billion people on earth living at low technology levels. Sustaining the earth's vital signs is a challenge to our perception of time, and the numbers - population, environmental damage, oil consumption, waste disposal - are too large to comprehend easily. There is a global debate about what sustainability means. In fact the challenge of sustainability is 6 different challenges: overcoming the tendency to deny inconvenient realities; establishing accurate indicators of human and ecological health; questions about the kinds of technology necessary to make the transition to sustainability; education; the need for an emotional bond between man and nature; rebuilding the existing democratic institutions. 16 refs

  1. Sustainable built environments

    CERN Document Server

    Haase, Dagmar

    2013-01-01

    Sustainable design is a collective process whereby the built environment achieves unprecedented levels of ecological balance through new and retrofit construction, with the goal of long-term viability and humanization of architecture. Focusing on the environmental context, sustainable design merges the natural, minimum resource conditioning solutions of the past (daylight, solar heat, and natural ventilation) with the innovative technologies of the present.  The desired result is an integrated “intelligent” system that supports individual control with expert negotiation for resource consciousness. International experts in the field address the fundamental questions of sustainable design and landscape management: How should the sustainability of landscapes and buildings be evaluated? Which targets have to be set and which thresholds should not be exceeded? What forms of planning and governance structures exist and to what extent do they further the goals of sustainability?  Gathering 30 peer-reviewed ent...

  2. Agroecology and Sustainable Agriculture

    Directory of Open Access Journals (Sweden)

    Fabio Caporali

    Full Text Available In the framework of the 16th National Meeting of the Italian Ecological Society (“Global Change, Ecological Diversity and Sustainability”, University of Tuscia, Viterbo, 19-22 September 2006, a symposium was devoted to “Agroecology and Sustainable Development”. A major goal of this symposium was to contribute to keeping the dialogue among the experts of the various disciplines alive. Sustainability of agriculture is a challenge for society world wide. Universities and society as a whole have a responsibility in re-examining current perception of nature, of the world and of human society in the light of natural resources depletion, increasing pollution and social inequalities. The urgency to address sustainability issues is increasingly being reflected in the manner in which institutions of higher education around the world are giving priority to the teaching, research and practice of sustainability. The University of Tuscia is involved in international initiatives concerning teaching and research in Agroecology and Sustainable Agriculture.

  3. Sustainability Marketing Commitment

    DEFF Research Database (Denmark)

    Tollin, Karin; Bech Christensen, Lars

    2017-01-01

    sustainability in marketing, processes associated with sustainability marketing commitment, drivers of sustainability marketing at the functional level of marketing, and its organizational context. Using survey data from 269 managers in marketing, covering a broad range of industries in Sweden and Denmark, we...... took a structural modelling approach to examine construct relationships, mediation, and moderation effects. Overall, the findings show that marketing capabilities associated with the innovation of new products, services, and business models constitute a strong driver to leverage sustainability......Corporate sustainability is an important strategy and value orientation for marketing, but scarce research addresses the organizational drivers and barriers to including it in companies’ marketing strategies and processes. The purpose of this study is to determine levels of commitment to corporate...

  4. Sustainability and Organizational Change

    Directory of Open Access Journals (Sweden)

    Catălina Sitnikov

    2012-06-01

    Full Text Available The relevant and, above all, remarkable feature of sustainability is due to its "duality": on the one hand, it is an indispensable element within the companies even if, on the other hand, it increases the costs of many activities and processes. Facing the challenge of sustainability will determine and create, in the coming years, emerging organizational forms. If ten years ago, many managers clearly expressed their doubts regarding the financial feasibility of sustainability, today, they admit the importance of sustainability for the competitive advantage of the companies they manage. Currently, companies have great opportunities to support build a sustainable global economy, becoming one of the solutions to the most pressing societal challenges. Whether it is about reducing pollution, global warming, reducing use of water resources and other limited resources or ensuring a better work environment for employees throughout the supply chain, there are many things that companies can and should do.

