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Sample records for field-reversed configuration formation

  1. Formation of Field-reversed-Configuration Plasma with Punctuated-betatron-orbit Electrons

    International Nuclear Information System (INIS)

    Welch, D.R.; Cohen, S.A.; Genoni, T.C.; Glasser, A.H.

    2010-01-01

    We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMFo). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMFo, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMFo phase. The predicted plasma density and electron energy distribution compare favorably with RMFo experiments.

  2. Formation of field reversed configurations in a slow, multi-turn coil system: Appendix B

    International Nuclear Information System (INIS)

    Slough, J.T.; Hoffman, A.L.

    1987-01-01

    A previous field-reversed theta pinch, TRX-1, has been modified by replacing the single turn main compression coil with an array of three-turn coils. Field reversed configurations (FRCs) have been formed at relatively low values of azimuthal electric field, where ohmic dissipation and axial compressive heating are substituted for the radial shock heating which is dominant in high voltage theta pinches. The longer magnetic field risetime has allowed various controls to be applied to the formation timing, so that the axial implosion can be made to coincide with the peak of the applied magnetic field. This 'programmed formation' control results in maximum plasma heating, and minimizes the formation dynamics

  3. Theory of field reversed configurations

    International Nuclear Information System (INIS)

    Steinhauer, L.C.

    1990-01-01

    This final report surveys the results of work conducted on the theory of field reversed configurations. This project has spanned ten years, beginning in early 1980. During this period, Spectra Technology was one of the leading contributors to the advances in understanding FRC. The report is organized into technical topic areas, FRC formation, equilibrium, stability, and transport. Included as an appendix are papers published in archival journals that were generated in the course of this report. 33 refs

  4. Plasma-gun-assisted field-reversed configuration formation in a conical θ-pinch

    Energy Technology Data Exchange (ETDEWEB)

    Weber, T. E., E-mail: tweber@lanl.gov; Intrator, T. P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Smith, R. J. [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States)

    2015-04-15

    Injection of plasma via an annular array of coaxial plasma guns during the pre-ionization phase of field-reversed configuration (FRC) formation is shown to catalyze the bulk ionization of a neutral gas prefill in the presence of a strong axial magnetic field and change the character of outward flux flow during field-reversal from a convective process to a much slower resistive diffusion process. This approach has been found to significantly improve FRC formation in a conical θ-pinch, resulting in a ∼350% increase in trapped flux at typical operating conditions, an expansion of accessible formation parameter space to lower densities and higher temperatures, and a reduction or elimination of several deleterious effects associated with the pre-ionization phase.

  5. Plasma-gun-assisted field-reversed configuration formation in a conical θ-pinch

    Science.gov (United States)

    Weber, T. E.; Intrator, T. P.; Smith, R. J.

    2015-04-01

    Injection of plasma via an annular array of coaxial plasma guns during the pre-ionization phase of field-reversed configuration (FRC) formation is shown to catalyze the bulk ionization of a neutral gas prefill in the presence of a strong axial magnetic field and change the character of outward flux flow during field-reversal from a convective process to a much slower resistive diffusion process. This approach has been found to significantly improve FRC formation in a conical θ-pinch, resulting in a ˜350% increase in trapped flux at typical operating conditions, an expansion of accessible formation parameter space to lower densities and higher temperatures, and a reduction or elimination of several deleterious effects associated with the pre-ionization phase.

  6. 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

  7. Flux loss and heating during the formation of a field-reversed configuration

    International Nuclear Information System (INIS)

    Sgro, A.G.; Armstrong, W.T.; Lipson, J.; Tuszewski, M.G.; Cochrane, J.C.

    1982-01-01

    The simulated time evolution of magnetic field profiles and trapped flux in a field-reversed configuration, when compared with the experiment, implies that the rapid decay of the initial reversed flux is due to a resistivity that is anomalously enhanced over its classical value. A tenuous plasma between the field-reversed configuration and the wall carries a significant fraction of the current, and about half of the anomalous Joule heating must be deposited directly in the ions in order to calculate the correct ion temperature. The fractional flux retention is most sensitive to an increase of applied bias field

  8. Numerical Study of Field-reversed Configurations: The Formation and Ion Spin-up

    International Nuclear Information System (INIS)

    Belova, E.V.; Davidson, R.C.; Ji, H.; Yamada, M.; Cothran, C.D.; Brown, M.R.; Schaffer, M.J.

    2005-01-01

    Results of three-dimensional numerical simulations of field-reversed configurations (FRCs) are presented. Emphasis of this work is on the nonlinear evolution of magnetohydrodynamic (MHD) instabilities in kinetic FRCs, and the new FRC formation method by counter-helicity spheromak merging. Kinetic simulations show nonlinear saturation of the n = 1 tilt mode, where n is the toroidal mode number. The n = 2 and n = 3 rotational modes are observed to grow during the nonlinear phase of the tilt instability due to the ion spin-up in the toroidal direction. The ion toroidal spin-up is shown to be related to the resistive decay of the internal flux, and the resulting loss of particle confinement. Three-dimensional MHD simulations of counter-helicity spheromak merging and FRC formation show good qualitative agreement with results from the SSX-FRC experiment. The simulations show formation of an FRC in about 20-30 Alfven times for typical experimental parameters. The growth rate of the n = 1 tilt mode is shown to be significantly reduced compared to the MHD growth rate due to the large plasma viscosity and field-line-tying effects

  9. Formation of Field Reversed Configuration (FRC on the Yingguang-I device

    Directory of Open Access Journals (Sweden)

    Qizhi Sun

    2017-09-01

    Full Text Available As a hybrid approach to realizing fusion energy, Magnetized Target Fusion (MTF based on the Field Reversed Configuration (FRC, which has the plasma density and confinement time in the range between magnetic and inertial confinement fusion, has been recently widely pursued around the world. To investigate the formation and confinement of the FRC plasma injector for MTF, the Yingguang-I, which is an FRC test device and contains a multi-bank program-discharged pulsed power sub-system, was constructed at the Institute of Fluid Physics (IFP, China. This paper presents the pulsed power components and their parameters of the device in detail, then gives a brief description of progress in experiments of FRC formation. Experimental results of the pulsed power sub-system show that the peak current/magnetic field of 110 kA/0.3 T, 10 kA/1.2 T and 1.7 MA/3.4 T were achieved in the bias, mirror and θ-pinch circuits with quarter cycle of 80 μs, 700 μs and 3.8 μs respectively. The induced electric field in the neutral gas was greater than 0.25 kV/cm when the ionization bank was charged to 70 kV. With H2 gas of 8 Pa, the plasma target of density 1016 cm−3, separatrix radius 4 cm, half-length 17 cm, equilibrium temperature 200 eV and lifetime 3 μs (approximately the half pulse width of the reversed field have been obtained through the θ-pinch method when the bias, mirror, ionization and θ-pinch banks were charged to 5 kV, 5 kV, 55 kV and ±45 kV respectively. The images from the high-speed end-on framing camera demonstrate the formation processes of FRC and some features agree well with the results with the two-dimension magneto hydrodynamics code (2D-MHD.

  10. Formation of a field reversed configuration for magnetic and electrostatic confinement of plasma

    Science.gov (United States)

    Rostoker, Norman; Binderbauer, Michl

    2003-12-16

    A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

  11. 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.

  12. 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.

  13. 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

  14. Theory of field-reversed configurations

    International Nuclear Information System (INIS)

    Steinhauer, L.C.

    1993-01-01

    This report summarizes results from the theoretical program on field reversed configurations (FRC) at STI Optronics. The program, which has spanned the last 13 years, has included analytical as well as computational components. It has led to published papers on every major topic of FRC theory. The report is outlined to summarize results from each of these topic areas: formation, equilibrium, stability, and confinement. Also briefly described are Steinhauer's activities as Compact Toroid Theory Listening Post. Appendix A is a brief listing of the major advances achieved in this program. Attached at the back of this report is a collection of technical papers in archival journals that resulted from work in this program. The discussion within each subsection is given chronologically in order to give a historical sense of the evolution of understanding of FRC physics

  15. Rotational instabilities in field reversed configurations

    International Nuclear Information System (INIS)

    Santiago, M.A.M.; Tsui, K.H.; Ponciano, B.M.B.; Sakanaka, P.H.

    1988-01-01

    The rotational instability (n = 2 toroidal mode) in field reversed configurations (FRC) using the ideal MHD equations in cylindrical geometry is studied. These equations are solved using a realistic densite profile, and the influence of some plasma parameters on the growth rate is analysed. The model shows good qualitative results. The growth rate increases rapidly as rotational frequency goes up and the mode m = 2 dominates over the m = 1 mode. With the variation of the density profile, it is observed that the growth rate decreases as the density dip at the center fills up. Calculated value ranges from 1/2 to 1/7 of the rotational frequency Ω whereas the measured value is around Ω/50. The developed analysis is valid for larger machines. The influence of the plasma resistivity on the mode stabilization is also analysed. The resistivity, which is the fundamental factor in the formation of compact torus, tends to decrease the growth rate. (author) [pt

  16. Numerical Study of the Formation, Ion Spin-up and Nonlinear Stability Properties of Field-reversed Configurations

    International Nuclear Information System (INIS)

    Belova, E.V.; Davidson, R.C.; Ji, H.; Yamada, M.; Cothran, C.D.; Brown, M.R.; Schaffer, M.J.

    2004-01-01

    Results of three-dimensional numerical simulations of field-reversed configurations (FRCs) are presented. Emphasis of this work is on the nonlinear evolution of magnetohydrodynamic (MHD) instabilities in kinetic FRCs and the new FRC formation method by the counter-helicity spheromak merging. Kinetic simulations show nonlinear saturation of the n = 1 tilt mode, where n is the toroidal mode number. The n = 2 and n = 3 rotational modes are observed to grow during the nonlinear phase of the tilt instability due to the ion spin-up in the toroidal direction. The ion toroidal spin-up is shown to be related to the resistive decay of the internal flux, and the resulting loss of particle confinement. Three-dimensional MHD simulations of counter-helicity spheromak merging and FRC formation show good agreement with results from the SSX-FRC experiment. Simulations show formation of an FRC in about 30 Alfven times for typical experimental parameters. The growth rate of the n = 1 tilt mode is shown to be significantly reduced compared to the MHD growth rate due to the large plasma viscosity and field-line-tying effects

  17. Particle transort in field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Tuszewski, M.; Linford, R.K.; Lipson, J.; Sgro, A.G.

    1981-01-01

    A field reversed configuration (FRC) is a compact toroid that contains no toroidal field. These plasmas are observed to be grossly stable for about 10-100 ..mu..sec. The lifetimes appear limited by an n = 2 rotational instability which may be caused by particle loss. Particle transport is therefore an important issue for these configurations. We investigate particle loss with a steady-state, 1-D model which approximates the experimental observation of elongated FRC equilibrium with about constant separatrix radius.

  18. Kinetic Stability of the Field Reversed Configuration

    International Nuclear Information System (INIS)

    E.V. Belova; R.C. Davidson; H. Ji; and M. Yamada

    2002-01-01

    New computational results are presented which advance the understanding of the stability properties of the Field-Reversed Configuration (FRC). The FRC is an innovative confinement approach that offers a unique fusion reactor potential because of its compact and simple geometry, translation properties, and high plasma beta. One of the most important issues is FRC stability with respect to low-n (toroidal mode number) MHD modes. There is a clear discrepancy between the predictions of standard MHD theory that many modes should be unstable on the MHD time scale, and the observed macroscopic resilience of FRCs in experiments

  19. Tilting mode in field-reversed configurations

    International Nuclear Information System (INIS)

    Schwarzmeier, J.L.; Barnes, D.C.; Lewis, H.R.; Seyler, C.E.; Shestakov, A.I.

    1982-01-01

    Field Reversed Configurations (FRCs) experimentally have exhibited remarkable stability on the magnetohydrodynamic (MHD) timescale, despite numerous MHD calculations showing FRCs to be unstable. It is easy to believe that local modes are stabilized by finite Larmor radius (FLR) effects, but more puzzling is the apparent stability of FRCs against global modes, where one would expect FLR effects to be less important. In this paper we study the tilting mode, which MHD has shown to be a rapidly growing global mode. The tilting mode in FRCs is driven by the pressure gradient, and magnetic compression and field line bending are the stabilizing forces. A schematic of the evolution of the tilting mode is shown. The tilting mode is considered dangerous, because it would lead to rapid tearing across the separatrix. Unlike spheromaks, the tilting mode in FRCs has a separatrix that is fixed in space, so that the mode is strictly internal

  20. Particle transport in field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Tuszewski, M.; Linford, R.K.

    1982-05-01

    Particle transport in field-reversed configurations is investigated using a one-dimensional, nondecaying, magnetic field structure. The radial profiles are constrained to satisfy an average ..beta.. condition from two-dimensional equilibrium and a boundary condition at the separatrix to model the balance between closed and open-field-line transport. When applied to the FRX-B experimental data and to the projected performance of the FRX-C device, this model suggests that the particle confinement times obtained with anomalous lower-hybrid-drift transport are in good agreement with the available numerical and experimental data. Larger values of confinement times can be achieved by increasing the ratio of the separatrix radius to the conducting wall radius. Even larger increases in lifetimes might be obtained by improving the open-field-line confinement.

  1. Particle transport in field-reversed configurations

    International Nuclear Information System (INIS)

    Tuszewski, M.; Linford, R.K.

    1982-01-01

    Particle transport in field-reversed configurations is investigated using a one-dimensional, nondecaying, magnetic field structure. The radial profiles are constrained to satisfy an average β condition from two-dimensional equilibrium and a boundary condition at the separatrix to model the balance between closed and open-field-line transport. When applied to the FRX-B experimental data and to the projected performance of the FRX-C device, this model suggests that the particle confinement times obtained with anomalous lower-hybrid-drift transport are in good agreement with the available numerical and experimental data. Larger values of confinement times can be achieved by increasing the ratio of the separatrix radius to the conducting wall radius. Even larger increases in lifetimes might be obtained by improving the open-field-line confinement

  2. Laser heating of field-reversed configurations

    International Nuclear Information System (INIS)

    Carson, R.S.; Vlases, G.C.

    1983-01-01

    The experimental facility is a 21-cm-long solenoid with a 5.5-cm bore. The 4-cm ID quartz tube is filled with slowly flowing H 2 to 0.5-3.0 torr. Fields up to 6.5 T in 3.7 μsec are produced, with reverse-bias fields up -1.9 T. Preionization is by 40kA axial discharge 4.5 μsec before field-reversal is begun. The CO 2 laser used produces 300 to 400 J in 2 μsec, in an annular beam that can be defocused for preheating the outer edges of the plasma, or focused tightly for central-column heating and beam propagation during formation. The focusing system includes a return mirror for multiple passing of the laser energy. Diagnostics include compensated, diamagnetic flux loops, internal field probes, cross-tube and axial interferometers, fast photography, and spectroscopy

  3. Kinetic stability of field-reversed configurations

    International Nuclear Information System (INIS)

    Staudenmeier, J.L.; Hsiao, M.-Y.

    1991-01-01

    The internal tilt mode is considered to be the biggest threat to Field-Reversed Configuration (FRC) global stability. The tilt stability of the FRC is studied using the MHD, Hall MHD, and the Vlasov-fluid (Vlasov ions, cold massless fluid electrons) models. Nonlinear Hall MHD calculations showed that the FRC was stable to the tilt mode when the s value of the FRC was below a critical value that was dependent on plasma length. The critical s value is larger for longer plasma equilibria. The stability of FRC's with toroidal field was studied with a linear initial value MHD code. The calculations showed an axial perturbation wavelength of the most unstable eigenfunction that was consistent with internal probe measurements made on translated FRC's. Linear Vlasov-fluid eigenvalue calculations showed that kinetic ion effects can change both the growth rate and the structure of the eigenfunctions when compared to the corresponding MHD modes. Calculations on short FRC equilibria indicate that MHD is not the appropriate small gyroradius limit of the Vlasov-fluid model because the axial transit time of a thermal ion is approximately equal to an MHD growth time for the tilt mode. Calculations were done using a small number of unstable MHD eigenfunctions as basis functions in order to reduce the dimensionality of the stability problem. The results indicated that this basis set can produce inaccurate growth rates at large value for s for some equilibria

  4. Coupled transport in field-reversed configurations

    Science.gov (United States)

    Steinhauer, L. C.; Berk, H. L.; TAE Team

    2018-02-01

    Coupled transport is the close interconnection between the cross-field and parallel fluxes in different regions due to topological changes in the magnetic field. This occurs because perpendicular transport is necessary for particles or energy to leave closed field-line regions, while parallel transport strongly affects evolution of open field-line regions. In most toroidal confinement systems, the periphery, namely, the portion with open magnetic surfaces, is small in thickness and volume compared to the core plasma, the portion with closed surfaces. In field-reversed configurations (FRCs), the periphery plays an outsized role in overall confinement. This effect is addressed by an FRC-relevant model of coupled particle transport that is well suited for immediate interpretation of experiments. The focus here is particle confinement rather than energy confinement since the two track together in FRCs. The interpretive tool yields both the particle transport rate χn and the end-loss time τǁ. The results indicate that particle confinement depends on both χn across magnetic surfaces throughout the plasma and τǁ along open surfaces and that they provide roughly equal transport barriers, inhibiting particle loss. The interpretation of traditional FRCs shows Bohm-like χn and inertial (free-streaming) τǁ. However, in recent advanced beam-driven FRC experiments, χn approaches the classical rate and τǁ is comparable to classic empty-loss-cone mirrors.

  5. Dynamic processes in field-reversed-configuration compact toroids

    International Nuclear Information System (INIS)

    Rej, D.J.

    1987-01-01

    In this lecture, the dynamic processes involved in field-reversed configuration (FRC) formation, translation, and compression will be reviewed. Though the FRC is related to the field-reversed mirror concept, the formation method used in most experiments is a variant of the field-reversed Θ-pinch. Formation of the FRC eqilibrium occurs rapidly, usually in less than 20 μs. The formation sequence consists of several coupled processes: preionization; radial implosion and compression; magnetic field line closure; axial contraction; equilibrium formation. Recent experiments and theory have led to a significantly improved understanding of these processes; however, the experimental method still relies on a somewhat empirical approach which involves the optimization of initial preionization plasma parameters and symmetry. New improvements in FRC formation methods include the use of lower voltages which extrapolate better to larger devices. The axial translation of compact toroid plasmas offers an attractive engineering convenience in a fusion reactor. FRC translation has been demonstrated in several experiments worldwide, and these plasmas are found to be robust, moving at speeds up to the Alfven velocity over distances of up to 16 m, with no degradation in the confinement. Compact toroids are ideal for magnetic compression. Translated FRCs have been compressed and heated by imploding liners. Upcoming experiments will rely on external flux compression to heat a translater FRC at 1-GW power levels. 39 refs

  6. Field-reversed configuration confinement in TRX-1

    International Nuclear Information System (INIS)

    Steinhauer, L.; Slough, J.

    1984-01-01

    Particle and poloidal flux lifetime data from the TRX-1, field-reversed theta pinch experiment, have been used to infer information on the basic transport behavior. The field-reversed configurations were created over a broad range of plasma parameters: separatrix radii, 4-8 cm; lengths, 35-80 cm; and temperature T/sub e/ + T/sub i/, 150-1000 eV. The confinement times covered a wide range as well: Particles, tau/sub N/ = 30-170 μs; poloidal flux, tau/sub phi/ = 30-140 μs; and energy tau/sub E/ = 20-75 μs. The experimental data was divided, a priori, into three classes: 1) the triggered-reconnection mode; 2) the programmed-formation mode with a good preionization (PI); and 3) programmed formation with poor PI

  7. The large-s field-reversed configuration experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Carey, L.N.; Crawford, E.A.; Harding, D.G.; DeHart, T.E.; McDonald, K.F.; McNeil, J.L.; Milroy, R.D.; Slough, J.T.; Maqueda, R.; Wurden, G.A.

    1993-01-01

    The Large-s Experiment (LSX) was built to study the formation and equilibrium properties of field-reversed configurations (FRCs) as the scale size increases. The dynamic, field-reversed theta-pinch method of FRC creation produces axial and azimuthal deformations and makes formation difficult, especially in large devices with large s (number of internal gyroradii) where it is difficult to achieve initial plasma uniformity. However, with the proper technique, these formation distortions can be minimized and are then observed to decay with time. This suggests that the basic stability and robustness of FRCs formed, and in some cases translated, in smaller devices may also characterize larger FRCs. Elaborate formation controls were included on LSX to provide the initial uniformity and symmetry necessary to minimize formation disturbances, and stable FRCs could be formed up to the design goal of s = 8. For x ≤ 4, the formation distortions decayed away completely, resulting in symmetric equilibrium FRCs with record confinement times up to 0.5 ms, agreeing with previous empirical scaling laws (τ∝sR). Above s = 4, reasonably long-lived (up to 0.3 ms) configurations could still be formed, but the initial formation distortions were so large that they never completely decayed away, and the equilibrium confinement was degraded from the empirical expectations. The LSX was only operational for 1 yr, and it is not known whether s = 4 represents a fundamental limit for good confinement in simple (no ion beam stabilization) FRCs or whether it simply reflects a limit of present formation technology. Ideally, s could be increased through flux buildup from neutral beams. Since the addition of kinetic or beam ions will probably be desirable for heating, sustainment, and further stabilization of magnetohydrodynamic modes at reactor-level s values, neutral beam injection is the next logical step in FRC development. 24 refs., 21 figs., 2 tabs

  8. Flux loss during the equilibrium phase of field-reversed configurations

    International Nuclear Information System (INIS)

    Tuszewski, M.; Armstrong, W.T.; Bartsch, R.R.; Chrien, R.E.; Cochrane, J.C. Jr.; Kewish, R.W. Jr.; Klingner, P.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.

    1982-01-01

    Field-reversed configurations are consistently formed at low filling pressures in the FRX-C device, with decay time of the trapped flux after formation much larger than the stable period. This contrasts with previous experimental observations

  9. Flux loss during the equilibrium phase of field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Tuszewski, M.; Armstrong, W.T.; Bartsch, R.R.; Chrien, R.E.; Cochrane, J.C. Jr.; Kewish, R.W. Jr.; Klingner, P.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.

    1982-10-01

    Field-reversed configurations are consistently formed at low filling pressures in the FRX-C device, with decay time of the trapped flux after formation much larger than the stable period. This contrasts with previous experimental observations.

  10. A Mirnov loop array for field-reversed configurations

    International Nuclear Information System (INIS)

    Tuszewski, M.

    1990-01-01

    An array of 64 magnetic pick-up loops has been used for stability studies of large field-reversed configurations in the FRX-C/LSM device. This array proved reliable, could resolve signals of a few Gauss, and allowed the detection of several plasma instabilities. 3 refs., 4 figs

  11. Analytic, two fluid, field reversed configuration equilibrium with sheared rotation

    International Nuclear Information System (INIS)

    Sobehart, J.R.

    1989-01-01

    A two fluid model is used to derive an analytical equilibrium for elongated field reversed configurations containing shear in both the electron and ion velocity profiles. Like some semiempirical models used previously, the analytical expressions obtained provide a satisfactory fit to the experimental results for all radii with a few key parameters. The present results reduce to the rigid rotor model and the infinite conductivity case for a specific choice of the parameters

  12. Adiabatic compression of elongated field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1983-06-01

    The adiabatic compression of an elongated field-reversed configuration (FRC) is computed by using a one-dimensional approximation. The one-dimensional results are checked against a two-dimensional equilibrium code. For ratios of FRC separatrix length to separatrix radius greater than about ten, the one-dimensional results are accurate within 10%. To this accuracy, the adiabatic compression of FRC's can be described by simple analytic formulas.

  13. Adiabatic compression of elongated field-reversed configurations

    International Nuclear Information System (INIS)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1983-01-01

    The adiabatic compression of an elongated field-reversed configuration (FRC) is computed by using a one-dimensional approximation. The one-dimensional results are checked against a two-dimensional equilibrium code. For ratios of FRC separatrix length to separatrix radius greater than about ten, the one-dimensional results are accurate within 10%. To this accuracy, the adiabatic compression of FRC's can be described by simple analytic formulas

  14. Experimental studies of field-reversed configuration translation

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.; Milroy, R.D.

    1986-03-01

    In the FRX-C/T experiment (Proceedings of the 9th Symposium for Engineering Problems of Fusion Research (IEEE, New York, 1981), p. 1751), field-reversed configuration (FRC) plasmas have been formed in, and launched from, a field-reversed theta-pinch source and subsequently trapped in an adjacent confinement region. No destructive instabilities or enhanced losses of poloidal flux, particles, or thermal energy are observed for FRC total trajectories of up to 16 m. The observed translation dynamics agree with two-dimensional magnetohydrodynamic (MHD) simulations. When translated into reduced external magnetic fields, FRC's are observed to accelerate, expand, and cool in partial agreement with adiabatic theory. The plasmas reflect from an external mirror and after each reflection, the axial kinetic energy is reduced by approximately 50%. Because of this reduction, FRC's are readily trapped without the need of pulsed gate magnet coils.

  15. Reactor prospects and present status of field-reversed configurations

    International Nuclear Information System (INIS)

    Hoffman, A.L.

    1995-01-01

    Field-Reversed Configurations (FRC) have an ideal geometry for a reactor, combining high beta toroidal confinement, with a linear external geometry. Present small diameter FRCs are thought to be stabilized by kinetic effects, but recent experiments in the Large s Experiment (LSX) have demonstrated stability as well into the MHD regime. Present empirical transport coefficients are already sufficient for a small pulsed reactor, but small steady state reactors will require about an order of magnitude reduction in plasma diffusivity. 13 refs., 4 figs., 1 tab

  16. Tilting mode in rigidly rotating field-reversed configurations

    International Nuclear Information System (INIS)

    Clemente, R.A.; Milovich, J.L.

    1983-01-01

    The tilting-mode stability of field-reversed configurations is analyzed taking into account plasma rotational effects that had not been included in previous theoretical treatments. It is shown that for a rigidly rotating plasma in stationary equilibrium, stability can be attained if the plasma rotational energy is of the same order as the thermal energy. Since presently available values of the rotational velocities are quite lower than required by the stabilization mechanism considered here, the contribution of this effect to the overall stability of the mode does not appear to be significant

  17. Non-stationary classical diffusion in field - reversed configurations

    International Nuclear Information System (INIS)

    Clemente, R.A.; Sakanaka, P.H.; Mania, A.J.

    1988-01-01

    Plasma decay in field-reversed configurations (FRC) is described using resistive MHD equations. Assuming non-stationariety together with uniform but time dependent plasma temperature and neglecting inertial effects in the momentum balance equation, it is possible to show that the functional dependence of the plasma pressure with the poloidal magnetic flux remains fixed during diffusion. This allows to describe FRC evolution as a continuous sequence of plasma equilibria satisfying proper boundary conditions. The method is applied to pressure profiles linear with the poloidal magnetic flux obtaining the evolution of the flux, the number of confined particles and the size of the plasma boundary. (author) [pt

  18. Compact toroid development: activity plan for field reversed configurations

    International Nuclear Information System (INIS)

    1984-06-01

    This document contains the description, goals, status, plans, and approach for the investigation of the properties of a magnetic configuration for plasma confinement identified as the field reversed configuration (FRC). This component of the magnetic fusion development program has been characterized by its potential for physical compactness and a flexible range of output power. The included material represents the second phase of FRC program planning. The first was completed in February 1983, and was reported in DOE/ER-0160; Compact Toroid Development. This planning builds on that previous report and concentrates on the detailed plans for the next several years of the current DOE sponsored program. It has been deliberately restricted to the experimental and theoretical efforts possible within the present scale of effort. A third phase of this planning exercise will examine the subsequent effort and resources needed to achieve near term (1987 to 1990) FRC technical objectives

  19. Profile stabilization of tilt mode in a Field Reversed Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, J.W.; Tajima, T. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Barnes, D.C. [Los Alamos National Lab., NM (United States)

    1993-06-01

    The possibility of stabilizing the tilt mode in Field Reversed Configurations without resorting to explicit kinetic effects such as large ion orbits is investigated. Various pressure profiles, P({Psi}), are chosen, including ``hollow`` profiles where current is strongly peaked near the separatrix. Numerical equilibria are used as input for an initial value simulation which uses an extended Magnetohydrodynamic (MHD) model that includes viscous and Hall terms. Tilt stability is found for specific hollow profiles when accompanied by high values of separatrix beta, {beta}{sub sep}. The stable profiles also have moderate to large elongation, racetrack separatrix shape, and lower values of 3, average ratio of Larmor radius to device radius. The stability is unaffected by changes in viscosity, but the neglect of the Hall term does cause stable results to become marginal or unstable. Implications for interpretation of recent experiments are discussed.

  20. Profile stabilization of tilt mode in a Field Reversed Configuration

    International Nuclear Information System (INIS)

    Cobb, J.W.; Tajima, T.

    1993-06-01

    The possibility of stabilizing the tilt mode in Field Reversed Configurations without resorting to explicit kinetic effects such as large ion orbits is investigated. Various pressure profiles, P(Ψ), are chosen, including ''hollow'' profiles where current is strongly peaked near the separatrix. Numerical equilibria are used as input for an initial value simulation which uses an extended Magnetohydrodynamic (MHD) model that includes viscous and Hall terms. Tilt stability is found for specific hollow profiles when accompanied by high values of separatrix beta, β sep . The stable profiles also have moderate to large elongation, racetrack separatrix shape, and lower values of 3, average ratio of Larmor radius to device radius. The stability is unaffected by changes in viscosity, but the neglect of the Hall term does cause stable results to become marginal or unstable. Implications for interpretation of recent experiments are discussed

  1. Los Alamos field-reversed configuration (FRC) research

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T.; Bartsch, R.R.; Cochrane, J.C.; Linford, R.K.; Lipson, J.; McKenna, K.F.; Platts, D.A.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1981-01-01

    Recent experimental results are discussed for a compact toroid produced by a field-reversed theta-pinch and containing purely poloidal magnetic fields. The confinement time is found to vary inversely with the ion gyro-radius and to be approximately independent of ion temperature for fixed gyro-radius. Within a coil of fixed radius, the plasmoid major radius R was varied by approx. 30% and the confinement appears to scale as R/sup 2/. A semi-empirical formation model has been formulated that predicts reasonably well the plasma parameters as magnetic field and fill pressure are varied in present experiments. The model is used to predict parameters in larger devices under construction.

  2. Los Alamos field-reversed configuration (FRC) research

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Bartsch, R.R.; Cochrane, J.C.; Linford, R.K.; Lipson, J.; McKenna, K.F.; Platts, D.A.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1981-01-01

    Recent experimental results are discussed for a compact toroid produced by a field-reversed theta-pinch and containing purely poloidal magnetic fields. The confinement time is found to vary inversely with the ion gyro-radius and to be approximately independent of ion temperature for fixed gyro-radius. Within a coil of fixed radius, the plasmoid major radius R was varied by approx. 30% and the confinement appears to scale as R 2 . A semi-empirical formation model has been formulated that predicts reasonably well the plasma parameters as magnetic field and fill pressure are varied in present experiments. The model is used to predict parameters in larger devices under construction

  3. Rotational stability of a long field-reversed configuration

    International Nuclear Information System (INIS)

    Barnes, D. C.; Steinhauer, L. C.

    2014-01-01

    Rotationally driven modes of long systems with dominantly axial magnetic field are considered. We apply the incompressible model and order axial wavenumber small. A recently developed gyro-viscous model is incorporated. A one-dimensional equilibrium is assumed, but radial profiles are arbitrary. The dominant toroidal (azimuthal) mode numbers ℓ=1 and ℓ=2 modes are examined for a variety of non-reversed (B) and reversed profiles. Previous results for both systems with rigid rotor equilibria are reproduced. New results are obtained by incorporation of finite axial wavenumber and by relaxing the assumption of rigid electron and ion rotation. It is shown that the frequently troublesome ℓ=2 field reversed configuration (FRC) mode is not strongly affected by ion kinetic effects (in contrast to non-reversed cases) and is likely stabilized experimentally only by finite length effects. It is also shown that the ℓ=1 wobble mode has a complicated behavior and is affected by a variety of configuration and profile effects. The rotationally driven ℓ=1 wobble is completely stabilized by strong rotational shear, which is anticipated to be active in high performance FRC experiments. Thus, observed wobble modes in these systems are likely not driven by rotation alone

  4. Rotational stability of a long field-reversed configuration

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, D. C., E-mail: coronadocon@msn.com; Steinhauer, L. C. [Tri Alpha Energy, Rancho Santa Margarita, California 92688 (United States)

    2014-02-15

    Rotationally driven modes of long systems with dominantly axial magnetic field are considered. We apply the incompressible model and order axial wavenumber small. A recently developed gyro-viscous model is incorporated. A one-dimensional equilibrium is assumed, but radial profiles are arbitrary. The dominant toroidal (azimuthal) mode numbers ℓ=1 and ℓ=2 modes are examined for a variety of non-reversed (B) and reversed profiles. Previous results for both systems with rigid rotor equilibria are reproduced. New results are obtained by incorporation of finite axial wavenumber and by relaxing the assumption of rigid electron and ion rotation. It is shown that the frequently troublesome ℓ=2 field reversed configuration (FRC) mode is not strongly affected by ion kinetic effects (in contrast to non-reversed cases) and is likely stabilized experimentally only by finite length effects. It is also shown that the ℓ=1 wobble mode has a complicated behavior and is affected by a variety of configuration and profile effects. The rotationally driven ℓ=1 wobble is completely stabilized by strong rotational shear, which is anticipated to be active in high performance FRC experiments. Thus, observed wobble modes in these systems are likely not driven by rotation alone.

  5. Resonance and Chaotic Trajectories in Magnetic Field Reversed Configuration

    Energy Technology Data Exchange (ETDEWEB)

    A.S. Landsman; S.A. Cohen; M. Edelman; G.M. Zaslavsky

    2005-04-13

    The nonlinear dynamics of a single ion in a field-reversed configuration (FRC) were investigated. FRC is a toroidal fusion device which uses a specific type of magnetic field to confine ions. As a result of angular invariance, the full three-dimensional Hamiltonian system can be expressed as two coupled, highly nonlinear oscillators. Due to the high nonlinearity in the equations of motion, the behavior of the system is extremely complex, showing different regimes, depending on the values of the conserved canonical angular momentum and the geometry of the fusion vessel. Perturbation theory and averaging were used to derive the unperturbed Hamiltonian and frequencies of the two degrees of freedom. The derived equations were then used to find resonances and compare to Poincar{copyright} surface-of-section plots. A regime was found where the nonlinear resonances were clearly separated by KAM [Kolmogorov-Arnold-Mosher] curves. The structure of the observed island chains was explained. The condition for the destruction of KAM curves and the onset of strong chaos was derived, using Chirikov island overlap criterion, and shown qualitatively to depend both on the canonical angular momentum and geometry of the device. After a brief discussion of the adiabatic regime the paper goes on to explore the degenerate regime that sets in at higher values of angular momenta. In this regime, the unperturbed Hamiltonian can be approximated as two uncoupled linear oscillators. In this case, the system is near-integrable, except in cases of a universal resonance, which results in large island structures, due to the smallness of nonlinear terms, which bound the resonance. The linear force constants, dominant in this regime, were derived and the geometry for a large one-to-one resonance identified. The above analysis showed good agreement with numerical simulations and was able to explain characteristic features of the dynamics.

  6. Resonance and Chaotic Trajectories in Magnetic Field Reversed Configuration

    International Nuclear Information System (INIS)

    Landsman, A.S.; Cohen, S.A.; Edelman, M.; Zaslavsky, G.M.

    2005-01-01

    The nonlinear dynamics of a single ion in a field-reversed configuration (FRC) were investigated. FRC is a toroidal fusion device which uses a specific type of magnetic field to confine ions. As a result of angular invariance, the full three-dimensional Hamiltonian system can be expressed as two coupled, highly nonlinear oscillators. Due to the high nonlinearity in the equations of motion, the behavior of the system is extremely complex, showing different regimes, depending on the values of the conserved canonical angular momentum and the geometry of the fusion vessel. Perturbation theory and averaging were used to derive the unperturbed Hamiltonian and frequencies of the two degrees of freedom. The derived equations were then used to find resonances and compare to Poincar(copyright) surface-of-section plots. A regime was found where the nonlinear resonances were clearly separated by KAM [Kolmogorov-Arnold-Mosher] curves. The structure of the observed island chains was explained. The condition for the destruction of KAM curves and the onset of strong chaos was derived, using Chirikov island overlap criterion, and shown qualitatively to depend both on the canonical angular momentum and geometry of the device. After a brief discussion of the adiabatic regime the paper goes on to explore the degenerate regime that sets in at higher values of angular momenta. In this regime, the unperturbed Hamiltonian can be approximated as two uncoupled linear oscillators. In this case, the system is near-integrable, except in cases of a universal resonance, which results in large island structures, due to the smallness of nonlinear terms, which bound the resonance. The linear force constants, dominant in this regime, were derived and the geometry for a large one-to-one resonance identified. The above analysis showed good agreement with numerical simulations and was able to explain characteristic features of the dynamics

  7. The separatrix radius measurement of field-reversed configuration plasma in FRX-L

    International Nuclear Information System (INIS)

    Zhang, Shouyin; Tejero, Erik M.; Taccetti, Jose Martin; Wurden, Glen A.; Intrator, Thomas; Waganaar, William J.

    2004-01-01

    Magnetic pick-up coils and single turn flux loops are installed on the FRX-L device. The combination of the two measurements provides the excluded flux radius that approximates the separatrix radius of the field-reversed configuration plasma. Arrays of similar probes are used to map out local magnetic field dynamics beyond both ends of the theta-coil confinement region to help understand the effects of cusp locations on flux trapping during the FRC formation process. Details on the probe design and system calibrations are presented. The overall system calibration of excluded flux radius measurement is examined by replacing FRC plasma with a known radius aluminum conductor cylinder.

  8. Field-reversed configuration produced by a linear theta-pinch, Tupa-1

    International Nuclear Information System (INIS)

    Kayama, M.E.; Boeckelmann, H.K.; Sakanaka, P.H.; Machida, M.

    1987-01-01

    The formation of field reversed configuration, FRC, in one meter mirrorless linear theta-pinch device Tupa-I was observed. This configuration was studied during the first half magnetic cycle of ringing main bank discharge using magnetic probes. The separatrix radius by the exclude flux probe and the ion temperature by visible spectroscopy were measured. The plasma dynamics was observed by the image converter camera. A clear indication of the formation of FRC due to reconnection of the antiparallel bias to the main field and a fast reconnection, less than 0.2 microsec, that is explained in terms of forced reconnection driven by the Kruskal-Schwarzschild instability, are also observed. (author) [pt

  9. Theoretical and experimental studies of field-reversed configurations

    International Nuclear Information System (INIS)

    Chrien, R.E.; Hugrass, W.N.; Armstrong, W.T.

    1986-01-01

    The FRX-C/T formation region has been enlarged in diameter by 50%, and quasi-steady cusp coils have been installed to compare tearing and non-tearing formation. FRCs with significantly larger poloidal flux (≤8 mWb) and s (≤4) have been formed. However, their flux confinement was degraded compared with earlier FRX-C results. The n = 2 rotational instability has been completely suppressed on translated FRCs in FRX-C/T. Nearly equal stabilization thresholds were observed for straight and helical quadrupole fields, in contrast with another experiment

  10. Theoretical and experimental studies of field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Chrien, R.E.; Hugrass, W.N.; Armstrong, W.T.; Caramana, E.J.; Lewis, H.R.; Linford, R.K.; Ling, K.M.; McKenna, K.F.; Rej, D.J.; Schwarzmeier, J.L.