  5. What is sustainability economics?

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertner, Stefan [Department of Sustainability Sciences, Leuphana University of Lueneburg (Germany); Department of Economics, Leuphana University of Lueneburg (Germany); Quaas, Martin [Department of Economics, University of Kiel (Germany)

    2010-01-15

    While economists have been contributing to the discussion of various aspects of sustainability for decades, it is just recently that the term 'sustainability economics' was used explicitly in the ecological, environmental, and resource economics community. Yet, the contributions that use the term 'sustainability economics' do not refer to any explicit definition of the term, and are not obviously joined by common or unifying characteristics, such as subject focus, methodology, or institutional background. The question thus arises: what is 'sustainability economics'? In this essay, we systematically define and delineate 'sustainability economics' in terms of its normative foundation, aims, subject matter, ontology, and genuine research agenda. (author)

  6. Sustainability and uncertainty

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint

    2007-01-01

    The widely used concept of sustainability is seldom precisely defined, and its clarification involves making up one's mind about a range of difficult questions. One line of research (bottom-up) takes sustaining a system over time as its starting point and then infers prescriptions from...... this requirement. Another line (top-down) takes an economical interpretation of the Brundtland Commission's suggestion that the present generation's needsatisfaction should not compromise the need-satisfaction of future generations as its starting point. It then measures sustainability at the level of society...... a clarified ethical goal, disagreements can arise. At present we do not know what substitutions will be possible in the future. This uncertainty clearly affects the prescriptions that follow from the measure of sustainability. Consequently, decisions about how to make future agriculture sustainable...

  7. Sustainability of abrasive processes

    DEFF Research Database (Denmark)

    Aurich, J.C.; Linke, B.; Hauschild, Michael Zwicky

    2013-01-01

    , the content of technical presentations in STC G, and the results of a comprehensive literature study. The approach to sustainability includes environmental, social, and economic sustainability in accordance with the definition proposed in the Brundtland Report of the United Nations [156]. The main focus......This paper presents an overview of research on sustainability of abrasive processes. It incorporates results from a round robin study on ‘‘energy-efficiency of abrasive processes’’ which has been carried out within the scientific technical committee ‘‘abrasive processes’’ (STC G) of CIRP...... is on environmental and social sustainability. Economic sustainability will be considered as manufacturing productivity. © 2013 CIRP....

  8. Sustainable Agricultural Marketing Initiatives

    Directory of Open Access Journals (Sweden)

    Hakan Adanacıoğlu

    2015-07-01

    Full Text Available Sustainable marketing is a holistic approach that puts equal emphasis on environmental, social equity, and economic concerns in the development of marketing strategies. The purpose of the study is to examine and discuss the sustainable agricultural marketing initiatives practiced throughout the World and Turkey, and to put forth suggestions to further improve the performance of agricultural marketing initiatives in Turkey. Some of the sustainable agricultural marketing initiatives practiced around the world are carried out through civil organizations. Furthermore; some of these initiatives have also launched by farmers, consumers, food processors and retailers. The long-term strategies to increase these initiatives should be determined due to the fact that examples of successful sustainable agricultural marketing initiatives are inadequate and cannot be spread in Turkey. In this context, first of all, the supports provided by the government to improve agricultural marketing systems, such as EU funds for rural development should be compatible with the goals of sustainable marketing. For this purpose, it should be examined whether all proposed projects related to agricultural marketing meet the social, economic, and environmental principles of sustainable marketing. It is important that supporting organizations, especially civil society organisations, should take an active role for faster dissemination and adoption of sustainable agricultural marketing practices in Turkey. These organizations may provide technical assistance in preparing successful project proposals and training to farm groups. In addition, the other organizations, such as local administrations, producers' associations, cooperatives, can contribute to the success of sustainable agricultural marketing initiatives. The use of direct marketing strategies and vertical integration attempts in sustainable agricultural marketing initiatives that will likely be implemented in Turkey is

  9. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  10. Plasma shutdown device

    International Nuclear Information System (INIS)

    Hosogane, Nobuyuki; Nakayama, Takahide.

    1985-01-01

    Purpose: To prevent concentration of plasma currents to the plasma center upon plasma shutdown in a torus type thermonuclear device by the injection of fuels to the plasma center thereby prevent plasma disruption at the plasma center. Constitution: The plasma shutdown device comprises a plasma current measuring device that measures the current distribution of plasmas confined within a vacuum vessel and outputs a control signal for cooling the plasma center when the plasma currents concentrate to the plasma center and a fuel supply device that supplies fuels to the plasma center for cooling the center. The fuels are injected in the form of pellets into the plasmas. The direction and the velocity of the injection are set such that the pellets are ionized at the center of the plasmas. (Horiuchi, T.)

  11. Boundary effects on the MHD dynamo in laboratory plasmas

    International Nuclear Information System (INIS)

    Ho, Y.L.; Prager, S.C.

    1989-07-01

    In recent laboratory experiments, a dynamo-like mechanism has been demonstrated in which a portion of the axisymmetric component of the magnetic field is believed to be sustained by 3D spatial fluctuations in the field and flow. With a conducting shell at the plasma surface, past MHD computation shows that sustainment arises from fluctuations which cause magnetic reconnection. If the conducting wall is retracted from the plasma surface, the fluctuations are amplified and the dynamo sustainment is still active for the times studied, but an increased energy input to the plasma is required through the applied electric field. The retraction of the conducting wall enhances the helicity dissipation rate by the intersection of the fields with the resistive surface which bounds the plasma. This enhanced helicity dissipation is balanced by the helicity injection that accompanies the increased applied electric field. 17 refs., 7 figs., 1 tab

  12. Interpreting sustainable development

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Over the past decade, the term" sustainable development"has emerged as the principal concept in the development field. The concept emerged in the 1970s and was first promoted in the international environmental and development communities with the publication of the " world conservation strategy"(1980). It was popularized by the Brundtland report, " Our common future"(1987). The Brundtland Commission defined sustainable development as " development which meets the needs of the present, without compromising the sustainability of future generation to meet their own needs". The Earth Summit(1992) established "sustainable development" as the most important policy of the 21st century. Since then, the relationship between development and environment has been widely discussed and sustainabale development is now an important part of the vocabulary of environmental policy research and analysis. In this paper, we begin by tracing the evolution of the concept of sustainable development. Definitions of sustainable development in ecology, economics and sociology are then explored and discussed. This paper also examine the contribution that a broadly-based concept of sustainable development can make: as a goal, an attitude and as a guiding principle for integrating economic development and environmental protection.

  13. Sustainable winegrowing: current perspectives

    Directory of Open Access Journals (Sweden)

    Mariani A

    2015-05-01

    Full Text Available Angela Mariani,1 Antonella Vastola2 1Department of Economic and Legal Studies, University Parthenope, Naples, 2School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Italy Abstract: The winegrowing sector worldwide is strongly committed to improving environmental and social sustainability. The aim of this work, based on a literature review, is to highlight current sustainability perspectives and the related main issues. There is a broad consensus that the challenge to achieve a greater spread of sustainable practices is to enhance environmental and social sustainability while maintaining economic viability. From the producers' point of view, the priority is to bridge the still substantial knowledge gaps in terms of perceived environmental benefits, economic benefits, and costs. Thus, an increased research effort focusing on the costs and benefits of different winegrowing practices and technical assistance with implementation might support their diffusion. Moreover, targeted marketing strategies are needed to: enhance consumers' involvement and their attitude toward sustainable wine; improve understanding and use of sustainable labels and claims; and raise awareness of some environmental credentials of wine packaging, mainly with reference to lightweight glass bottles. Keywords: winegrower, sustainability, wine, consumer, marketing strategies

  14. Sustainability Infused Curriculum

    Science.gov (United States)

    Ibarra, D. L.