    1986-01-01

    The FRX-C/T formation region has been enlarged in diameter by 50%, and quasi-steady cusp coils have been installed to compare tearing and non-tearing formation. FRCs with significantly larger poloidal flux (less than or equal to8 mWb) and s (less than or equal to4) have been formed. However, their flux confinement was degraded compared with earlier FRX-C results. The n = 2 rotational instability has been completely suppressed on translated FRCs in FRX-C/T. Nearly equal stabilization thresholds were observed for straight and helical quadrupole fields, in contrast with another experiment.

  11. Design of a new large s field reversed configuration experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Slough, J.T.

    1986-01-01

    The present TRX facility utilizes programmed formation techniques to form s = 2 plasmas in a 20 cm diameter by 1 m long plasma tube. LSX will have an 80 cm diameter by 4 m long plasma tube and will employ the same programmed formation techniques as TRX. This should result in s = 8 plasmas and FRC flux and energy lifetimes in the msec range if the presently measured scaling persists. LSX will be initially restricted to an external field of 7.5 kG, and typical plasma conditions will be 300 eV electron and ion temperatures and electron or ion densities of about 2x10/sup 15/ cm/sup -3/. The low voltage formation techniques developed in TRX-2 (Eθ /sub values of about 100 volts/cm) will also be employed on LSX, so that relatively low voltage power supplies can be utilized. A modified form of second half cycle circuitry is planned to replace the function of a large reverse bias capacitor bank. The increase in total power supply efficiency allows the primary magnet energy storage to be less that 1 MJ

  12. Observation of tilt asymmetries in field-reversed configurations

    International Nuclear Information System (INIS)

    Tuszewski, M.; Barnes, D.C.; Klingner, P.; Ng, Chung.

    1989-01-01

    In recent years, part of the experimental effort on the FRX-C/LSM device has been devoted to understanding why good FRC confinement is observed only in a narrow window of the operating parameter space (fill pressures less than 5 mtorr and bias fields less than 0.8--0.9 kG). The transition from good to bad confinement has been shown for some time to correlate with strong axial shocks, suggesting a formation or stability problem. More recently, FRC magnetic asymmetries have been observed whenever the confinement was poor. To gain further understanding, a 64-coil probe array was built, and data from over 700 discharges were collected during the summer of 1989. We summarize in this paper the results of a preliminary analysis of these data. 5 refs., 4 figs

  13. Translation experiment of a plasma with field reversed configuration

    International Nuclear Information System (INIS)

    Tanjyo, Masayasu; Okada, Shigefumi; Ito, Yoshifumi; Kako, Masashi; Ohi, Shoichi

    1984-01-01

    Experiments to translate the FRC plasma from is formation area (pinch coil) into two kinds of metal vessels (magnetic flux conservers) with larger and smaller bore than that of the pinch coil have been carried out in OCT with an aim of improving the particle confinement time tau sub(N) by increasing xsub(s) (ratio of the plasma radius to that of the conducting wall). Demonstrated were successful translations of the plasma into both vessels. The xsub(s) of the translated plasma increased to 0.6 in the larger bore vessel and to 0.7 in the smaller one from 0.4 of the source plasma in the pinch coil. With the increase in xsub(s), tau sub(N) and also decay time of the trapped magnetic flux are extended from 15 - 20 μs of the source plasma to 50 - 80 μs. The tau sub(N) is found to have stronger dependence on xsub(s) than on rsub(s). During the translation phase, almost half of the total particle and the plasma energy are lost. The plasma volume is, therefore, about half of that expected from the analysis on the ideal translation process. It is also found that the translation process is nearly isothermal as is expected from the analysis. (author)

  14. Computational study of the influence of mirror parameters on FRC (field-reversed configuration) equilibria:

    International Nuclear Information System (INIS)

    Fuentes, N.O.; Sakanaka, P.H.

    1990-01-01

    Field-reversed configuration equilibria are studied by solving the Grad-Shafranov equation. A multiple coil system (main coil and end mirrors) is considered to simulate the coil geometry of CNEA device. First results are presented for computed two-dimensional FRC equilibria produced varying the mirror coil current with two different mirror lenghts. (Author)

  15. Field-reversed configuration translation studies in FRX-C/T

    International Nuclear Information System (INIS)

    Chrien, R.E.; Armstrong, W.T.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    Field-Reversed Configuration (FRC) translation is being studied in the FRX-C/T device. The main goals of this experiment are to demonstrate translation into a dc field region with minimal losses and to study modification of the equilibrium profiles of the FRC by varying x/sub s/, the ratio of separatrix radius (r/sub s/) to conducting wall radius (r/sub w/), through translation. FRC's are formed with a range of densities (1→5 x 10/sup 15/ cm/sup -3/) and x/sub s/ (0.35→0.55) in the FRX-C source, configured as a slightly conical theta pinch coil (r/sub w/ increases from 0.22 m to 0.28 m in four steps over 2 m). In 10→40 μs after formation, the FRC enters a 0.20-m radius stainless steel vessel with a dc field up to 8 kG. The translation velocity varies from 5→12 cm/μs and is typically about one-half the FRC Alfven velocity

  16. 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

  17. Particle-confinement criteria for axisymmetric field-reversed magnetic configurations

    International Nuclear Information System (INIS)

    Hsiao, M.Y.; Miley, G.H.

    1984-01-01

    Based on two constants of motion, H and Psub(theta), where H is the total energy of a particle and Psub(theta) is its canonical angular momentum, particle confinement criteria are derived which impose constraints on H and Psub(theta). With no electric field at the ends of field-reversed magnetic configurations, confinement criteria for closed-field and absolute confinements are obtained explicitly, including both lower and upper bounds of Psub(theta)/q, where q is the charge of the species considered, for a class of Hill's vortex field-reversed magnetic configurations. The commonly used criterion for the Hamiltonian, H 0 Psub(theta), where ω 0 is identical to qB 0 /mc, is deduced from a more general form as a special case. In this special case, it is found necessary to impose a new criterion, -B 0 R 2 sub(w)/2c 0 is the vacuum field, which reduces the confinement region in (H,Psub(theta)) space. With the presence of electric fields at the ends of field-reversed magnetic configurations, confinement criteria are obtained for two interesting cases. In addition to lower and upper bounds of H, both lower and upper bounds of Psub(theta)/q are found. For axially confined particles, the lower bound of Psub(theta)/q reduces the confinement region in (H,Psub(theta)) space and represents a new criterion. These results can be applied to calculations for field-reversed mirrors and field-reversed theta pinches. (author)

  18. FIREBIRD - a conceptual design of a field reversed configuration compact torus fusion reactor (CTFR)

    International Nuclear Information System (INIS)

    Raman, R.; Zubrin, R.M.

    1987-01-01

    This paper is a summary of the work carried out by the Nuclear Engineering 512 design team at the University of Washington on a conceptual design study of a Compact-Torus (Field-Reversed) Fusion Reactor Configuration (CTFR). The primary objective of the study was to develop a reactor design that strived for high engineering power density, modest recirculating power and competitive cost of electrical power. A Conceptual design was developed for a translating field-reversed configuration reactor; based on the Physics developed by Tuszewski and Lindford at LANL and by Hoffman and Milroy at MSNW. Furthermore, it also appears possible to operate a simplified form of this reactor using a pure D-D fuel cycle after an initial D-T ignition ramp to reach the advanced fuel operating regime. One optimistic reactor so designed has a length of about 35 meters, producing a net electrical power of about 375 MWe

  19. FRC formation studies in a field reversed theta pinch with a variable length coil

    International Nuclear Information System (INIS)

    Maqueda, R.; Sobehart, J.; Rodrigo, A.B.

    1987-01-01

    The formation phase of field reversed configurations (FRC) produced using a theta pinch has received considerable attention lately in connection with the possibility of developing formation methods in time scales longer than the Alven radial time, which would permit the use of low-voltage technology and represent an important engineering simplification in the trend towards larger scale machines sup (1)). The mechanisms leading to the loss of trapped reversed flux during the preheating 2 ) and formation sup (3,4)) stages, looking for maximization of this quantity in order to improve on the stability and transport properties of the configuration in its final equilibrium state are investigated. As a result, semi-emperical scaling laws have been obtained relating the reversed flux loss with experimental operating parameters during the early stages of the formation process 1 ). (author) [pt

  20. High Fidelity Modeling of Field-Reversed Configuration (FRC) Thrusters (Briefing Charts)

    Science.gov (United States)

    2017-05-24

    THRUSTERS (Briefing Charts) Robert Martin , Eder Sousa, Jonathan Tran Air Force Research Laboratory (AFMC) AFRL/RQRS 1 Ara Drive Edwards AFB, CA 93524... Martin N/A HIGH FIDELITY MODELING OF FIELD-REVERSED CONFIGURATION (FRC) THRUSTERS Robert Martin1, Eder Sousa2, Jonathan Tran2 1AIR FORCE RESEARCH...Distribution is unlimited. PA Clearance No. 17314 MARTIN , SOUSA, TRAN (AFRL/RQRS) DISTRIBUTION A - APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. PA

  1. Translation of field-reversed configurations in the FRX C/T experiment

    International Nuclear Information System (INIS)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device

  2. Translation of field-reversed configurations in the FRX C/T experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Milroy, R.D.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device.

  3. Final report for the field-reversed configuration power plant critical-issue scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Santarius, John F.; Mogahed, Elsayed A.; Emmert, Gilbert A.; Khater, Hesham Y.; Nguyen, Canh N.; Ryzhkov, Sergei V.; Stubna, Michael D.; Steinhauer, Loren C.; Miley, George H.

    2001-03-01

    This report describes research in which a team from the Universities of Wisconsin, Washington, and Illinois performed a scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis of deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core.

  4. Electron density and temperature profile diagnostics for C-2 field reversed configuration plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Deng, B. H.; Kinley, J. S.; Schroeder, J. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

    2012-10-15

    The 9-point Thomson scattering diagnostic system for the C-2 field reversed configuration plasmas is improved and the measured electron temperature profiles are consistent with theoretical expectations. Rayleigh scattering revealed a finite line width of the ruby laser emission, which complicates density calibration. Taking advantage of the plasma wobble motion, density profile reconstruction accuracy from the 6-chord two-color CO{sub 2}/HeNe interferometer data is improved.

  5. FRC [field-reversed configuration] translation studies on FRX-C/LSM

    International Nuclear Information System (INIS)

    Rej, D.; Barnes, G.; Baron, M.

    1989-01-01

    In preparation for upcoming compression-heating experiments, field-reversed configurations (FRCs) have been translated out of the FRX-C/LSM θ-pinch source, and into the 0.4-m-id, 6.7-m-long translation region formerly used on FRX-C/T. Unlike earlier experiments FRCs are generated without magnetic tearing in the larger FRX-C/LSM source (nominal coil id = 0.70 m, length = 2 m); larger, lower-energy-density FRCs are formed: r/sub s/ ≅ 0.17 m, B/sub ext/ ≅ 0.35 T, ≅ 7 /times/ 10 20 m/sup /minus/3/ and T/sub e/ + T/sub i/ ≅ 400 eV. An initial 3-mtorr D 2 pressure is introduced by either static or puff fill. Asymmetric fields from auxiliary end coils (used for non-tearing formation) provide the accelerating force on the FRC, thereby eliminating the need for a conical θ-pinch coil. An important feature is the abrupt 44% decrease in the flux-conserving wall radius at the transition between the θ-pinch and translation region, similar to that in the compressor. In this paper we review a variety of issues addressed by the recent translation experiments: translation dynamics; translation through a modulated magnetic field; stabilization of the n = 2 rotational instability by weak helical quadrupole fields; and confinement properties. Results from internal magnetic field measurements in translating FRCs may be found in a companion paper. 10 refs., 5 figs

  6. End-shorting and electric field in edge plasmas with application to field-reversed configurations

    International Nuclear Information System (INIS)

    Steinhauer, Loren C.

    2002-01-01

    The shorting of open field lines where they intersect external boundaries strongly modifies the transverse electric field all along the field lines. The modified electric field is found by an extension of the familiar Boltzmann relation for the electric potential. This leads to a prediction of the electric drift. Flow generation by electrical shorting is applied here to three aspects of elongated field-reversed configurations: plasma rotation rate; the particle-loss spin-up mechanism; and the sustainability of the rotating magnetic field current drive method

  7. Tearing relaxation and the globalization of transport in field-reversed configurations

    International Nuclear Information System (INIS)

    Steinhauer, Loren; Barnes, D. C.

    2009-01-01

    Tearing instability of field-reversed configurations (FRC) is investigated using the method of neighboring equilibria. It is shown that the conducting wall position in experiment lies very close to the location needed for tearing stability. This strongly suggests that vigorous but benign tearing modes, acting globally, are the engine of continual self-organization in FRCs, i.e., tearing relaxation. It also explains the ''profile consistency'' and anomalous loss rate of magnetic flux. In effect, tearing globalizes the effect of edge-driven transport.

  8. CFRX, a one-and-a-quarter-dimensional transport code for field-reversed configuration studies

    International Nuclear Information System (INIS)

    Hsiao Mingyuan

    1989-01-01

    A one-and-a-quarter-dimensional transport code, which includes radial as well as some two-dimensional effects for field-reversed configurations, is described. The set of transport equations is transformed to a set of new independent and dependent variables and is solved as a coupled initial-boundary value problem. The code simulation includes both the closed and open field regions. The axial effects incorporated include global axial force balance, axial losses in the open field region, and flux surface averaging over the closed field region. A typical example of the code results is also given. (orig.)

  9. Experimental profile evolution of a high-density field-reversed configuration

    International Nuclear Information System (INIS)

    Ruden, E. L.; Zhang, Shouyin; Intrator, T. P.; Wurden, G. A.

    2006-01-01

    A field-reversed configuration (FRC) gains angular momentum over time, eventually resulting in an n=2 rotational instability (invariant under rotation by π) terminating confinement. To study this, a laser interferometer probes the time history of line integrated plasma density along eight chords of the high-density (∼10 17 cm -3 ) field-reversed configuration experiment with a liner. Abel and tomographic inversions provide density profiles during the FRC's azimuthally symmetric phase, and over a period when the rotational mode has saturated and rotates with a roughly fixed profile, respectively. During the latter part of the symmetric phase, the FRC approximates a magnetohydrodynamic (MHD) equilibrium, allowing the axial magnetic-field profile to be calculated from pressure balance. Basic FRC properties such as temperature and poloidal flux are then inferred. The subsequent two-dimensional n=2 density profiles provide angular momentum information needed to set bounds on prior values of the stability relevant parameter α (rotational to ion diamagnetic drift frequency ratio), in addition to a view of plasma kinematics useful for benchmarking plasma models of higher order than MHD

  10. Macroscopic electromagnetic properties of the Irvine Field-Reversed Configuration: Equilibrium, power balance and fluctuations

    Science.gov (United States)

    Trask, Erik Harold

    The plasma parameters and characteristics of the Irvine Field-Reversed Configuration (IFRC) are summarized in this thesis. Particular emphasis is placed on the development of the different diagnostics used to make measurements in the experiment, as well as the measurements themselves. Whenever possible, actual measurements are used in lieu of theoretical or analytical fits to data. Analysis of magnetic probes (B-dots) comprises the bulk of what is known about the IFRC. From these B-dot probes, the magnetic field structure in a two dimensional plane at constant toroidal position has been determined, and has been found to be consistent with a field-reversed configuration. Peak reversed fields of approximately 250 Gauss have been observed. Further analyses have been developed to extract information from the magnetic field structure, including components of the electric field, the current density, and plasma pressure in the same two dimensional plane. Electric field magnitudes reach 600 V/m, concurrent with current densities greater than 105 Amps/m2 and thermal pressures over 200 Pa. Spectroscopic analysis of hydrogen lines has been done to make estimates of the electron temperature, while spectroscopic measurements of the Doppler broadening of the Halpha line31 have allowed an estimate of the ion temperature. Particle losses out one axial end plane measured by an array of Faraday cups quantify the how well the configuration traps particles. Spectral information derived from B-dot probes indicates that there is substantial power present at frequencies lying between the hydrogen cyclotron and mean gyrofrequency. These various measurements are used to find the following parameters that characterize the Irvine FRC: (1) Electromagnetic and thermal stored energies as functions of time. (2) Power balance, including input power from the field coils, resistive heating, power lost by particle transport and radiation, and particle and energy confinement times. (3) Strong

  11. Importance of field-reversing ion ring formation in hot electron plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, K.

    1975-11-01

    Formation of the field reversing ion ring in the mirror confined hot electron plasma may offer a device to confine the fusion plasma even under the restriction of the present technology. (Author) (GRA)

  12. Advanced Biasing Experiments on the C-2 Field-Reversed Configuration Device

    Science.gov (United States)

    Thompson, Matthew; Korepanov, Sergey; Garate, Eusebio; Yang, Xiaokang; Gota, Hiroshi; Douglass, Jon; Allfrey, Ian; Valentine, Travis; Uchizono, Nolan; TAE Team

    2014-10-01

    The C-2 experiment seeks to study the evolution, heating and sustainment effects of neutral beam injection on field-reversed configuration (FRC) plasmas. Recently, substantial improvements in plasma performance were achieved through the application of edge biasing with coaxial plasma guns located in the divertors. Edge biasing provides rotation control that reduces instabilities and E × B shear that improves confinement. Typically, the plasma gun arcs are run at ~ 10 MW for the entire shot duration (~ 5 ms), which will become unsustainable as the plasma duration increases. We have conducted several advanced biasing experiments with reduced-average-power plasma gun operating modes and alternative biasing cathodes in an effort to develop an effective biasing scenario applicable to steady state FRC plasmas. Early results show that several techniques can potentially provide effective, long-duration edge biasing.

  13. Hall magnetohydrodynamics simulations of end-shorting induced rotation in field-reversed configurations

    International Nuclear Information System (INIS)

    Macnab, A. I. D.; Milroy, R. D.; Kim, C. C.; Sovinec, C. R.

    2007-01-01

    End-shorting of the open field lines that surround a field-reversed configuration (FRC) is believed to contribute to its observed rotation. In this study, nonlinear extended magnetohydrodynamics (MHD) simulations were performed that detail the end-shorting process and the resulting spin-up of the FRC. The tangential component of the electric field E T is set to zero at the axial boundaries in an extended MHD model that includes the Hall and ∇P e terms. This shorting of the electric field leads to the generation of toroidal fields on the open field lines, which apply a torque leading to a rotation of the ions on the open field lines. The FRC then gains angular momentum through a viscous transfer from the open field line region. In addition, it is shown that spin-up is still induced when insulating boundaries are assumed

  14. Equilibrium of field reversed configurations with rotation. II. One space dimension and many ion species

    International Nuclear Information System (INIS)

    Qerushi, Artan; Rostoker, Norman

    2002-01-01

    In a previous paper [N. Rostoker and A. Qerushi, Phys. Plasmas 9, 3057 (2002)] it was shown that a complete description of equilibria of field reversed configurations with rotation can be obtained by solving a generalized Grad-Shafranov equation for the flux function. In this paper we show how to solve this equation in the case of one space dimension and many ion species. The following fusion fuels are considered: D-T, D-He 3 , and p-B 11 . Using a Green's function the generalized Grad-Shafranov equation is converted to an equivalent integral equation. The integral equation can be solved by iteration. Approximate analytic solutions for a plasma with many ion species are found. They are used as starting trial functions of the iterations. They turn out to be so close to the true solutions that only a few iterations are needed

  15. Equilibrium of field reversed configurations with rotation. IV. Two space dimensions and many ion species

    International Nuclear Information System (INIS)

    Qerushi, Artan; Rostoker, Norman

    2003-01-01

    In a previous paper [N. Rostoker and A. Qerushi, Phys. Plasmas 9, 3057 (2002)] a generalized Grad-Shafranov equation for the plasma flux function was derived which provides a complete description of equilibria of field reversed configurations with rotation. In this paper this fundamental equation is solved for two space dimensions and many ion species. The following fusion fuels are considered: D-T, D-He 3 , and p-B 11 . Using periodic boundary conditions the original differential equation is converted to an equivalent integral equation which involves a Green's function. The integral equation is solved by iteration. Approximate solutions are found for all the fusion fuels considered using a two-dimensional equilibrium model for one type of ion [A. Qerushi and N. Rostoker, Phys. Plasmas 9, 5001 (2002)]. They are used as starting trial functions of the iterations. They turn out to be so close to the real solutions that only a few iterations are needed

  16. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

    Energy Technology Data Exchange (ETDEWEB)

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.; Khater, H. Y.; Nguyen, C. N.; Ryzhkov, S. V.; Stubna, M. D.

    2000-03-31

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, good thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics.

  17. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

    International Nuclear Information System (INIS)

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.; Khater, H. Y.; Nguyen, C. N.; Ryzhkov, S. V.; Stubna, M. D.

    2000-01-01

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, good thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics

  18. One-dimensional modeling of plasma diffusion in field reversed configurations

    International Nuclear Information System (INIS)

    Hamasaki, S.; Krall, N.A.

    1986-03-01

    Over the past several years, a picture has emerged of transport in field reversed configuration (FRC) which explains many, though not all, of the loss phenomena observed in that device. That picture is complicated by the geometry, which includes both magnetically connected and magnetically isolated regions, and by the transport process, which includes a substantial contribution from short wavelength, fast time scale processes. This paper extends our previous work on this topic by carrying a one-dimensional model as far as it can be carried, in terms of goemetrical and physical consistency, and isolates the difference between the model and experiment as coming from phenomena beyond the scope of 1-D anomalous transport

  19. Profile relaxation and tilt instability in a field-reversed configuration

    International Nuclear Information System (INIS)

    Ohtani, H.; Horiuchi, R.; Sato, T.

    2003-01-01

    The profile relaxation from a magnetic hydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) is investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulation is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

  20. Profile relaxation and tilt instability in a field-reversed configuration

    International Nuclear Information System (INIS)

    Ohtani, H.; Horiuchi, R.; Sato, T.

    2002-10-01

    The profile relaxation from a magnetohydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) is investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulation is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

  1. Profile relaxation and tilt instability in a field-reversed configuration

    International Nuclear Information System (INIS)

    Ohtani, H.; Horiuchi, R.; Sato, T.

    2002-01-01

    The profile relaxation from a magnetichydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) in investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulations is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic is effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

  2. Positional stability of field-reversed-configurations in the presence of resistive walls

    Energy Technology Data Exchange (ETDEWEB)

    Rath, N., E-mail: nrath@trialphanenergy.com; Onofri, M.; Barnes, D. C. [Tri Alpha Energy, P.O. Box 7010, Rancho Santa Margarita, California 92688-7010 (United States)

    2016-06-15

    We show that in a field-reversed-configuration, the plasma is unstable to either transverse or axial rigid displacement, but never to both. Driving forces are found to be parallel to the direction of displacement with no orthogonal components. Furthermore, we demonstrate that the properties of a resistive wall (geometry and resistivity) in the vicinity of the plasma do not affect whether the plasma is stable or unstable, but in the case of an unstable system determine the instability growth rate. Depending on the properties of the wall, the instability growth is dominated by plasma inertia (and not affected by wall resistivity) or dominated by ohmic dissipation of wall eddy currents (and thus proportional to the wall resistivity).

  3. Tilt stability and compression heating studies of field-reversed configurations

    International Nuclear Information System (INIS)

    Rej, D.J.; Tuszewski, M.; Barnes, D.C.; Barnes, G.A.; Chrien, R.E.; Siemon, R.E.; Taggart, D.P.; Webster, R.B.; Wright, B.L.; Milroy, R.D.; Crawford, E.A.; Slough, J.T.; Steinhauer, L.C.; Bailey, A.D.; Baron, M.H.; Cobb, J.W.; Staudenmeier, J.L.; Sugimoto, S.; Takahashi, T.

    1990-01-01

    The first observations of internal tilt instabilities in field-reversed configurations (FRCs) are reported. Detailed comparisons with theory establish that data from an array of external magnetic probes are signatures of these destructive plasma instabilities. This work reconciles theory and experiments and suggests that grossly stable FRCs are restricted to very kinetic and elongated plasmas. Self-consistent three-dimensional numerical simulations demonstrate tilt stabilization by the addition of a beam ion component. High-power compression heating experiments with stable equilibrium FRCs are also reported. Plasmas formed in a tapered theta-pinch coil have been translated along a guide magnetic field into a new single-turn compression coil where the external field is increased up to 7 times the initial value in 55 μs. Substantial heating is observed accompanied by a decrease in confinement time. 17 refs

  4. Kinetic Effects on the Stability Properties of Field-reversed Configurations: I. Linear Stability

    Energy Technology Data Exchange (ETDEWEB)

    Elena V. Belova; Ronald C. Davidson; Hantao Ji; Masaaki Yamada

    2003-01-28

    New computational results are presented which advance the understanding of the stability properties of the Field-Reversed Configuration (FRC). We present results of hybrid and two-fluid (Hall-MHD) simulations of prolate FRCs. The n = 1 tilt instability mechanism and growth rate reduction mechanisms are investigated in detail including resonant particle effects, finite Larmor radius and Hall stabilization, and profile effects. It is shown that the Hall effect determines the mode rotation and the change in the linear mode structure in the kinetic regime; however, the reduction in the growth rate is mostly due to finite Larmor radius effects. Resonant wave-particle interactions are studied as a function of (a) elongation, (b) the kinetic parameter S*, which is proportional to the ratio of the separatrix radius to the thermal ion Larmor radius, and (c) the separatrix shape. It is demonstrated that, contrary to the usually assumed stochasticity of the ion orbits in the FRC, a large fraction of the orbits are regular in long configurations when S* is small. A stochasticity condition is found, and a scaling with the S* parameter is presented. Resonant particle effects are shown to maintain the instability in the large gyroradius regime regardless of the separatrix shape.

  5. Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

    Science.gov (United States)

    Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

    2012-10-01

    A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

  6. Passive Superconducting Flux Conservers for Rotating-Magnetic-Field-Driven Field-Reversed Configurations

    International Nuclear Information System (INIS)

    EOz, E.; Myers, C.E.; Edwards, M.R.; Berlinger, B.; Brooks, A.; Cohen, S.A.

    2011-01-01

    The Princeton Field-Reversed Configuration (PFRC) experiment employs an odd-parity rotating magnetic field (RMFo) current drive and plasma heating system to form and sustain high-β plasmas. For radial confinement, an array of coaxial, internal, passive, flux-conserving (FC) rings applies magnetic pressure to the plasma while still allowing radio-frequency RMF o from external coils to reach the plasma. The 3 ms pulse duration of the present experiment is limited by the skin time (τ fc ) of its room-temperature copper FC rings. To explore plasma phenomena with longer characteristic times, the pulse duration of the next-generation PFRC-2 device will exceed 100 ms, necessitating FC rings with τ fc > 300 ms. In this paper we review the physics of internal, discrete, passive FCs and describe the evolution of the PFRC's FC array. We then detail new experiments that have produced higher performance FC rings that contain embedded high-temperature superconducting (HTS) tapes. Several HTS tape winding configurations have been studied and a wide range of extended skin times, from 0.4 s to over 10 3 s, has been achieved. The new FC rings must carry up to 3 kA of current to balance the expected PFRC-2 plasma pressure, so the dependence of the HTS-FC critical current on the winding configuration and temperature was also studied. From these experiments, the key HTS-FC design considerations have been identified and HTS-FC rings with the desired performance characteristics have been produced.

  7. Resonant effects on the low frequency vlasov stability of axisymmetric field reversed configurations

    International Nuclear Information System (INIS)

    Finn, J.M.; Sudan, R.N.

    We investigate the effect of particle resonances on low frequency MHD modes in field-reversed geometries, e.g., an ion ring. It is shown that, for sufficiently high field reversal, modes which are hydromagnetically stable can be driven unstable by ion resonances. The stabilizing effect of a toroidal magnetic field is discussed

  8. Detection and Analysis of X Ray Emission from the Princeton-Field-Reversed Configuration (PFRC-2)

    Science.gov (United States)

    Bosh, Alexandra; Swanson, Charles; Jandovitz, Peter; Cohen, Samuel

    2016-10-01

    The PFRC is an odd-parity rotating-magnetic-field-driven field-reversed-configuration magnetic confinement experiment. Studying X rays produced via electron Bremsstrahlung with neutral particles is crucial to the further understanding of the energy and particle confinement of the PFRC. The data on the x rays are collected using a detector system comprised of two, spatially scannable Amptek XR-100 CR detectors and a Amptek XR-100 SDD detector that view the plasma column at two axial locations, one in the divertor and one near the axial midplane. These provide X-ray energy and arrival-time information. (Data analysis requires measurement of each detector's efficiency, a parameter that is modified by window transmission. Detector calibrations were performed with a custom-made X-ray tube that impinged 1-microamp 1-5 kV electron beams onto a carbon target.) From the analyzed data, the average electron energy, effective temperature, and electron density can be extracted. Spatial scans then allow the FRC's internal energy to be measured. We present recent measurements of the Bremsstrahlung spectrum from 0.8 to 6 keV and the inferred electron temperature in the PFRC device as functions of heating power, magnetic field and fill gas pressure. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466.

  9. Equilibrium paradigm for field-reversed configurations and application to experiments

    International Nuclear Information System (INIS)

    Steinhauer, Loren C.; Intrator, T. P.

    2009-01-01

    Fresh insights on field-reversed configurations (FRCs) are incorporated in a new paradigm for equilibria. In particular four new or unappreciated properties are accounted for: an empirically based scrape-off layer thickness; a new, more accurate axial force balance relation; viscous force regularity at the O-point; and the broken-surface effect. The new paradigm corrects glaring defects of previous models (rigid rotor, Hill's vortex). Further, the new paradigm is simple enough to be easily used as an interpretive tool despite the limited data suite in most experiments. It is applied to the newly enhanced FRC data compendium, a database of 69 records from 15 facilities. Several important observations and corrections on the previous understanding of FRCs follow, three of which stand out. (1) The traditional axial force balance ('average-β' relation) gives an inaccurate scaling with the separatrix-to-wall radius ratio. (2) The improved equilibrium paradigm yields separatrix particle transport rates of 3-5 m 2 /s for 'best confinement' examples; this is a factor of three lower than crude 'bulk' estimates commonly used. (3) The transport compared to the Bohm rate shows a great deal of scatter (40% scatter/mean ratio), i.e., 'Bohm' is not a useful representation for transport scaling.

  10. Equilibrium of field reversed configurations with rotation. I. One space dimension and one type of ion

    International Nuclear Information System (INIS)

    Rostoker, Norman; Qerushi, Artan

    2002-01-01

    Self-consistent solutions of the Vlasov-Maxwell equations are obtained. They involve rigid rotor distributions. This selection is justified on physical grounds. For this selection the Vlasov equation can be replaced by moment equations which terminate without any additional assumptions. For one-dimensional equilibria with one type of ion these equations have exact solutions. A complete equilibrium solution appropriate to a field reversed configuration with rotation can be obtained by solving a generalized Grad-Shafranov equation for the flux function. From this solution all other physical quantities can be determined. A Green's function method is developed to solve this equation, which provides a basis for an iterative solution. This method has the advantage that at every iteration the boundary conditions are satisfied. In this paper cylindrical geometry with one space dimension and one type of ion is considered, where analytic solutions are available. The convergence of the Green's function method is established. For this nonlinear problem there is usually more than one solution for completely specified boundary conditions (bifurcation). The present method selects one solution. It is applicable to equilibria with many ion species and to two dimensions

  11. Overview of C-2W Field-Reversed Configuration Experimental Program

    Science.gov (United States)

    Gota, H.; Binderbauer, M. W.; Tajima, T.; Putvinski, S.; Tuszewski, M.; Dettrick, S.; Korepanov, S.; Romero, J.; Smirnov, A.; Song, Y.; Thompson, M. C.; van Drie, A.; Yang, X.; Ivanov, A. A.; TAE Team

    2017-10-01

    Tri Alpha Energy's research has been devoted to producing a high temperature, stable, long-lived field-reversed configuration (FRC) plasma state by neutral-beam injection (NBI) and edge biasing/control. C-2U experiments have demonstrated drastic improvements in particle and energy confinement properties of FRC's, and the plasma performance obtained via 10 MW NBI has achieved plasma sustainment of up to 5 ms and plasma (diamagnetism) lifetimes of 10 + ms. The emerging confinement scaling, whereby electron energy confinement time is proportional to a positive power of the electron temperature, is very attractive for higher energy plasma confinement; accordingly, verification of the observed Te scaling law will be a key future research objective. The new experimental device, C-2W (now also called ``Norman''), has the following key subsystem upgrades from C-2U: (i) higher injected power, optimum energies, and extended pulse duration of the NBI system; (ii) installation of inner divertors with upgraded edge-biasing systems; (iii) fast external equilibrium/mirror-coil current ramp-up capability; and (iv) installation of trim/saddle coils for active feedback control of the FRC plasma. This paper will review highlights of the C-2W program.

  12. Rethermalization of a field-reversed configuration plasma in translation experiments

    International Nuclear Information System (INIS)

    Himura, H.; Okada, S.; Sugimoto, S.; Goto, S.

    1995-01-01

    A translation experiment of field-reversed configuration (FRC) plasma is performed on the FIX machine [Shiokawa and Goto, Phys. Fluids B 5, 534 (1993)]. The translated FRC bounces between magnetic mirror fields at both ends of a confinement region. The plasma loses some of its axial kinetic energy when it is reflected by the magnetic mirror field, and eventually settles down in the confinement region. In this reflection process, the plasma temperature rises significantly. Such plasma rethermalization has been observed in OCT-L1 experiments [Ito et al., Phys. Fluids 30, 168 (1987)], but rarely in FRX-C/T experiments [Rej et al., Phys. Fluids 29, 852 (1986)]. It is found that the rethermalization depends on the relation between the plasma temperature and the translation velocity. The rethermalization occurs only in the case where the translation velocity exceeds the sound velocity. This result implies the rethermalization is caused by a shock wave induced within the FRC when the plasma is reflected by the magnetic mirror field. copyright 1995 American Institute of Physics

  13. Effects of background neutral particles on a field-reversed configuration plasma in the translation process

    International Nuclear Information System (INIS)

    Matsuzawa, Yoshiki; Asai, Tomohiko; Takahashi, Tsutomu; Takahashi, Toshiki

    2008-01-01

    A field-reversed configuration (FRC) plasma was translated into a weakly ionized plasma and the effects of heating and particle buildup of the FRC plasma due to the background neutral particles and plasma injection in the translation process were investigated. Improvement of the particle and poloidal flux confinements and delay of onset of n=2 rotational instability were observed in the translation process. It was found that the internal structure of the plasma pressure (plasma temperature and density) at the separatrix and field null was deformed by the particle injection. FRC plasma translation through the background particles was equivalent to an end-on particle beam injection to the FRC plasma. Particles and energy were supplied during the translation. The results obtained for the phenomena of particle supply and plasma heating were also supported by the results of two-dimensional particle simulation. The effects of background particle injection appear to be a promising process for the regeneration of translation kinetic energy to plasma internal energy

  14. Measurements of Plasma Power Losses in the C-2 Field-Reversed Configuration Experiment

    Science.gov (United States)

    Korepanov, Sergey; Smirnov, Artem; Garate, Eusebio; Donin, Alexandr; Kondakov, Alexey; Singatulin, Shavkat

    2013-10-01

    A high-confinement operating regime with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection in the C-2 field-reversed configuration (FRC) experiment. To analyze the power balance in C-2, two new diagnostic instruments - the pyroelectric (PE) and infrared (IR) bolometers - were developed. The PE bolometer, designed to operate in the incident power density range from 0.1-100 W/cm2, is used to measure the radial power loss, which is dominated by charge-exchange neutrals and radiation. The IR bolometer, which measures power irradiated onto a thin metal foil inserted in the plasma, is designed for the power density range from 0.5-5 kW/cm2. The IR bolometer is used to measure the axial power loss from the plasma near the end divertors. The maximum measurable pulse duration of ~ 10 ms is limited by the heat capacitance of the IR detector. Both detectors have time resolution of about 10-100 μs and were calibrated in absolute units using a high power neutral beam. We present the results of first direct measurements of axial and radial plasma power losses in C-2.

  15. Electron temperature in field reversed configurations and theta pinches with closed magnetic field lines

    International Nuclear Information System (INIS)

    Newton, A.A.

    1986-01-01

    Field-reversed configurations (FRC) and theta pinches with trapped reversed bias field are essentially the same magnetic confinement systems using closed magnetic field lines inside an open-ended magnetic flux tube. A simple model of joule heating and parallel electron thermal conduction along the open flux lines to an external heat sink gives the electron temperature as Tsub(e)(eV) approx.= 0.05 Bsup(2/3)(G)Lsup(1/3)(cm), where B is the magnetic field and L is the coil length. This model appears to agree with measurements from present FRC experiments and past theta-pinch experiments which cover a range of 40-900 eV. The energy balance in the model is dominated by (a) parallel electron thermal conduction along the open field lines which has a steep temperature dependence, Q is proportional to Tsub(e)sup(7/2), and (b) the assumed rapid perpendicular transport in the plasma bulk which, in experiments to date, may be due to the small number of ion gyroradii across the plasma. (author)

  16. Power deposition by neutral beam injected fast ions in field-reversed configurations

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasaka, Naotaka

    2004-04-01

    Effects of Coulomb collisions on neutral beam (NB) injected fast ions into Field-Reversed Configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing down and pitch angle collisions. The Monte-Carlo method is used for the pitch angle scattering, and the friction term is added to the equation of motion to show effects of slowing down collision such as the deposited power profile. Calculation parameters used are relevant to the NB injection on the FRC Injection Experiment (FIX) device. It is found that the dominant local power deposition occurs in the open field region between the X-point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found negligible. The loss mechanism due to non-adiabatic fast ion motion, which is intrinsic in non-uniform FRC plasmas, affects much greater than the pitch angle scattering by Coulomb collision. (author)

  17. Power deposition by neutral beam injected fast ions in field-reversed configurations

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

    2004-01-01

    The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

  18. 1.4D quasistatic profile model of transport in a field-reversed configuration (FRC)

    International Nuclear Information System (INIS)

    Steinhauer, L.C.

    1990-01-01

    Global confinement models are useful for determining how a given transport mechanism (dependent on local parameters) translates into global confinement times. Such models are also useful for inferring the overall magnitudes of transport rates, and limited information about their spatial profiles. They are especially important in a field reversed configuration (FRC) where the equilibrium and transport rates are so intimately coupled, and where the flux loss time is such an important factor. An earlier global FRC confinement model, sometimes called QUASI, was based on the assumption of a quasi-steady equilibrium. The equilibrium was assumed to have square-ends with some features of 2D equilibria: (1) equal pressure on inner and outer branches of the flux lines; and (2) average-beta relation. Models of this type have been called 1-1/4D transport models. The same general approach has now been applied in a straightforward way to an equilibrium with realistic axial structure. This might be called a 1.4D quasisteady transport model. The assumed axial structure can be that of an analytic equilibrium, or a more complicated computed equilibrium as desired. The example used here is an elongated Hill's vortex equilibrium. As will be shown later, the equilibrium is reflected by two integral quantities that appear in the quasistatic diffusion equation

  19. Compact toroid injection fueling in a large field-reversed configuration

    Science.gov (United States)

    Asai, T.; Matsumoto, T.; Roche, T.; Allfrey, I.; Gota, H.; Sekiguchi, J.; Edo, T.; Garate, E.; Takahashi, Ts.; Binderbauer, M.; Tajima, T.