    2015-12-01

    The Independent Schools Foundation Academy (ISF) in Hong Kong established a sustainability policy in 2015, which explicitly states, "an experimentally integrated, environmentally and ethically sustainable system of science education and conservation practices based on the 2012 Jeju Declaration of the World Conservation Congress will be implemented through the school". ISF Academy is a private Chinese bilingual school in Hong Kong serving over 1500 students K-12, following the framework and curriculum of the International Baccalaureate Organization (IBO). The strategy behind the implementation of this policy includes: development of a scientific sustainable curriculum that is age appropriate; establish a culture of sustainability within the ISF community and beyond to the wider HK community; install sustainable infrastructure that allows students to learn; and learn first hand sustainable living practices. It is well understood that solutions to the environmental challenges facing Hong Kong and our planet will require multiple disciplines. The current sustainability programs at ISF include: a) a whole school aerobic food waste composting system and organic farming, b) energy consumption monitoring of existing buildings, c) upcoming installation of an air pollution monitoring equipment that will correlate with the AQHI data collected by the Hong Kong government, d) a Renewable Energy Education Center (REEC) that will teach students about RE and also produce solar energy for classroom consumption, and e) student lead environmental group that manages the paper and used cooking oil recycling on campus. The Shuyuan Science and Sustainability faculty work closely with classroom teachers to ensure that the above mentioned projects are incorporated into the curriculum throughout the school. Interdisciplinary units (IDU) of study are being developed that encourage faculty and students to work across subject areas. Projects include Personal Projects, Extended Essays

  15. Textiles and clothing sustainability nanotextiles and sustainability

    CERN Document Server

    2017-01-01

    This book highlights the sustainability aspects of textiles and clothing sector in light of nanomaterials and technologies. The invasion of nano in every industrial sector has been important and has made remarkable changes as well as posed new challenges, including the textiles and clothing sector. There is quite a great deal of research happening in terms of nano materials for textiles across the globe, some of which are covered in this book. .

  16. The sustainable development

    International Nuclear Information System (INIS)

    Robreau, Y.; Porcher, P.

    2002-11-01

    This document aims to define the sustainable development concept with a special attention for France and Israel position. The first part recalls the history of the sustainable development from the ''Man and Biosphere'' program of the UNESCO to Rio protocol. Then are described the principles of the sustainable development, the France plans and the France position at Johannesburg conference. The last part is devoted to the Israel position and a short presentation of the consequences of the greenhouse gases on the human health and the environment. (A.L.B.)

  17. Lean maturity, lean sustainability

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Matthiesen, Rikke; Nielsen, Jacob

    2007-01-01

    . A framework for describing levels of lean capability is presented, based on a brief review of the literature and experiences from 12 Danish companies currently implementing lean. Although still in its emerging phase, the framework contributes to both theory and practice by describing developmental stages......Although lean is rapidly growing in popularity, its implementation is far from problem free and companies may experience difficulties sustaining long term success. In this paper, it is suggested that sustainable lean requires attention to both performance improvement and capability development...... that support lean capability development and consequently, lean sustainability....

  18. Sustainable Facilities Management

    DEFF Research Database (Denmark)

    Nielsen, Susanne Balslev; Elle, Morten; Hoffmann, Birgitte

    2004-01-01

    The Danish public housing sector has more than 20 years of experience with sustainable facilities management based on user involvement. The paper outlines this development in a historical perspective and gives an analysis of different approaches to sustainable facilities management. The focus...... is on the housing departments and strateies for the management of the use of resources. The research methods used are case studies based on interviews in addition to literature studies. The paper explores lessons to be learned about sustainable facilities management in general, and points to a need for new...

  19. Sustainable development - an entrepreneur's view

    International Nuclear Information System (INIS)

    Fahrni, F.

    1995-01-01

    The following topics are dealt with in this paper: prizing the environment, inducing change, getting the right mix, energy and market place, financing sustainable development, trade and sustainable development, managing corporate change, the Sulzer strategy for sustainable development. (author)

  20. Analyse that! : understanding sustainable design

    NARCIS (Netherlands)

    Brand, van den G.J.W.; Wit, de M.H.

    2004-01-01

    This paper describes a method for the analysis of sustainable building projects. Sustainable technology measures can easily be misinterpreted, consequently leading to unsustainable building solutions. Our research and educations aims at discovering new approaches for sustainable design. For building

  1. Sustainable Transportation and Health

    Directory of Open Access Journals (Sweden)

    Norbert Mundorf

    2018-03-01

    Full Text Available We are experiencing a shift in thinking about Transportation and Mobility, which makes this Special Issue on Sustainable Transportation and Health in the International Journal of Environmental Research and Public Health especially timely.[...