    2017-07-01

    A repetitively driven compact toroid (CT) injector has been developed for the large field-reversed configuration (FRC) facility of the C-2/C-2U, primarily for particle refueling. A CT is formed and injected by a magnetized coaxial plasma gun (MCPG) exclusively developed for the C-2/C-2U FRC. To refuel the particles of long-lived FRCs, multiple CT injections are required. Thus, a multi-stage discharge circuit was developed for a multi-pulsed CT injection. The drive frequency of this system can be adjusted up to 1 kHz and the number of CT shots per injector is two; the system can be further upgraded for a larger number of injection pulses. The developed MCPG can achieve a supersonic ejection velocity in the range of ~100 km s-1. The key plasma parameters of electron density, electron temperature and the number of particles are ~5  ×  1021 m-3, ~30 eV and 0.5-1.0  ×  1019, respectively. In this project, single- and double-pulsed counter CT injection fueling were conducted on the C-2/C-2U facility by two CT injectors. The CT injectors were mounted 1 m apart in the vicinity of the mid-plane. To avoid disruptive perturbation on the FRC, the CT injectors were operated at the lower limit of the particle inventory. The experiments demonstrated successful refueling with a significant density build-up of 20-30% of the FRC particle inventory per single CT injection without any deleterious effects on the C-2/C-2U FRC.

  20. 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)

  1. Internal magnetic field measurements in a translating field-reversed configuration

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Chrien, R.E.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    Magnetic field probes have been employed to study the internal field structure of Field-Reversed Configurations (FRCs) translating past the probes in the FRX-C/T device. Internal closed flux surfaces can be studied in this manner with minimal perturbation because of the rapid transit of the plasma (translational velocity v/sub z/ approx. 10 cm/μs). Data have been taken using a low-field (5 kG), 5-mtorr-D 2 gas-puff mode of operation in the FRC source coil which yields an initial plasma density of approx. 1 x 10 15 cm -3 and x/sub s/ approx. 0.04. FRCs translate from the approx. 25 cm radius source coil into a 20 cm radius metal translation vessel. Two translation conditions are studied: (1) translation into a 4 kG guide field (matched guide-field case), resulting in similar plasma parameters but with x/sub s/ approx. .45, and (2) translation into a 1 kG guide field (reduced guide-field case), resulting in expansion of the FRC to conditions of density approx. 3 x 10 14 , external field B 0 approx. 2 kG and x/sub s/ approx. 0.7. The expected reversed B/sub z/ structure is observed in both cases. However, the field measurements indicate a possible sideways offset of the FRC from the machine axis in the matched case. There is also evidence of island structure in the reduced guide-field case. Fluctuating levels of B/sub theta/ are ovserved with amplitudes less than or equal to B 0 /3 in both cases. Field measurements on the FRC symmetry axis in the reduced guide-field case indicate β on the separatrix of β/sub s/ approx. = 0.3 (indexed to the external field) has been achieved. This decrease of β/sub s/ with increased x/sub s/ is expected, and desirable for improved plasma confinement

  2. A high voltage pulse generator based on silicon-controlled rectifier for field-reversed configuration experiment.

    Science.gov (United States)

    Lin, Munan; Liu, Ming; Zhu, Guanghui; Wang, Yanpeng; Shi, Peiyun; Sun, Xuan

    2017-08-01

    A high voltage pulse generator based on a silicon-controlled rectifier has been designed and implemented for a field reversed configuration experiment. A critical damping circuit is used in the generator to produce the desired pulse waveform. Depending on the load, the rise time of the output trigger signal can be less than 1 μs, and the peak amplitudes of trigger voltage and current are up to 8 kV and 85 A in a single output. The output voltage can be easily adjusted by changing the voltage on a capacitor of the generator. In addition, the generator integrates an electrically floating heater circuit so it is capable of triggering either pseudosparks (TDI-type hydrogen thyratron) or ignitrons. Details of the circuits and their implementation are described in the paper. The trigger generator has successfully controlled the discharging sequence of the pulsed power supply for a field reversed configuration experiment.

  3. Internal tilting and classical transport for field-reversed configurations based on the Maschke--Hernegger solution

    International Nuclear Information System (INIS)

    Clemente, R.A.; Grillo, C.E.

    1984-01-01

    It is shown that elongated field-reversed configurations based on the Maschke--Hernegger solution of the Grad--Shafranov equation are unstable to internal tilting. The particle transport properties across the flux surfaces of such a model are also considered in the limit of large elongation of the separatrix. An estimation of the time of confinement of particles in terms of classical conductivity, which is lower than previous estimates, is given

  4. Dual wavelength imaging of a scrape-off layer in an advanced beam-driven field-reversed configuration

    Energy Technology Data Exchange (ETDEWEB)

    Osin, D.; Schindler, T., E-mail: dosin@trialphaenergy.com [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688-7010 (United States)

    2016-11-15

    A dual wavelength imaging system has been developed and installed on C-2U to capture 2D images of a He jet in the Scrape-Off Layer (SOL) of an advanced beam-driven Field-Reversed Configuration (FRC) plasma. The system was designed to optically split two identical images and pass them through 1 nm FWHM filters. Dual wavelength images are focused adjacent on a large format CCD chip and recorded simultaneously with a time resolution down to 10 μs using a gated micro-channel plate. The relatively compact optical system images a 10 cm plasma region with a spatial resolution of 0.2 cm and can be used in a harsh environment with high electro-magnetic noise and high magnetic field. The dual wavelength imaging system provides 2D images of either electron density or temperature by observing spectral line pairs emitted by He jet atoms in the SOL. A large field of view, combined with good space and time resolution of the imaging system, allows visualization of macro-flows in the SOL. First 2D images of the electron density and temperature observed in the SOL of the C-2U FRC are presented.

  5. Non-local kinetic transport studies of a field-reversed configuration. Annual technical report, July 1, 1987-June 30, 1988

    International Nuclear Information System (INIS)

    Choi, C.K.

    1988-01-01

    The Field Reversed Configuration (FRC) is a type of plasma experiment of current interest in fusion research. The life of an FRC can be divided into two periods, a highly dynamic formation phase followed by a quiescent equilibrium phase. The FRC can be a viable source of fusion energy only if the confinement properties of the equilibrium phase are sufficient for breakeven. The purpose of this report is to provide the FRC theory community with equilibrium models that have been found to be useful. Three equilibrium models are presented: a kinetic model, a rigidly rotating model, and an MHD model

  6. Mitigation of rotational instability of high-beta field-reversed configuration by double-sided magnetized plasmoid injection

    Energy Technology Data Exchange (ETDEWEB)

    Itagaki, H.; Inomoto, M. [Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Asai, T.; Takahashi, Ts. [College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)

    2014-03-15

    Active control of destructive rotational instability in a high-beta field-reversed configuration (FRC) plasma was demonstrated by using double-sided plasmoid injection technique. The elliptical deformation of the FRC's cross section was mitigated as a result of substantial suppression of spontaneous spin-up by the plasmoid injection. It was found that the injected plasmoid provided better stability against the rotational mode, suggesting that the compensation of the FRC's decaying magnetic flux might help to suppress its spin-up.

  7. Electron Acceleration in the Field-reversed Configuration (FRC) by Slowly Rotation Odd-parity Magnetic Fields (RMFo)

    International Nuclear Information System (INIS)

    Glasser, A.H.; Cohen, S.A.

    2001-01-01

    The trajectories of individual electrons are studied numerically in a 3D, prolate, FRC [field-reversed configuration] equilibrium magnetic geometry with added small-amplitude, slowly rotating, odd-parity magnetic fields (RMFos). RMFos cause electron heating by toroidal acceleration near the O-point line and by field-parallel acceleration away from it, both followed by scattering from magnetic-field inhomogeneities. Electrons accelerated along the O-point line move antiparallel to the FRC's current and attain average toroidal angular speeds near that of the RMFo, independent of the sense of RMFo rotation. A conserved transformed Hamiltonian, dependent on electron energy and RMFo sense, controls electron flux-surface coordinate

  8. A one-and-a-quarter-dimensional transport code for field-reversed configuration studies: A user's guide for CFRX

    International Nuclear Information System (INIS)

    Hsiao, Ming-Yuan; Werley, K.A.; Ling, Kuok-Mee.

    1988-05-01

    A one-and-a-quarter-dimensional transport code, which includes radial as well as some two-dimensional effects for field-reversed configurations, is described. The set of transport equations is transformed to a set of new independent and dependent variables and is solved as a coupled initial-boundary value problem. The code simulation includes both the closed and open field regions. The axial effects incorporated include global axial force balance, axial losses in the open field region, and flux surface averaging over the closed field region. Input, output, and structure of the code are described in detail. A typical example of the code results is also given. 20 refs., 21 figs., 7 tabs

  9. Rebound coefficient of collisionless gas in a rigid vessel. A model of reflection of field-reversed configuration

    International Nuclear Information System (INIS)

    Takaku, Yuichi; Hamada, Shigeo

    1996-01-01

    A system of collisionless neutral gas contained in a rigid vessel is considered as a simple model of reflection of field-reversed configuration (FRC) plasma by a magnetic mirror. The rebound coefficient of the system is calculated as a function of the incident speed of the vessel normalized by the thermal velocity of the gas before reflection. The coefficient is compared with experimental data of FIX (Osaka U.) and FRX-C/T(Los Alamos N.L.). Agreement is good for this simple model. Interesting is that the rebound coefficient takes the smallest value (∼0.365) as the incident speed tends to zero and approaches unity as it tends to infinity. This behavior is reverse to that expected for a system with collision dominated fluid instead of collisionless gas. By examining the rebound coefficient, therefore, it could be successfully inferred whether the ion mean free path in each experiment was longer or shorter than the plasma length. (author)

  10. Production of field-reversed configurations with a magnetized coaxial plasma gun

    International Nuclear Information System (INIS)

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

    1980-01-01

    Compact toroids were generated which can be made to come to rest in a cylindrical resistive flux conserver. They are observed to rotate so that their major axis is perpendicular to the axis of the flux conserver. Subsequently they appear to remain stationary and decay with a time constant of about 100 μs. We have also generated compact toroids in an oblate geometry which remain aligned with the axis of the flux conserver and decay with a time constant of 150 μs. The magnetic field reconnection time for compact toroid formation is measured in the latter case to be much shorter than the decay time

  11. Production of field-reversed configurations with a magnetized coaxial plasma gun

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-01-01

    Compact toroids were generated which can be made to come to rest in a cylindrical resistive flux conserver. They are observed to rotate so that their major axis is perpendicular to the axis of the flux conserver. Subsequently they appear to remain stationary and decay with a time constant of about 100 ..mu..s. We have also generated compact toroids in an oblate geometry which remain aligned with the axis of the flux conserver and decay with a time constant of 150 ..mu..s. The magnetic field reconnection time for compact toroid formation is measured in the latter case to be much shorter than the decay time.

  12. Study on improvement of the lifetime of a field-reversed configuration by tangential neutron beam injection

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Kondoh, Yoshiomi; Hirano, Yoichi; Asai, Tomohiko; Takahashi, Tsutomu; Mizuguchi, Naoki; Tomita, Yukihiro

    2006-01-01

    The numerical analysis of neutron beam injection (NBI) is carried out to keep the stationary conditions of the field-reversed configuration (FRC) plasma. The ionization process of neutron beam was reproduced by the Monte Carlo method. A confinement of 15 keV beam ion was investigated using the sharp of stormer region obtained by the position and velocity at a moment of ionization. The relation between the external magnetic field B ex [T] and radius of machine r w [m] was shown by B ex = 0.1 r w -3/4 . The power imparted to plasma was estimated by beam ion orbital calculation. The confinement coefficient of beam ion was lost by re-charge-exchange reaction with deuterium; this fact was discovered at first. In order to keep the configuration of plasma under the conditions of 0.2 T of the external magnetic field, 0.4 m of radius, and 100 eV ion temperature, about 17 MW/m NBI power is needed. (S.Y.)

  13. Development of a magnetized coaxial plasma gun for compact toroid injection into the C-2 field-reversed configuration device

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, T., E-mail: cstd14003@g.nihon-u.ac.jp; Sekiguchi, J.; Asai, T. [College of Science and Technology, Nihon University, 1-8-14 Kanda, Chiyoda-ku, Tokyo 1018308 (Japan); Gota, H.; Garate, E.; Allfrey, I.; Valentine, T.; Morehouse, M.; Roche, T.; Kinley, J.; Aefsky, S.; Cordero, M.; Waggoner, W.; Binderbauer, M. [Tri Alpha Energy, Inc., P.O. Box 7010 Rancho Santa Margarita, California 92688 (United States); Tajima, T. [Tri Alpha Energy, Inc., P.O. Box 7010 Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

    2016-05-15

    A compact toroid (CT) injector was developed for the C-2 device, primarily for refueling of field-reversed configurations. The CTs are formed by a magnetized coaxial plasma gun (MCPG), which consists of coaxial cylindrical electrodes and a bias coil for creating a magnetic field. First, a plasma ring is generated by a discharge between the electrodes and is accelerated by Lorenz self-force. Then, the plasma ring is captured by an interlinkage flux (poloidal flux). Finally, the fully formed CT is ejected from the MCPG. The MCPG described herein has two gas injection ports that are arranged tangentially on the outer electrode. A tungsten-coated inner electrode has a head which can be replaced with a longer one to extend the length of the acceleration region for the CT. The developed MCPG has achieved supersonic CT velocities of ∼100 km/s. Plasma parameters for electron density, electron temperature, and the number of particles are ∼5 × 10{sup 21} m{sup −3}, ∼40 eV, and 0.5–1.0 × 10{sup 19}, respectively.

  14. Losses of neutral injected fast ions due to adiabaticity breaking processes in a field-reversed configuration

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Inoue, Koji; Ishizuka, Takashi; Kondoh, Yoshiomi; Iwasawa, Naotaka

    2004-02-01

    Losses of neutral beam (NB) injected fast ions from the confinement region of a Field-Reversed Configuration (FRC) with a strong magnetic mirror are numerically analyzed for parameters relevant to NB injection experiments on the FIX (FRC injection experiment) device [T. Asai et al., Phys. Plasmas 7, 2294 (2000)]. Ionization processes of beam particles are calculated by the Monte Carlo method. The confinement of beam ions is discussed with the concept of accessible regions that restrict the ion excursion and are determined from two constants of motion, the kinetic energy and canonical angular momentum, in the case of an axisymmetric and a steady state FRC without an electrostatic field. From the calculation of the accessible regions, it is found that all the fast ions suffer from the orbit loss on the wall surface and/or the end loss. Single particle orbits are also calculated to find a difference of confinement properties from the results by employing the accessible regions. The magnetic moment is observed to show non-adiabatic motions of the beam ions, which cause a gradual orbit loss on the wall even in a case that a strong magnetic mirror is applied. The results show that the correlation of the magnetic moment disappears as the fast ions experience the density gradient around the separatrix surface and the field-null points. (author)

  15. Development of a magnetized coaxial plasma gun for compact toroid injection into the C-2 field-reversed configuration device.

    Science.gov (United States)

    Matsumoto, T; Sekiguchi, J; Asai, T; Gota, H; Garate, E; Allfrey, I; Valentine, T; Morehouse, M; Roche, T; Kinley, J; Aefsky, S; Cordero, M; Waggoner, W; Binderbauer, M; Tajima, T

    2016-05-01

    A compact toroid (CT) injector was developed for the C-2 device, primarily for refueling of field-reversed configurations. The CTs are formed by a magnetized coaxial plasma gun (MCPG), which consists of coaxial cylindrical electrodes and a bias coil for creating a magnetic field. First, a plasma ring is generated by a discharge between the electrodes and is accelerated by Lorenz self-force. Then, the plasma ring is captured by an interlinkage flux (poloidal flux). Finally, the fully formed CT is ejected from the MCPG. The MCPG described herein has two gas injection ports that are arranged tangentially on the outer electrode. A tungsten-coated inner electrode has a head which can be replaced with a longer one to extend the length of the acceleration region for the CT. The developed MCPG has achieved supersonic CT velocities of ∼100 km/s. Plasma parameters for electron density, electron temperature, and the number of particles are ∼5 × 10(21) m(-3), ∼40 eV, and 0.5-1.0 × 10(19), respectively.

  16. 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.

  17. Development of a magnetized coaxial plasma gun for compact toroid injection into the C-2 field-reversed configuration device

    International Nuclear Information System (INIS)

    Matsumoto, T.; Sekiguchi, J.; Asai, T.; Gota, H.; Garate, E.; Allfrey, I.; Valentine, T.; Morehouse, M.; Roche, T.; Kinley, J.; Aefsky, S.; Cordero, M.; Waggoner, W.; Binderbauer, M.; Tajima, T.

    2016-01-01

    A compact toroid (CT) injector was developed for the C-2 device, primarily for refueling of field-reversed configurations. The CTs are formed by a magnetized coaxial plasma gun (MCPG), which consists of coaxial cylindrical electrodes and a bias coil for creating a magnetic field. First, a plasma ring is generated by a discharge between the electrodes and is accelerated by Lorenz self-force. Then, the plasma ring is captured by an interlinkage flux (poloidal flux). Finally, the fully formed CT is ejected from the MCPG. The MCPG described herein has two gas injection ports that are arranged tangentially on the outer electrode. A tungsten-coated inner electrode has a head which can be replaced with a longer one to extend the length of the acceleration region for the CT. The developed MCPG has achieved supersonic CT velocities of ∼100 km/s. Plasma parameters for electron density, electron temperature, and the number of particles are ∼5 × 10"2"1 m"−"3, ∼40 eV, and 0.5–1.0 × 10"1"9, respectively.

  18. Fast imaging diagnostics on the C-2U advanced beam-driven field-reversed configuration device

    Energy Technology Data Exchange (ETDEWEB)

    Granstedt, E. M., E-mail: egranstedt@trialphaenergy.com; Petrov, P.; Knapp, K.; Cordero, M.; Patel, V. [Tri Alpha Energy, P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2016-11-15

    The C-2U device employed neutral beam injection, end-biasing, and various particle fueling techniques to sustain a Field-Reversed Configuration (FRC) plasma. As part of the diagnostic suite, two fast imaging instruments with radial and nearly axial plasma views were developed using a common camera platform. To achieve the necessary viewing geometry, imaging lenses were mounted behind re-entrant viewports attached to welded bellows. During gettering, the vacuum optics were retracted and isolated behind a gate valve permitting their removal if cleaning was necessary. The axial view incorporated a stainless-steel mirror in a protective cap assembly attached to the vacuum-side of the viewport. For each system, a custom lens-based, high-throughput optical periscope was designed to relay the plasma image about half a meter to a high-speed camera. Each instrument also contained a remote-controlled filter wheel, set between shots to isolate a particular hydrogen or impurity emission line. The design of the camera platform, imaging performance, and sample data for each view is presented.

  19. A multiframe soft x-ray camera with fast video capture for the LSX field reversed configuration (FRC) experiment

    International Nuclear Information System (INIS)

    Crawford, E.A.

    1992-01-01

    Soft x-ray pinhole imaging has proven to be an exceptionally useful diagnostic for qualitative observation of impurity radiation from field reversed configuration plasmas. We used a four frame device, similar in design to those discussed in an earlier paper [E. A. Crawford, D. P. Taggart, and A. D. Bailey III, Rev. Sci. Instrum. 61, 2795 (1990)] as a routine diagnostic during the last six months of the Large s Experiment (LSX) program. Our camera is an improvement over earlier implementations in several significant aspects. It was designed and used from the onset of the LSX experiments with a video frame capture system so that an instant visual record of the shot was available to the machine operator as well as facilitating quantitative interpretation of intensity information recorded in the images. The camera was installed in the end region of the LSX on axis approximately 5.5 m from the plasma midplane. Experience with bolometers on LSX showed serious problems with ''particle dumps'' at the axial location at various times during the plasma discharge. Therefore, the initial implementation of the camera included an effective magnetic sweeper assembly. Overall performance of the camera, video capture system, and sweeper is discussed

  20. Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment.

    Science.gov (United States)

    Sheftman, D; Gupta, D; Roche, T; Thompson, M C; Giammanco, F; Conti, F; Marsili, P; Moreno, C D

    2016-11-01

    Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field-reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements. Results of these measurements provide the jet ion temperature and axial velocity, electron density, and high frequency density fluctuations.

  1. Field reversal in mirror machines

    International Nuclear Information System (INIS)

    Pearlstein, L.D.; Anderson, D.V.; Boozer, A.H.

    1978-01-01

    This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-β 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-consistent model of ion currents is presented. Conditions for stability of field-reversed configurations to E x B driven rotations are determined

  2. Compact toroid formation using barrier fields and controlled reconnection in the TRX-1 field reversed theta pinch

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Armstrong, W.T.

    1982-01-01

    TRX-1 is a new 20 cm diameter, 1-m long field reversed theta pinch with a magnetic field swing of 10 kG in 3 μsec. It employs z discharge preionization and octopole barrier fields to maximize flux trapping on first half cycle operation. Cusp coils are used at the theta pinch ends to delay reconnection and fast mirror coils are used to trigger reconnection at a time designed to maximize axial heating efficiency and toroid lifetime. These controls are designed to study toroid formation methods which are claimed to be especially efficient by Russian experimenters. Studies have been conducted on flux trapping efficiency, triggered reconnection, and equilibrium and lifetime

  3. Observations of plasma tearing instabilities and associated axial translation in field-reversed experiments

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Cochrane, J.C.; Lipson, J.; Tuszewski, M.

    1981-02-01

    Tearing and reconnection processes during the formation and quiescent periods of a field-reversed configuration are studied with an axial array of compensated diamagnetic loops. Several representative plasma shots are documented

  4. Design of a fully-fiber multi-chord interferometer and a new phase-shift demodulation method for field-reversed configuration

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Dongfan, E-mail: fangdongfan1208@126.com; Sun, Qizhi; Zhao, Xiaoming; Jia, Yuesong [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAEP, P. O. Box 919-108, Mianyang, Sichuan 621999 (China)

    2014-05-15

    A 633 nm laser interferometer has been designed based on a novel concept, which, without the acousto-optic modulator or the demodulator circuit, adopts the fibers to connect all elements except photodetectors and oscilloscope in this system to make it more compact, portable, and efficient. The noteworthy feature is to mathematically compare the two divided interference signals, which have the same phase-shift caused by the electron density but possess the different initial phase and low angular frequencies. It is possible to read the plasma density directly on the oscilloscope by our original mathematic demodulation method without a camera. Based on the Abel inversion algorithm, the radial electron density profiles versus time can be obtained by using the multi-chord system. The designed measurable phase shift ranges from 0 to 2π rad corresponding to the maximum line integral of electron density less than 3.5 × 10{sup 17} cm{sup −2}, and the phase accuracy is about 0.017 rad corresponding to the line integral of electron density accuracy of 1 × 10{sup 15} cm{sup −2}. After the construction of eight-chord interferometer, it will provide the detailed time resolved information of the spatial distribution of the electron density in the field-reversed configuration (FRC) plasma target produced by the “Yingguang-1” programmed-discharge device, which is being constructed in the Key Laboratory of Pulsed Power, China Academy of Engineering Physics.

  5. Simulations of High Harmonic Fast Wave Heating on the C-2U Advanced Beam-Driven Field-Reversed Configuration Device

    Science.gov (United States)

    Yang, Xiaokang; Petrov, Yuri; Ceccherini, Francesco; Koehn, Alf; Galeotti, Laura; Dettrick, Sean; Binderbauer, Michl

    2017-10-01

    Numerous efforts have been made at Tri-Alpha Energy (TAE) to theoretically explore the physics of microwave electron heating in field-reversed configuration (FRC) plasmas. For the fixed 2D profiles of plasma density and temperature for both electrons and thermal ions and equilibrium field of the C-2U machine, simulations with GENRAY-C ray-tracing code have been conducted for the ratios of ω/ωci[D] in the range of 6 - 20. Launch angles and antenna radial and axial positions have been optimized in order to simultaneously achieve good wave penetration into the core of FRC plasmas and efficient power damping on electrons. It is found that in an optimal regime, single pass absorption efficiency is 100% and most of the power is deposited inside the separatrix of FRC plasmas, with power damping efficiency of about 72% on electrons and less than 19% on ions. Calculations have clearly demonstrated that substantial power absorption on electrons is mainly attributed to high beta enhancement of magnetic pumping; complete power damping occurs before Landau damping has a significant effect on power absorption.

  6. Simulations of High Harmonic Fast Wave Heating on the C-2U Advanced Beam-Driven Field-Reversed Configuration Device

    Directory of Open Access Journals (Sweden)

    Yang Xiaokang

    2017-01-01

    Full Text Available Numerous efforts have been made at Tri-Alpha Energy (TAE to theoretically explore the physics of microwave electron heating in field-reversed configuration (FRC plasmas. For the fixed 2D profiles of plasma density and temperature for both electrons and thermal ions and equilibrium field of the C-2U machine, simulations with GENRAY-C ray-tracing code have been conducted for the ratios of ω/ωci[D] in the range of 6 - 20. Launch angles and antenna radial and axial positions have been optimized in order to simultaneously achieve good wave penetration into the core of FRC plasmas and efficient power damping on electrons. It is found that in an optimal regime, single pass absorption efficiency is 100% and most of the power is deposited inside the separatrix of FRC plasmas, with power damping efficiency of about 72% on electrons and less than 19% on ions. Calculations have clearly demonstrated that substantial power absorption on electrons is mainly attributed to high beta enhancement of magnetic pumping; complete power damping occurs before Landau damping has a significant effect on power absorption.

  7. Initial Design of the 60 Megawatt Rotating Magnetic Field (RMF) Oscillator System for the University of Washington ''TCS'' Field Reversed Configuration Experiment

    International Nuclear Information System (INIS)

    Reass, W.A.; Miera, D.A.; Wurden, G.A.

    1997-01-01

    This paper presents the initial electrical and mechanical design of two phase-locked 30 Megawatt RMS, 150 kHz oscillator systems used for current drive and plasma sustainment of the ''Translation, Confinement, and Sustainment'' (TCS) field reversed configuration (FRC) plasma. By the application of orthogonally-placed saddle coils on the surface of the glass vacuum vessel, the phase-controlled rotating magnetic field perturbation will induce an electric field in the plasma which should counter the intrinsic ohmic decay of the plasma, and maintain the FRC. Each system utilizes a bank of 6 parallel magnetically beamed ML8618 triodes. These devices are rated at 250 Amperes cathode current and a 45 kV plate voltage. An advantage of the magnetically beamed triode is their extreme efficiency, requiring only 2.5 kW of filament and a few amps and a few kV of grid drive. Each 3.5 uH saddle coil is configured with an adjustable tank circuit (for tuning). Assuming no losses and a nominal 18 kV plate voltage, the tubes can circulate about 30 kV and 9 kA (pk to pk) in the saddle coil antenna, a circulating power of over 33 megawatts RMS. On each cycle the tubes can kick in up to 1500 Amperes, providing a robust phase control. DC high-voltage from the tubes is isolated from the saddle coil antennas and tank circuits by a 1:1 coaxial air-core balun transformer. To control the ML8618's phase and amplitude, fast 150 Ampere ''totem-pole'' grid drivers, an ''on'' hot-deck and an ''off'' hot-deck are utilized. The hot-decks use up to 6 each 3CPX1500A7 slotted radial beam triodes. By adjusting the conduction angle, amplitude may be regulated, with inter-pulse timing, phase angle can be controlled. A central feedback timing chassis monitors each systems' saddle coil antenna and appropriately derives each systems timing signals. Fiber-optic cables are used to isolate between the control room timing chassis and the remote power oscillator system. Complete system design detail will be

  8. US-Japan workshop on field-reversed configurations with steady-state high-temperature fusion plasmas and the 11th US-Japan workshop on compact toroids

    International Nuclear Information System (INIS)

    Barnes, D.C.; Fernandez, J.C.; Rej, D.J.

    1990-05-01

    The US-Japan Workshop on Field-Reversed Configurations with Steady-State High-Temperature Fusion Plasma and the 11th US-Japan Workshop on Compact Toroids were held at Los Alamos National Laboratory, Los Alamos, New Mexico on November 7--9, 1989. These proceedings contain the papers presented at the workshops as submitted by the authors. These papers have been indexed separately

  9. US-Japan workshop on field-reversed configurations with steady-state high-temperature fusion plasmas and the 11th US-Japan workshop on compact toroids

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, D.C.; Fernandez, J.C.; Rej, D.J. (comps.)

    1990-05-01

    The US-Japan Workshop on Field-Reversed Configurations with Steady-State High-Temperature Fusion Plasma and the 11th US-Japan Workshop on Compact Toroids were held at Los Alamos National Laboratory, Los Alamos, New Mexico on November 7--9, 1989. These proceedings contain the papers presented at the workshops as submitted by the authors. These papers have been indexed separately.

  10. Stability of the field-reversed mirror

    International Nuclear Information System (INIS)

    Morse, E.C.

    1979-01-01

    The stability of a field reversed mirror plasma configuration is studied with an energy principle derived from the Vlasov equation. Because of finite orbit effects, the stability properties of a field-reversed mirror are different from the stability properties of similar magnetohydrodynamic equilibria. The Vlasov energy principle developed here is applied to a computer simulation of an axisymmetric field-reversed mirror state. It has been possible to prove that the l = 0 modes, called tearing modes, satisfy a sufficient condition for stability. Precessional modes, with l = 1, 2, are found to be unstable at low growth rate. This suggests possible turbulent behavior (Bohm confinement) in the experimental devices aiming at field reversal. Techniques for suppressing these instabilities are outlined, and the applicability of the Vlasov energy principle to more complicated equilibrium models is shown

  11. Flux trapping during field reversal in a field reversed theta pinch

    International Nuclear Information System (INIS)

    Milroy, R.D.; Hoffman, A.L.; Slough, J.T.; Harding, D.G.

    1983-01-01

    In this paper we present new results from both numerical and experimental studies of the formation of the conducting sheath near the tube wall and its effectiveness in trapping bias flux during field reversal

  12. Quasi-adiabatic particle acceleration in a magnetic field reversals and the formation of the plasma sheet boundary layer in the earth's magnetotail

    International Nuclear Information System (INIS)

    Zelenyi, L.M.; Vogin, D.V.; Buechner, J.

    1989-01-01

    Two types of regularity exist for the particle motion in the two-dimensional magnetic field reversals (MFR) with the strongly curves magnetic field lines - the usual adiabatic and another one which we called 'quasiadiabatic'. Here we consider the acceleration of MFR particles in stationary and homogeneous electric field induced by the motion of MFR through the ambient plasma (i.e. solar wind). Assuming that the time scale of acceleration is slow in comparison with the period of orbital motion we introduce the new longitudinal invariant I κ . This enables to describe the process of acceleration in a closed form and to obtain for the first time the laws governing the quasiadiabatic ion acceleration in the Earth's mangetotail. The similarities and differences in adiabatic and quasiadiabatic acceleration mechanisms are discussed. The obtained results give and important insights to the problem of the particle heating in hte Earth's magnetotail and to the formation of accelerated plasma streams along the edges of the plasma sheet. (author). 17 refs.; 7 figs

  13. Poloidal flux loss in a field-reversed theta pinch

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Milroy, R.D.; Steinhauer, L.C.

    1981-01-01

    Poloidal flux loss has been measured in field-reversed configurations and related to anomalous resistivity near the magnetic field null. The results indicate that mechanisms in addition to the lower-hybrid drift instability are affecting transport

  14. Modification of the magnetic field structure in the vicinity of the x-points by the strong mirror field for a field-reversed configuration (FRC) with the Thick Edge-Layer plasma

    International Nuclear Information System (INIS)

    Suzuki, Yukihisa; Okada, Shigefumi; Goto, Seiichi

    2003-01-01

    Modification of the magnetic field structure in the vicinity of the x-points and changes of the separatrix shape are investigated under the pressure effects due to an edge-layer plasma together with a mirror field by the two-dimensional (2-D) MHD equilibrium solutions of field-reversed configuration (FRC) obtained from the Grad-Shafranov equation. To explore the coupling pressure effects caused by edge-layer plasma and mirror field, the equilibrium calculations are performed by the combinations of several values of mirror ratio (R m ) and of edge-layer width (δ), respectively. A summary of results for present study is as follows. In the condition of weak mirror field (1.0 m m > 1.6, ψ=0 surface never opens up for any δ. These original results make it clear that large magnetic curvature produced by the strong mirror field enhances the magnetic stress around the x-point, so that the ends of FRC are effectively sustained by this enhanced magnetic stress, which counteracts the edge-layer plasma pressure effect. (author)

  15. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  16. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1979-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  17. Field reversed theta pinch TC-I UNICAMP

    International Nuclear Information System (INIS)

    Honda, R.Y.; Machida, M.; Aramaki, E.A.; Porto, P.; Berni, L.A.

    1990-01-01

    Field reversed configuration TC-I device is 16 cm diameter, 1 meter long with two mirror coils and 30 kJ field reversed theta pinch working for over two years at University of Campinas. Its implosion dynamics and field reversal parameters have been studied using flux excluded loops, internal magnetic probe, visible spectroscopy, photodiode array and image converter camera. The vacuum vessel is a pyrex tube of 14,5 cm diameter pumped with a liquid nitrogen cooled diffusion pump to a base pressure of 6 x 10 -7 Torr. The schematic view of the machine and experimental set up are shown. (Author)

  18. Field-reversed mirror reactor

    International Nuclear Information System (INIS)

    Carlson, G.A.

    1978-01-01

    The reactor design is a multicell arrangement wherein a series of field-reversed plasma layers are arranged along the axis of a long superconducting solenoid which provides the background magnetic field. Normal copper mirror coils and Ioffe bars placed at the first wall radius provide shallow axial and radial magnetic wells for each plasma layer. Each of 11 plasma layers requires the injection of 3.6 MW of 200 keV deuterium and tritium and produces 20 MW of fusion power. The reactor has a net electric output of 74 MWe and an estimated direct capital cost of $1200/kWe

  19. Network Configuration Analysis for Formation Flying Satellites

    Science.gov (United States)

    Knoblock, Eric J.; Wallett, Thomas M.; Konangi, Vijay K.; Bhasin, Kul B.

    2001-01-01

    The performance of two networks to support autonomous multi-spacecraft formation flying systems is presented. Both systems are comprised of a ten-satellite formation, with one of the satellites designated as the central or 'mother ship.' All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/EP over ATM protocol architecture within the formation, and the second system uses the IEEE 802.11 protocol architecture within the formation. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IP queuing delay, IP queue size and IP processing delay at the mother ship as well as end-to-end delay for both systems. In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  20. Configurations of self-identity formations of adults who stutter

    Directory of Open Access Journals (Sweden)

    Harsha Kathard

    2010-12-01

    Full Text Available The aims of this paper are twofold: Firstly, to describe the configuration of self-identity formations evident across and within research stories of adults living with stuttering; and secondly, to discuss the clinical implications of these findings. The study on which this paper is based used life history narratives to describe the types, processes and configurations of self-identity formations of adults who stuttered since childhood. Through open-ended, in-depth interviews 7 participants shared their experiences of living with stuttering. The interviews were analysed at a first level using narrative analysis and at a second level to further describe the types, processes and configurations of self-identity formations evident in the stories. The findings on configurations of self-identity formations were that the two types of self-identity formations Able and DisOther were present in singular and dual configurations. The dual self-identity formations occurred in co-existing, competing and coalescing relationships within particular time periods in their stories. The clinical implications of the findings are discussed.

  1. Atmospheric helium and geomagnetic field reversals.

    Science.gov (United States)

    Sheldon, W. R.; Kern, J. W.

    1972-01-01

    The problem of the earth's helium budget is examined in the light of recent work on the interaction of the solar wind with nonmagnetic planets. It is proposed that the dominant mode of helium (He4) loss is ion pumping by the solar wind during geomagnetic field reversals, when the earth's magnetic field is very small. The interaction of the solar wind with the earth's upper atmosphere during such a period is found to involve the formation of a bow shock. The penetration altitude of the shock-heated solar plasma is calculated to be about 700 km, and ionization rates above this level are estimated for a cascade ionization (electron avalanche) process to average 10 to the 9th power ions/sq cm/sec. The calculated ionization rates and the capacity of the solar wind to remove ionized helium (He4) from the upper atmosphere during geomagnetic dipole reversals are sufficient to yield a secular equilibrium over geologic time scales. The upward transport of helium from the lower atmosphere under these conditions is found to be adequate to sustain the proposed loss rate.

  2. Estimation of neutral-beam-induced field reversal in MFTF by an approximate scaling law

    International Nuclear Information System (INIS)

    Shearer, J.W.

    1980-01-01

    Scaling rules are derived for field-reversed plasmas whose dimensions are common multiples of the ion gyroradius in the vacuum field. These rules are then applied to the tandem MFTF configuration, and it is shown that field reversal appears to be possible for neutral beam currents of the order of 150 amperes, provided that the electron temperature is at least 500 eV

  3. Detection of electric field around field-reversed configuration plasma

    International Nuclear Information System (INIS)

    Ikeyama, Taeko; Hiroi, Masanori; Nogi, Yasuyuki; Ohkuma, Yasunori

    2010-01-01

    Electric-field probes consisting of copper plates are developed to measure electric fields in a vacuum region around a plasma. The probes detect oscillating electric fields with a maximum strength of approximately 100 V/m through a discharge. Reproducible signals from the probes are obtained with an unstable phase dominated by a rotational instability. It is found that the azimuthal structure of the electric field can be explained by the sum of an n=2 mode charge distribution and a convex-surface electron distribution on the deformed separatrix at the unstable phase. The former distribution agrees with that anticipated from the diamagnetic drift motions of plasma when the rotational instability occurs. The latter distribution suggests that an electron-rich plasma covers the separatrix.

  4. Translation Studies on an Annular Field Reversed Configuration Device

    Science.gov (United States)

    2012-10-01

    step H( f ) Transfer function Isat + Ion saturation current Ii Inner coil current Io Outer coil current Ip Plasmoid current Ibit Impulse bit Ien...density can be calculated from the ion saturation current. The ion saturation current is [72] Isat + = ecn0Ap √ kBTe 2πmi ii(X) (5.28) where n0 is the

  5. Adiabatic compression of elongated field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1982-01-01

    The simplest model of plasma dynamics is the adiabatic model. In this model the plasma is assumed to be in MHD equilibrium at each instant of time. The equilibria are connected by the requirement that they all have the same entropy per unit flux, i.e., the equilibria form a sequence generated by adiabatic changes. The standard way of computing such a sequence of equilibria was developed by Grad, but its practical use requires a fairly complicated code. It would be helpful if approximately the same results could be gotten either with a much simpler code or by analytical techniques. In Sec. II a one-dimensional equilibrium code is described and its results are checked against a two-dimensional equilibrium code; in Sec. III an even simpler analytic calculation is presented.

  6. High Fidelity Modeling of Field Reversed Configuration (FRC) Thrusters

    Science.gov (United States)

    2017-04-22

    plasma. Anomalous resistivity eects can be measured and the rst indications point to them being at least one order of magnitude larger than the Spitzer...uid codes to provide detailed spectra for validation with experimental measurements as described in Section C.3. The inelastic cross-sections...Equi- librium ( LTE ) assumption is often used to describe the state of the gas in the discharge region [4–17]. However, Non Local Thermodynamic

  7. Virtual cathode formations in nested-well configurations

    International Nuclear Information System (INIS)

    Stephens, K. F. II; Ordonez, C. A.; Peterkin, R. E. Jr.

    1999-01-01

    Complete transmission of an electron beam through a cavity is not possible if the current exceeds the space-charge limited current. The formation of a virtual cathode reflects some of the beam electrons and reduces the current transmitted through the cavity. Transients in the injected current have been shown to lower the transmitted current below the value predicted by the electrostatic Child-Langmuir law. The present work considers the propagation of an electron beam through a nested-well configuration. Electrostatic particle-in-cell simulations are used to demonstrate that ions can be trapped in the electric potential depression of an electron beam. Furthermore, the trapped ions can prevent the formation of a virtual cathode for beam currents exceeding the space-charge limit

  8. Field reversal produced by a plasma gun

    International Nuclear Information System (INIS)

    Hartman, C.W.; Condit, W.; Granneman, E.H.A.; Prono, D.; Smith, A.C. Jr.; Taska, J.; Turner, W.C.

    1980-01-01

    Experimental results are presented of the production of Field-Reversed Plasma with a high energy coaxial plasma gun. The gun is magnetized with solenoids inside the center electrode and outside the outer electrode so that plasma emerging from the gun entrains the radial fringer field at the muzzle. The plasma flow extends field lines propagating a high electrical conductivity, the flux inside the center electrode should be preserved. However, for low flux, the trapped flux exceeds by 2 or more the initial flux, possibly because of helical deformation of the current channel extending from the center electrode

  9. Conceptual design of the field-reversed mirror reactor

    International Nuclear Information System (INIS)

    Carlson, G.A.; Condit, W.C.; Devoto, R.S.; Fink, J.H.; Hanson, J.D.; Neef, W.S.; Smith, A.C. Jr.

    1978-01-01

    For this reactor a reference case conceptual design was developed in some detail. The parameters of the design result partly from somewhat arbitrary physics assumptions and partly from optimization procedures. Two of the assumptions--that only 10% of the alpha-particle energy is deposited in the plasma and that particle confinement scales with the ion-ion collision time--may prove to be overly conservative. A number of possible start-up scenarios for the field-reversed plasmas were considered, but the choice of a specific start-up method for the conceptual design was deferred, pending experimental demonstration of one or more of the schemes in a mirror machine. Basic to our plasma model is the assumption that, once created, the plasma can be stably maintained by injection of a neutral-beam current sufficient to balance the particle-loss rate. The reference design is a multicell configuration with 11 field-reversed toroidal plasma layers arranged along the horizontal axis of a long-superconducting solenoid. Each plasma layer requires the injection of 3.6 MW of 200-keV deuterium and tritium, and produces 20 MW of fusion power. The reactor has a net electric output of 74 MWe. The preliminary estimate for the direct capital cost of the reference design is $1200/kWe. A balance-of-plant study is now underway and will result in a more accurate cost estimate

  10. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    Energy Technology Data Exchange (ETDEWEB)

    Podulka, W J; Greenly, J B; Anderson, D E; Glidden, S C; Hammer, D A; Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

    1997-12-31

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10{sup 17} protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs.

  11. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    International Nuclear Information System (INIS)

    Podulka, W.J.; Greenly, J.B.; Anderson, D.E.; Glidden, S.C.; Hammer, D.A.; Omelchenko, Yu.A.; Sudan, R.N.

    1996-01-01

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10 17 protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs

  12. Domino model for geomagnetic field reversals.

    Science.gov (United States)

    Mori, N; Schmitt, D; Wicht, J; Ferriz-Mas, A; Mouri, H; Nakamichi, A; Morikawa, M

    2013-01-01

    We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macrospins aligned along a ring. Each spin has unit length and is described by its angle with respect to the rotational axis. The orientation of the spins can vary in time due to spin-spin interaction and random forcing. We statistically describe the behavior of the sum of all spins for different parameters. The term "domino model" in the title refers to the interaction among the spins. We compare the model results with geomagnetic field reversals and dynamo simulations and find strikingly similar behavior. The aggregate of all spins keeps the same direction for a long time and, once in a while, begins flipping to change the orientation by almost 180 degrees (mimicking a geomagnetic reversal) or to move back to the original direction (mimicking an excursion). Most of the time the spins are aligned or antialigned and deviate only slightly with respect to the rotational axis (mimicking the secular variation of the geomagnetic pole with respect to the geographic pole). Reversals are fast compared to the times in between and they occur at random times, both in the model and in the case of the Earth's magnetic field.

  13. Tandem mirror and field-reversed mirror experiments

    Energy Technology Data Exchange (ETDEWEB)

    Coensgen, F.H.; Simonen, T.C.; Turner, W.C.

    1979-08-21

    This paper is largely devoted to tandem mirror and field-reversed mirror experiments at the Lawrence Livermore Laboratory (LLL), and briefly summarizes results of experiments in which field-reversal has been achieved. In the tandem experiment, high-energy, high-density plasmas (nearly identical to 2XIIB plasmas) are located at each end of a solenoid where plasma ions are electrostatically confined by the high positive poentials arising in the end plug plasma. End plug ions are magnetically confined, and electrons are electrostatically confined by the overall positive potential of the system. The field-reversed mirror reactor consists of several small field-reversed mirror plasmas linked together for economic reasons. In the LLL Beta II experiment, generation of a field-reversed plasma ring will be investigated using a high-energy plasma gun with a transverse radial magnetic field. This plasma will be further heated and sustained by injection of intense, high-energy neutral beams.

  14. Results from TRX-2 slow field-reversed-theta-pinch

    International Nuclear Information System (INIS)

    Slough, J.T.; Harding, D.; Hoffman, A.L.

    1984-01-01

    FRCs have been successfully generated in the TRX-2 slow risetime theta pinch. Initial studies indicate that the flux trapping through field reversal is about as good (''50%) as on TRX-1, although the quarter cycle time of the main coil was increased from 3 to 10 μsec. Formation studies have been started using the programmed formation techniques developed on TRX-1. The plasma dynamics are very similar to those exhibited in the faster rise TRX-1 experiments. The formation phase shows the same high degree of symmetry and reproducibility that was observed in TRX-1. Equilibrium behaviour of the FRCs formed is very similar to that observed on TRX-1, as long as impurity content is kept low. T/sub e/ + T/sub i/ temperatures of 400 to 500 eV are obtained and confirmed by impurity line broadening and decay rates. Flux and particle lifetimes ≅ 100 μsec have been observed and show the same strong scaling with x/sub s/ that was observed on TRX-1

  15. Fusion proton diagnostic for the C-2 field reversed configurationa)

    Science.gov (United States)

    Magee, R. M.; Clary, R.; Korepanov, S.; Smirnov, A.; Garate, E.; Knapp, K.; Tkachev, A.

    2014-11-01

    Measurements of the flux of fusion products from high temperature plasmas provide valuable insights into the ion energy distribution, as the fusion reaction rate is a very sensitive function of ion energy. In C-2, where field reversed configuration plasmas are formed by the collision of two compact toroids and partially sustained by high power neutral beam injection [M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010); M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012)], measurements of DD fusion neutron flux are used to diagnose ion temperature and study fast ion confinement and dynamics. In this paper, we will describe the development of a new 3 MeV proton detector that will complement existing neutron detectors. The detector is a large area (50 cm2), partially depleted, ion implanted silicon diode operated in a pulse counting regime. While the scintillator-based neutron detectors allow for high time resolution measurements (˜100 kHz), they have no spatial or energy resolution. The proton detector will provide 10 cm spatial resolution, allowing us to determine if the axial distribution of fast ions is consistent with classical fast ion theory or whether anomalous scattering mechanisms are active. We will describe in detail the diagnostic design and present initial data from a neutral beam test chamber.

  16. Magnetic reconnection and current sheet formation in 3D magnetic configurations

    International Nuclear Information System (INIS)

    Frank, A.G.

    1999-01-01

    The problem of magnetic reconnection in three-dimensional (3D) magnetic configurations has been studied experimentally. The research has concentrated on the possibilities of formation of current sheets, which represent crucial objects for a realization of magnetic reconnection phenomena. Different types of 3D magnetic configurations were examined, including configurations with singular lines of the X-type, non-uniform fields containing isolated magnetic null-points and without null-points. It was revealed that formation of quasi-one-dimensional current sheets is the universal process for plasma dynamics in 3D magnetic fields both with null-points and without. At the same time the peculiarities of current sheets, plasma dynamics and magnetic reconnection processes depend essentially on characteristics of 3D magnetic configurations. The result of principal significance obtained was that magnetic reconnection phenomena can take place in a wide range of 3D magnetic configurations as a consequence of their ability to form current sheets. (author)

  17. Field-reversed experiments (FRX) on compact toroids

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-11-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10/sup 15/ cm/sup -3/ to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10/sup 15/ cm/sup -3/. Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 ..mu..sec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed.

  18. Field-reversed experiments (FRX) on compact toroids

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-01-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10 15 cm -3 to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10 15 cm -3 . Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 μsec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed

  19. Regimes of pulsed formation of a compact plasma configuration with a high energy input

    Energy Technology Data Exchange (ETDEWEB)

    Romadanov, I. V.; Ryzhkov, S. V., E-mail: svryzhkov@bmstu.ru [Bauman Moscow State Technical University (Russian Federation)

    2015-10-15

    Results of experiments on the formation of a compact toroidal magnetic configuration at the Compact Toroid Challenge setup are presented. The experiments were primarily aimed at studying particular formation stages. Two series of experiments, with and without an auxiliary capacitor bank, were conducted. The magnetic field was measured, its time evolution and spatial distribution over the chamber volume were determined, and its influence on the formation regimes was investigated.

  20. Formation of compact toroidal configurations for magnetic confinement of high temperature plasmas

    International Nuclear Information System (INIS)

    Fuentes, N.O.; Rodrigo, A.B.

    1986-01-01

    The formation stage of inverted magnetic field toroidal configurations (FRC) for hot plasmas confinement using a low energy linear theta pinch is studied. The diagnostic techniques used are based on optical spectroscopy, ultrarapid photography, magnetic probes and excluded flux compensated bonds. The generalities of the present research program, the used diagnostic techniques and the results obtained are discussed. (Author)

  1. Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

    International Nuclear Information System (INIS)

    Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

    1980-01-01

    Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

  2. Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

    International Nuclear Information System (INIS)

    Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

    1980-01-01

    Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are dramatically improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

  3. Probability of primordial black hole formation and its dependence on the radial profile of initial configurations

    International Nuclear Information System (INIS)

    Hidalgo, J. C.; Polnarev, A. G.

    2009-01-01

    In this paper we derive the probability of the radial profiles of spherically symmetric inhomogeneities in order to provide an improved estimation of the number density of primordial black holes (PBHs). We demonstrate that the probability of PBH formation depends sensitively on the radial profile of the initial configuration. We do this by characterizing this profile with two parameters chosen heuristically: the amplitude of the inhomogeneity and the second radial derivative, both evaluated at the center of the configuration. We calculate the joint probability of initial cosmological inhomogeneities as a function of these two parameters and then find a correspondence between these parameters and those used in numerical computations of PBH formation. Finally, we extend our heuristic study to evaluate the probability of PBH formation taking into account for the first time the radial profile of curvature inhomogeneities.

  4. Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal

    Science.gov (United States)

    Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.

    2016-01-01

    The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

  5. Moving-ring field-reversed mirror reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1981-01-01

    We describe a first prototype fusion reactor design of the Moving-Ring Field-Reversed Mirror Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma. The plamsa rings, formed by a coaxial plasma gun, are magnetically compressed to ignition temperature while they are being injected into the reactor's burner section. DT ice pellets refuel the rings during the burn at a rate which maintains constant fusion power. A steady train of plasma rings moves at constant speed through the reactor under the influence of a slightly diverging magnetic field. The aluminum first wall and breeding zone structure minimize induced radioactivity; hands-on maintenance is possible on reactor components outside the breeding blanket. Helium removes the heat from the Li 2 O tritium breeding blanket and is used to generate steam. The reactor produces a constant, net power of 376 MW

  6. Stochastic behaviour of particle orbits in field reversed geometries

    International Nuclear Information System (INIS)

    Finn, J.M.

    1979-01-01

    Studies of stochastic or ergodic behaviour of beam particle orbits in axisymmetric systems with field reversal produced by ion rings or by neutral injection are presented. In the former case a large class of orbits is ergodic, whereas in the latter most are integrable. Effects of ergodic behaviour on particle confinement, equilibrium, magnetic compression, and stability are discussed. The modification, due to ergodic orbits of the stability criterion for low frequency (ω << ωsub(ci)) resonant instabilities is presented. (author)

  7. Gravitational collapse of dark energy field configurations and supermassive black hole formation

    International Nuclear Information System (INIS)

    Jhalani, V.; Kharkwal, H.; Singh, A.

    2016-01-01

    Dark energy is the dominant component of the total energy density of our Universe. The primary interaction of dark energy with the rest of the Universe is gravitational. It is therefore important to understand the gravitational dynamics of dark energy. Since dark energy is a low-energy phenomenon from the perspective of particle physics and field theory, a fundamental approach based on fields in curved space should be sufficient to understand the current dynamics of dark energy. Here, we take a field theory approach to dark energy. We discuss the evolution equations for a generic dark energy field in curved space-time and then discuss the gravitational collapse for dark energy field configurations. We describe the 3 + 1 BSSN formalism to study the gravitational collapse of fields for any general potential for the fields and apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting equations for the time evolution of field configurations and the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our Universe. We also demonstrate the black hole formation as a result of the gravitational collapse of the dark energy field configurations. The black holes produced by the collapse of dark energy fields are in the supermassive black hole category with the masses of these black holes being comparable to the masses of black holes at the centers of galaxies.

  8. Gravitational collapse of dark energy field configurations and supermassive black hole formation

    Energy Technology Data Exchange (ETDEWEB)

    Jhalani, V.; Kharkwal, H.; Singh, A., E-mail: anupamsingh.iitk@gmail.com [L. N. Mittal Institute of Information Technology, Physics Department (India)

    2016-11-15

    Dark energy is the dominant component of the total energy density of our Universe. The primary interaction of dark energy with the rest of the Universe is gravitational. It is therefore important to understand the gravitational dynamics of dark energy. Since dark energy is a low-energy phenomenon from the perspective of particle physics and field theory, a fundamental approach based on fields in curved space should be sufficient to understand the current dynamics of dark energy. Here, we take a field theory approach to dark energy. We discuss the evolution equations for a generic dark energy field in curved space-time and then discuss the gravitational collapse for dark energy field configurations. We describe the 3 + 1 BSSN formalism to study the gravitational collapse of fields for any general potential for the fields and apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting equations for the time evolution of field configurations and the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our Universe. We also demonstrate the black hole formation as a result of the gravitational collapse of the dark energy field configurations. The black holes produced by the collapse of dark energy fields are in the supermassive black hole category with the masses of these black holes being comparable to the masses of black holes at the centers of galaxies.

  9. Fueling moving ring field-reversed mirror reactor plasmas

    International Nuclear Information System (INIS)

    Felber, F.S.

    1980-01-01

    The concept of small fusion reactors is being studied jointly by Lawrence Livermore Laboratory General Atomic Company, and Pacific Gas and Electric Company. The objective is to investigate alternatives and then to develop a conceptual design for a small reactor that could produce useful, though not necessarily economical, energy by the late 1980s. Three methods of fueling a small moving ring field-reversed mirror are considered: injection of fuel pellets accelerated by laser ablation, injection of fuel pellets accelerated by deflagration-gun ablation, and direct injection of plasma by a deflagration gun. 13 refs

  10. Maintenance of a multi-cell field reversed mirror reactor

    International Nuclear Information System (INIS)

    Neef, W.S. Jr.

    1978-01-01

    The Field Reversed Mirror Reactor is composed of a horizontal linear chain of cells, each of which requires neutral beam injection. Blanket replacement is achieved by lifting one complete cell module from the reactor and replacing it with a preassembled and tested identical module. Ioffe bar connectors eliminate redundant bus bars. Asymmetric cell design simplifies magnet construction and reduces replacement time. A tapered cylindrical coolant distributor simplifies blanket removal. An evacuated housing surrounds the reactor reducing cell-to-cell sealing problems related to maintenance. Remote couplings are used for coolant and accessories. Hot-cell location and design permits immediate reconditioning or storage of replacement cells

  11. Classical transport in field reversed mirrors: reactor implications

    International Nuclear Information System (INIS)

    Auerbach, S.P.; Condit, W.C.

    1980-01-01

    Assuming that the field-reversed mirror (or the closely related spheromak) turns out to be stable, the next crucial issue is transport of particles and heat. Of particular concern is the field null on axis (the X-point), which at first glance seems to allow particles to flow out unhindered. We have evaluated the classical diffusion coefficients for particles and heat in field-reversed mirrors, with particular reference to a class of Hill's vortex models. Two fairly surprising results emerge from this study. First, the diffusion-driven flow of particles and heat is finite at the X-points. This may be traced to the geometrical constraint that the current (and hence the ion-electron drag force, which causes cross-field transport) must vanish on axis. This conclusion holds for any transport model. Second, the classical diffusion coefficient D(psi), which governs both particle and heat flux, is finite on the separatrix. Indeed, in a wide class of Hill's vortex equilibria (spherical, oblate, or prolate) D(psi) is essentially independent of psi (except for the usual factor of n

  12. Field-reversed mirror pilot reactor. Annual report

    International Nuclear Information System (INIS)

    Devoto, R.S.; Erickson, J.L.; Fink, J.H.

    1980-09-01

    This report concludes a two-year effort to design a near-term small-scale fusion power plant which, through its construction and operation, would be a direct and important step toward the commercialization of fusion energy. The fusion reactor pilot plant was designed under the ground rules that it must produce net power, be compact, have minimum total cost, and use near-term (late 1980's) engineering technology. The neutral beam driven, field-reversed mirror (FRM) was selected as the fusion plasma confinement concept around which the pilot plant was designed. Although the physics data base for this design is not yet well in hand, it is being pursued within the magnetic field-reversal framework of the US Mirror Fusion Program. Depending on the plasma size, the pilot plant would gross up to 19.8 MW(e) and would produce up to 10.7 MW(e) net, with the recirculated power used principally for the neutral beam injectors and refrigeration for the superconducting magnets

  13. Comparison of temperature calculations for an arbitrary high-level waste disposal configuration in salt formations

    International Nuclear Information System (INIS)

    Kevenaar, J.W.A.M.; Janssen, L.G.J.; Ploumen, P.; Winske, P.

    1979-05-01

    The objective of this report is the comparison of the results of temperature analyses for an arbitrary high-level radioactive waste disposal configuration in salt formations. The analyses were carried out at the RWTH and ECN. The computer programs used are based on finite difference and finite element techniques. From the local temperature analyses that were intended to check the solution techniques, it could be concluded that both finite difference and finite elements are capable to analyse this type of problems. From the global temperature analyses it could be concluded that both analysis approaches: temperature dependent and iteratively determined temperature independent material properties, are suited to analyse the global temperature distribution in the salt formation

  14. Variations of current profiles in tokamaks. Formation mechanism and confinement property of current-hole configuration

    International Nuclear Information System (INIS)

    Takizuka, Tomonori

    2003-01-01

    The formation mechanism of the current hole in tokamak plasmas is reviewed. Experimental results of JT-60U are shown. Increase of the off-central noninductive current is a key factor for the current-hole formation. The internal Transport Barrier (ITB), which generates large bootstrap current, plays an important role. The central current density in the hole stays nearly 0. The idea of a new equilibrium for a tokamak plasma with a current hole is introduced. This equilibrium configuration called Axisymmetric Tri-Magnetic-Islands (ATMI) equilibrium', has three islands along the R direction (a central-negative-current island and side-positive-current islands). The equilibrium is stable with the elongation coils when the current in the ATMI region is limited to a small amount. The confinement properties of a current-hole configuration with box-type ITB is described. A scaling of the core poloidal beta inside the ITB, β p,core , is given as ε f β p,core approx. = 1, which suggests the equilibrium limit (ε f : inverse aspect ratio at the ITB foot). Though the core stored energy is little dependent on the heating power, the estimated heat diffusivity in the ITB region moderately correlates with a neoclassical diffusivity. (author)

  15. Field reversal experiments: FRX-A and FRX-B results

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-01-01

    The equilibrium, stability, and confinement properties of the Field Reversed Configuration (FRC) are being studied in two theta pinch facilities referred to as FRX-A, and FRX-B. The configuration is a toroidal plasma confined in a purely poloidal field configuration containing both closed and open field lines. The FRX system produces highly elongated tori with major radius R=3 to 5 cm, minor radius a approx. 2 cm, and a full length l approx. 35 to 50 cm. Plasma conditions have ranged from T/sub e/ approx. 150 eV, T/sub i/ approx. 800 eV, and n/sub max/ approx. 10 15 /cm 3 to T/sub e/ approx. 100 eV, T/sub i/ approx. 150 eV, and n/sub max/ approx. 4 x 10 15 /cm 3 . The plasma remains in a stable equilibrium for up to 50 μs followed by an n = 2 rotational instability which results in termination of the FRC. The plasma behavior with respect to equilibrium, stability, and rotation is consistent with recent theoretical work in these areas

  16. Theoretical studies of field-reversed configurations (FRC) and experimental study of the FRC during translation

    International Nuclear Information System (INIS)

    Siemon, R.E.; Armstrong, W.T.; Chrien, R.E.

    1985-01-01

    Theoretical studies of FRC stability and transport are summarized. Finite Larmor radius theories are shown to be unreliable for explaining the experimentally observed stability to tilting. Control of the n=2 rotational instability has been demonstrated in two-dimensional hybrid code simulations, and the stability appears to be described within MHD if the nearly square equilibria that result from quadrupole fields are taken into account. Simulations of the lower hybrid drift instability in parameter regimes relevant to experiments show good agreement with a non-local theory of the instability. A 1.5-dimensional transport code shows agreement with the energy confinement time but disagreement with the flux loss time observed in FRX-C. The process of FRC translation in which the plasma is formed, translated into a DC solenoid and trapped by magnetic mirrors, has been studied in the FRX-C/T experiment. Efficient transfer of particles, energy and internal magnetic flux are observed with no enhancement of loss processes over in-situ FRC experiments. The axial velocity of the FRC can be estimated reasonably well with a simple model based on conservation of energy. Internal magnetic field probing during translation shows the expected structure of poloidal field and a complex distribution of generally weak toroidal fields. Measurements of radiated power indicate that radiation is a small fraction of the total plasma power loss (typically 8%). Translation has facilitated scaling studies of confinement over a wider range of parameters than were achieved by in-situ FRX-C experiments. For example, the variable xsub(s), the ratio of the separatrix radius to the metal wall radius, has been increased to about 0.7 by allowing the FRC to expand during translation. In all cases, particle confinement times agree within a factor of two with predictions by models that assume a lower hybrid drift resistivity. However, for the conditions studied there are indications that the experimental scaling departs in functional form from that predicted theoretically

  17. Study of the Synchronous Operation of an Annular Field Reversed Configuration Plasma Device

    Science.gov (United States)

    2008-05-05

    ondly, a gravity dump switch automatically (in the case of power failure) discharges the capacitors across a 5-kJ, 14 Ω electrolytic resistor network [2...bank discharge 31 Fiber Optic Trigger Module Main Discharge Coils Ignitron Electrolytic Dump Resistors Capacitor Bank Charging Supply Isolated DC...Additionally, the flange connects to a MKS Series 910 Dual Trans combination Micro Pirani/ Piezo Pressure Transducer that is accurate from 10−5 to 103 Torr

  18. Theoretical studies of field-reversed configurations (FRCs) and experimental study of the FRC during translation

    Energy Technology Data Exchange (ETDEWEB)

    Siemon, R.E.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Schwarzmeier, J.L.; Sgro, A.; Sherwood, E.G.

    1984-08-01

    Theoretical studies of FRC stability and tranport are summarized. Finite Larmor radius theories are shown to be unreliable for explaining the experimentally observed stability to tilting. Control of the n=2 rotational instability has been demonstrated in 2-dimensional hybrid-code simulations, and the stability appears to be described within MHD if the nearly square equilibria that result from quadrupole fields are taken into account. Simulations of the lower-hybrid-drift instability in parameter regimes relevant to experiments show good agreement with a nonlocal theory of the instability. A 1.5-dimensional transport code shows agreement with the energy confinement time but disagreement with the flux loss time observed in FRX-C. The process of FRC translation in which the plasma is formed, translated into a dc solenoid, and trapped by magnetic mirrors has been studied in the FRX-C/T experiment.

  19. Numerical Analysis of Neutral Entrainment Effect on Field-Reversed Configuration Thruster Efficiency

    Science.gov (United States)

    2014-12-01

    Δx < ζλe in order to avoid the finite grid instability. Here, ωpe is the electron plasma frequency, and λe is the electron Debye length . In an...Celeste3D results in highly efficient simulations based on ion length and timescales (and not electron scales as explicit methods do) while retaining

  20. Theoretical studies of field-reversed configurations (FRCs) and experimental study of the FRC during translation

    International Nuclear Information System (INIS)

    Siemon, R.E.; Armstrong, W.T.; Chrien, R.E.

    1984-08-01

    Theoretical studies of FRC stability and tranport are summarized. Finite Larmor radius theories are shown to be unreliable for explaining the experimentally observed stability to tilting. Control of the n=2 rotational instability has been demonstrated in 2-dimensional hybrid-code simulations, and the stability appears to be described within MHD if the nearly square equilibria that result from quadrupole fields are taken into account. Simulations of the lower-hybrid-drift instability in parameter regimes relevant to experiments show good agreement with a nonlocal theory of the instability. A 1.5-dimensional transport code shows agreement with the energy confinement time but disagreement with the flux loss time observed in FRX-C. The process of FRC translation in which the plasma is formed, translated into a dc solenoid, and trapped by magnetic mirrors has been studied in the FRX-C/T experiment

  1. Feasibility study of microwave electron heating on the C-2 field-reversed configuration device

    International Nuclear Information System (INIS)

    Yang, Xiaokang; Ceccherini, Francesco; Dettrick, Sean; Binderbauer, Michl; Koehn, Alf; Petrov, Yuri

    2015-01-01

    Different microwave heating scenarios for the C-2 plasmas have been investigated recently with use of both the Genray ray-racing code and the IPF-FDMC full-wave code, and the study was focused on the excitation of the electron Bernstein wave (EBW) with O-mode launch. For a given antenna position on C-2 and the fixed 2D plasma density and equilibrium field profiles, simulations have been done for six selected frequencies (2.45 GHz, 5 GHz, 8 GHz, 18 GHz, 28 GHz, and 50 GHz). Launch angles have been optimized for each case in order to achieve high coupling efficiencies to the EBW by the O-X-B mode conversion process and high power deposition. Results show that among those six frequencies, the case of 8 GHz is the most promising scenario, which has both high mode conversion efficiency (90%) and the relatively deeper power deposition

  2. Linear kinetic stability of a field-reversed configuration with two ion components

    International Nuclear Information System (INIS)

    Staudenmeier, J.L.; Barnes, D.C.; Lewis, H.R.

    1990-01-01

    It has been suggested that a small fraction of non-axis encircling high energy ions may be sufficient to stabilize the tilt mode in a large s FRC. Experimental alteration of the ion distribution function in this manner might be achieved by rf heating the tail of the distribution function or by neutral beam injection. A linear Vlasov-fluid eigenfunction-eigenfrequency approach was used to investigate possible stabilization of the tilt mode by a high energy component. The ion distribution function is modeled as the sum of two Maxwellians with separate temperatures and no ion flow velocity. The cold component has a thermal s = 7, where s is the approximate number of ion gyroradii contained between the field null and the separatrix. The temperature ratio of the hot component to the cold component (T H /T T ) was varied from 2 to 100. Global hot particle fractions (n H ) up to ∼ .5 were used in the computations

  3. Non-potential Field Formation in the X-shaped Quadrupole Magnetic Field Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Kawabata, Y.; Shimizu, T. [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Inoue, S., E-mail: kawabata.yusuke@ac.jaxa.jp [Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3 D-37077 Göttingen (Germany)

    2017-06-20

    Some types of solar flares are observed in X-shaped quadrupolar field configuration. To understand the magnetic energy storage in such a region, we studied non-potential field formation in an X-shaped quadrupolar field region formed in the active region NOAA 11967, which produced three X-shaped M-class flares on 2014 February 2. Nonlinear force-free field modeling was applied to a time series of vector magnetic field maps from the Solar Optical Telescope on board Hinode and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory . Our analysis of the temporal three-dimensional magnetic field evolution shows that the sufficient free energy had already been stored more than 10 hr before the occurrence of the first M-class flare and that the storage was observed in a localized region. In this localized region, quasi-separatrix layers (QSLs) started to develop gradually from 9 hr before the first M-class flare. One of the flare ribbons that appeared in the first M-class flare was co-spatial with the location of the QSLs, suggesting that the formation of the QSLs is important in the process of energy release. These QSLs do not appear in the potential field calculation, indicating that they were created by the non-potential field. The formation of the QSLs was associated with the transverse photospheric motion of the pre-emerged flux and the emergence of a new flux. This observation indicates that the occurrence of the flares requires the formation of QSLs in the non-potential field in which free magnetic energy is stored in advance.

  4. Moving ring field-reversed mirror blanket design considerations

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Cheng, E.T.; Creedon, L.; Kessel, C.; Norman, J.; Schultz, K.R.

    1981-01-01

    A blanket design for the Moving Ring Field-Reversed Mirror Reactor (MRFRM) is presented in this paper. The design emphasis is placed on minimizing the induced radioactivities in the first-wall, blanket and shield. To this end, aluminum-alloy was selected as the reference structural material, giving dose rates two weeks after shutdown that are 3 to 4 orders of magnitude lower than comparable steel structures. The aluminum first-wall is water-cooled and thermally insulated from the high temperature SiC-clad Li 2 O tritium breeding zone. A local tritium breeding ratio of 1.05 was obtained for the design. The tritium is extracted from the Li 2 O by the use of a small dry helium purge stream through the SiC tubes. About 1 ppM hydrogen is added to the helium purge stream to enhance the tritium recovery rate. Helium at 28 atmospheres pressure is circulated through the blanket and shield, with an outlet temperature of 850 0 C, which is coupled with an existing small size closed-cycle gas turbine (CCGT) power conversion system. The spatial and temporal variations of the first-wall temperature caused by the translational movement of the plasma rings along the axis of the cylindrical reactor were evaluated. The after-heat cooling problems of the first-wall were also considered

  5. Classical diffusion in a field-reversed mirror

    International Nuclear Information System (INIS)

    Auerbach, S.P.; Condit, W.C.

    1981-01-01

    Classical transport of particles and heat in field-reversed mirrors is discussed. The X-points (field nulls on axis) are shown to have no deleterious effect on transport; this conclusion is true for any transport model. For an elongated Hill's vortex equilibrium the classical diffusion coefficient is calculated analytically and used to construct an analytic solution to the transport equation for particles or energy; this yields exact results for particle and energy confinement times. These life-times are roughly 3 to 6 times shorter than previous heuristic estimates. Experimentally determined life-times are within a factor of 3 to 4 of our estimates. To assess the impact of these results on reactor designs, the authors construct an analytic reactor model in which neutral-beam input balances ion heat loss. Energy loss due to synchrotron radiation is calculated analytically and shown to be negligible, even with no wall reflection. Formulas are presented which give the reactor parameters in terms of plasma temperature, energy multiplication factor Q, and allowed neutron wall loading. The effect of anomalous resistivity is incorporated heuristically by assuming an anomalous resistivity which is enhanced by a factor A over classical resistivity. For large A the minimum power of a reactor scales as Asup(11/6). A=50 gives a reactor design which still seems reasonable, but A=200 leads to extremely large, high-power reactors. (author)

  6. Transport and equilibrium in field-reversed mirrors

    International Nuclear Information System (INIS)

    Boyd, J.K.

    1982-09-01

    Two plasma models relevant to compact torus research have been developed to study transport and equilibrium in field reversed mirrors. In the first model for small Larmor radius and large collision frequency, the plasma is described as an adiabatic hydromagnetic fluid. In the second model for large Larmor radius and small collision frequency, a kinetic theory description has been developed. Various aspects of the two models have been studied in five computer codes ADB, AV, NEO, OHK, RES. The ADB code computes two dimensional equilibrium and one dimensional transport in a flux coordinate. The AV code calculates orbit average integrals in a harmonic oscillator potential. The NEO code follows particle trajectories in a Hill's vortex magnetic field to study stochasticity, invariants of the motion, and orbit average formulas. The OHK code displays analytic psi(r), B/sub Z/(r), phi(r), E/sub r/(r) formulas developed for the kinetic theory description. The RES code calculates resonance curves to consider overlap regions relevant to stochastic orbit behavior

  7. Study of fusion product effects in field-reversed mirrors

    International Nuclear Information System (INIS)

    Driemeyer, D.E.

    1980-01-01

    The effect of fusion products (fps) on Field-Reversed Mirror (FRM) reactor concepts has been evaluated through the development of two new computer models. The first code (MCFRM) treats fps as test particles in a fixed background plasma, which is represented as a fluid. MCFRM includes a Monte Carlo treatment of Coulomb scattering and thus provides an accurate treatment of fp behavior even at lower energies where pitch-angle scattering becomes important. The second code (FRMOD) is a steady-state, globally averaged, two-fluid (ion and electron), point model of the FRM plasma that incorporates fp heating and ash buildup values which are consistent with the MCFRM calculations. These codes have been used extensively in the development of an advanced-fuel FRM reactor design (SAFFIRE). A Catalyzed-D version of the plant is also discussed along with an investigation of the steady-state energy distribution of fps in the FRM. User guides for the two computer codes are also included

  8. Zero field reversal probability in thermally assisted magnetization reversal

    Science.gov (United States)

    Prasetya, E. B.; Utari; Purnama, B.

    2017-11-01

    This paper discussed about zero field reversal probability in thermally assisted magnetization reversal (TAMR). Appearance of reversal probability in zero field investigated through micromagnetic simulation by solving stochastic Landau-Lifshitz-Gibert (LLG). The perpendicularly anisotropy magnetic dot of 50×50×20 nm3 is considered as single cell magnetic storage of magnetic random acces memory (MRAM). Thermally assisted magnetization reversal was performed by cooling writing process from near/almost Curie point to room temperature on 20 times runs for different randomly magnetized state. The results show that the probability reversal under zero magnetic field decreased with the increase of the energy barrier. The zero-field probability switching of 55% attained for energy barrier of 60 k B T and the reversal probability become zero noted at energy barrier of 2348 k B T. The higest zero-field switching probability of 55% attained for energy barrier of 60 k B T which corespond to magnetif field of 150 Oe for switching.

  9. 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)

  10. Tensor representation techniques for full configuration interaction: A Fock space approach using the canonical product format.

    Science.gov (United States)

    Böhm, Karl-Heinz; Auer, Alexander A; Espig, Mike

    2016-06-28

    In this proof-of-principle study, we apply tensor decomposition techniques to the Full Configuration Interaction (FCI) wavefunction in order to approximate the wavefunction parameters efficiently and to reduce the overall computational effort. For this purpose, the wavefunction ansatz is formulated in an occupation number vector representation that ensures antisymmetry. If the canonical product format tensor decomposition is then applied, the Hamiltonian and the wavefunction can be cast into a multilinear product form. As a consequence, the number of wavefunction parameters does not scale to the power of the number of particles (or orbitals) but depends on the rank of the approximation and linearly on the number of particles. The degree of approximation can be controlled by a single threshold for the rank reduction procedure required in the algorithm. We demonstrate that using this approximation, the FCI Hamiltonian matrix can be stored with N(5) scaling. The error of the approximation that is introduced is below Millihartree for a threshold of ϵ = 10(-4) and no convergence problems are observed solving the FCI equations iteratively in the new format. While promising conceptually, all effort of the algorithm is shifted to the required rank reduction procedure after the contraction of the Hamiltonian with the coefficient tensor. At the current state, this crucial step is the bottleneck of our approach and even for an optimistic estimate, the algorithm scales beyond N(10) and future work has to be directed towards reduction-free algorithms.

  11. Adiabatic, chaotic and quasi-adiabatic charged particle motion in two-dimensional magnetic field reversals

    International Nuclear Information System (INIS)

    Buechner, J.M.

    1989-01-01

    For a number of problems in the Plasma Astrophysics it is necessary to know the laws, which govern the non adiabatic charged particle dynamics in strongly curves magnetic field reversals. These are, e.q., the kinetic theory of the microscopic and macroscopicstability of current sheets in collionless plasma, of microturbulence, causing anomalous resistivity and dissipating currents, the problem of spontaneous reconnection, the formation of non Maxwellian distribution functions, particle acceleration and the use of particles as a diagnostic tool ('tracers'). To find such laws we derived from the differential equations of motion discrete mappings. These mappings allow an investigation of the motion after the break down of the adiabaticity of the magnetic moment. (author). 32 refs.; 5 figs.; 1 tab

  12. Internal hydraulic control in the Little Belt, Denmark - observations of flow configurations and water mass formation

    Science.gov (United States)

    Holtegaard Nielsen, Morten; Vang, Torben; Chresten Lund-Hansen, Lars

    2017-12-01

    Internal hydraulic control, which occurs when stratified water masses are forced through an abrupt constriction, plays an enormous role in nature on both large and regional scales with respect to dynamics, circulation, and water mass formation. Despite a growing literature on this subject surprisingly few direct observations have been made that conclusively show the existence of and the circumstances related to internal hydraulic control in nature. In this study we present observations from the Little Belt, Denmark, one of three narrow straits connecting the Baltic Sea and the North Sea. The observations (comprised primarily of along-strait, detailed transects of salinity and temperature; continuous observations of flow velocity, salinity, and temperature at a permanent station; and numerous vertical profiles of salinity, temperature, fluorescence, and flow velocity in various locations) show that internal hydraulic control is a frequently occurring phenomenon in the Little Belt. The observations, which are limited to south-going flows of approximately two-layered water masses, show that internal hydraulic control may take either of two configurations, i.e. the lower or the upper layer being the active, accelerating one. This is connected to the depth of the pycnocline on the upstream side and the topography, which is both deepening and contracting toward the narrow part of the Little Belt. The existence of two possible flow configurations is known from theoretical and laboratory studies, but we believe that this has never been observed in nature and reported before. The water masses formed by the intense mixing, which is tightly connected with the presence of control, may be found far downstream of the point of control. The observations show that these particular water masses are associated with chlorophyll concentrations that are considerably higher than in adjacent water masses, showing that control has a considerable influence on the primary production and

  13. Formation of a compact torus by a rotating relativistic electron beam

    International Nuclear Information System (INIS)

    Jain, K.K.; John, P.I.

    1986-01-01

    A closed field-reversed configuration has been produced by a long pulse duration (roughly-equal 500 nsec) intense electron beam injected into hydrogen gas. The field reversal is created by the beam current during the duration of beam propagation, but is sustained by the beam-induced plasma currents after the exit of the beam. Reconnection of the antiparallel field lines has been observed, which results in formation of a prolate spheroid. The axial extent of the spheroid is 80.0 cm. It contracts immediately after its formation with the supersonic velocity. Attempts were made to close axial currents along the closed poloidal field lines

  14. Non ideal instabilities in field reversed O-pinches

    International Nuclear Information System (INIS)

    Santiago, M.A.M.; Gomes, A.S.