  2. Food, Globalization and Sustainability

    NARCIS (Netherlands)

    Oosterveer, P.J.M.; Sonnenfeld, D.A.

    2011-01-01

    Food is increasingly traded internationally, thereby transforming the organisation of food production and consumption globally and influencing most food-related practices. This transition is generating unfamiliar challenges related to sustainability of food provision, the social impacts of

  3. The macroecology of sustainability

    Science.gov (United States)

    Burger, Joseph R.; Allen, Craig D.; Brown, James H.; Burnside, William R.; Davidson, Ana D.; Fristoe, Trevor S.; Hamilton, Marcus J.; Mercado-Silva, Norman; Nekola, Jeffrey C.; Okie, Jordan G.; Zuo, Wenyun

    2012-01-01

    The discipline of sustainability science has emerged in response to concerns of natural and social scientists, policymakers, and lay people about whether the Earth can continue to support human population growth and economic prosperity. Yet, sustainability science has developed largely independently from and with little reference to key ecological principles that govern life on Earth. A macroecological perspective highlights three principles that should be integral to sustainability science: 1) physical conservation laws govern the flows of energy and materials between human systems and the environment, 2) smaller systems are connected by these flows to larger systems in which they are embedded, and 3) global constraints ultimately limit flows at smaller scales. Over the past few decades, decreasing per capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socioeconomic development.

  4. Environmentally Sustainable Economic Growth

    Directory of Open Access Journals (Sweden)

    Stelian Brad

    2016-05-01

    Full Text Available Economic growth and sustainable development are important issues for social prosperity. Sustainable development strives for moderate and responsible use within the economic activity of the limited resources of our planet, whereas economic growth does not limit the resource exploitation and energy, being mainly focused on productivity increase. From this perspective, both conceptual and operational contradictions occur between the two pillars of prosperity. This paper looks to these contradictions and proposes some streams of intervention such as economic growth and environmental sustainability to operate in harmony. A structured framework for innovative problem solving is considered in this respect. Results of this research show that it is possible to induce smart measures in the economic system for directing businesses towards new paradigms where economic growth is possible without negative effects on environmental sustainability.

  5. Sustainable Materials Management

    Science.gov (United States)

    To introduce businesses, NGOs, and government officials to the concept of Sustainable Materials Management (SMM). To provide tools to allow stakeholders to take a lifecycle approach managing their materials, & to encourage them to join a SMM challenge.

  6. Sustainable roadway lighting seminar.

    Science.gov (United States)

    2014-07-01

    The objective of this project was to develop and conduct a half-day educational seminar on sustainable : roadway lighting at three locations within New York State: Rochester, New York City, and Albany. : Primary attendees were engineers from the New ...

  7. Sustainable Practices Innovation

    Science.gov (United States)

    Better sustainability means more environmentally conscious and efficient businesses and communities. EPA helps modify the way we consume energy, deal with waste, and grow our economy through programs such as Energy Star, E3, Smart Growth, and WaterSense.

  8. Sustainable Building Operation

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole

    2009-01-01

    of sustainable building operation and a survey amongst building administrators from the private and the social housing sector. Our results show that there are many good examples on sustainable building operation in Danish housing estates, where local building managers, residents etc. have gained impressive......Energy-savings in the existing building stock have becomes a main goal in national and international policies. Often focus is on building-renovations, whereas the potential of sustainable building operation to a large extent has been neglected. Nevertheless, international research as well...... as practical experiences from Danish housing estates indicates that there are large potentials for energy savings by focusing on the operation of the buildings. We suggest that in order to achieve sustainability in the existing housing, renovation and operations should be seen as integrated parts...