    1987-01-01

    Rotational instabilities and resistive tearing modes are the most striking modes observed in high temperature θ-pinches with zero orversed bias field. The configurations which have the effect of a rigid rotation of the plasma column are studied. Some recent experimental data indicate that an m=2 mode appears after the rotation reaches a critical value. It is shown that the growth rate of the m=2 mode may be greater than that of the m=1 resistive kink mode, depending on the experimental conditions. The result are applied to several experimental data in the literature. (author) [pt

  15. Suitable configurations for triangular formation flying about collinear libration points under the circular and elliptic restricted three-body problems

    Science.gov (United States)

    Ferrari, Fabio; Lavagna, Michèle

    2018-06-01

    The design of formations of spacecraft in a three-body environment represents one of the most promising challenges for future space missions. Two or more cooperating spacecraft can greatly answer some very complex mission goals, not achievable by a single spacecraft. The dynamical properties of a low acceleration environment such as the vicinity of libration points associated to a three-body system, can be effectively exploited to design spacecraft configurations able of satisfying tight relative position and velocity requirements. This work studies the evolution of an uncontrolled formation orbiting in the proximity of periodic orbits about collinear libration points under the Circular and Elliptic Restricted Three-Body Problems. A three spacecraft triangularly-shaped formation is assumed as a representative geometry to be investigated. The study identifies initial configurations that provide good performance in terms of formation keeping, and investigates key parameters that control the relative dynamics between the spacecraft within the three-body system. Formation keeping performance is quantified by monitoring shape and size changes of the triangular formation. The analysis has been performed under five degrees of freedom to define the geometry, the orientation and the location of the triangle in the synodic rotating frame.

  16. Field-reversal experiments in the mirror fusion test facility (MFTF)

    International Nuclear Information System (INIS)

    Shearer, J.W.; Condit, W.C.

    1977-01-01

    Detailed consideration of several aspects of a field-reversal experiment was begun in the Mirror Fusion Test Facility (MFTF): Model calculations have provided some plausible parameters for a field-reversed deuterium plasma in the MFTF, and a buildup calculation indicates that the MFTF neutral-beam system is marginally sufficient to achieve field reversal by neutral injection alone. However, the many uncertainties indicate the need for further research and development on alternate buildup methods. A discussion of experimental objectives is presented and important diagnostics are listed. The range of parameter space accessible with the MFTF magnet design is explored, and we find that with proper aiming of the neutral beams, meaningful experiments can be performed to advance toward these objectives. Finally, it is pointed out that if we achieve enhanced n tau confinement by means of field reversal, then quasi-steady-state operation of MFTF is conceivable

  17. Controlled alpha-sexithiophene nanostructure formation in standard and inverted configuration organic solar cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Goszczak, Arkadiusz Jaroslaw; Fernandes Cauduro, André Luis

    -type domains in the active organic layer. The molecular packing in these is of same importance, as it strongly affects the carrier transport in the cells. In this work, we present the study of alpha-sexithiophene (α 6T) temperature dependent growth for standard, on gold anodes, and inverted, on electron...... accepting C60 layers, solar cell configurations. Furthermore, a comparative study of the correlation between the α-6T morphology and device performance parameters for standard and inverted solar cell configurations is presented. The morphology of the α 6T layer is controlled by means of the substrate...

  18. Configurational Reassignment and Improved Preparation of the Competitive IL-6 Receptor Antagonist 20R,21R-Epoxyresibufogenin-3-formate

    Science.gov (United States)

    Boos, Terrence L.; Cheng, Kejun; Greiner, Elisabeth; Deschamps, Jeffrey R.; Jacobson, Arthur E.; Rice, Kenner C.

    2012-01-01

    20R,21R-Epoxyresibufogenin-3-formate (1) and 20S,21S-epoxyresibufogenin-3-formate (2) were synthesized from commercial resibufogenin (3) using known procedures. The major product (1) was dextrorotatory, as was the major product from the reported synthesis of epoxyresibufogenin-3-formate; however, the literature (+)-compound was assigned the 20S,21S-configuration based on NMR data. We have now unequivocally determined, using single-crystal X-ray structure analyses of the major and minor products of the synthesis and of their derivatives, that the major product from the synthesis was (+)-20R,21R-epoxyresibufogenin-3-formate (1). Our minor synthetic product was determined to have the (-)-20S,21S-configuration (2). The (+)-20R,21R-compound 1 has been found to have high affinity for the IL-6 receptor and to act as an IL-6 antagonist. A greatly improved synthesis of 1 was achieved through oxidation of preformed resibufogenin-3-formate. This has enabled us to prepare, from the very expensive commercial resibufogenin, considerably larger quantities of 1, the only known non-peptide small molecule IL-6 antagonist. PMID:22360661

  19. Field reversal experiments (FRX). [Equilibrium, confinement, and stability

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10/sup 15/ cm/sup -3/. After the plasma reaches equilibrium, the RFC remains stable for up to 30 ..mu..s followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value.

  20. Field reversing magnetotail current sheets: earth, Venus, and Comet Giacobini-Zinner

    International Nuclear Information System (INIS)

    McComas, D.J.

    1986-09-01

    This dissertation examines the field reversing magnetotail current sheets at the earth, Venus, and Comet Giacobini-Zinner. In the near earth study a new analysis technique is developed to calculate the detailed current density distributions within the cross tail current sheet for the first time. This technique removes the effects of a variable sheet velocity by inverting intersatellite timings between the co-orbiting satellites ISEE-1 and -2. Case studies of three relatively geomagnetically quiet crossings are made; sheet thicknesses and peak current densities are ∼1-5 x 10 4 km and ∼5-50 nA/m 2 . Current density distributions reveal a high density central region, lower density shoulders, and considerable fine structure throughout. In the Venus study another new analysis technique is developed to reconstruct the average tail configuration from a correlation between field magnitude and draping angle in a large statistical data set. In the comet study, high resolution magnetic field and plasma electron data from the ICE traversal of Giacobini-Zinner are combined for the first time to determine the tail/current sheet geometry and calculate certain important but unmeasured local ion and upstream properties. Pressure balance across the tail gives ion temperatures and betas of ∼1.2 x 10 5 K and ∼40 in the center of the current sheet to ∼1 x 10 6 K and ∼3 in the outer lobes. Axial stress balance shows that the velocity shear upstream near the nucleus is >6 (∼1 at ICE), and that a region of strongly enhanced mass loading (ion source rate ∼24 times that upstream from lobes) exists upstream from the current sheet. The integrated downtail mass flux is ∼2.6 x 10 26 H 2 O+/sec, which is only ∼1% of the independently determined total cometary efflux. 79 refs., 37 figs

  1. Compact-Toroid Fusion Reactor (CTOR) based on the Field-Reversed Theta Pinch

    International Nuclear Information System (INIS)

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

    1981-01-01

    Scoping studies of a translating Compact Torus Reactor (CTOR) have been made on the basis of a dynamic plasma model and an overall systems approach. This CTOR embodiment uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plamoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radition shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15

  2. Compact-Toroid fusion reactor based on the field-reversed theta pinch

    International Nuclear Information System (INIS)

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

    1981-03-01

    Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CTOR) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radiation shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15

  3. Production of field-reversed plasma with a magnetized coaxial plasma gun

    International Nuclear Information System (INIS)

    Turner, W.C.; Granneman, E.H.A.; Hartman, C.W.; Prono, D.S.; Taska, J.; Smith, A.C. Jr.

    1981-01-01

    Experimental data are presented on the production of field-reversed deuterium plasma by a modified coaxial plasma gun. The coaxial gun is constructed with solenoid coils along the inner and outer electrodes that, together with an external guide field solenoid, form a magnetic cusp at the gun muzzle. The net flux inside the inner electrode is arranged to be opposite the external guide field and is the source of field-reversed flux trapped by the plasma. The electrode length is 145 cm, the diameter of the inner (outer) electrode is 15 cm (32 cm). The gun discharge is driven with a 232-μF 40-kV capacitor bank. Acceleration of plasma through the magnetic cusp at the gun muzzle results in entrainment of field-reversed flux that is detected by magnetic probes 75 cm from the gun muzzle. Field-reversed plasma has been produced for a variety of experimental conditions. In one typical case, the guide magnetic field was B 0 =4.8 kG and the change in axial magnetic field ΔB/sub z/ normalized to B 0 was ΔB/sub z/ /B 0 =-3.1. Total field-reversed flux (poloidal flux) obtained by integrating ΔB/sub z/ profiles is in the range 2 x 10 3 kG cm 2 . Measurement of the orthogonal field component indicates a sizable toroidal field peaked off axis at rapprox. =10 cm with a magnitude of roughly one-half the poloidal field component that is measured on magnetic axis. Reconnection of the poloidal field lines has not been established for the data reported in the paper and will be addressed in future experiments which attempt to trap and confine the field-reversed plasma in a magnetic mirror

  4. The Formation of Opportunity Feasibility Beliefs in Social Entrepreneurship: A Configurational Analysis of Institutional Conditions

    OpenAIRE

    Munoz, P; Kibler, E

    2013-01-01

    This paper deals with the impact of local institutional conditions on the formation of opportunity feasibility beliefs in social entrepreneurship. Embedded in the recent literature on entrepreneurial cognitions, institutions and social entrepreneurship, this study provides a systematic analysis of 776 social entrepreneurs in the UK to identify combinations of causal institutional conditions that collectively explain how early-stage social entrepreneurs form beliefs of feasibility regarding th...

  5. Effect of junction configurations on microdroplet formation in a T-junction microchannel

    Science.gov (United States)

    Lih, F. L.; Miao, J. M.

    2015-03-01

    This study investigates the dynamic formation process of water microdroplets in a silicon oil flow in a T-junction microchannel. Segmented water microdroplets are formed at the junction when the water flow is perpendicularly injected into the silicon oil flow in a straight rectangular microchannel. This study further presents the effects of the water flow inlet geometry on hydrodynamic characteristics of water microdroplet formation. A numerical multiphase volume of fluid (VOF) scheme is coupled to solve the unsteady three-dimensional laminar Navier-Stokes equations to depict the droplet formation phenomena at the junction. Predicted results on the length and generated frequency of the microdroplets agree well with experimental results in a T-junction microchannel with straight and flat inlets (the base model) for both fluid flows. Empirical correlations are reported between the volumetric flow ratio and the dimensionless microdroplet length or dimensionless frequency of droplet generation at a fixed capillary number of 4.7 · 10-3. The results of this study indicate a reduction in the droplet length of approximately 21% if the straight inlet for the water flow is modified to a downstream sudden contraction inlet for the water flow.

  6. Formation of magnetic islands due to field perturbations in toroidal stellarator configurations

    International Nuclear Information System (INIS)

    Lee, D.K.; Harris, J.H.; Lee, G.S.

    1990-06-01

    An explicit formulation is developed to determine the width of a magnetic island separatrix generated by magnetic field perturbations in a general toroidal stellarator geometry. A conventional method is employed to recast the analysis in a magnetic flux coordinate system without using any simplifying approximations. The island width is seen to be proportional to the square root of the Fourier harmonic of B ρ /B ζ that is in resonance with the rational value of the rotational transform, where B ρ and B ζ are contravariant normal and toroidal components of the perturbed magnetic field, respectively. The procedure, which is based on a representation of three-dimensional flux surfaces by double Fourier series, allows rapid and fairly accurate calculation of the island widths in real vacuum field configurations, without the need to follow field lines through numerical integration of the field line equations. Numerical results of the island width obtained in the flux coordinate representation for the Advanced Toroidal Facility agree closely with those determined from Poincare puncture points obtained by following field lines. 22 refs., 5 tabs

  7. Torus C-I field reversed theta-pinch at UNICAMP

    International Nuclear Information System (INIS)

    Machida, M.; Collares, M.P.; Honda, R.Y.; Sakanaka, P.H.; Scheid, V.H.B.

    1984-01-01

    The influence of multipole fields (octopole and quadrupole) on supressing the n=2 rotational instability, field reconnection, particle loss effects is studied, and the viability of transforming the theta-pinch from Campinas, Brazil (100Kv, 55Kj) to the field reversed theta-pinch with plasma translation program is analyzed. (E.G.) [pt

  8. Use of coaxial plasma guns to start up field-reversed-mirror reactors

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Carlson, G.A.; Eddleman, J.L.; Hartman, C.W.; Neef, W.S. Jr.

    1980-01-01

    Application of a magnetized coaxial plasma gun for start-up of a field-reversed-mirror reactor is considered. The design is based on preliminary scaling laws and is compared to the design of the start-up gun used in the Beta II experiment

  9. The effect of quadrupole fields on particle confinement in a field-reversed mirror

    International Nuclear Information System (INIS)

    McColl, D.B.; Berk, H.L.; Hammer, J.; Morse, E.C.

    1982-01-01

    A particle simulation code has been modified to simulate particle loss caused by quadrupole magnetic fields on a field-reversed mirror plasma device. Since analytic fields are chosen for the equilibrium, the numerical algorithm is highly accurate for long-time integrations of particle orbits. The resultant particle loss due to the quadrupole fields can be competitive with collisional loss in the device

  10. Table-driven configuration and formatting of telemetry data in the Deep Space Network

    Science.gov (United States)

    Manning, Evan

    1994-01-01

    With a restructured software architecture for telemetry system control and data processing, the NASA/Deep Space Network (DSN) has substantially improved its ability to accommodate a wide variety of spacecraft in an era of 'better, faster, cheaper'. In the new architecture, the permanent software implements all capabilities needed by any system user, and text tables specify how these capabilities are to be used for each spacecraft. Most changes can now be made rapidly, outside of the traditional software development cycle. The system can be updated to support a new spacecraft through table changes rather than software changes, reducing the implementation, test, and delivery cycle for such a change from three months to three weeks. The mechanical separation of the text table files from the program software, with tables only loaded into memory when that mission is being supported, dramatically reduces the level of regression testing required. The format of each table is a different compromise between ease of human interpretation, efficiency of computer interpretation, and flexibility.

  11. Numerical studies of the formation and destruction of vortices in a motored four-stroke piston-cylinder configuration

    Science.gov (United States)

    Schock, H. J.; Sosoka, D. J.; Ramos, J. I.

    1983-01-01

    A finite-difference procedure which solves the conservation equations of mass, momentum, and energy is used to investigate the effects of the compression ratio, engine speed, bore-to-stroke ratio, and air intake flow angle on the turbulent flow field within an axisymmetric piston-cylinder configuration. It is shown that in a four-stroke piston-cylinder configuration, the intake stroke is characterized by the formation of a piston vortex. The piston vortex is stretched during the intake stroke, and the head vortex has an almost constant diameter. For a 0-deg air intake flow angle, both vortices disappear by the end of the compression stroke; for an air intake flow angle of 45 deg, the flow field within the cylinder shows three elongated vortices which persist into the compression stroke and then break up and merge. It is also shown that larger bore-to-stroke ratios give rise to lower turbulent levels than smaller bore-to-stroke ratios and that the turbulent intensity is almost independent of the rpm.

  12. Studies of the formation of field reversed plasma by a magnetized co-axial plasma gun

    International Nuclear Information System (INIS)

    Turner, W.C.; Granneman, E.H.A.; Hartman, C.W.; Prono, D.S.; Taska, J.; Smith, A.C. Jr.

    1980-01-01

    The gun injects axially into a drift tank followed by a magnetic mirror. For the experiments reported here, only the guide coils outside the vacuum vessel and solenoids on the plasma gun electrodes were used; the mirror coil was not energized. A stainless steel flux conserver is placed in the mirror throat to prevent the plasma from contacting the nonconducting vacuum wall in the region of the mirror. An axis encircling array of magnetic loop probes includes four diamagnetic loops and a loop which measures the azimuthally averaged outward pointing radial component of magnetic field. These loop probes are stainless steel jacketed and form a flux conserving boundary (at a radius = 30 cm) for plasma emitted from the gun. A five tip probe that can be positioned anywhere along the axis of the experiment is used to measure internal components of magnetic field

  13. Heating of field-reversed plasma rings estimated with two scaling models

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, J.W.

    1978-05-18

    Scaling calculations are presented of the one temperature heating of a field-reversed plasma ring. Two sharp-boundary models of the ring are considered: the long thin approximation and a pinch model. Isobaric, adiabatic, and isovolumetric cases are considered, corresponding to various ways of heating the plasma in a real experiment by using neutral beams, or by raising the magnetic field. It is found that the shape of the plasma changes markedly with heating. The least sensitive shape change (as a function of temperature) is found for the isovolumetric heating case, which can be achieved by combining neutral beam heating with compression. The complications introduced by this heating problem suggest that it is desirable, if possible, to create a field reversed ring which is already quite hot, rather than cold.

  14. Reassessment of the requirements to obtain field reversal in mirror machines

    International Nuclear Information System (INIS)

    Baldwin, D.E.; Fowler, T.K.

    1977-01-01

    Requirements to obtain field reversal by neutral injection are re-examined to take account of a cancellation of currents at a field null caused by electron-ion collisions that drag the electrons along with the moving ions. We find that for cases of interest even a small admixture of higher-Z ions generates a residual current (the Ohkawa current) that is sufficient to maintain field reversal in steady state with a lifetime comparable to the usual magnetic diffusion time. An approximate prescription is given for buildup to such a state; namely, the neutral injection current must be sufficient to reduce the field to zero on axis with open confinement for an initial plasma radius of r 1 = 4r/sub Li/, where r/sub Li/ is the ion Larmor radius in the vacuum field. Again high-Z ions are needed to bring about the transition to a field-reversed state, r 1 = 4r/sub Li/ being the initial radius that minimizes the injection current needed to do this for a reasonable high-Z ion content (10% helium, or less of a higher-Z gas). Since 4r/sub Li/ is about 2 times the radius in past 2XIIB experiments, it is concluded that either the injection current or the energy confinement time must be substantially increased, by about a factor of 3, if field reversal is to be achieved in 2XIIB. Auxiliary injection by pulsed ion sources or plasma guns might reduce the current requirements significantly if 6 kilojoules of energy could be deposited in the plasma

  15. Production of field-reversed mirror plasma with a coaxial plasma gun

    Science.gov (United States)

    Hartman, C.W.; Shearer, J.W.

    The use of a coaxial plasma gun to produce a plasma ring which is directed into a magnetic field so as to form a field-reversed plasma confined in a magnetic mirror. Plasma thus produced may be used as a target for subsequent neutral beam injection or other similarly produced and projected plasma rings or for direct fusion energy release in a pulsed mode.

  16. Possible relationship between the Earth's rotation variations and geomagnetic field reversals over the past 510 Myr

    OpenAIRE

    Pacca, Igor G.; Frigo, Everton; Hartmann, Gelvam A.

    2015-01-01

    The Earth's rotation can change as a result of several internal and external processes, each of which is at a different timescale. Here, we present some possible connections between the Earth's rotation variations and the geomagnetic reversal frequency rates over the past 120 Myr. In addition, we show the possible relationship between the geomagnetic field reversal frequency and the δ18O oscillations. Because the latter reflects the glacial and interglacial periods, we hypothesize that it can...

  17. Production of field-reversed mirror plasma with a coaxial plasma gun

    International Nuclear Information System (INIS)

    Hartman, C.W.; Shearer, J.W.

    1982-01-01

    The use of a coaxial plasma gun to produce a plasma ring which is directed into a magnetic field so as to form a field-reversed plasma confined in a magnetic mirror. Plasma thus produced may be used as a target for subsequent neutral beam injection or other similarly produced and projected plasma rings or for direct fusion energy release in a pulsed mode

  18. Kink stability of a field-reversed ion layer in a background plasma

    International Nuclear Information System (INIS)

    Ishida, A.; Sudan, R.N.; Rosenbluth, M.N.; Engquist, M.G.

    1986-01-01

    By means of the two-fluid energy principle, the kink stability boundary of a field-reversed ion layer of arbitrary thickness immersed in a dense low-temperature background plasma is investigated theoretically. This system is found to have a stability window against kinks. The dependence of the kink stability regime on the equilibrium properties of the system is also shown. In the thin layer limit, a comparison is made between the previous theories and the present theory

  19. PIC simulations of post-pulse field reversal and secondary ionization in nanosecond argon discharges

    Science.gov (United States)

    Kim, H. Y.; Gołkowski, M.; Gołkowski, C.; Stoltz, P.; Cohen, M. B.; Walker, M.

    2018-05-01

    Post-pulse electric field reversal and secondary ionization are investigated with a full kinetic treatment in argon discharges between planar electrodes on nanosecond time scales. The secondary ionization, which occurs at the falling edge of the voltage pulse, is induced by charge separation in the bulk plasma region. This process is driven by a reverse in the electric field from the cathode sheath to the formerly driven anode. Under the influence of the reverse electric field, electrons in the bulk plasma and sheath regions are accelerated toward the cathode. The electron movement manifests itself as a strong electron current generating high electron energies with significant electron dissipated power. Accelerated electrons collide with Ar molecules and an increased ionization rate is achieved even though the driving voltage is no longer applied. With this secondary ionization, in a single pulse (SP), the maximum electron density achieved is 1.5 times higher and takes a shorter time to reach using 1 kV 2 ns pulse as compared to a 1 kV direct current voltage at 1 Torr. A bipolar dual pulse excitation can increase maximum density another 50%–70% above a SP excitation and in half the time of RF sinusoidal excitation of the same period. The first field reversal is most prominent but subsequent field reversals also occur and correspond to electron temperature increases. Targeted pulse designs can be used to condition plasma density as required for fast discharge applications.

  20. Improved density profile measurements in the C-2U advanced beam-driven Field-Reversed Configuration (FRC) plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Beall, M., E-mail: mbeall@trialphaenergy.com; Deng, B. H.; Gota, H. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2016-11-15

    In the prior C-2 experiment, electron density was measured using a two-color 6-chord CO{sub 2}/HeNe interferometer. Analysis shows that high-frequency common mode phase noise can be reduced by a factor of 3 by constructing a reference chord. In the system upgrade from C-2 to C-2U a 4-chord far-infrared laser interferometer was developed, which demonstrated superior sensitivity (1 × 10{sup 16} m{sup −2} at >1 MHz bandwidth) and solved the under spatial sampling issue of the C-2 interferometer system. Improved density-profile measurement results are presented in this paper, including evidence of fast-ion modified density profile and stabilization of the n = 1 plasma wobble mode.

  1. Self-stabilized discharge filament in plane-parallel barrier discharge configuration: formation, breakdown mechanism, and memory effects

    Science.gov (United States)

    Tschiersch, R.; Nemschokmichal, S.; Bogaczyk, M.; Meichsner, J.

    2017-10-01

    Single self-stabilized discharge filaments were investigated in the plane-parallel electrode configuration. The barrier discharge was operated inside a gap of 3 mm shielded by glass plates to both electrodes, using helium-nitrogen mixtures and a square-wave feeding voltage at a frequency of 2 kHz. The combined application of electrical measurements, ICCD camera imaging, optical emission spectroscopy and surface charge diagnostics via the electro-optic Pockels effect allowed the correlation of the discharge development in the volume and on the dielectric surfaces. The formation criteria and existence regimes were found by systematic variation of the nitrogen admixture to helium, the total pressure and the feeding voltage amplitude. Single self-stabilized discharge filaments can be operated over a wide parameter range, foremost, by significant reduction of the voltage amplitude after the operation in the microdischarge regime. Here, the outstanding importance of the surface charge memory effect on the long-term stability was pointed out by the recalculated spatio-temporally resolved gap voltage. The optical emission revealed discharge characteristics that are partially reminiscent of both the glow-like barrier discharge and the microdischarge regime, such as a Townsend pre-phase, a fast cathode-directed ionization front during the breakdown and radially propagating surface discharges during the afterglow.

  2. Velocity-space particle loss in field-reversed theta pinches

    International Nuclear Information System (INIS)

    Hsiao, M.Y.

    1983-01-01

    A field-reversed theta pinch (FRTP) is a compact device for magnetic fusion. It has attracted much attention in recent years since encouraging experimental results have been obtained. However, the definite causes for the observed particle loss rate and plasma rotation are not well known. In this work, we study the velocity-space particle loss (VSPL), i.e., particle loss due to the existence of a loss region in velocity space, in FRTP's in order to have a better understanding about the characteristics of this device

  3. Pioneer 7 observations of plasma flow and field reversal regions in the distant geomagnetic tail

    International Nuclear Information System (INIS)

    Walker, R.C.; Villante, U.; Lazarus, A.J.

    1975-01-01

    We present the results of an extensive analysis of plasma and magnetic field data from Pioneer 7 taken in the geomagnetic tail approximately 1000 R/sub E/ downstream from earth. The principal observations are (1) measurable fluxes of protons in the tail, flowing away from earth, sometimes with a double-peaked velocity distribution; (2) field reversal regions in which the field changes from radial to antiradial by a vector rotation in the north-south plane; and (3) general characteristics of the tail similar to those observed near earth with good correlation between taillike magnetic fields and plasma

  4. Pioneer 7 observations of plasma flow and field reversal regions in the distant geomagnetic tail

    Science.gov (United States)

    Walker, R. C.; Lazarus, A. J.; Villante, U.

    1975-01-01

    The present paper gives the results of an extensive analysis of plasma and magnetic-field data from Pioneer 7 taken in the geomagnetic tail approximately 1000 earth radii downstream from earth. The principal observations are: (1) measurable fluxes of protons in the tail, flowing away from earth, sometimes with a double-peaked velocity distribution; (2) field reversal regions in which the field changes from radial to antiradial by a vector rotation in the north-south plane; and (3) general characteristics of the tail similar to those observed near earth with good correlation between taillike magnetic fields and plasma.

  5. A bi-stable SOC model for Earth's magnetic field reversals

    International Nuclear Information System (INIS)

    Papa, A.R.R.; Espírito Santo, M.A. do; Barbosa, C.S.; Oliva, D.

    2013-01-01

    We introduce a simple model for Earth's magnetic field reversals. The model consists in random nodes simulating vortices in the liquid core which through a simple updating algorithm converge to a self-organized critical state, with inter-reversal time probability distributions functions in the form of power-laws for long persistence times (as supposed to be in actual reversals). A detailed description of reversals should not be expected. However, we hope to reach a profounder knowledge on reversals through some of the basic characteristic that are well reproduced. The work opens several future research trends.

  6. Particle-in-cell simulations of Earth-like magnetosphere during a magnetic field reversal

    Science.gov (United States)

    Barbosa, M. V. G.; Alves, M. V.; Vieira, L. E. A.; Schmitz, R. G.

    2017-12-01

    The geologic record shows that hundreds of pole reversals have occurred throughout Earth's history. The mean interval between the poles reversals is roughly 200 to 300 thousand years and the last reversal occurred around 780 thousand years ago. Pole reversal is a slow process, during which the strength of the magnetic field decreases, become more complex, with the appearance of more than two poles for some time and then the field strength increases, changing polarity. Along the process, the magnetic field configuration changes, leaving the Earth-like planet vulnerable to the harmful effects of the Sun. Understanding what happens with the magnetosphere during these pole reversals is an open topic of investigation. Only recently PIC codes are used to modeling magnetospheres. Here we use the particle code iPIC3D [Markidis et al, Mathematics and Computers in Simulation, 2010] to simulate an Earth-like magnetosphere at three different times along the pole reversal process. The code was modified, so the Earth-like magnetic field is generated using an expansion in spherical harmonics with the Gauss coefficients given by a MHD simulation of the Earth's core [Glatzmaier et al, Nature, 1995; 1999; private communication to L.E.A.V.]. Simulations show the qualitative behavior of the magnetosphere, such as the current structures. Only the planet magnetic field was changed in the runs. The solar wind is the same for all runs. Preliminary results show the formation of the Chapman-Ferraro current in the front of the magnetosphere in all the cases. Run for the middle of the reversal process, the low intensity magnetic field and its asymmetrical configuration the current structure changes and the presence of multiple poles can be observed. In all simulations, a structure similar to the radiation belts was found. Simulations of more severe solar wind conditions are necessary to determine the real impact of the reversal in the magnetosphere.

  7. Paleomagnetic record of a geomagnetic field reversal from late miocene mafic intrusions, southern nevada.

    Science.gov (United States)

    Ratcliff, C D; Geissman, J W; Perry, F V; Crowe, B M; Zeitler, P K

    1994-10-21

    Late Miocene (about 8.65 million years ago) mafic intrusions and lava flows along with remagnetized host rocks from Paiute Ridge, southern Nevada, provide a high-quality paleomagnetic record of a geomagnetic field reversal. These rocks yield thermoremanent magnetizations with declinations of 227 degrees to 310 degrees and inclinations of -7 degrees to 49 degrees , defining a reasonably continuous virtual geomagnetic pole path over west-central Pacific longitudes. Conductive cooling estimates for the intrusions suggest that this field transition, and mafic magmatism, lasted only a few hundred years. Because this record comes principally from intrusive rocks, rather than sediments or lavas, it is important in demonstrating the longitudinal confinement of the geomagnetic field during a reversal.

  8. 40Ar/39Ar Dating of the Brunhes-Matuyama Geomagnetic Field Reversal.

    Science.gov (United States)

    Baksi, A K; Hsu, V; McWilliams, M O; Farrar, E

    1992-04-17

    Magnetostratigraphic studies are widely used in conjunction with the geomagnetic polarity time scale (GPTS) to date events in the range 0 to 5 million years ago. A critical tie point on the GPTS is the potassium-argon age of the most recent (Brunhes-Matuyama) geomagnetic field reversal. Astronomical values for the forcing frequencies observed in the oxygen isotope record in Ocean Drilling Project site 677 suggest that the age of this last reversal is 780 ka (thousand years ago), whereas the potassium-argon-based estimate is 730 ka. Results from 4039; Ar incremental heating studies on a series of lavas from Maui that straddle the Brunhes-Matuyama reversal give an age of 783 + 11 ka, in agreement with the astronomically derived value. The astronomically based technique appears to be a viable tool for dating young sedimentary sequences.

  9. Magnetic islands at the field reversal surface in reversed field pinches

    International Nuclear Information System (INIS)

    Pinsker, R.I.; Reiman, A.H.

    1985-09-01

    In the reversed field pinch (RFP), magnetic field perturbations having zero poloidal mode number and any toroidal mode number are resonant at the field reversal surface. Such perturbations are a particular threat to the RFP because of their weak radial dependence at low toroidal mode number, and because the toroidal field ripple is essentially of this type. The widths of the resulting islands are calculated in this paper. The self-consistent plasma response is included through the assumption that the plasma relaxes to a Taylor force-free state. The connection with linear tearing mode theory is established for those limits where arbitrarily large islands result from infinitesimal perturbations. Toroidal effects are considered, and application of the theory to RFP experiments is discussed

  10. Symmetric dynamic behaviour of a superconducting proximity array with respect to field reversal

    International Nuclear Information System (INIS)

    Lankhorst, M; Poccia, N

    2017-01-01

    As the complexity of strongly correlated systems and high temperature superconductors increases, so does also the essential complexity of defects found in these materials and the complexity of the supercurrent pathways. It can be therefore convenient to realize a solid-state system with regular supercurrent pathways and without the disguising effects of disorder in order to capture the essential characteristics of a collective dynamics. Using a square array of superconducting islands placed on a normal metal, we observe a state in which magnetic field-induced vortices are frozen in the dimples of the egg crate potential by their strong repulsion interaction. In this system a dynamic vortex Mott insulator transition has been previously observed. In this work, we will show the symmetric dynamic behaviour with respect to field reversal and we will compare it with the asymmetric behaviour observed at the dynamic vortex Mott transition. (paper)

  11. Compact-toroid fusion reactor based on the field-reversed theta pinch: reactor scaling and optimization for CTOR

    International Nuclear Information System (INIS)

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

    1980-01-01

    Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CT) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conduction shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radiation shielding. On the basis of this batch-burn but thermally steady-state approach a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15

  12. Enhancement of the guide field during the current sheet formation in the three-dimensional magnetic configuration with an X line

    International Nuclear Information System (INIS)

    Frank, Anna; Bugrov, Sergey; Markov, Vladimir

    2009-01-01

    Results are presented from studies of the formation of current sheets during exciting a current aligned with the X line of the 3D magnetic configuration, in the CS-3D device. Enhancement of the guide field (parallel to the X line) was directly observed for the first time, on the basis of magnetic measurements. After the current sheet formation, the guide field inside the sheet exceeds its initial value, as well as the field outside. It is convincingly demonstrated that an enhancement of the guide field is due to its transportation by plasma flows on the early stage of the sheet formation. The in-plane plasma currents, which produce the excess guide field, are comparable to the total current along the X line that initiates the sheet itself.

  13. The correlation between geomagnetic field reversals, Hawaiian volcanism, and the motion of the Pacific plate

    Directory of Open Access Journals (Sweden)

    W. Dong

    1996-06-01

    Full Text Available The correlation between geomagnetic field reversals and volcanism is investigated, according to the speculated consequence on volcanoes of the transient electric currents in the geodynamo, through Joule's heating, before and after every reversal event. We evaluate the temporal variation during the last ~ 70 Ma both of the magma emplacement rate Q(t from the Hawaii hot spot, and of the speed v(t of the Pacific plate, by means of the observed volumes of islands and seamounts along the Hawaii/Emperor Seamounts chain, and their respective radiometric datings. Results confirm expectations. A justification of the volcanic crises that lead to the generation of the large igneous provinces during the last ~ 250 Ma also emerged. We describe in detail the complex pattern of the timings of the different effects. Joule's power is generally responsible for ~ 75-80% of magmatism, and friction power only for ~ 20-25%; but, on some occasions almost ~ 100% is fuelled by friction alone. The visco-elastic coupling between lithosphere and asthenosphere results ~ 96% viscous, and ~ 4% elastic.

  14. Electron currents in field reversed mirror dynamics: Theory and hybrid simulation

    International Nuclear Information System (INIS)

    Stark, R.A.

    1987-01-01

    To model the dynamics of the Field-Reversed Mirror (FRM) as a whole we have developed a 1-D radical hybrid code which also incorporates the above electron null current model. This code, named FROST, models the plasma as azimuthally symmetric with no axial dependence. A multi-group method in energy and canonical angular momentum describes the large-orbit ions from the beam. Massless fluid equations describe electrons and low energy ions. Since a fluid treatment for electrons is invalid near a field null, the null region electron current model discussed above has been included for this region, a unique feature. Results of simulation of neutral beam start-up in a 2XIIB-like plasma is discussed. There FROST predicts that electron currents will retard, but not prevent reversal of the magnetic field at the plasma center. These results are optimistic when compared to actual reversal experiments in 2XIIB, because there finite axial length effects and micro-instabilities substantially deteriorated the ion confinement. Nevertheless, because of the importance of the electron current in a low field region in the FRM, FROST represents a valuable intermediate step toward a more complete description of FRM dynamics. 54 refs., 50 figs., 3 tabs

  15. 3-D studies of the formation and stability of strong ion rings

    International Nuclear Information System (INIS)

    Omelchenko, Yu.A.; Sudan, R.N.

    1996-01-01

    Complex 3-D simulations were conducted in support of the on-going experimental program, FIREX( (Field-Reversed Ion Ring Experiment) launched at the Cornell University to produce an ion ring magnetic field-reversed configuration by injecting an intense annular proton beam across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Previous axisymmetric PIC simulations performed with the FIRE code have demonstrated that strong ion rings (with a self-magnetic field large enough to reverse the applied field on axis) can be created using this technique on the equipment designed and assembled at Cornell. A new parallel object-oriented 3-D hybrid PIC code FLAME has been created to study questions of extreme importance to the success of the FIREX program, namely, the 3-D injection of a powerful ion beam into a strongly magnetized plasma, formation of a field-reversed ring, and the stability and equilibrium of such rings to toroidal perturbations. Using FLAME, the stability was studied of the ring formation during the injection phase and at later times when the ring is virtually stopped and the applied magnetic field is nearly reversed. The simulations revealed the effect of toroidal aberrations in the axially ramped magnetic field on the ion ring formation. (author). 4 figs., 4 refs

  16. 3-D studies of the formation and stability of strong ion rings

    Energy Technology Data Exchange (ETDEWEB)

    Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

    1997-12-31

    Complex 3-D simulations were conducted in support of the on-going experimental program, FIREX( (Field-Reversed Ion Ring Experiment) launched at the Cornell University to produce an ion ring magnetic field-reversed configuration by injecting an intense annular proton beam across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Previous axisymmetric PIC simulations performed with the FIRE code have demonstrated that strong ion rings (with a self-magnetic field large enough to reverse the applied field on axis) can be created using this technique on the equipment designed and assembled at Cornell. A new parallel object-oriented 3-D hybrid PIC code FLAME has been created to study questions of extreme importance to the success of the FIREX program, namely, the 3-D injection of a powerful ion beam into a strongly magnetized plasma, formation of a field-reversed ring, and the stability and equilibrium of such rings to toroidal perturbations. Using FLAME, the stability was studied of the ring formation during the injection phase and at later times when the ring is virtually stopped and the applied magnetic field is nearly reversed. The simulations revealed the effect of toroidal aberrations in the axially ramped magnetic field on the ion ring formation. (author). 4 figs., 4 refs.

  17. Evaluation of using ferrofluid as an interface material for a field-reversible thermal connector

    Science.gov (United States)

    Yousif, Ahmed S.

    The electrical functionality of an avionics chassis is limited due to heat dissipation limits. The limits arise due to the fact that components in an avionic computer boxes are packed very compactly, with the components mounted onto plug-in cards, and the harsh environment experienced by the chassis limits how heat can be dissipated from the cards. Convective and radiative heat transfer to the ambient are generally not possible. Therefore it is necessary to have heat transferred from the components conducted to the edge of the plug-in cards. The heat then needs to conduct from the card edge to a cold block that not only holds the card in place, but also removes the generated heat by some heat transfer fluid that is circulated through the cold block. The interface between the plug-in card and the cold block typically has a high thermal resistance since it is necessary for the card to have the capability to be re-workable, meaning that the card can be removed and then returned to the chassis. Reducing the thermal resistance of the interface is the objective of the current study and the topic of this thesis. The current design uses a pressure interface between the card and cold block. The contact pressure is increased through the addition of a wedgelock, which is a field-reversible mechanical connector. To use a wedgelock, the cold block has channels milled on the surface with widths that are larger than the thickness of the plug-in card and the un-expanded wedgelock. The card edge is placed in the channel and placed against one of the channel walls. A wedgelock is then placed between the card and the other channel wall. The wedgelock is then expanded by using either a screw or a lever. As the wedgelock expands it fills in the remaining channel gap and bears against the other face of the plug-in card. The majority of heat generated by the components on the plug-in card is forced to conduct from the card into the wall of the cold block, effectively a single sided, dry

  18. Formation of edge transport barrier in the ergodic field layer of helical divertor configuration on the Large Helical Device

    International Nuclear Information System (INIS)

    Toi, K; Ohdachi, S; Watanabe, F; Narihara, K; Morisaki, T; Sakakibara, S; Morita, S; Goto, M; Ida, K; Masuzaki, S; Miyazawa, K; Tanaka, K; Tokuzawa, T; Watanabe, K W; Yoshinuma, M

    2006-01-01

    On the Large Helical Device (LHD), low to high confinement (L-H) transition and edge transport barrier (ETB) formation were observed in the low beta regime ((β dia ) dia ): volume-averaged beta derived from diamagnetic measurement) as well as in relatively high beta regime (>1.5%). In most of ETB plasmas electron density preferentially increases in the edge region without a substantial rise of the edge electron temperature. The ETB zone develops inside the ergodic field layer calculated in the vacuum field. The ETB formation strongly destabilizes edge coherent modes such as m/n = 2/3 or 1/2 (m, n: poloidal and toroidal mode numbers), because the plasma edge region is in the magnetic hill. The ETB is partially destroyed by the combination of these edge MHD modes and ELM-like activities. For a particular experimental condition, the forced generation of a sizable m/n = 1/1 magnetic island near the edge by application of external field perturbations facilitates the L-H transition at a lower electron density and suppresses edge MHD modes and ELM-like activities to lower levels

  19. Formation of a compact toroid for enhanced efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Mozgovoy, A. G. [P.N. Lebedev Physical Institute, Moscow 119991 (Russian Federation); Romadanov, I. V.; Ryzhkov, S. V., E-mail: ryzhkov@power.bmstu.ru [Bauman Moscow State Technical University, Moscow 105005 (Russian Federation)

    2014-02-15

    We report here our results on the formation of a plasma configuration with the generic name of compact toroid (CT). A method of compact toroid formation to confine, heat and compress a plasma is investigated. Formation of a compact torus using an additional toroidal magnetic field helps to increase the plasma current to a maintainable level of the original magnetic field. We design the Compact Toroid Challenge (CTC) experiment in order to improve the magnetic flux trapping during field reversal in the formation of a compact toroid. The level of the magnetic field immersed in the plasma about 70% of the primary field is achieved. The CTC device and scheme of high level capturing of magnetic flux are presented.

  20. Modelling of SOL flows and target asymmetries in JET field reversal experiments with EDGE2D code

    International Nuclear Information System (INIS)

    Chankin, A.; Coad, J.; Corrigan, G.

    1999-11-01

    The EDGE2D code with drifts can reproduce the main trends of target asymmetries observed in field reversal experiments. It also re-produces qualitatively the main feature of recent JET results obtained with double-sided reciprocating Langmuir probes introduced near the top of the torus: the reversal of parallel plasma flow with toroidal field reversal. The code results suggest that the major contributor to the observed target asymmetries is the co-current toroidal momentum generated inside the scrape-off layer (SOL) by j r xB forces due to the presence of large up-down pressure asymmetries. Contrary to previous expectations of the predominant role of ExB drifts in creating target asymmetries, ∇B and centrifugal drifts were found to be mainly responsible for both parallel flows and target asymmetries. (author)

  1. Configuration Management

    International Nuclear Information System (INIS)

    Morcos, A.; Taylor, H. S.

    1989-01-01

    This paper will briefly discuss the reason for and content of configuration management both for new plants and, when adapted, for older plants. It will then address three types of activities a utility may undertake as part of a nuclear CAM program and with which Sargent and Leyden has been actively involved. The first activity is a methodology for preparing design-basis documentation. The second is the identification of essential data required to be kept by the utility in support of the operation of a nuclear plant. The third activity is a computerized classification system of plant components, allowing ready identification of plant functional and physical characteristics. Plant configuration documentation describes plant components, the ways they arranged to interact, and the ways they are enabled to interact. Configuration management, on the other hand, is more than the control of such documentation. It is a dynamic process for ensuring that a plant configuration meets all relevant requirements for safety and economy, even while the configuration changes and even while the requirements change. Configuration management for a nuclear plant is so complex that it must be implemented in phases and modules. It takes advantage of and integrates existing programs. Managing complexity and streamlining the change process become important additional objectives of configuration management. The example activities fulfill essential goals of an overall CAM program: definition of design baseline, definition of essential plant data, and classification of plant components

  2. MHD simulation of relaxation to a flipped ST configuration

    Energy Technology Data Exchange (ETDEWEB)

    Kagei, Y [Department of Electrical Engineering and Computer Sciences, Himeji Institute of Technology, Himeji, Hyogo (Japan); Nagata, M [Department of Electrical Engineering and Computer Sciences, Himeji Institute of Technology, Himeji, Hyogo (Japan); Suzuki, Y [Center for Promotion of Computational Science and Engineering, Japan Atomic Energy Research Institute, Taito-ku, Tokyo (Japan); Kishimoto, Y [Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka-machi, Ibaraki (Japan); Hayashi, T [National Institute for Fusion Science, Toki, Gifu (Japan); Uyama, T [Department of Electrical Engineering and Computer Sciences, Himeji Institute of Technology, Himeji, Hyogo (Japan)

    2003-02-01

    The dynamics of spherical torus (ST) plasmas, when the external toroidal magnetic field is decreased to zero and then increased in the opposite direction, has been investigated using three-dimensional magnetohydrodynamic (MHD) numerical simulations. It has been found that the flipped ST configuration is self-organized after the ST configuration collapses because of the growth of the n = 1 mode in the open flux region and a following magnetic reconnection event. During the transition between these configurations, not only the paramagnetic toroidal field but also the poloidal field reverses polarity spontaneously. (letter to the editor)

  3. Effect of interlayer configurations on joint formation in TLP bonding of Ti-6AI-4V to Mg-AZ31

    International Nuclear Information System (INIS)

    Atieh, A. M.; Khan, T. I.

    2013-01-01

    In this research work, the transient liquid phase (TLP) bonding process was utilized to fabricate joints using thin (20 micro m) nickel and copper foils placed between two bonding surfaces to help facilitate joint formation. Two joint configurations were investigated, first, Ti-6Al-4V/CuNi/Mg-AZ31 and second, Ti-6Al-4V/NiCu/Mg-AZ3L The effect of bonding time on microstructural developments across the joint and the changes in mechanical properties were studied as a function of bonding temperature and pressure. The bonded specimens were examined by metallographic analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). In both cases, intermetallic phase of CuMg/sub 2/ and Mg/sub 3/AlNi/sub 2/ was observed inside the joint region. The results show that joint shear strengths for the Ti-6Al-4V/CuNi/Mg-AZ31 setup produce joints with shear strength of 57 MPa compared to 27MPa for joints made using the Ti-6Al-4V/NiCu/Mg-AZ31 layer arrangement. (author)

  4. Effect of interlayer configurations on joint formation in TLP bonding of Ti-6Al-4V to Mg-AZ31

    International Nuclear Information System (INIS)

    Atieh, A M; Khan, T I

    2014-01-01

    In this research work, the transient liquid phase (TLP) bonding process was utilized to fabricate joints using thin (20μm) nickel and copper foils placed between two bonding surfaces to help facilitate joint formation. Two joint configurations were investigated, first, Ti-6Al-4V/CuNi/Mg-AZ31 and second, Ti-6Al-4V/NiCu/Mg-AZ3L The effect of bonding time on microstructural developments across the joint and the changes in mechanical properties were studied as a function of bonding temperature and pressure. The bonded specimens were examined by metallographic analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). In both cases, intermetallic phase of CuMg 2 and Mg 3 AlNi 2 was observed inside the joint region. The results show that joint shear strengths for the Ti-6Al-4V/CuNi/Mg-AZ31 setup produce joints with shear strength of 57 MPa compared to 27MPa for joints made using the Ti-6Al-4V/NiCu/Mg-AZ31 layer arrangement

  5. High Energy Research and Applications (HERA) Pulsed Power and Pulsed Power Systems R&D for Magnetized Target Fusion Using Field Reversed Configurations (MTF-FRC)

    Science.gov (United States)

    2013-03-12

    that we also advocate for potentially increasing the plasma lifetime. The first is the use of a coaxial plasma gun on axis to effectively bias the FRC...of their FRC plasmas by a factor of three over what had been achieved before using the gun . Admittedly, their plasmas are larger and lower density...were able to show, by the use of the plasma gun , that distortion and centering improved dramatically, and this stabilization is believed to be a major

  6. Possible relationship between the Earth’s rotation variations and geomagnetic field reversals over the past 510 Myr

    Directory of Open Access Journals (Sweden)

    Igor Gil Pacca

    2015-04-01

    Full Text Available The Earth’s rotation can change as a result of several internal and external processes, each of which is at a different timescale. Here, we present some possible connections between the Earth’s rotation variations and the geomagnetic reversal frequency rates over the past 120 Myr. In addition, we show the possible relationship between the geomagnetic field reversal frequency and the δ18O oscillations. Because the latter reflects the glacial and interglacial periods, we hypothesize that it can be used as a possible indicator to explain the length of day (LOD variations and consequently the reversal field frequency over the past 510 Myr. Therefore, our analysis suggests that the relationships between the geomagnetic reversal frequency rates and the Earth’s rotation changes during the Phanerozoic. However, more reversal data are required for periods before the KRS to strengthen the perspective of using the geomagnetic reversal data as a marker for the LOD variations through geological times.

  7. Configuration management

    International Nuclear Information System (INIS)

    Beavers, R.R.; Sumiec, K.F.

    1989-01-01

    Increasing regulatory and industry attention has been focused on properly controlling electrical design changes. These changes can be controlled by using configuration management techniques. Typically, there are ongoing modifications to various process systems or additions due to new requirements at every power plant. Proper control of these changes requires that an organized method be used to ensure that all important parameters of the electrical auxiliary systems are analyzed and that these parameters are evaluated accurately. This process, commonly referred to as configuration management, is becoming more important on both fossil and nuclear plants. Recent NRC- and utility-initiated inspections have identified problems due to incomplete analysis of changes to electrical auxiliary systems at nuclear stations

  8. Detailed Jaramillo field reversals recorded in lake sediments from Armenia - Lower mantle influence on the magnetic field revisited

    Science.gov (United States)

    Kirscher, U.; Winklhofer, M.; Hackl, M.; Bachtadse, V.

    2018-02-01

    While it is well established that the Earth's magnetic field is generated by a self sustaining dynamo that reversed its polarity at irregular intervals in the geological past, the very mechanisms causing field reversals remain obscure. Paleomagnetic reconstructions of polarity transitions have been essential for physically constraining the underlying mechanisms in terms of time scale, but thus far remain ambiguous with regard to the transitional field geometry. Here we present new paleomagnetic records from a rapidly deposited lacustrine sediment sequence with extraordinarily stable paleomagnetic signals, which has captured in unprecedented detail the bottom (reverse to normal: R-N) and top (normal to reverse: N-R) transitions of the Jaramillo subchron (at 1.072 Ma and at 0.988 Ma). The obtained virtual geomagnetic pole (VGP) path indicates an oscillatory transitional field behavior with four abrupt transequatorial precursory jumps across the Pacific. The distribution of VGP positions indicates regions of preferred occurrence. Our results are in agreement with previously proposed bands of transitional VGP occurrence over the Americas and Australia/northwest Pacific. Additionally, our VGP positions seem to avoid large low shear velocity provinces (LLSVPs) above the core mantle boundary (CMB). Thus, our data supports the idea that the transitional field geometry is controlled by heat flux heterogeneities at the CMB linked to LLSVPs.

  9. Effects of the resistivity profile on the formation of a reversed configuration and single helicity states in compressible simulations of the reversed-field pinch

    International Nuclear Information System (INIS)

    Onofri, M.; Malara, F.

    2013-01-01

    Compressible magnetohydrodynamics simulations of the reversed-field pinch (RFP) are presented. Previous simulations of the RFP, including density and pressure evolution, showed that a stationary state with a reversed toroidal magnetic field could not be obtained, contrary to the results produced with numerical codes neglecting density and pressure dynamics. The simulations described in the present paper show that including density and pressure evolution, a stationary RFP configuration can be obtained if the resistivity has a radial profile steeply increasing close to the wall. Such resistivity profile is more realistic than a uniform resistivity, since the temperature at the wall is lower than in the plasma core

  10. Merging formation of FRC and its application to high-beta ST formation

    International Nuclear Information System (INIS)

    Ono, Y.; Inomoto, M.; Ueda, Y.; Matsuyama, T.; Ohshima, Y.; Katsurai, M.

    2001-01-01

    Merging formation of field-reversed configuration (FRC) explored not only a new scenario of highly-efficient FRC formation/amplification experiment but also a new boundary research between FRC, spheromak and spherical tokamak (ST). A new finding is that the produced FRC is transformed stably into an ultra-high-β ST by applying external toroidal field B t,ext . The toroidal field was observed to vanish around magnetic axis after the B t,ext application to the FRC, indicating formation of diamagnetic ST. The hollow current profile of FRC was maintained during the equilibrium transition, eliminating a need for the difficult hollow-current-formation process of start-up discharge of high-β ST. The energy-conversion effect of merging transformed the force-free merging spheromaks with paramagnetic current into the FRC with diamagnetic current and the further application of B t,ext did the FRC into the ultra-high-β (>60%)/diamagnetic ST, indicating the close relationship between FRC and ST in second stability. (author)

  11. Stable configurations in social networks

    Science.gov (United States)

    Bronski, Jared C.; DeVille, Lee; Ferguson, Timothy; Livesay, Michael

    2018-06-01

    We present and analyze a model of opinion formation on an arbitrary network whose dynamics comes from a global energy function. We study the global and local minimizers of this energy, which we call stable opinion configurations, and describe the global minimizers under certain assumptions on the friendship graph. We show a surprising result that the number of stable configurations is not necessarily monotone in the strength of connection in the social network, i.e. the model sometimes supports more stable configurations when the interpersonal connections are made stronger.

  12. The benefits of ITER for the portfolio of fusion configurations

    International Nuclear Information System (INIS)

    Goldston, R.J.

    2002-01-01

    Recent plasma science challenges are 1) what limits the pressure in plasmas? (macroscopic stability), 2) how do hot particles and plasma waves interact in the non-linear regime? (wave-particle interactions), 3) what causes plasma transport? (microscopic turbulence and transport) and 4) how can high-temperature plasma and material surface co-exist? (plasma-material interactions). This fusion plasma science is addressed using a 'Portfolio' of configurations, like Stellarator, Tokamak, Spherical Torus, Reversed Field Pinch, Spheromak, and Field Reversed Configuration. Namely, the scientific results from one configuration benefit progress in others. Recent example of this effort can be found in NCSX, NSTX and RFP. ITER will provide very significant benefits to the development of the full fusion portfolio; macroscopic stability, wave-particle interactions, microturbulence and transport, plasma-material interactions, and technical demonstration of an integrated fusion system. (author)

  13. The benefits of ITER for the portfolio of fusion configurations

    Energy Technology Data Exchange (ETDEWEB)

    Goldston, R.J. [Princeton Plasma Physics Lab., NJ (United States)

    2002-10-01

    Recent plasma science challenges are 1) what limits the pressure in plasmas? (macroscopic stability), 2) how do hot particles and plasma waves interact in the non-linear regime? (wave-particle interactions), 3) what causes plasma transport? (microscopic turbulence and transport) and 4) how can high-temperature plasma and material surface co-exist? (plasma-material interactions). This fusion plasma science is addressed using a 'Portfolio' of configurations, like Stellarator, Tokamak, Spherical Torus, Reversed Field Pinch, Spheromak, and Field Reversed Configuration. Namely, the scientific results from one configuration benefit progress in others. Recent example of this effort can be found in NCSX, NSTX and RFP. ITER will provide very significant benefits to the development of the full fusion portfolio; macroscopic stability, wave-particle interactions, microturbulence and transport, plasma-material interactions, and technical demonstration of an integrated fusion system. (author)

  14. Stratigraphic and structural configuration of the Navajo (Jurassic) through Ouray (Mississippian-Devonian) formations in the vicinity of Davis and Lavender Canyons, southeastern Utah

    International Nuclear Information System (INIS)

    McCleary, J.R.; Romie, J.E.

    1986-04-01

    This study developed a three-dimensional computer model of stratigraphic and structural relationships within a 3497-km 2 (1350-mi 2 ) study area centered on the proposed site for a high-level nuclear waste repository in southeastern Utah. The model consists of a sequence of internally reconciled isopach and structure contour maps horizontally registered and stored in stratigraphic order. This model can be used to display cross sections, perspective block diagrams, or fence diagrams at any orientation; estimate depth of formation contacts and thicknesses for any new stratigraphic or hydrologic boreholes; facilitate ground-water modeling studies; and evaluate the structural and stratigraphic evolution of the study area. This study also includes limited evaluations of aquifer continuity in the Elephant Canyon and Honaker Trail Formations, and of salt dissolution and flowage features as interpreted from geophysical logs. The study identified a long history of movement in the fault system in the north-central part of the study area and a major salt flowage feature in the northeastern part. It describes the Elephant Canyon Formation aquifer as laterally limited, the Honaker Trail Formation aquifer as fairly continuous over the area, and Beef Basin in the southern part of the area as a probable dissolution feature. It also concludes that the Shay-Bridger Jack-Salt Creek Graben system is apparently a vertically continuous feature between the basement and ground surface. No stratigraphic or structural discontinuities were detected in the vicinity of Davis Canyon that appear to be detrimental to the siting of a waste repository

  15. Characterization of compact-toroid injection during formation, translation, and field penetration

    Science.gov (United States)

    Matsumoto, T.; Roche, T.; Allfrey, I.; Sekiguchi, J.; Asai, T.; Gota, H.; Cordero, M.; Garate, E.; Kinley, J.; Valentine, T.; Waggoner, W.; Binderbauer, M.; Tajima, T.

    2016-11-01

    We have developed a compact toroid (CT) injector system for particle refueling of the advanced beam-driven C-2U field-reversed configuration (FRC) plasma. The CT injector is a magnetized coaxial plasma gun (MCPG), and the produced CT must cross the perpendicular magnetic field surrounding the FRC for the refueling of C-2U. To simulate this environment, an experimental test stand has been constructed. A transverse magnetic field of ˜1 kG is established, which is comparable to the C-2U axial magnetic field in the confinement section, and CTs are fired across it. On the test stand we have been characterizing and studying CT formation, ejection/translation from the MCPG, and penetration into transverse magnetic fields.

  16. Characterization of compact-toroid injection during formation, translation, and field penetration

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, T., E-mail: cstd14003@g.nihon-u.ac.jp; Sekiguchi, J.; Asai, T. [Nihon University, Chiyoda-ku, Tokyo 101-8308 (Japan); Roche, T.; Allfrey, I.; Gota, H.; Cordero, M.; Garate, E.; Kinley, J.; Valentine, T.; Waggoner, W.; Binderbauer, M. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States); Tajima, T. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

    2016-11-15

    We have developed a compact toroid (CT) injector system for particle refueling of the advanced beam-driven C-2U field-reversed configuration (FRC) plasma. The CT injector is a magnetized coaxial plasma gun (MCPG), and the produced CT must cross the perpendicular magnetic field surrounding the FRC for the refueling of C-2U. To simulate this environment, an experimental test stand has been constructed. A transverse magnetic field of ∼1 kG is established, which is comparable to the C-2U axial magnetic field in the confinement section, and CTs are fired across it. On the test stand we have been characterizing and studying CT formation, ejection/translation from the MCPG, and penetration into transverse magnetic fields.

  17. Simulation study of wave phenomena from the sheath region in single frequency capacitively coupled plasma discharges; field reversals and ion reflection

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.; Turner, M. M. [National Centre for Plasma Science and Technology, School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

    2013-07-15

    Capacitively coupled radio-frequency (RF) discharges have great significance for industrial applications. Collisionless electron heating in such discharges is important, and sometimes is the dominant mechanism. This heating is usually understood to originate in a stochastic interaction between electrons and the electric fields. However, other mechanisms may also be important. There is evidence of wave emission with a frequency near the electron plasma frequency, i.e., ω{sub pe}, from the sheath region in collisionless capacitive RF discharges. This is the result of a progressive breakdown of quasi-neutrality close to the electron sheath edge. These waves are damped in a few centimeters during their propagation from the sheath towards the bulk plasma. The damping occurs because of the Landau damping or some related mechanism. This research work reports that the emission of waves is associated with a field reversal during the expanding phase of the sheath. Trapping of electrons near to this field reversal region is observed. The amplitude of the wave increases with increasing RF current density amplitude J(tilde sign){sub 0} until some maximum is reached, beyond which the wave diminishes and a new regime appears. In this new regime, the density of the bulk plasma suddenly increases because of ion reflection, which occurs due to the presence of strong field reversal near sheath region. Our calculation shows that these waves are electron plasma waves. These phenomena occur under extreme conditions (i.e., higher J(tilde sign){sub 0} than in typical experiments) for sinusoidal current waveforms, but similar effects may occur with non-sinusoidal pulsed waveforms for conditions of experimental interest, because the rate of change of current is a relevant parameter. The effect of electron elastic collisions on plasma waves is also investigated.

  18. Deployable reflector configurations

    Science.gov (United States)

    Meinel, A. B.; Meinel, M. P.; Woolf, N. J.

    Both the theoretical reasons for considering a non-circular format for the Large Deployable Reflector, and a potentially realizable concept for such a device, are discussed. The optimum systems for diffraction limited telescopes with incoherent detection have either a single filled aperture, or two such apertures as an interferometer to synthesize a larger aperture. For a single aperture of limited area, a reflector in the form of a slot can be used to give increased angular resolution. It is shown how a 20 x 8 meter telescope can be configured to fit the Space Shuttle bay, and deployed with relatively simple operations. The relationship between the sunshield design and the inclination of the orbit is discussed. The possible use of the LDR as a basic module to permit the construction of supergiant space telescopes and interferometers both for IR/submm studies and for the entire ultraviolet through mm wave spectral region is discussed.

  19. Software configuration management

    International Nuclear Information System (INIS)

    Arribas Peces, E.; Martin Faraldo, P.

    1993-01-01

    Software Configuration Management is directed towards identifying system configuration at specific points of its life cycle, so as to control changes to the configuration and to maintain the integrity and traceability of the configuration throughout its life. SCM functions and tasks are presented in the paper

  20. Conceptualizing Embedded Configuration

    DEFF Research Database (Denmark)

    Oddsson, Gudmundur Valur; Hvam, Lars; Lysgaard, Ole

    2006-01-01

    and services. The general idea can be named embedded configuration. In this article we intend to conceptualize embedded configuration, what it is and is not. The difference between embedded configuration, sales configuration and embedded software is explained. We will look at what is needed to make embedded...... configuration systems. That will include requirements to product modelling techniques. An example with consumer electronics will illuminate the elements of embedded configuration in settings that most can relate to. The question of where embedded configuration would be relevant is discussed, and the current...

  1. Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

    Science.gov (United States)

    Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

    2017-05-01

    How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of

  2. A unix configuration engine

    International Nuclear Information System (INIS)

    Burgess, M.

    1994-06-01

    A high level description language is presented for the purpose of automatically configuring large heterogeneous networked unix environments, based on class-oriented abstractions. The configuration engine is portable and easily extensible

  3. MICROCONTROLLER PIN CONFIGURATION TOOL

    OpenAIRE

    Bhaskar Joshi; F. Mohammed Rizwan; Dr. Rajashree Shettar

    2012-01-01

    Configuring the micro controller with large number of pins is tedious. Latest Infine on microcontroller contains more than 200 pins and each pin has classes of signals. Therefore the complexity of the microcontroller is growing. It evolves looking into thousands of pages of user manual. For a user it will take days to configure the microcontroller with the peripherals. We need an automated tool to configure the microcontroller so that the user can configure the microcontroller without having ...

  4. Operational Dynamic Configuration Analysis

    Science.gov (United States)

    Lai, Chok Fung; Zelinski, Shannon

    2010-01-01

    Sectors may combine or split within areas of specialization in response to changing traffic patterns. This method of managing capacity and controller workload could be made more flexible by dynamically modifying sector boundaries. Much work has been done on methods for dynamically creating new sector boundaries [1-5]. Many assessments of dynamic configuration methods assume the current day baseline configuration remains fixed [6-7]. A challenging question is how to select a dynamic configuration baseline to assess potential benefits of proposed dynamic configuration concepts. Bloem used operational sector reconfigurations as a baseline [8]. The main difficulty is that operational reconfiguration data is noisy. Reconfigurations often occur frequently to accommodate staff training or breaks, or to complete a more complicated reconfiguration through a rapid sequence of simpler reconfigurations. Gupta quantified a few aspects of airspace boundary changes from this data [9]. Most of these metrics are unique to sector combining operations and not applicable to more flexible dynamic configuration concepts. To better understand what sort of reconfigurations are acceptable or beneficial, more configuration change metrics should be developed and their distribution in current practice should be computed. This paper proposes a method to select a simple sequence of configurations among operational configurations to serve as a dynamic configuration baseline for future dynamic configuration concept assessments. New configuration change metrics are applied to the operational data to establish current day thresholds for these metrics. These thresholds are then corroborated, refined, or dismissed based on airspace practitioner feedback. The dynamic configuration baseline selection method uses a k-means clustering algorithm to select the sequence of configurations and trigger times from a given day of operational sector combination data. The clustering algorithm selects a simplified

  5. Initial ionization stage of FRC formation

    International Nuclear Information System (INIS)

    Commisso, R.J.; Armstrong, W.T.; Cochrane, J.C.; Ekdahl, C.A.; Lipson, J.; Linford, R.K.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1980-01-01

    A Field-Reversed Configuration (FRC) is a prolate compact torus that is confined by poloidal fields only. Theta-pinch formation of an FRC employs an initial bias field, B 1 , whose direction is opposite to that of the main theta-pinch field. Some fraction of the flux associated with this bias field eventually constitutes the closed-field-line flux of the FRC. Experimental and theoretical evidence suggest that the longest-lived FRC's are obtained when the closed flux is maximized. Because the initial ionization is done in the presence of the bias field, the actual bias flux available at the time of application of the main theta-pinch field depends strongly on the initial ionization, or preionization, technique used. In this paper we report on experiments characterizing the previously used theta-pinch preionization technique that employed a net field (bias plus preionization) null, or zero-crossing, of the axial component of the magnetic field to break down the gas. We also discuss results of experiments designed to develop preionization techniques in which the gas breakdown is not accomplished by a zero-crossing

  6. Initial ionization stage of FRC formation

    Energy Technology Data Exchange (ETDEWEB)

    Commisso, R.J.; Armstrong, W.T.; Cochrane, J.C.; Ekdahl, C.A.; Lipson, J.; Linford, R.K.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1980-01-01

    A Field-Reversed Configuration (FRC) is a prolate compact torus that is confined by poloidal fields only. Theta-pinch formation of an FRC employs an initial bias field, B/sub 1/, whose direction is opposite to that of the main theta-pinch field. Some fraction of the flux associated with this bias field eventually constitutes the closed-field-line flux of the FRC. Experimental and theoretical evidence suggest that the longest-lived FRC's are obtained when the closed flux is maximized. Because the initial ionization is done in the presence of the bias field, the actual bias flux available at the time of application of the main theta-pinch field depends strongly on the initial ionization, or preionization, technique used. In this paper we report on experiments characterizing the previously used theta-pinch preionization technique that employed a net field (bias plus preionization) null, or zero-crossing, of the axial component of the magnetic field to break down the gas. We also discuss results of experiments designed to develop preionization techniques in which the gas breakdown is not accomplished by a zero-crossing.

  7. HLT configuration management system

    CERN Document Server

    Daponte, Vincenzo

    2015-01-01

    The CMS High Level Trigger (HLT) is implemented running a streamlined version of the CMS offline reconstruction software running on thousands of CPUs. The CMS software is written mostly in C++, using Python as its configuration language through an embedded CPython interpreter. The configuration of each process is made up of hundreds of modules, organized in sequences and paths. As an example, the HLT configurations used for 2011 data taking comprised over 2200 different modules, organized in more than 400 independent trigger paths. The complexity of the HLT configurations and the large number of configuration produced require the design of a suitable data management system. The present work describes the designed solution to manage the considerable number of configurations developed and to assist the editing of new configurations. The system is required to be remotely accessible and OS-independent as well as easly maintainable easy to use. To meet these requirements a three-layers architecture has been choose...

  8. Configurational isomerism in polyoxovanadates

    Energy Technology Data Exchange (ETDEWEB)

    Mahnke, Lisa K.; Naether, Christian; Bensch, Wolfgang [Institut fuer Anorganische Chemie, Christian-Albrechts-Universitaet, Kiel (Germany); Kondinski, Aleksandar; Van Leusen, Jan; Monakhov, Kirill Yu.; Koegerler, Paul [Institut fuer Anorganische Chemie, RWTH Aachen University (Germany); Warzok, Ulrike; Schalley, Christoph A. [Institut fuer Chemie und Biochemie, Freie Universitaet Berlin (Germany)

    2018-03-05

    A water-soluble derivative of the polyoxovanadate {V_1_5E_6O_4_2} (E=semimetal) archetype enables the study of cluster shell rearrangements driven by supramolecular interactions. A reaction unique to E=Sb, induced exclusively by ligand metathesis in peripheral [Ni(ethylenediamine){sub 3}]{sup 2+} counterions, results in the formation of the metastable α{sub 1}* configurational isomer of the {V_1_4Sb_8O_4_2} cluster type. Contrary to all other polyoxovanadate shell architectures, this isomer comprises an inward-oriented vanadyl group and is ca. 50 and 12 kJ mol{sup -1} higher in energy than the previously isolated α and β isomers, respectively. We discuss this unexpected reaction in light of supramolecular Sb-O..V and Sb-O..Sb contacts manifested in {V_1_4Sb_8O_4_2}{sub 2} dimers detected in the solid state. ESI MS experiments confirm the stability of these dimers also in solution and in the gas phase. DFT calculations indicate that other, as of yet elusive isomers of {V_1_4Sb_8}, might be accessible as well. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Average configuration of the geomagnetic tail

    International Nuclear Information System (INIS)

    Fairfield, D.H.

    1979-01-01

    Over 3000 hours of Imp 6 magnetic field data obtained between 20 and 33 R/sub E/ in the geomagnetic tail have been used in a statistical study of the tail configuration. A distribution of 2.5-min averages of B/sub z/ as a function of position across the tail reveals that more flux crosses the equatorial plane near the dawn and dusk flanks (B-bar/sub z/=3.γ) than near midnight (B-bar/sub z/=1.8γ). The tail field projected in the solar magnetospheric equatorial plane deviates from the x axis due to flaring and solar wind aberration by an angle α=-0.9 Y/sub SM/-2.7, where Y/sub SM/ is in earth radii and α is in degrees. After removing these effects, the B/sub y/ component of the tail field is found to depend on interplanetary sector structure. During an 'away' sector the B/sub y/ component of the tail field is on average 0.5γ greater than that during a 'toward' sector, a result that is true in both tail lobes and is independent of location across the tail. This effect means the average field reversal between northern and southern lobes of the tail is more often 178 0 rather than the 180 0 that is generally supposed

  10. Software configuration management

    CERN Document Server

    Keyes, Jessica

    2004-01-01

    Software Configuration Management discusses the framework from a standards viewpoint, using the original DoD MIL-STD-973 and EIA-649 standards to describe the elements of configuration management within a software engineering perspective. Divided into two parts, the first section is composed of 14 chapters that explain every facet of configuration management related to software engineering. The second section consists of 25 appendices that contain many valuable real world CM templates.

  11. CONFIGURATION GENERATOR MODEL

    International Nuclear Information System (INIS)

    Alsaed, A.

    2004-01-01

    ''The Disposal Criticality Analysis Methodology Topical Report'' prescribes an approach to the methodology for performing postclosure criticality analyses within the monitored geologic repository at Yucca Mountain, Nevada. An essential component of the methodology is the ''Configuration Generator Model for In-Package Criticality'' that provides a tool to evaluate the probabilities of degraded configurations achieving a critical state. The configuration generator model is a risk-informed, performance-based process for evaluating the criticality potential of degraded configurations in the monitored geologic repository. The method uses event tree methods to define configuration classes derived from criticality scenarios and to identify configuration class characteristics (parameters, ranges, etc.). The probabilities of achieving the various configuration classes are derived in part from probability density functions for degradation parameters. The NRC has issued ''Safety Evaluation Report for Disposal Criticality Analysis Methodology Topical Report, Revision 0''. That report contained 28 open items that required resolution through additional documentation. Of the 28 open items, numbers 5, 6, 9, 10, 18, and 19 were concerned with a previously proposed software approach to the configuration generator methodology and, in particular, the k eff regression analysis associated with the methodology. However, the use of a k eff regression analysis is not part of the current configuration generator methodology and, thus, the referenced open items are no longer considered applicable and will not be further addressed

  12. Ansible configuration management

    CERN Document Server

    Hall, Daniel

    2013-01-01

    Ansible Configuration Management"" is a step-by-step tutorial that teaches the use of Ansible for configuring Linux machines.This book is intended for anyone looking to understand the basics of Ansible. It is expected that you will have some experience of how to set up and configure Linux machines. In parts of the book we cover configuration files of BIND, MySQL, and other Linux daemons, therefore a working knowledge of these would be helpful but are certainly not required.

  13. Configuration management at NEK

    International Nuclear Information System (INIS)

    Podhraski, M.

    1999-01-01

    Configuration Management (CM) objectives at NEK are to ensure consistency between Design Requirements, Physical Plant Configuration and Configuration Information. Software applications, supporting Design Change, Work Control and Document Control Processes, are integrated in one module-oriented Management Information System (MIS). Master Equipment Component List (MECL) database is central MIS module. Through a combination of centralized database and process migrated activities it is ensured that the CM principles and requirements (accurate, current design data matching plant's physical configuration while complying to applicable requirements), are followed and fulfilled.(author)

  14. Resistive m=o mode in reverse-field configurations

    International Nuclear Information System (INIS)

    Galvao, R.M.O.; Santiago, M.A.M.

    1982-01-01

    The resistive m=0 mode is studied. Where m is the azimuthal mode number in magnetic confinement configurations with parallel field lines such that the magnetic field reverses direction inside the plasma. A cylindrical plasma column which rotates rigidly with a rotation velocity Ω is considered. It is found that the growth rate of the mode γ scales differently with the plasma resistivity depending on whether Ω vanishes or not; γα sup(3/5) for Ω=0 and γα sup(1/3) for Ω different 0. When the Hall term is also included in the generalized Ohm's law, γα sup(1/2) is obtained. This last result is in disagreement with the results of Krappraff et al. (Author) [pt

  15. Simulator configuration maintenance

    International Nuclear Information System (INIS)

    2006-01-01

    Requirements and recommendations of this section defines NPP personnel activity aimed to the provision of the simulator configuration compliance with the current configuration of the power-generating unit-prototype, standard and technical requirements and describe a monitoring procedure for a set of simulator software and hardware, training, organizational and technical documents

  16. PIV Logon Configuration Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Glen Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-04

    This document details the configurations and enhancements implemented to support the usage of federal Personal Identity Verification (PIV) Card for logon on unclassified networks. The guidance is a reference implementation of the configurations and enhancements deployed at the Los Alamos National Laboratory (LANL) by Network and Infrastructure Engineering – Core Services (NIE-CS).

  17. Business Model Process Configurations

    DEFF Research Database (Denmark)

    Taran, Yariv; Nielsen, Christian; Thomsen, Peter

    2015-01-01

    , by developing (inductively) an ontological classification framework, in view of the BM process configurations typology developed. Design/methodology/approach – Given the inconsistencies found in the business model studies (e.g. definitions, configurations, classifications) we adopted the analytical induction...

  18. Risk-based configuration control

    International Nuclear Information System (INIS)

    Szikszai, T.

    1997-01-01

    The presentation discusses the following issues: The Configuration Control; The Risk-based Configuration Control (during power operation mode, and during shutdown mode). PSA requirements. Use of Risk-based Configuration Control System. Configuration Management (basic elements, benefits, information requirements)

  19. The LHCb configuration database

    CERN Document Server

    Abadie, Lana; Gaspar, Clara; Jacobsson, Richard; Jost, Beat; Neufeld, Niko

    2005-01-01

    The Experiment Control System (ECS) will handle the monitoring, configuration and operation of all the LHCb experimental equipment. All parameters required to configure electronics equipment under the control of the ECS will reside in a configuration database. The database will contain two kinds of information: 1.\tConfiguration properties about devices such as hardware addresses, geographical location, and operational parameters associated with particular running modes (dynamic properties). 2.\tConnectivity between devices : this consists of describing the output and input connections of a device (static properties). The representation of these data using tables must be complete so that it can provide all the required information to the ECS and must cater for all the subsystems. The design should also guarantee a fast response time, even if a query results in a large volume of data being loaded from the database into the ECS. To fulfil these constraints, we apply the following methodology: Determine from the d...

  20. Drupal 8 configuration management

    CERN Document Server

    Borchert, Stefan

    2015-01-01

    Drupal 8 Configuration Management is intended for people who use Drupal 8 to build websites, whether you are a hobbyist using Drupal for the first time, a long-time Drupal site builder, or a professional web developer.

  1. Configuration by Modularisation

    DEFF Research Database (Denmark)

    Riitahuhta, Asko; Andreasen, Mogens Myrup

    1998-01-01

    Globally operating companies have realized that locally customized products and services are today the prerequisite for the success. The capability or the paradigm to act locally in global markets is called Mass Customization [Victor 1997]. The prerequisite for Mass Customization is Configuration...... Management and i Configuration Management the most important means is Modularisation.The goal of this paper is to show Configuration Management as a contribution to the Mass Customisation and Modularisation as a contribution to the industrialisation of the design area [Andreasen 1997]. A basic model...... for the creation of a structured product family is presented and examples are given. The concepts of a novel Dynamic Modularisation method, Metrics for Modularisation and Design for Configurability are presented....

  2. Configuration Management Automation (CMA) -

    Data.gov (United States)

    Department of Transportation — Configuration Management Automation (CMA) will provide an automated, integrated enterprise solution to support CM of FAA NAS and Non-NAS assets and investments. CMA...

  3. Computer software configuration management

    International Nuclear Information System (INIS)

    Pelletier, G.

    1987-08-01

    This report reviews the basic elements of software configuration management (SCM) as defined by military and industry standards. Several software configuration management standards are evaluated given the requirements of the nuclear industry. A survey is included of available automated tools for supporting SCM activities. Some information is given on the experience of establishing and using SCM plans of other organizations that manage critical software. The report concludes with recommendations of practices that would be most appropriate for the nuclear power industry in Canada

  4. Computational methods for stellerator configurations

    International Nuclear Information System (INIS)

    Betancourt, O.

    1992-01-01

    This project had two main objectives. The first one was to continue to develop computational methods for the study of three dimensional magnetic confinement configurations. The second one was to collaborate and interact with researchers in the field who can use these techniques to study and design fusion experiments. The first objective has been achieved with the development of the spectral code BETAS and the formulation of a new variational approach for the study of magnetic island formation in a self consistent fashion. The code can compute the correct island width corresponding to the saturated island, a result shown by comparing the computed island with the results of unstable tearing modes in Tokamaks and with experimental results in the IMS Stellarator. In addition to studying three dimensional nonlinear effects in Tokamaks configurations, these self consistent computed island equilibria will be used to study transport effects due to magnetic island formation and to nonlinearly bifurcated equilibria. The second objective was achieved through direct collaboration with Steve Hirshman at Oak Ridge, D. Anderson and R. Talmage at Wisconsin as well as through participation in the Sherwood and APS meetings

  5. Reference frame for Product Configuration

    DEFF Research Database (Denmark)

    Ladeby, Klaes Rohde; Oddsson, Gudmundur Valur

    2011-01-01

    a reference frame for configuration that permits 1) a more precise understanding of a configuration system, 2) a understanding of how the configuration system relate to other systems, and 3) a definition of the basic concepts in configuration. The total configuration system, together with the definition...