  9. Teaching sustainable design

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, P.; Haggard, K.; Knuckles, A.; Le Noble, J. [California Polytechnic State Univ., San Luis Obispo, CA (United States)

    1995-11-01

    Sustainable design is inclusive, holistic and integrative. It require humility and guts, caring and a certain degree of stubbornness. It helps to do it cooperatively in a group. Human interest in sustainability has gained a great deal of impetus over the last several years as the problems of the late 20th and the early 21st century have become clearer. Design for sustainability broadens and integrates many previously separate design concerns to create a unified approach that is both compelling and ripe with new possibilities. Ecosystem regeneration, ecological land use planning, biometric design, regional environmental and economic viability, natural landscape maintenance, resource optimization, integrated infrastructure system, neotraditional and pedestrian oriented urban design, passive solar architecture, appropriate technology, renewable building materials, healthy buildings, and the aesthetics of place; are a few of these design concerns that, when welded together, can create sustainability.

  10. Sustainable Enterprise Excellence

    DEFF Research Database (Denmark)

    Edgeman, Rick; Williams, Joseph; Eskildsen, Jacob Kjær

    , supply chain, customer-related, human capital, financial, marketplace, societal, and environmental performance. Sustainable Enterprise Excellence integrates ethical, efficient and effective (E3) enterprise governance with 3E (equity, ecology, economy) Triple Top Line strategy throughout enterprise...

  11. Education for Sustainable development

    African Journals Online (AJOL)

    ESD (education for sustainable development) planning and implementation, and regular ... between the environment and socio-economic issues of poverty and ..... capacity to make informed decisions (T7) and a sense of responsibility (T9), ...

  12. Sustainable Buildings in Interaction

    DEFF Research Database (Denmark)

    Elle, Morten

    2007-01-01

    The first attempts to build sustainable buildings in Denmark were typically located on the countryside. The basic idea was to create buildings that were independent of the technical infrastructure. District heating has, however, been the dominating solution to heating in buildings in Denmark......, and the focus on sustainable building have gradually turned from special houses on the countryside to normally looking houses in the urban fabric, integrated in the technical infrastructure. Some new built urban areas in Denmark will, however, not have to be supplied with district heating – these developments...... are going to consist of passive houses. The first sustainable buildings were built by their users, and the user – building interaction still play a decisive role for the performance of the present sustainable buildings. The users have to understand how the building functions. Urban design is essential...

  13. Towards Intelligently - Sustainable Cities?

    Directory of Open Access Journals (Sweden)

    Luca Salvati

    2013-04-01

    Full Text Available In the quest for achieving sustainable cities, Intelligent and Knowledge City Programmes (ICPs and KCPs represent cost-efficient strategies for improving the overall performance of urban systems. However, even though nobody argues on the desirability of making cities “smarter”, the fundamental questions of how and to what extent can ICPs and KCPs contribute to the achievement of urban sustainability lack a precise answer. In the attempt of providing a structured answer to these interrogatives, this paper presents a methodology developed for investigating the modalities through which ICPs and KCPs contribute to the achievement or urban sustainability. Results suggest that ICPs and KCPs efficacy lies in supporting cities achieve a sustainable urban metabolism through optimization, innovation and behavior changes.

  14. Packaging for Sustainability

    CERN Document Server

    Lewis, Helen; Fitzpatrick, Leanne

    2012-01-01

    The packaging industry is under pressure from regulators, customers and other stakeholders to improve packaging’s sustainability by reducing its environmental and societal impacts. This is a considerable challenge because of the complex interactions between products and their packaging, and the many roles that packaging plays in the supply chain. Packaging for Sustainability is a concise and readable handbook for practitioners who are trying to implement sustainability strategies for packaging. Industry case studies are used throughout the book to illustrate possible applications and scenarios. Packaging for Sustainability draws on the expertise of researchers and industry practitioners to provide information on business benefits, environmental issues and priorities, environmental evaluation tools, design for environment, marketing strategies, and challenges for the future.

  15. Energy and Sustainable Development

    International Nuclear Information System (INIS)

    2013-01-01

    None of the eight Millennium Development Goals (MDGs) adopted by the United Nations in 2000 directly addressed energy, although for nearly all of them - from eradicating poverty and hunger to improving education and health - progress has depended on greater access to modern energy. Thirteen years later, energy is being given more attention. The target date for the MDGs is 2015, and in 2012 the UN began deliberations to develop sustainable development goals to guide support for sustainable development beyond 2015. The Future We Want, the outcome document of the 2012 United Nations Conference on Sustainable Development (also known as Rio+20) gives energy a central role: ''We recognize the critical role that energy plays in the development process, as access to sustainable modern energy services contributes to poverty eradication, saves lives, improves health and helps provide for basic human needs''

  16. Strategic sustainability performance plan

    Science.gov (United States)

    2010-06-01

    In October 2009, President Obama signed Executive Order (EO) 13514 that sets sustainability : goals for Federal agencies and focuses on making improvements in environmental, energy and : economic performance. The Executive Order requires Federal agen...

  17. System Innovation for Sustainability

    DEFF Research Database (Denmark)

    System Innovation for Sustainability 2 focuses on change towards sustainable personal mobility based on implemented cases analysed from a system perspective. It examines what changes can be made to help us reduce our need for mobility, or start to make use of more sustainable mobility systems...... in order to provide sustainable solutions to our current ‘lock-in’ problems. Three major problem areas are considered (the ‘three Cs’): carbon emissions (and the growing contribution of mobility to the climate change crisis), congestion, and casualties. And each strategy proposed addresses one or more...... of these problem areas. Among the cases discussed are: Norway’s carbon compensation scheme for air travel; Madrid’s high-occupancy vehicle lanes; London’s congestion charge scheme; market-based instruments such as eco-labelling for cars; and taxation. The book identifies opportunities for actors...

  18. Biorefinery Sustainability Analysis

    DEFF Research Database (Denmark)

    J. S. M. Silva, Carla; Prunescu, Remus Mihail; Gernaey, Krist

    2017-01-01

    This chapter deals with sustainability analysis of biorefinery systems in terms of environmental and socio-economic indicators . Life cycle analysis has methodological issues related to the functional unit (FU), allocation , land use and biogenic carbon neutrality of the reference system and of t......This chapter deals with sustainability analysis of biorefinery systems in terms of environmental and socio-economic indicators . Life cycle analysis has methodological issues related to the functional unit (FU), allocation , land use and biogenic carbon neutrality of the reference system...... and of the biorefinery-based system. Socio-economic criteria and indicators used in sustainability frameworks assessment are presented and discussed. There is not one single methodology that can aptly cover the synergies of environmental, economic, social and governance issues required to assess the sustainable...

  19. Sustainable Enterprise Excellence

    DEFF Research Database (Denmark)

    Edgeman, Rick

    2013-01-01

    Structured Abstract Purpose: Sustainable Enterprise Excellence (SEE) is defined and developed through integration and expansion of business excellence modeling and sustainability thought. The intent is to enable simple yet reliable enterprise assessment of triple bottom line (TBL) performance...... and produce actionable enterprise foresight that can enable next best practices and sources of sustainable competitive advantage through innovation. Methodology: Key elements of SEE are identified from various business excellence and sustainability reporting sources, including the Global Reporting Initiative...... assessment approach similar in structure to those behind established excellence awards are developed that enable enterprise assessment of progress toward SEE. The resulting assessment is delivered in a highly consumable, combined narrative and graphic format referred to as a SEE NEWS Report. Practical...

  20. Fur and sustainability

    DEFF Research Database (Denmark)

    Skjold, Else; Ræbild, Ulla; Tanderup, Sisse

    2016-01-01

    interviews and observations at the premises of Kopenhagen Fur, as well as with stakeholders and collaborate partners in Denmark and in China. The definition of sustainability in the report must be seen as related to Design School Kolding's research umbrella of Sustainable Futures - a term chosen to unite...... practices around retail and communication (by Else Skjold, PhD in user studies and business management). On the basis of these four sub-projects, the report concludes the following: Currently, fur is placed very centrally in the moral debates around sustainability, as fur farming highligts environmental...... sustainability within the garment sector at large, and to define its own unique position for the future. With a departure in the the four sub-projects, the report lists a line of recommendations for how it would be possible to develop and revitalise traditional and current practices around fur design...