  6. Remembering facial configurations.

    Science.gov (United States)

    Bruce, V; Doyle, T; Dench, N; Burton, M

    1991-02-01

    Eight experiments are reported showing that subjects can remember rather subtle aspects of the configuration of facial features to which they have earlier been exposed. Subjects saw several slightly different configurations (formed by altering the relative placement of internal features of the face) of each of ten different faces, and they were asked to rate the apparent age and masculinity-femininity of each. Afterwards, subjects were asked to select from pairs of faces the configuration which was identical to one previously rated. Subjects responded strongly to the central or "prototypical" configuration of each studied face where this was included as one member of each test pair, whether or not it had been studied (Experiments 1, 2 and 4). Subjects were also quite accurate at recognizing one of the previously encountered extremes of the series of configurations that had been rated (Experiment 3), but when unseen prototypes were paired with seen exemplars subjects' performance was at chance (Experiment 5). Prototype learning of face patterns was shown to be stronger than that for house patterns, though both classes of patterns were affected equally by inversion (Experiment 6). The final two experiments demonstrated that preferences for the prototype could be affected by instructions at study and by whether different exemplars of the same face were shown consecutively or distributed through the study series. The discussion examines the implications of these results for theories of the representation of faces and for instance-based models of memory.

  7. Configuration Control Office

    CERN Multimedia

    Beltramello, O

    In order to enable Technical Coordination to manage the detector configuration and to be aware of all changes in this configuration, a baseline of the envelopes has been created in April 2001. Fifteen system and multi-system envelope drawings have been approved and baselined. An EDMS file is associated with each approved envelope, which provides a list of the current known unsolved conflicts related to the envelope and a list of remaining drawing inconsistencies to be corrected. The envelope status with the associated drawings and EDMS file can be found on the web at this adress: http://atlasinfo.cern.ch/Atlas/TCOORD/Activities/Installation/Configuration/ Any modification in the baseline has to be requested via the Engineering Change Requests. The procedure can be found under: http://atlasinfo.cern.ch/Atlas/TCOORD/Activities/TcOffice/Quality/ECR/ TC will review all the systems envelopes in the near future and manage conflict resolution with the collaboration of the systems.

  8. The LHCb configuration database

    CERN Document Server

    Abadie, L; Van Herwijnen, Eric; Jacobsson, R; Jost, B; Neufeld, N

    2005-01-01

    The aim of the LHCb configuration database is to store information about all the controllable devices of the detector. The experiment's control system (that uses PVSS ) will configure, start up and monitor the detector from the information in the configuration database. The database will contain devices with their properties, connectivity and hierarchy. The ability to store and rapidly retrieve huge amounts of data, and the navigability between devices are important requirements. We have collected use cases to ensure the completeness of the design. Using the entity relationship modelling technique we describe the use cases as classes with attributes and links. We designed the schema for the tables using relational diagrams. This methodology has been applied to the TFC (switches) and DAQ system. Other parts of the detector will follow later. The database has been implemented using Oracle to benefit from central CERN database support. The project also foresees the creation of tools to populate, maintain, and co...

  9. Oxygen configurations in silica

    International Nuclear Information System (INIS)

    Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

    2000-01-01

    We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O 2 bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society

  10. Stirling Engine Configuration Selection

    Directory of Open Access Journals (Sweden)

    Jose Egas

    2018-03-01

    Full Text Available Unlike internal combustion engines, Stirling engines can be designed to work with many drive mechanisms based on the three primary configurations, alpha, beta and gamma. Hundreds of different combinations of configuration and mechanical drives have been proposed. Few succeed beyond prototypes. A reason for poor success is the use of inappropriate configuration and drive mechanisms, which leads to low power to weight ratio and reduced economic viability. The large number of options, the lack of an objective comparison method, and the absence of a selection criteria force designers to make random choices. In this article, the pressure—volume diagrams and compression ratios of machines of equal dimensions, using the main (alpha, beta and gamma crank based configurations as well as rhombic drive and Ross yoke mechanisms, are obtained. The existence of a direct relation between the optimum compression ratio and the temperature ratio is derived from the ideal Stirling cycle, and the usability of an empirical low temperature difference compression ratio equation for high temperature difference applications is tested using experimental data. It is shown that each machine has a different compression ratio, making it more or less suitable for a specific application, depending on the temperature difference reachable.

  11. Global Value Chain Configuration

    DEFF Research Database (Denmark)

    Hernandez, Virginia; Pedersen, Torben

    2017-01-01

    modes chosen and the different ways of coordinating them. We also examine the outcomes of a global value chain configuration in terms of performance and upgrading. Our aim is to review the state of the art of these issues, identify research gaps and suggest new lines for future research that would...

  12. Inclusive Services Innovation Configuration

    Science.gov (United States)

    Holdheide, Lynn R.; Reschly, Daniel J.

    2011-01-01

    Teacher preparation to deliver inclusive services to students with disabilities is increasingly important because of changes in law and policy emphasizing student access to, and achievement in, the general education curriculum. This innovation configuration identifies the components of inclusive services that should be incorporated in teacher…

  13. Ansible configuration management

    CERN Document Server

    Hall, Daniel

    2015-01-01

    This book is intended for anyone who wants to learn Ansible starting from the basics. Some experience of how to set up and configure Linux machines and a working knowledge of BIND, MySQL, and other Linux daemons is expected.

  14. Symmetries of cluster configurations

    International Nuclear Information System (INIS)

    Kramer, P.

    1975-01-01

    A deeper understanding of clustering phenomena in nuclei must encompass at least two interrelated aspects of the subject: (A) Given a system of A nucleons with two-body interactions, what are the relevant and persistent modes of clustering involved. What is the nature of the correlated nucleon groups which form the clusters, and what is their mutual interaction. (B) Given the cluster modes and their interaction, what systematic patterns of nuclear structure and reactions emerge from it. Are there, for example, families of states which share the same ''cluster parents''. Which cluster modes are compatible or exclude each other. What quantum numbers could characterize cluster configurations. There is no doubt that we can learn a good deal from the experimentalists who have discovered many of the features relevant to aspect (B). Symmetries specific to cluster configurations which can throw some light on both aspects of clustering are discussed

  15. Analyzing Visibility Configurations.

    Science.gov (United States)

    Dachsbacher, C

    2011-04-01

    Many algorithms, such as level of detail rendering and occlusion culling methods, make decisions based on the degree of visibility of an object, but do not analyze the distribution, or structure, of the visible and occluded regions across surfaces. We present an efficient method to classify different visibility configurations and show how this can be used on top of existing methods based on visibility determination. We adapt co-occurrence matrices for visibility analysis and generalize them to operate on clusters of triangular surfaces instead of pixels. We employ machine learning techniques to reliably classify the thus extracted feature vectors. Our method allows perceptually motivated level of detail methods for real-time rendering applications by detecting configurations with expected visual masking. We exemplify the versatility of our method with an analysis of area light visibility configurations in ray tracing and an area-to-area visibility analysis suitable for hierarchical radiosity refinement. Initial results demonstrate the robustness, simplicity, and performance of our method in synthetic scenes, as well as real applications.

  16. Mechanical configuration and maintenance

    International Nuclear Information System (INIS)

    Brown, T.G.; Casini, G.; Churakov, G.F.

    1982-01-01

    The INTOR engineering design has been strongly influenced by considerations for assembly and maintenance. A maintenance philosophy was established at the outset of the conceptual design to insure that the tokamak configuration would be developed to accommodate maintenance requirements. The main features of the INTOR design are summarized in this paper with primary emphasis on the impact of maintenance considerations. The most apparent configuration design feature is the access provided for torus maintenance. Particular attention was given to the size and location of superconducting magnets and the location of vacuum boundaries. All of the poloidal field (PF) coils are placed outside of the bore of the toroidal field (TF) coils and located above and below an access opening between adjacent TF coils through which torus sectors are removed. A magnet structural configuration consisting of mechanically attached reinforcing members has been designed which facilitates the open access space for torus sector removal. For impurity control, a single null poloidal divertor was selected over a double null design in order to maintain sufficient access for pumping and maintenance of the collector. A double null divertor was found to severely limit access to the torus with the addition of divertor collectors and pumping at the top. For this reason, a single null concept was selected in spite of the more difficult design problems associated with the required asymmetric PF system and higher particle loadings

  17. System configuration on Web with mashup.

    OpenAIRE

    清水, 宏泰; SHIMIZU, Hiroyasu

    2014-01-01

    Mashup become trend for create Web service due to popularizing cloud service. Mashup is method for create Web service from several Web services and API. Mashup has a few problems. One of the problem is deference of data format and label. Semantic Web can solve it. This paper propose method of building a system on Web with mashup using semantic Web. Mashup system configuration can express as URL. So, editing URL for mashup is editing system configuration. And any device can use this system on ...

  18. 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

  19. Configuration Management Program Plan

    International Nuclear Information System (INIS)

    1991-01-01

    Westinghouse Savannah River Company (WSRC) has established a configuration management (CM) plan to execute the SRS CM Policy and the requirements of the DOE Order 4700.1. The Reactor Restart Division (RRD) has developed its CM Plan under the SRS CM Program and is implementing it via the RRD CM Program Plan and the Integrated Action Plan. The purpose of the RRD CM program is to improve those processes which are essential to the safe and efficient operation of SRS production reactors. This document provides details of this plan

  20. Ames Optimized TCA Configuration

    Science.gov (United States)

    Cliff, Susan E.; Reuther, James J.; Hicks, Raymond M.

    1999-01-01

    Configuration design at Ames was carried out with the SYN87-SB (single block) Euler code using a 193 x 49 x 65 C-H grid. The Euler solver is coupled to the constrained (NPSOL) and the unconstrained (QNMDIF) optimization packages. Since the single block grid is able to model only wing-body configurations, the nacelle/diverter effects were included in the optimization process by SYN87's option to superimpose the nacelle/diverter interference pressures on the wing. These interference pressures were calculated using the AIRPLANE code. AIRPLANE is an Euler solver that uses a unstructured tetrahedral mesh and is capable of computations about arbitrary complete configurations. In addition, the buoyancy effects of the nacelle/diverters were also included in the design process by imposing the pressure field obtained during the design process onto the triangulated surfaces of the nacelle/diverter mesh generated by AIRPLANE. The interference pressures and nacelle buoyancy effects are added to the final forces after each flow field calculation. Full details of the (recently enhanced) ghost nacelle capability are given in a related talk. The pseudo nacelle corrections were greatly improved during this design cycle. During the Ref H and Cycle 1 design activities, the nacelles were only translated and pitched. In the cycle 2 design effort the nacelles can translate vertically, and pitch to accommodate the changes in the lower surface geometry. The diverter heights (between their leading and trailing edges) were modified during design as the shape of the lower wing changed, with the drag of the diverter changing accordingly. Both adjoint and finite difference gradients were used during optimization. The adjoint-based gradients were found to give good direction in the design space for configurations near the starting point, but as the design approached a minimum, the finite difference gradients were found to be more accurate. Use of finite difference gradients was limited by the

  1. Gas/liquid flow configurations

    International Nuclear Information System (INIS)

    Bonin, Jacques; Fitremann, J.-M.

    1978-01-01

    Prediction of flow configurations (morphology) for gas/liquid or liquid/vapour mixtures is an important industrial problem which is not yet fully understood. The ''Flow Configurations'' Seminar of Societe Hydrotechnique de France has framed recommendations for investigation of potential industrial applications for flow configurations [fr

  2. Software Configurable Multichannel Transceiver

    Science.gov (United States)

    Freudinger, Lawrence C.; Cornelius, Harold; Hickling, Ron; Brooks, Walter

    2009-01-01

    Emerging test instrumentation and test scenarios increasingly require network communication to manage complexity. Adapting wireless communication infrastructure to accommodate challenging testing needs can benefit from reconfigurable radio technology. A fundamental requirement for a software-definable radio system is independence from carrier frequencies, one of the radio components that to date has seen only limited progress toward programmability. This paper overviews an ongoing project to validate the viability of a promising chipset that performs conversion of radio frequency (RF) signals directly into digital data for the wireless receiver and, for the transmitter, converts digital data into RF signals. The Software Configurable Multichannel Transceiver (SCMT) enables four transmitters and four receivers in a single unit the size of a commodity disk drive, programmable for any frequency band between 1 MHz and 6 GHz.

  3. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Seeberg, Jens; Christensen, Fie Lund Lindegaard

    2017-01-01

    Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...... is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism....

  4. Application of Configurators in Networks

    DEFF Research Database (Denmark)

    Malis, Martin; Hvam, Lars

    2003-01-01

    Shorter lead-time, improved quality of product specifications and better communication with customers and suppliers are benefits derived from the application of configurators. Configurators are knowledge-based IT-systems that can be applied to deal with product knowledge and to support different...... processes in a company. Traditionally, configurators have been used as an internal tool. In this paper focus will be on the application of configurators in a network of companies, and a procedure for developing product configurators in a network of companies will be presented. The aim is to present...... a structured guideline, tools and methods on how to successfully develop configurators in a network perspective. Findings presented in this paper are supported by research in a case company. The results from the empirical work show a huge potential for the application of configurators in networks of companies....

  5. Configuration space Faddeev calculations

    International Nuclear Information System (INIS)

    Payne, G.L.; Klink, W.H.; Ployzou, W.N.

    1991-01-01

    The detailed study of few-body systems provides one of the most precise tools for studying the dynamics of nuclei. Our research program consists of a careful theoretical study of the nuclear few-body systems. During the past year we have completed several aspects of this program. We have continued our program of using the trinucleon system to investigate the validity of various realistic nucleon-nucleon potentials. Also, the effects of meson-exchange currents in nuclear systems have been studied. Initial calculations using the configuration-space Faddeev equations for nucleon-deuteron scattering have been completed. With modifications to treat relativistic systems, few-body methods can be applied to phenomena that are sensitive to the structure of the individual hadrons. We have completed a review of Relativistic Hamiltonian Dynamics in Nuclear and Particle Physics for Advances in Nuclear Physics. Although it is called a review, it is a large document that contains a significant amount of new research

  6. Simulator configuration management system

    International Nuclear Information System (INIS)

    Faulent, J.; Brooks, J.G.

    1990-01-01

    The proposed revisions to ANS 3.5-1985 (Section 5) require Utilities to establish a simulator Configuration Management System (CMS). The proposed CMS must be capable of: Establishing and maintaining a simulator design database. Identifying and documenting differences between the simulator and its reference plant. Tracking the resolution of identified differences. Recording data to support simulator certification, testing and maintenance. This paper discusses a CMS capable of meeting the proposed requirements contained in ANS 3.5. The system will utilize a personal computer and a relational database management software to construct a simulator design database. The database will contain records to all reference nuclear plant data used in designing the simulator, as well as records identifying all the software, hardware and documentation making up the simulator. Using the relational powers of the database management software, reports will be generated identifying the impact of reference plant changes on the operation of the simulator. These reports can then be evaluated in terms of training needs to determine if changes are required for the simulator. If a change is authorized, the CMS will track the change through to its resolution and then incorporate the change into the simulator design database

  7. Synaptonemal complex analysis of interracial hybrids between the Moscow and Neroosa chromosomal races of the common shrew Sorex araneus showing regular formation of a complex meiotic configuration (ring-of-four).

    Science.gov (United States)

    Matveevsky, Sergey N; Pavlova, Svetlana V; Maret M Acaeva; Oxana L Kolomiets

    2012-01-01

    Immunocytochemical and electron microscopic analysis of synaptonemal complexes (SCs) was carried out for the first time in homozygotes and complex Robertsonian heterozygotes (hybrids) of the common shrew, Sorex araneus Linnaeus, 1758, from a newly discovered hybrid zone between the Moscow and the Neroosa chromosomal races. These races differ in four monobrachial homologous metacentrics, and closed SC tetravalent is expected to be formed in meiosis of a hybrid. Indeed, such a multivalent was found at meiotic prophase I in hybrids. Interactions between multivalent and both autosomes and/or the sex chromosomes were observed. For the first time we have used immunocytochemical techniques to analyse asynapsis in Sorex araneus and show that the multivalent pairs in an orderly fashion with complete synapsis. Despite some signs of spermatocytes arrested in the meiotic prophase I, hybrids had large number of active sperm. Thus, Moscow - Neroosa hybrid males that form a ring-of-four meiotic configuration are most likely not sterile. Our results support previous demonstrations that monobrachial homology of metacentrics of the common shrew does not lead to complete reproductive isolation between parapatric chromosomal races of the species.

  8. Synaptonemal complex analysis of interracial hybrids between the Moscow and Neroosa chromosomal races of the common shrew Sorex araneus showing regular formation of a complex meiotic configuration (ring-of-four

    Directory of Open Access Journals (Sweden)

    Sergey Matveevsky

    2012-09-01

    Full Text Available Immunocytochemical and electron microscopic analysis of synaptonemal complexes (SCs was carried out for the first time in homozygotes and complex Robertsonian heterozygotes (hybrids of the common shrew, Sorex araneus Linnaeus, 1758, from a newly discovered hybrid zone between the Moscow and the Neroosa chromosomal races. These races differ in four monobrachial homologous metacentrics, and closed SC tetravalent is expected to be formed in meiosis of a hybrid. Indeed, such a multivalent was found at meiotic prophase I in hybrids. Interactions between multivalent and both autosomes and/or the sex chromosomes were observed. For the first time we have used immunocytochemical techniques to analyse asynapsis in S. araneus and show that the multivalent pairs in an orderly fashion with complete synapsis. Despite some signs of spermatocytes arrested in the meiotic prophase I, hybrids had large number of active sperm. Thus, Moscow – Neroosa hybrid males that form a ring-of-four meiotic configuration are most likely not sterile. Our results support previous demonstrations that monobrachial homology of metacentrics of the common shrew does not lead to complete reproductive isolation between parapatric chromosomal races of the species.

  9. Field-reversing electron and ion rings for the confinement and heating of plasmas. Annual progress report, October 1, 1985-September 30, 1986

    International Nuclear Information System (INIS)

    Fleischmann, H.H.

    1986-10-01

    During the present, second period of our contract, the effort of our RECE-group was focussed mainly in four areas: (1) the design and construction of our new main experimental device, the megavolt ion coil experiment (MICE, aimed at generating 1-MeV ion rings) was continued. The device construction was completed and injection experiments recently have started using a half-cusp arrangement. (2) Using our smaller MERGE device (500 keV electrons, cusp injection), we investigated as expected the precessional stabilization of strong electron rings by a resistive wall. As expected, the experiments are completed. The results show excellent agreement with the basic theoretical expectations of our earlier analytic calculations and also with a more detailed computer code recently compiled. (3) Also, our MERGE device was completed as expected; experiments showed successful generation of electron and plasma rings; first experiments on the merging of these rings show a rapid attraction between the rings, which is to be properly slowed down by the introduction of a resistive wall. (4) Our pilot model calculations on mixed-CT configurations were nearly completed; including a survey of relevant plasma ring equilibria with a strong large-orbit particle components. Rough stability limits were obtained by studying the magnetic interaction between the two components

  10. DICOM supported sofware configuration by XML files

    International Nuclear Information System (INIS)

    LucenaG, Bioing Fabian M; Valdez D, Andres E; Gomez, Maria E; Nasisi, Oscar H

    2007-01-01

    A method for the configuration of informatics systems that provide support to DICOM standards using XML files is proposed. The difference with other proposals is base on that this system does not code the information of a DICOM objects file, but codes the standard itself in an XML file. The development itself is the format for the XML files mentioned, in order that they can support what DICOM normalizes for multiple languages. In this way, the same configuration file (or files) can be use in different systems. Jointly the XML configuration file generated, we wrote also a set of CSS and XSL files. So the same file can be visualized in a standard browser, as a query system of DICOM standard, emerging use, that did not was a main objective but brings a great utility and versatility. We exposed also some uses examples of the configuration file mainly in relation with the load of DICOM information objects. Finally, at the conclusions we show the utility that the system has already provided when the edition of DICOM standard changes from 2006 to 2007

  11. Configuration studies of LHD plasmas

    International Nuclear Information System (INIS)

    Okamoto, M.

    1997-01-01

    Configuration studies are performed on the plasmas of The Large Helical Device (LHD), the construction of which is almost completed at the National Institute for Fusion Science. The LHD has flexibility as an experimental device and can have various configurations by changing the poloidal magnetic fields, the pitch of the helical coils (pitch parameter), and the ratio of currents flowing in the two helical coils. Characteristics of the plasma are investigated for the standard configuration, the change in the pitch parameter, and the helical axis configuration

  12. Configuration studies of LHD plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Masao

    1997-03-01

    Configuration studies are performed on the plasmas of The Large Helical Device (LHD), the construction of which is almost completed at the National Institute for Fusion Science. The LHD has flexibility as an experimental device and can have various configurations by changing the poloidal magnetic fields, the pitch of the helical coils (pitch parameter), and the ratio of currents flowing in the two helical coils. Characteristics of the plasma are investigated for the standard configuration, the change in the pitch parameter, and the helical axis configuration. (author)

  13. Applying design principles to fusion reactor configurations for propulsion in space

    International Nuclear Information System (INIS)

    Carpenter, S.A.; Deveny, M.E.; Schulze, N.R.

    1993-01-01

    The application of fusion power to space propulsion requires rethinking the engineering-design solution to controlled-fusion energy. Whereas the unit cost of electricity (COE) drives the engineering-design solution for utility-based fusion reactor configurations; initial mass to low earth orbit (IMLEO), specific jet power (kW(thrust)/kg(engine)), and reusability drive the engineering-design solution for successful application of fusion power to space propulsion. Three design principles (DP's) were applied to adapt and optimize three candidate-terrestrial-fusion-reactor configurations for propulsion in space. The three design principles are: provide maximum direct access to space for waste radiation, operate components as passive radiators to minimize cooling-system mass, and optimize the plasma fuel, fuel mix, and temperature for best specific jet power. The three candidate terrestrial fusion reactor configurations are: the thermal barrier tandem mirror (TBTM), field reversed mirror (FRM), and levitated dipole field (LDF). The resulting three candidate space fusion propulsion systems have their IMLEO minimized and their specific jet power and reusability maximized. A preliminary rating of these configurations was performed, and it was concluded that the leading engineering-design solution to space fusion propulsion is a modified TBTM that we call the Mirror Fusion Propulsion System (MFPS)

  14. Configurational entropy of glueball states

    Energy Technology Data Exchange (ETDEWEB)

    Bernardini, Alex E., E-mail: alexeb@ufscar.br [Departamento de Física, Universidade Federal de São Carlos, PO Box 676, 13565-905, São Carlos, SP (Brazil); Braga, Nelson R.F., E-mail: braga@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RJ 21941-972 (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [CMCC, Universidade Federal do ABC, UFABC, 09210-580, Santo André (Brazil)

    2017-02-10

    The configurational entropy of glueball states is calculated using a holographic description. Glueball states are represented by a supergravity dual picture, consisting of a 5-dimensional graviton–dilaton action of a dynamical holographic AdS/QCD model. The configurational entropy is studied as a function of the glueball spin and of the mass, providing information about the stability of the glueball states.

  15. Dynamics and configurations of galaxy triplets

    International Nuclear Information System (INIS)

    Anosova, J.P.; Orlov, V.V.; Chernin, A.D.; Ivanov, A.V.; Kiseleva, L.G.

    1990-01-01

    The purpose is to infer the probable dynamical states of galaxy triplets by the observed data on their configurations. Two methods are proposed for describing the distributions of the triplet configuration parameters characterizing a tendency to alignment and hierarchy: (1) obtaining a representative sample of configurations and determining its statistical parameters (moments and percentages); and (2) dividing the region of possible configurations of triple systems (Agekian and Anosova, 1967) into a set of segments and finding the probabilities for the configurations to find themselves in each of them. Both these methods allow representation of the data by numerical simulations as well as observations. The effect of projection was studied. It rather overestimates the alignment and hierarchy of the triple systems. Among the parameters of interest there are found some parameters that are least sensitive to projection effects. The samples consist of simulated galaxy triplets (with hidden mass) as well as of 46 probably physical triple galaxies (Karachentseva et al., 1979). The observed triples as well as numerical models show a tendency to alignment. The triple galaxies do not show any tendency to hierarchy (formation of the temporary binaries), but this tendency may be present for simulated triplets without significant dark matter. The significant hidden mass (of order ten times the total mass of a triplet) decreases the probability of forming a binary and so weakens the hierarchy. Small galaxy groups consisting of 3 to 7 members are probably the most prevalent types of galaxy aggregate (Gorbatsky, 1987). Galaxy triplets are the simplest groups, but dynamically nontrivial ones

  16. Viscous Design of TCA Configuration

    Science.gov (United States)

    Krist, Steven E.; Bauer, Steven X. S.; Campbell, Richard L.

    1999-01-01

    The goal in this effort is to redesign the baseline TCA configuration for improved performance at both supersonic and transonic cruise. Viscous analyses are conducted with OVERFLOW, a Navier-Stokes code for overset grids, using PEGSUS to compute the interpolations between overset grids. Viscous designs are conducted with OVERDISC, a script which couples OVERFLOW with the Constrained Direct Iterative Surface Curvature (CDISC) inverse design method. The successful execution of any computational fluid dynamics (CFD) based aerodynamic design method for complex configurations requires an efficient method for regenerating the computational grids to account for modifications to the configuration shape. The first section of this presentation deals with the automated regridding procedure used to generate overset grids for the fuselage/wing/diverter/nacelle configurations analysed in this effort. The second section outlines the procedures utilized to conduct OVERDISC inverse designs. The third section briefly covers the work conducted by Dick Campbell, in which a dual-point design at Mach 2.4 and 0.9 was attempted using OVERDISC; the initial configuration from which this design effort was started is an early version of the optimized shape for the TCA configuration developed by the Boeing Commercial Airplane Group (BCAG), which eventually evolved into the NCV design. The final section presents results from application of the Natural Flow Wing design philosophy to the TCA configuration.

  17. A Software Configuration Management Course

    DEFF Research Database (Denmark)

    Asklund, U.; Bendix, Lars Gotfred

    2003-01-01

    Software Configuration Management has been a big success in research and creation of tools. There are also many vendors in the market of selling courses to companies. However, in the education sector Software Configuration Management has still not quite made it - at least not into the university...... curriculum. It is either not taught at all or is just a minor part of a general course in software engineering. In this paper, we report on our experience with giving a full course entirely dedicated to Software Configuration Management topics and start a discussion of what ideally should be the goal...

  18. Device configuration-management system

    International Nuclear Information System (INIS)

    Nowell, D.M.

    1981-01-01

    The Fusion Chamber System, a major component of the Magnetic Fusion Test Facility, contains several hundred devices which report status to the Supervisory Control and Diagnostic System for control and monitoring purposes. To manage the large number of diversity of devices represented, a device configuration management system was required and developed. Key components of this software tool include the MFTF Data Base; a configuration editor; and a tree structure defining the relationships between the subsystem devices. This paper will describe how the configuration system easily accomodates recognizing new devices, restructuring existing devices, and modifying device profile information

  19. Airport Configuration Prediction, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There is presently poor knowledge throughout the National Airspace System (NAS) of the airport configurations currently in use at each airport. There is even less...

  20. Belene NPP project configuration management

    International Nuclear Information System (INIS)

    Matveev, A.

    2009-01-01

    The configuration management includes: change identification; change assessment; change coordination; change approval or rejection; Change introduction. One of the main tasks while implementing the above processes is the analysis of the effect of one change upon all the related elements

  1. Bayesian image restoration, using configurations

    OpenAIRE

    Thorarinsdottir, Thordis

    2006-01-01

    In this paper, we develop a Bayesian procedure for removing noise from images that can be viewed as noisy realisations of random sets in the plane. The procedure utilises recent advances in configuration theory for noise free random sets, where the probabilities of observing the different boundary configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the re...

  2. Knowledge Based Product Configuration - a documentatio tool for configuration projects

    DEFF Research Database (Denmark)

    Hvam, Lars; Malis, Martin

    2003-01-01

    . A lot of knowledge isput into these systems and many domain experts are involved. This calls for an effective documentation system in order to structure this knowledge in a way that fits to the systems. Standard configuration systems do not support this kind of documentation. The chapter deals...... with the development of a Lotus Notes application that serves as a knowledge based documentation tool for configuration projects. A prototype has been developed and tested empirically in an industrial case-company. It has proved to be a succes....

  3. Moderator Configuration Options for ESS

    DEFF Research Database (Denmark)

    Zanini, L.; Batkov, K.; Klinkby, Esben Bryndt

    2016-01-01

    The current, still evolving status of the design and the optimization work for the moderator configuration for the European Spallation Source is described. The moderator design has been strongly driven by the low-dimensional moderator concept recently proposed for use in spallation neutron sources...... or reactors. Quasi-two dimensional, disc- or tube-shaped moderators,can provide strong brightness increase (factor of 3 or more) with respect to volume para-H2moderators, which constitute the reference, state-of-the-art technology for high-intensity coupled moderators. In the design process other, more...... conventional, principles were also considered,such as the importance of moderator positioning, of the premoderator, and beam extraction considerations. Different design and configuration options are evaluated and compared with the reference volume moderator configuration described in the ESS Technical Design...

  4. Development of Simulator Configuration Tool

    International Nuclear Information System (INIS)

    Nedrelid, Olav; Pettersen, Geir

    1996-01-01

    The main objective of the development of a Simulator Configuration Tool (SCT) is to achieve faster and more efficient production of dynamic simulators. Through application of versatile graphical interfaces, the simulator builder should be able to configure different types of simulators including full-scope process simulators. The SCT should be able to serve different simulator environments. The configuration tool communicates with simulator execution environments through a TCP/IP-based interface, Communication with a Model Server System developed at Institutt for energiteknikk has been established and used as test case. The system consists of OSF/Motif dialogues for operations requiring textual input, list selections etc., and uses the Picasso-3 User Interface Management System to handle presentation of static and dynamic graphical information. (author)

  5. BAYESIAN IMAGE RESTORATION, USING CONFIGURATIONS

    Directory of Open Access Journals (Sweden)

    Thordis Linda Thorarinsdottir

    2011-05-01

    Full Text Available In this paper, we develop a Bayesian procedure for removing noise from images that can be viewed as noisy realisations of random sets in the plane. The procedure utilises recent advances in configuration theory for noise free random sets, where the probabilities of observing the different boundary configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for salt and pepper noise. The inference in the model is discussed in detail for 3 X 3 and 5 X 5 configurations and examples of the performance of the procedure are given.

  6. Projective configurations in projectivegeometrical drawings

    Directory of Open Access Journals (Sweden)

    Ivashchenko Andrey Viktorovich

    2015-05-01

    Full Text Available The article focuses on the optimization of the earlier discussed computer method of obtaining new forms of polyhedra based on projective geometry drawings (trace Diagrams.While working on getting new multifaceted forms by projective geometry methods based on the well-known models of polyhedra on the first stage of the work it is required to calculate the parameters of projective geometry drawings, and then to build them. This is an often used apparatus of analytical geometry. According to it, at first the parameters of the polyhedron (core system of planes are calculated, then we obtain the equation of the plane of the face of the polyhedron, and finally we obtain the equations of lines the next plane faces on the selected curve plane. At each stage of application such a method requires the use of the algorithms of floating point arithmetic, on the one hand, leads to some loss of accuracy of the results and, on the other hand, the large amount of computer time to perform these operations in comparison with integer arithmetic operations.The proposed method is based on the laws existing between the lines that make up the drawing - the known configurations of projective geometry (complete quadrilaterals, configuration of Desargues, Pappus et al..The authors discussed in detail the analysis procedure of projective geometry drawing and the presence of full quadrilaterals, Desargues and Pappus configurations in it.Since the composition of these configurations is invariant with respect to projective change of the original nucleus, knowing them, you can avoid the calculations when solving the equations for finding direct projective geometry drawing analytically, getting them on the basis of belonging to a particular configuration. So you can get a definite advantage in accuracy of the results, and in the cost of computer time. Finding these basic configurations significantly enriches the set of methods and the use of projective geometry drawings.

  7. Instance-specific algorithm configuration

    CERN Document Server

    Malitsky, Yuri

    2014-01-01

    This book presents a modular and expandable technique in the rapidly emerging research area of automatic configuration and selection of the best algorithm for the instance at hand. The author presents the basic model behind ISAC and then details a number of modifications and practical applications. In particular, he addresses automated feature generation, offline algorithm configuration for portfolio generation, algorithm selection, adaptive solvers, online tuning, and parallelization.    The author's related thesis was honorably mentioned (runner-up) for the ACP Dissertation Award in 2014,

  8. Dynamical similarity of geomagnetic field reversals.

    Science.gov (United States)

    Valet, Jean-Pierre; Fournier, Alexandre; Courtillot, Vincent; Herrero-Bervera, Emilio

    2012-10-04

    No consensus has been reached so far on the properties of the geomagnetic field during reversals or on the main features that might reveal its dynamics. A main characteristic of the reversing field is a large decrease in the axial dipole and the dominant role of non-dipole components. Other features strongly depend on whether they are derived from sedimentary or volcanic records. Only thermal remanent magnetization of lava flows can capture faithful records of a rapidly varying non-dipole field, but, because of episodic volcanic activity, sequences of overlying flows yield incomplete records. Here we show that the ten most detailed volcanic records of reversals can be matched in a very satisfactory way, under the assumption of a common duration, revealing common dynamical characteristics. We infer that the reversal process has remained unchanged, with the same time constants and durations, at least since 180 million years ago. We propose that the reversing field is characterized by three successive phases: a precursory event, a 180° polarity switch and a rebound. The first and third phases reflect the emergence of the non-dipole field with large-amplitude secular variation. They are rarely both recorded at the same site owing to the rapidly changing field geometry and last for less than 2,500 years. The actual transit between the two polarities does not last longer than 1,000 years and might therefore result from mechanisms other than those governing normal secular variation. Such changes are too brief to be accurately recorded by most sediments.

  9. FARADAY ROTATION: EFFECT OF MAGNETIC FIELD REVERSALS

    International Nuclear Information System (INIS)

    Melrose, D. B.

    2010-01-01

    The standard formula for the rotation measure (RM), which determines the position angle, ψ = RMλ 2 , due to Faraday rotation, includes contributions only from the portions of the ray path where the natural modes of the plasma are circularly polarized. In small regions of the ray path where the projection of the magnetic field on the ray path reverses sign (called QT regions) the modes are nearly linearly polarized. The neglect of QT regions in estimating RM is not well justified at frequencies below a transition frequency where mode coupling changes from strong to weak. By integrating the polarization transfer equation across a QT region in the latter limit, I estimate the additional contribution Δψ needed to correct this omission. In contrast with a result proposed by Broderick and Blandford, Δψ is small and probably unobservable. I identify a new source of circular polarization, due to mode coupling in an asymmetric QT region. I also identify a new circular-polarization-dependent correction to the dispersion measure at low frequencies.

  10. FARADAY ROTATION: EFFECT OF MAGNETIC FIELD REVERSALS

    Energy Technology Data Exchange (ETDEWEB)

    Melrose, D B [SIfA, School of Physics, University of Sydney, NSW 2006 (Australia)

    2010-12-20

    The standard formula for the rotation measure (RM), which determines the position angle, {psi} = RM{lambda}{sup 2}, due to Faraday rotation, includes contributions only from the portions of the ray path where the natural modes of the plasma are circularly polarized. In small regions of the ray path where the projection of the magnetic field on the ray path reverses sign (called QT regions) the modes are nearly linearly polarized. The neglect of QT regions in estimating RM is not well justified at frequencies below a transition frequency where mode coupling changes from strong to weak. By integrating the polarization transfer equation across a QT region in the latter limit, I estimate the additional contribution {Delta}{psi} needed to correct this omission. In contrast with a result proposed by Broderick and Blandford, {Delta}{psi} is small and probably unobservable. I identify a new source of circular polarization, due to mode coupling in an asymmetric QT region. I also identify a new circular-polarization-dependent correction to the dispersion measure at low frequencies.

  11. NCCDS configuration management process improvement

    Science.gov (United States)

    Shay, Kathy

    1993-01-01

    By concentrating on defining and improving specific Configuration Management (CM) functions, processes, procedures, personnel selection/development, and tools, internal and external customers received improved CM services. Job performance within the section increased in both satisfaction and output. Participation in achieving major improvements has led to the delivery of consistent quality CM products as well as significant decreases in every measured CM metrics category.

  12. Kramers Pairs in configuration interaction

    DEFF Research Database (Denmark)

    Avery, John Scales; Avery, James Emil

    2003-01-01

    The theory of symmetry-preserving Kramers pair creation operators is reviewed and formulas for applying these operators to configuration interaction calculations are derived. A new and more general type of symmetry-preserving pair creation operator is proposed and shown to commute with the total ...

  13. Bayesian image restoration, using configurations

    DEFF Research Database (Denmark)

    Thorarinsdottir, Thordis

    configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for salt and pepper noise. The inference in the model is discussed...

  14. Bayesian image restoration, using configurations

    DEFF Research Database (Denmark)

    Thorarinsdottir, Thordis Linda

    2006-01-01

    configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for the salt and pepper noise. The inference in the model is discussed...

  15. Equilibrium: three-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    This chapter considers toroidal MHD configurations that are inherently three-dimensional. The motivation for investigation such complicated equilibria is that they possess the potential for providing toroidal confinement without the need of a net toroidal current. This leads to a number of advantages with respect to fusion power generation. First, the attractive feature of steady-state operation becomes more feasible since such configurations no longer require a toroidal current transformer. Second, with zero net current, one potentially dangerous class of MHD instabilities, the current-driven kink modes, is eliminated. Finally, three-dimensional configurations possess nondegenerate flux surfaces even in the absence of plasma pressure and plasma current. Although there is an enormous range of possible three-dimensional equilibria, the configurations of interest are accurately described as axisymmetric tori with superimposed helical fields; furthermore, they possess no net toroidal current. Instead, two different and less obvious restoring forces are developed: the helical sideband force and the toroidal dipole current force. Each is discussed in detail in Chapter 7. A detailed discussion of the parallel current constraint, including its physical significance, is given in section 7.2. A general analysis of helical sideband equilibria, along with a detailed description of the Elmo bumpy torus, is presented in sections 7.3 and 7.4. A general description of toroidal dipole-current equilibria, including a detailed discussion of stellarators, heliotrons, and torsatrons, is given in sections 7.5 and 7.6

  16. Product Configuration Systems and Productivity

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Lindgaard; Edwards, Kasper

    2004-01-01

    Twelve companies have been interviewed with the purpose to get information about technical, economic and organisational matters in respect of Product Configuration Systems (PCS).Combinations of qualitative interviews and quantitative scoring have been used in ranking expected and realized results...

  17. Environmental restoration project configuration control

    International Nuclear Information System (INIS)

    Hutterman, L.L.

    1991-01-01

    This paper provides an overview of the approach that Westinghouse Idaho Nuclear Company, Inc. (WINCO) is using for the implementation of the configuration control requirements for a major system acquisition under the guidance of US Department of Energy (DOE) Order 4700.1, open-quotes Project Management System,close quotes for environmental restoration. The two major features of the WINCO environmental restoration approach relate to (1) the product and (2) the maintenance of the baseline for many sites in different phases at the same time. Historically, a project has typically produced a product. Environmental restoration in some ways produces no typical project product. Essentially, what is produced and what configuration control management is exercised on is one of the following: (1) the development of clean dirt, (2) the documentation to support clean dirt, or (3) the track record of each of the sites. It is the latter approach that this paper deals with. This approach is unique in that there are four baselines [cost, schedule, scope, and technical (the track record product)] rather than the typical three. This is essential in configuration management due to the lack of a uniquely identifiable product for each site. Essentially, the philosophy behind the four-part configuration controls allows the technical baseline to fulfill the function typically met by the identifiable product

  18. Deployable reflector configurations. [for space telescope

    Science.gov (United States)

    Meinel, A. B.; Meinel, M. P.; Woolf, N. J.

    1983-01-01

    Both the theoretical reasons for considering a non-circular format for the Large Deployable Reflector, and a potentially realizable concept for such a device, are discussed. The optimum systems for diffraction limited telescopes with incoherent detection have either a single filled aperture, or two such apertures as an interferometer to synthesize a larger aperture. For a single aperture of limited area, a reflector in the form of a slot can be used to give increased angular resolution. It is shown how a 20 x 8 meter telescope can be configured to fit the Space Shuttle bay, and deployed with relatively simple operations. The relationship between the sunshield design and the inclination of the orbit is discussed. The possible use of the LDR as a basic module to permit the construction of supergiant space telescopes and interferometers both for IR/submm studies and for the entire ultraviolet through mm wave spectral region is discussed.

  19. MarFS-Requirements-Design-Configuration-Admin

    Energy Technology Data Exchange (ETDEWEB)

    Kettering, Brett Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Grider, Gary Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-08

    This document will be organized into sections that are defined by the requirements for a file system that presents a near-POSIX (Portable Operating System Interface) interface to the user, but whose data is stored in whatever form is most efficient for the type of data being stored. After defining the requirement the design for meeting the requirement will be explained. Finally there will be sections on configuring and administering this file system. More and more, data dominates the computing world. There is a “sea” of data out there in many different formats that needs to be managed and used. “Mar” means “sea” in Spanish. Thus, this product is dubbed MarFS, a file system for a sea of data.

  20. Configuring Symantec AntiVirus

    CERN Document Server

    Shimonski, Robert

    2003-01-01

    This is the only book that will teach system administrators how to configure, deploy, and troubleshoot Symantec Enterprise Edition in an enterprise network. The book will reflect Symantec''s philosophy of "Centralized Antivirus Management." For the same reasons that Symantec bundled together these previously separate products, the book will provide system administrators with a holistic approach to defending their networks from malicious viruses. This book will also serve as a Study Guide for those pursuing Symantec Product Specialist Certifications.Configuring Symantec AntiVirus Enterprise Edition contains step-by-step instructions on how to Design, implement and leverage the Symantec Suite of products in the enterprise.ØFirst book published on market leading product and fast-growing certification. Despite the popularity of Symantec''s products and Symantec Product Specialist certifications, there are no other books published or announced.ØLess expensive substitute for costly on-sight training. Symantec off...

  1. Snowflake Divertor Configuration in NSTX

    International Nuclear Information System (INIS)

    Soukhanovskii, V.A.; Ahn, Joonwook; Bell, R.E.; Gates, D.A.; Gerhardt, S.; Kaita, R.; Kolemen, E.; Kugel, H.W.; LeBlanc, B.; Maingi, Rajesh; Maqueda, R.J.; McLean, Adam G.; Menard, J.E.; Mueller, D.; Paul, S.F.; Raman, R.; Roquemore, L.; Ryutov, D.D.; Scott, H.A.

    2011-01-01

    Steady-state handling of divertor heat flux is a critical issue for present and future conventional and spherical tokamaks with compact high power density divertors. A novel 'snowflake' divertor (SFD) configuration that takes advantage of magnetic properties of a second-order poloidal null has been predicted to have a larger plasma-wetted area and a larger divertor volume, in comparison with a standard first-order poloidal X-point divertor configuration. The SFD was obtained in 0.8 MA, 4-6 MW NBI-heated H-mode discharges in NSTX using two divertor magnetic coils. The SFD led to a partial detachment of the outer strike point even in low-collisionality scrape-off layer plasma obtained with lithium coatings in NSTX. Significant divertor peak heat flux reduction and impurity screening have been achieved simultaneously with good core confinement and MHD properties.

  2. 'Snowflake' divertor configuration in NSTX

    International Nuclear Information System (INIS)

    Soukhanovskii, V.A.; Ahn, J.-W.; Bell, R.E.; Gates, D.A.; Gerhardt, S.; Kaita, R.; Kolemen, E.; Kugel, H.W.; LeBlanc, B.P.; Maingi, R.; Maqueda, R.; McLean, A.; Menard, J.E.; Mueller, D.M.; Paul, S.F.; Raman, R.; Roquemore, A.L.; Ryutov, D.D.; Scott, H.A.

    2011-01-01

    Steady-state handling of divertor heat flux is a critical issue for present and future conventional and spherical tokamaks with compact high power density divertors. A novel 'snowflake' divertor (SFD) configuration that takes advantage of magnetic properties of a second-order poloidal null has been predicted to have a larger plasma-wetted area and a larger divertor volume, in comparison with a standard first-order poloidal X-point divertor configuration. The SFD was obtained in 0.8 MA, 4-6 MW NBI-heated H-mode discharges in NSTX using two divertor magnetic coils. The SFD led to a partial detachment of the outer strike point even in low-collisionality scrape-off layer plasma obtained with lithium coatings in NSTX. Significant divertor peak heat flux reduction and impurity screening have been achieved simultaneously with good core confinement and MHD properties.

  3. "Snowflake" divertor configuration in NSTX

    Science.gov (United States)

    Soukhanovskii, V. A.; Ahn, J.-W.; Bell, R. E.; Gates, D. A.; Gerhardt, S.; Kaita, R.; Kolemen, E.; Kugel, H. W.; Leblanc, B. P.; Maingi, R.; Maqueda, R.; McLean, A.; Menard, J. E.; Mueller, D. M.; Paul, S. F.; Raman, R.; Roquemore, A. L.; Ryutov, D. D.; Scott, H. A.

    2011-08-01

    Steady-state handling of divertor heat flux is a critical issue for present and future conventional and spherical tokamaks with compact high power density divertors. A novel "snowflake" divertor (SFD) configuration that takes advantage of magnetic properties of a second-order poloidal null has been predicted to have a larger plasma-wetted area and a larger divertor volume, in comparison with a standard first-order poloidal X-point divertor configuration. The SFD was obtained in 0.8 MA, 4-6 MW NBI-heated H-mode discharges in NSTX using two divertor magnetic coils. The SFD led to a partial detachment of the outer strike point even in low-collisionality scrape-off layer plasma obtained with lithium coatings in NSTX. Significant divertor peak heat flux reduction and impurity screening have been achieved simultaneously with good core confinement and MHD properties.

  4. Automatic creation of simulation configuration

    International Nuclear Information System (INIS)

    Oudot, G.; Poizat, F.

    1993-01-01

    SIPA, which stands for 'Simulator for Post Accident', includes: 1) a sophisticated software oriented workshop SWORD (which stands for 'Software Workshop Oriented towards Research and Development') designed in the ADA language including integrated CAD system and software tools for automatic generation of simulation software and man-machine interface in order to operate run-time simulation; 2) a 'simulator structure' based on hardware equipment and software for supervision and communications; 3) simulation configuration generated by SWORD, operated under the control of the 'simulator structure' and run on a target computer. SWORD has already been used to generate two simulation configurations (French 900 MW and 1300 MW nuclear power plants), which are now fully operational on the SIPA training simulator. (Z.S.) 1 ref

  5. Microsoft System Center Configuration Manager

    CERN Document Server

    Sandbu, Marius

    2013-01-01

    This book is a step-by-step tutorial that guides you through the key steps in implementing best solutions for high availability and performance tuning. It is split into two distinct approaches: client and site side HA and optimization.Microsoft SCCM High Availability and Performance Tuning is for IT professionals and consultants working with Configuration Manager who wish to learn the skills to deploy a redundant and scalable solution.

  6. Safe Configuration of TLS Connections

    Science.gov (United States)

    2013-10-16

    comparison with observed flows to flag inconsistencies. Keywords: Transport Layer Security ( TLS ), Secure Socket Layer ( SSL ), configuration, secure...servers. SSL / TLS has evolved over 18 years from SSL 1.0 to TLS 1.2 and has been widely deployed and accepted across Internet servers. This has made...and provides a large-scale view of TLS properties across Internet web sites. The guidance provided in [10] describes best practices for SSL / TLS

  7. Drupal 7 Multi Sites Configuration

    CERN Document Server

    Butcher, Matt

    2012-01-01

    Follow the creation of a multi-site instance with Drupal. The practical examples and accompanying screenshots will help you to get multiple Drupal sites set up in no time. This book is for Drupal site builders. It is assumed that readers are familiar with Drupal already, with a basic grasp of its concepts and components. System administration concepts, such as configuring Apache, MySQL, and Vagrant are covered but no previous knowledge of these tools is required.

  8. Low emittance configuration for spear

    International Nuclear Information System (INIS)

    Blumberg, L.N.; Harris, J.; Stege, R.; Cerino, J.; Hettel, R.; Hofmann, A.; Liu, R.Z.; Wiedemann, H.; Winick, H.

    1985-01-01

    The quality of synchrotron radiation beams from SPEAR, in particular the brilliance of undulator radiation, can be improved significantly by reducing the emittance of the stored electron beam. A reduction of the horizontal emittance by a factor of 3.5 to a value of 130 nanometer-radians (nm-r) at 3 GeV has been achieved by using stronger focussing, mainly in the horizontal plane. The low emittance configuration also reduces the dispersion and vertical beta functions in the straight sections, making them more suitable for wigglers. The higher betatron tunes lead to a larger phase advance between the two kickers, which has to be corrected during injection by shunting current from some quadrupoles. The configuration was optimized within SPEAR hardware limitations and tested for dynamic aperture with the tracking program PATRICIA. After implementation of this scheme, beam was successfully injected and accumulated. The measured emittance of the stored beam was in agreement with calculations. Presently the configuration is being made operational

  9. Configuration Management Process Assessment Strategy

    Science.gov (United States)

    Henry, Thad

    2014-01-01

    Purpose: To propose a strategy for assessing the development and effectiveness of configuration management systems within Programs, Projects, and Design Activities performed by technical organizations and their supporting development contractors. Scope: Various entities CM Systems will be assessed dependent on Project Scope (DDT&E), Support Services and Acquisition Agreements. Approach: Model based structured against assessing organizations CM requirements including best practices maturity criteria. The model is tailored to the entity being assessed dependent on their CM system. The assessment approach provides objective feedback to Engineering and Project Management of the observed CM system maturity state versus the ideal state of the configuration management processes and outcomes(system). center dot Identifies strengths and risks versus audit gotcha's (findings/observations). center dot Used "recursively and iteratively" throughout program lifecycle at select points of need. (Typical assessments timing is Post PDR/Post CDR) center dot Ideal state criteria and maturity targets are reviewed with the assessed entity prior to an assessment (Tailoring) and is dependent on the assessed phase of the CM system. center dot Supports exit success criteria for Preliminary and Critical Design Reviews. center dot Gives a comprehensive CM system assessment which ultimately supports configuration verification activities.*

  10. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  11. Transport modelling for ergodic configurations

    International Nuclear Information System (INIS)

    Runov, A.; Kasilov, S.V.; McTaggart, N.; Schneider, R.; Bonnin, X.; Zagorski, R.; Reiter, D.

    2004-01-01

    The effect of ergodization, either by additional coils like in TEXTOR-dynamic ergodic divertor (DED) or by intrinsic plasma effects like in W7-X, defines the need for transport models that are able to describe the ergodic configuration properly. A prerequisite for this is the concept of local magnetic coordinates allowing a correct discretization with minimized numerical errors. For these coordinates the appropriate full metric tensor has to be known. To study the transport in complex edge geometries (in particular for W7-X) two possible methods are used. First, a finite-difference discretization of the transport equations on a custom-tailored grid in local magnetic coordinates is used. This grid is generated by field-line tracing to guarantee an exact discretization of the dominant parallel transport (thus also minimizing the numerical diffusion problem). The perpendicular fluxes are then interpolated in a plane (a toroidal cut), where the interpolation problem for a quasi-isotropic system has to be solved by a constrained Delaunay triangulation (keeping the structural information for magnetic surfaces if they exist) and discretization. All toroidal terms are discretized by finite differences. Second, a Monte Carlo transport model originally developed for the modelling of the DED configuration of TEXTOR is used. A generalization and extension of this model was necessary to be able to handle W7-X. The model solves the transport equations with Monte Carlo techniques making use of mappings of local magnetic coordinates. The application of this technique to W7-X in a limiter-like configuration is presented. The decreasing dominance of parallel transport with respect to radial transport for electron heat, ion heat and particle transport results in increasingly steep profiles for the respective quantities within the islands. (author)

  12. Variable configuration plasmas in TCV

    International Nuclear Information System (INIS)

    Lister, J.B.; Hofmann, F.; Anton, M.

    1994-01-01

    During its first year of operation, TCV has achieved a wide variety of plasma shapes, limited and diverted, attaining 810 kA plasma current and elongation over 2.0. Ohmic H-Modes have been regularly produced, with a maximum confinement time of 80 msec and maximum normalised β N of 1.9. The conditions for the H-Mode transition differ from other experiments. The transitions from ELM-free to ELMy H-Modes and back have been selectively triggered for configurations close to a Double-Null. (author) 3 figs., 5 refs

  13. Variable configuration plasmas in TCV

    International Nuclear Information System (INIS)

    Lister, J.B.; Hofmann, F.; Anton, M.

    1995-01-01

    During its first year of operation, TCV has achieved a wide variety of plasma shapes, limited and diverted, attaining 810 kA plasma current and elongation over 2.0. Ohmic H modes have been regularly produced, with a maximum confinement time of 80 ms and a maximum normalized β N of 1.9. The conditions for the H mode transition differ from other experiments. The transitions from ELM free to ELMy H modes and back have been selectively triggered for configurations close to a double-null. (author). 5 refs, 3 figs

  14. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  15. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  16. Dimensional regularization in configuration space

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1995-09-01

    Dimensional regularization is introduced in configuration space by Fourier transforming in D-dimensions the perturbative momentum space Green functions. For this transformation, Bochner theorem is used, no extra parameters, such as those of Feynman or Bogoliubov-Shirkov are needed for convolutions. The regularized causal functions in x-space have ν-dependent moderated singularities at the origin. They can be multiplied together and Fourier transformed (Bochner) without divergence problems. The usual ultraviolet divergences appear as poles of the resultant functions of ν. Several example are discussed. (author). 9 refs

  17. A (Re)Configuration Mechanism for Resource-Constrained Embedded Systems

    DEFF Research Database (Denmark)

    Guo, Yu; Sierszecki, Krzysztof; Angelov, Christo K.

    2008-01-01

    An embedded application, developed under the COMDES framework, is built from reusable components implemented as executable function blocks. These are stored in a component repository in a relocatable binary format, whereby the application is configured from prefabricated components, rather than...

  18. A qualitative examination of wheelchair configuration for optimal mobility performance in wheelchair sports : a pilot study

    NARCIS (Netherlands)

    Mason, Barry S.; Porcellato, Lorna; van der Woude, Lucas H. V.; Goosey-Tolfrey, Victoria L.

    Objective: To examine wheelchair athletes' perceptions of wheelchair configuration in relation to aspects of mobility performance. Methods: Nine elite wheelchair athletes from wheelchair basketball, wheelchair rugby and wheelchair tennis were interviewed using a semi-structured format. Interview

  19. Example of software configuration management model

    International Nuclear Information System (INIS)

    Roth, P.

    2006-01-01

    Software configuration management is the mechanism used to track and control software changes and may include the following actions: A tracking system should be established for any changes made to the existing software configuration. Requirement of the configuration management system are the following: - Backup the different software configuration; - Record the details (the date, the subject, the filenames, the supporting documents, the tests, ...) of the changes introduced in the new configuration; - Document all the differences between the different versions. Configuration management allows simultaneous exploitation of one specific version and development of the next version. Minor correction can be perform in the current exploitation version

  20. Magnetization configurations and hysteresis loops of small permalloy ellipses

    International Nuclear Information System (INIS)

    Schneider, M; Liszkowski, J; Rahm, M; Wegscheider, W; Weiss, D; Hoffmann, H; Zweck, J

    2003-01-01

    We investigated systematically the easy axis magnetization reversal of 20 nm thick permalloy ellipses with a fixed major axis of 1.47 μm and minor axes of 0.22-1.47 μm. Lorentz transmission electron microscopy was used to image the micromagnetic configurations during magnetization reversal. Hysteresis loops of single ellipses were recorded by means of micro-Hall magnetometry and could be traced back to certain reversal mechanisms observed by Lorentz microscopy. In most cases, the magnetization reversal is initiated by the evolution of a magnetization buckling, followed by the formation of a single, a double, or a trapped vortex configuration. For ellipses with high aspect ratio (length-to-width ratio), the magnetization switches in the reversed magnetic field without creation of a stable vortex configuration. Our experiments show that the characteristic field values for vortex creation, single vortex annihilation, and switching strongly depend on the shape anisotropy of the elements

  1. Vertical and horizontal access configurations

    International Nuclear Information System (INIS)

    Spampinato, P.T.

    1987-01-01

    A number of configuration features and maintenance operations are influenced by the choice of whether a design is based on vertical or horizontal access for replacing reactor components. The features which are impacted most include the first wall/blanket segmentation, the poloidal field coil locations, the toroidal field coil number and size, access port size for in-vessel components, and facilities. Since either configuration can be made to work, the choice between the two is not clear cut because both have certain advantages. It is apparent that there are large cost benefits in the poloidal field coil system for ideal coil locations for high elongation plasmas and marginal savings for the INTOR case. If we assume that a new tokamak design will require a higher plasma elongation, the recommendation is to arrange the poloidal field coils in a cost-effective manner while providing reasonable midplane access for heating interfaces and test modules. If a new design study is not based on a high elongation plasma, it still appears prudent to consider this approach so that in-vessel maintenance can be accomplished without moving very massive structures such as the bulk shield. 10 refs., 29 figs., 3 tabs

  2. Valence configurations in 214Rn

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Bark, R.A.; Poletti, A.R.

    1987-01-01

    Excited states of 214 Rn, up to spins of ≅ 24 ℎ have been studied using γ-ray and electron spectroscopy following the 208 Pb( 9 Be,3n) 214 Rn reaction. The level scheme (which differs substantially from earlier work) is compared with the results of a semi-empirical shell model calculation. The availability of high-spin orbitals for the four valence protons and two valence neutrons, and the effect of the attractive proton-neutron interaction, leads to the prediction of high-spin states at an unusually low excitation energy. Experimentally, the high level density leads to difficulties in the level scheme assignments at high spin. Nevertheless, configuration assignments, supported by transition strengths deduced from the measured lifetimes (in the nanosecond region) are suggested for the main yrast states. The decay properties also suggest that configuration mixing is important. The possibility of a gradual transition to octupole deformation, implied by the decay properties of the 11 - and 10 + yrast states is also discussed. (orig.)

  3. Equilibrium: two-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In Chapter 6, the problem of toroidal force balance is addressed in the simplest, nontrivial two-dimensional geometry, that of an axisymmetric torus. A derivation is presented of the Grad-Shafranov equation, the basic equation describing axisymmetric toroidal equilibrium. The solutions to equations provide a complete description of ideal MHD equilibria: radial pressure balance, toroidal force balance, equilibrium Beta limits, rotational transform, shear, magnetic wall, etc. A wide number of configurations are accurately modeled by the Grad-Shafranov equation. Among them are all types of tokamaks, the spheromak, the reversed field pinch, and toroidal multipoles. An important aspect of the analysis is the use of asymptotic expansions, with an inverse aspect ratio serving as the expansion parameter. In addition, an equation similar to the Grad-Shafranov equation, but for helically symmetric equilibria, is presented. This equation represents the leading-order description low-Beta and high-Beta stellarators, heliacs, and the Elmo bumpy torus. The solutions all correspond to infinitely long straight helices. Bending such a configuration into a torus requires a full three-dimensional calculation and is discussed in Chapter 7

  4. Tank waste remediation system configuration management plan

    International Nuclear Information System (INIS)

    Vann, J.M.

    1998-01-01

    The configuration management program for the Tank Waste Remediation System (TWRS) Project Mission supports management of the project baseline by providing the mechanisms to identify, document, and control the functional and physical characteristics of the products. This document is one of the tools used to develop and control the mission and work. It is an integrated approach for control of technical, cost, schedule, and administrative information necessary to manage the configurations for the TWRS Project Mission. Configuration management focuses on five principal activities: configuration management system management, configuration identification, configuration status accounting, change control, and configuration management assessments. TWRS Project personnel must execute work in a controlled fashion. Work must be performed by verbatim use of authorized and released technical information and documentation. Application of configuration management will be consistently applied across all TWRS Project activities and assessed accordingly. The Project Hanford Management Contract (PHMC) configuration management requirements are prescribed in HNF-MP-013, Configuration Management Plan (FDH 1997a). This TWRS Configuration Management Plan (CMP) implements those requirements and supersedes the Tank Waste Remediation System Configuration Management Program Plan described in Vann, 1996. HNF-SD-WM-CM-014, Tank Waste Remediation System Configuration Management Implementation Plan (Vann, 1997) will be revised to implement the requirements of this plan. This plan provides the responsibilities, actions and tools necessary to implement the requirements as defined in the above referenced documents

  5. Hanford Environmental Information System Configuration Management Plan

    International Nuclear Information System (INIS)

    1996-06-01

    The Hanford Environmental Information System (HEIS) Configuration Management Plan establishes the software and data configuration control requirements for the HEIS and project-related databases maintained within the Environmental Restoration Contractor's data management department

  6. Configurations and level structure of 219Rn

    International Nuclear Information System (INIS)

    Sheline, R.K.; Liang, C.F.; Paris, P.

    1998-01-01

    The level structure of 219 Rn has been studied using the alpha decay of 223 Ra and coincident gamma rays. While only modest changes are required in the level structure, and only above 342.8 keV, severe changes are required throughout the level scheme in the spin assigments. These changes allow the assignment of two sets of anomalous bands with K=5/2 ± and K=3/2 ± . The K=5/2 ± bands have configurations intermediate between the reflection asymmetric configuration and the g 9/2 shell model configuration, while the K=3/2 ± bands have configurations intermediate between the mixed reflection asymmetric configuration and the i 11/2 shell model configuration. Comparison of the systematics of 219 Rn with neighboring isotones, isobars, and isotopes shows clearly the collapse of the quadrupole-octupole-type configurations into the less degenerate shell model configurations. copyright 1998 The American Physical Society

  7. Configuration management theory, practice, and application

    CERN Document Server

    Quigley, Jon M

    2015-01-01

    Configuration Management: Theory, Practice, and Application details a comprehensive approach to configuration management from a variety of product development perspectives, including embedded and IT. It provides authoritative advice on how to extend products for a variety of markets due to configuration options. The book also describes the importance of configuration management to other parts of the organization. It supplies an overview of configuration management and its process elements to provide readers with a contextual understanding of the theory, practice, and application of CM. Explaining what a configuration item is and what it implies, the book illustrates the interplay of configuration and data management with all enterprise resources during each phase of a product lifecycle. It also demonstrates the interrelationship of CM to functional resources. Shedding light on current practice, the book describes CM baselines, configuration identification, management baseline changes, and acceptance criteria ...

  8. Industrial requirements for interactive product configurators

    DEFF Research Database (Denmark)

    Queva, Matthieu Stéphane Benoit; Probst, Christian W.; Vikkelsøe, Per

    2009-01-01

    The demand for highly customized products at low cost is driving the industry towards Mass Customization. Interactive product configurators play an essential role in this new trend, and must be able to support more and more complex features. The purpose of this paper is, firstly, to identify...... requirements for modern interactive configurators. Existing modeling and solving technologies for configuration are then reviewed and their limitations discussed. Finally, a proposition for a future product configuration system is described....

  9. Offshore Vendors’ Software Development Team Configurations

    DEFF Research Database (Denmark)

    Chakraborty, Suranjan; Sarker, Saonee; Rai, Sudhanshu

    2012-01-01

    This research uses configuration theory and data collected from a major IT vendor organization to examine primary configurations of distributed teams in a global off-shoring context. The study indicates that off-shoring vendor organizations typically deploy three different types of configurations...

  10. Multi level configuration of ETO products

    DEFF Research Database (Denmark)

    Petersen, Thomas Ditlev; Jørgensen, Kaj Asbjørn; Hvolby, Hans-Henrik

    2007-01-01

    The paper introduces and defines central concepts related to multi level configuration and analyzes which challenges an engineer to order company must deal with to be able to realize a multi level configuration system. It is argued that high flexibility can be achieved and focus can be directed...... in certain business processes if a multi level configuration system is realized....

  11. Configuration mixing for spin-isospin modes

    International Nuclear Information System (INIS)

    Ichimura, Munetake

    2005-01-01

    Development of theories of configuration mixing is reviewed, concentrating on their application to spin-isospin modes, especially to the Gamow-Teller transitions. This talk is divided into three historical stages, the first order configuration mixing as the first stage, the second order configuration mixing as the second stage, and the delta-isobar-hole mixing as the third stage

  12. Code organization and configuration management

    International Nuclear Information System (INIS)

    Wellisch, J.P.; Ashby, S.; Williams, C.; Osborne, I.

    2001-01-01

    Industry experts are increasingly focusing on team productivity as the key to success. The base of the team effort is the four-fold structure of software in terms of logical organisation, physical organisation, managerial organisation, and dynamical structure. The authors describe the ideas put into action within the CMS software for organising software into sub-systems and packages, and to establish configuration management in a multi-project environment. The authors use a structure that allows to maximise the independence of software development in individual areas, and at the same time emphasises the overwhelming importance of the interdependencies between the packages and components in the system. The authors comment on release procedures, and describe the inter-relationship between release, development, integration, and testing

  13. Knowledge Engineering for Embedded Configuration

    DEFF Research Database (Denmark)

    Oddsson, Gudmundur Valur

    2008-01-01

    into the system the knowledge needed to achieve them. In order to understand the system, one draws simplified functional streams and identifies archetypes from the product assortment, and then one maps the two together into a system breakdown model. The system model indicates how many encapsulation models (EMs......This thesis presents a way to simplify setup of complex product systems with the help of embedded configuration. To achieve this, one has to focus on what subsystems need to communicate between themselves. The required internal knowledge is then structured at three abstraction levels......, and predefined relation types are suggested. The models are stringent and thought out so they can be implemented in software. They should allow both import and export of product knowledge from the knowledge-based system. The purpose of this work is to simplify the installation process of product systems...

  14. Study of High Lift Configurations

    Science.gov (United States)

    Edward, Jack R.; Hassan, Hassan A.

    2000-01-01

    This project focus on the implementation of the Warren-Hassan transition / turbulence model (Journal of Aircraft, Vol. 35, No. 5) into the NASA code CFL3D and its testing for multi-element airfoils in landing configuration at different angles of attack. The Warren-Hassan transition model solves an evolution equation for a kinetic energy characteristic of non-turbulent fluctuations. This is combined with an empirical estimate of the frequency of the most amplified first-mode disturbance to yield an expression for an eddy viscosity characteristic of non-turbulent fluctuations. This is combined with the k - zeta model for fully turbulent flow to yield a unified approach capable of predicting both transition onset and extent. Blending of the non-turbulent and turbulent components of the model is accomplished by an intermittency function based on the work of Dhawan and Narasimha (Journal of Fluid Mechanics, Vol. 3, No. 4).

  15. Reactor Configuration Development for ARIES-CS

    International Nuclear Information System (INIS)

    Ku LP

    2005-01-01

    New compact, quasi-axially symmetric stellarator configurations have been developed as part of the ARIES-CS reactor studies. These new configurations have good plasma confinement and transport properties, including low losses of α particles and good integrity of flux surfaces at high β. We summarize the recent progress by showcasing two attractive classes of configurations--configurations with judiciously chosen rotational transforms to avoid undesirable effects of low order resonances on the flux surface integrity and configurations with very small aspect ratios (∼2.5) that have excellent quasi-axisymmetry and low field ripples

  16. Exercise in Configurable Products using Creo parametric

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    2017-01-01

    Family tables is a long know method with ProEngineer/Creo parametric to make families of products – like families of bolts and roller bearings. Configurable Products expand these possibilities in two major ways: First it makes configurable assemblies possible where one topologically different com...... been available as: configurable assemblies in earlier versions of Creo) An example of a practical application of configurable products is shown below where an outdoor Play/Exercise system is transferred from AutoCAD 2D to a 3D configurable product in Creo 3.0....

  17. Supply chain configuration concepts, solutions, and applications

    CERN Document Server

    Chandra, Charu

    2016-01-01

    This book discusses the models and tools available for solving configuration problems, emphasizes the value of model integration to obtain comprehensive and robust configuration decisions, proposes solutions for supply chain configuration in the presence of stochastic and dynamic factors, and illustrates application of the techniques discussed in applied studies. It is divided into four parts, which are devoted to defining the supply chain configuration problem and identifying key issues, describing solutions to various problems identified, proposing technologies for enabling supply chain confirmations, and discussing applied supply chain configuration problems. Its distinguishing features are: an explicit focus on the configuration problem an in-depth coverage of configuration models an emphasis on model integration and application of information modeling techniques in decision-making New to this edition is Part II: Technologies, which introduces readers to various technologies being utilized for supply chai...

  18. Magnetic helicity and active filament configuration

    Science.gov (United States)

    Romano, P.; Zuccarello, F.; Poedts, S.; Soenen, A.; Zuccarello, F. P.

    2009-11-01

    Context: The role of magnetic helicity in active filament formation and destabilization is still under debate. Aims: Although active filaments usually show a sigmoid shape and a twisted configuration before and during their eruption, it is unclear which mechanism leads to these topologies. In order to provide an observational contribution to clarify these issues, we describe a filament evolution whose characteristics seem to be directly linked to the magnetic helicity transport in corona. Methods: We applied different methods to determine the helicity sign and the chirality of the filament magnetic field. We also computed the magnetic helicity transport rate at the filament footpoints. Results: All the observational signatures provided information on the positive helicity and sinistral chirality of the flux rope containing the filament material: its forward S shape, the orientation of its barbs, the bright and dark threads at 195 Å. Moreover, the magnetic helicity transport rate at the filament footpoints showed a clear accumulation of positive helicity. Conclusions: The study of this event showed a correspondence between several signatures of the sinistral chirality of the filament and several evidences of the positive magnetic helicity of the filament magnetic field. We also found that the magnetic helicity transported along the filament footpoints showed an increase just before the change of the filament shape observed in Hα images. We argued that the photospheric regions where the filament was rooted might be the preferential ways where the magnetic helicity was injected along the filament itself and where the conditions to trigger the eruption were yielded.

  19. Configurable software for satellite graphics

    Energy Technology Data Exchange (ETDEWEB)

    Hartzman, P D

    1977-12-01

    An important goal in interactive computer graphics is to provide users with both quick system responses for basic graphics functions and enough computing power for complex calculations. One solution is to have a distributed graphics system in which a minicomputer and a powerful large computer share the work. The most versatile type of distributed system is an intelligent satellite system in which the minicomputer is programmable by the application user and can do most of the work while the large remote machine is used for difficult computations. At New York University, the hardware was configured from available equipment. The level of system intelligence resulted almost completely from software development. Unlike previous work with intelligent satellites, the resulting system had system control centered in the satellite. It also had the ability to reconfigure software during realtime operation. The design of the system was done at a very high level using set theoretic language. The specification clearly illustrated processor boundaries and interfaces. The high-level specification also produced a compact, machine-independent virtual graphics data structure for picture representation. The software was written in a systems implementation language; thus, only one set of programs was needed for both machines. A user can program both machines in a single language. Tests of the system with an application program indicate that is has very high potential. A major result of this work is the demonstration that a gigantic investment in new hardware is not necessary for computing facilities interested in graphics.

  20. Metrics for measuring distances in configuration spaces

    International Nuclear Information System (INIS)

    Sadeghi, Ali; Ghasemi, S. Alireza; Schaefer, Bastian; Mohr, Stephan; Goedecker, Stefan; Lill, Markus A.

    2013-01-01

    In order to characterize molecular structures we introduce configurational fingerprint vectors which are counterparts of quantities used experimentally to identify structures. The Euclidean distance between the configurational fingerprint vectors satisfies the properties of a metric and can therefore safely be used to measure dissimilarities between configurations in the high dimensional configuration space. In particular we show that these metrics are a perfect and computationally cheap replacement for the root-mean-square distance (RMSD) when one has to decide whether two noise contaminated configurations are identical or not. We introduce a Monte Carlo approach to obtain the global minimum of the RMSD between configurations, which is obtained from a global minimization over all translations, rotations, and permutations of atomic indices

  1. In-memory interconnect protocol configuration registers

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Kevin Y.; Roberts, David A.

    2017-09-19

    Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

  2. Contrast configuration influences grouping in apparent motion.

    Science.gov (United States)

    Ma-Wyatt, Anna; Clifford, Colin W G; Wenderoth, Peter

    2005-01-01

    We investigated whether the same principles that influence grouping in static displays also influence grouping in apparent motion. Using the Ternus display, we found that the proportion of group motion reports was influenced by changes in contrast configuration. Subjects made judgments of completion of these same configurations in a static display. Generally, contrast configurations that induced a high proportion of group motion responses were judged as more 'complete' in static displays. Using a stereo display, we then tested whether stereo information and T-junction information were critical for this increase in group motion. Perceived grouping was consistently higher for same contrast polarity configurations than for opposite contrast polarity configurations, regardless of the presence of stereo information or explicit T-junctions. Thus, while grouping in static and moving displays showed a similar dependence on contrast configuration, motion grouping showed little dependence on stereo or T-junction information.

  3. In-memory interconnect protocol configuration registers

    Science.gov (United States)

    Cheng, Kevin Y.; Roberts, David A.

    2017-09-19

    Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

  4. A configurable CDS for the production laboratory

    CERN Document Server

    Meek, Irish

    2003-01-01

    Various aspects of a configurable chromatography data system (CDS) for the production laboratory are discussed. The Atlas CDS can be configured extensively to fit the production laboratory work flow and meet the needs of analysts. The CDS can also be configured to automatically create a sample sequence with the required number of injections and download methods to the dedicated instrument. The Atlas Quick Start wizard offers uses quick way of generating a sequence from a predefined template and starting a run. (Edited abstract).

  5. Visualization of the CMS python configuration system

    International Nuclear Information System (INIS)

    Erdmann, M; Fischer, R; Klimkovich, T; Mueller, G; Steggemann, J; Hegner, B; Hinzmann, A

    2010-01-01

    The job configuration system of the CMS experiment is based on the Python programming language. Software modules and their order of execution are both represented by Python objects. In order to investigate and verify configuration parameters and dependencies naturally appearing in modular software, CMS employs a graphical tool. This tool visualizes the configuration objects, their dependencies, and the information flow. Furthermore it can be used for documentation purposes. The underlying software concepts as well as the visualization are presented.

  6. Visualization of the CMS python configuration system

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, M; Fischer, R; Klimkovich, T; Mueller, G; Steggemann, J [RWTH Aachen University, Physikalisches Institut 3A, 52062 Aachen (Germany); Hegner, B [CERN, CH-1211 Geneva 23 (Switzerland); Hinzmann, A, E-mail: andreas.hinzmann@cern.c

    2010-04-01

    The job configuration system of the CMS experiment is based on the Python programming language. Software modules and their order of execution are both represented by Python objects. In order to investigate and verify configuration parameters and dependencies naturally appearing in modular software, CMS employs a graphical tool. This tool visualizes the configuration objects, their dependencies, and the information flow. Furthermore it can be used for documentation purposes. The underlying software concepts as well as the visualization are presented.

  7. International Space Station Configuration Analysis and Integration

    Science.gov (United States)

    Anchondo, Rebekah

    2016-01-01

    Ambitious engineering projects, such as NASA's International Space Station (ISS), require dependable modeling, analysis, visualization, and robotics to ensure that complex mission strategies are carried out cost effectively, sustainably, and safely. Learn how Booz Allen Hamilton's Modeling, Analysis, Visualization, and Robotics Integration Center (MAVRIC) team performs engineering analysis of the ISS Configuration based primarily on the use of 3D CAD models. To support mission planning and execution, the team tracks the configuration of ISS and maintains configuration requirements to ensure operational goals are met. The MAVRIC team performs multi-disciplinary integration and trade studies to ensure future configurations meet stakeholder needs.

  8. Pair creation by dynamic field configurations

    International Nuclear Information System (INIS)

    Aoyama, H.

    1982-01-01

    This thesis deals with the dynamics of the classical configuration of a quantum field unstable due to pair creation. The effective action method is developed first to treat such problems for a simple two-field model. Physical quantities such as pair creation probabilities are related to a complex function called the effective configuration, which is defined to minimize the effective action. Unitarity of the S-matrix is verified at the lowest order of the weak-field approximation. At the same order, the real valued vacuum expectation value of the quantum field, named the real configuration, is constructed in terms of the effective configuration. An integro-differential equation for the real configuration is given and is used to show that the real configuration is causal, while the effective configuration is not. Two practical applications of the effective action method are discussed. The first deals with pair creation in an anisotropic universe, and the real geometry is given in terms of the effective geometry in the samll anisotropy limit. The second deals with expanding vacuum bubbles. Corresponding to three possible situations, three kinds of field equations of each of the effective configuration and the real configuration are obtained. The behavior of the bubble is also studied by a semi-classical method, and one of the three situations is suggested to be plausible

  9. The Ragnarok Architectural Software Configuration Management Model

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    1999-01-01

    The architecture is the fundamental framework for designing and implementing large scale software, and the ability to trace and control its evolution is essential. However, many traditional software configuration management tools view 'software' merely as a set of files, not as an architecture....... This introduces an unfortunate impedance mismatch between the design domain (architecture level) and configuration management domain (file level.) This paper presents a software configuration management model that allows tight version control and configuration management of the architecture of a software system...

  10. Configuration management: Phase II implementation guidance

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    Configuration management (CM) is essential to maintaining an acceptable level of risk to the public, workers, environment, or mission success. It is a set of activities and techniques used to maintain consistency among physical and functional configuration, applicable requirements, and key documents. This document provides guidance for continuing the implementation of CM in a phased and graded manner. It describes a cost-effective approach to documented consistency with requirements, with early emphasis on items most important to safety and environmental protection. It is intended to help responsible line managers and configuration management staff personnel in meeting the Energy Systems configuration management policy standard.

  11. Comparison between four dissimilar solar panel configurations

    Science.gov (United States)

    Suleiman, K.; Ali, U. A.; Yusuf, Ibrahim; Koko, A. D.; Bala, S. I.

    2017-12-01

    Several studies on photovoltaic systems focused on how it operates and energy required in operating it. Little attention is paid on its configurations, modeling of mean time to system failure, availability, cost benefit and comparisons of parallel and series-parallel designs. In this research work, four system configurations were studied. Configuration I consists of two sub-components arranged in parallel with 24 V each, configuration II consists of four sub-components arranged logically in parallel with 12 V each, configuration III consists of four sub-components arranged in series-parallel with 8 V each, and configuration IV has six sub-components with 6 V each arranged in series-parallel. Comparative analysis was made using Chapman Kolmogorov's method. The derivation for explicit expression of mean time to system failure, steady state availability and cost benefit analysis were performed, based on the comparison. Ranking method was used to determine the optimal configuration of the systems. The results of analytical and numerical solutions of system availability and mean time to system failure were determined and it was found that configuration I is the optimal configuration.

  12. Structure of the magnetic field line diversion in Helias configurations

    International Nuclear Information System (INIS)

    Strumberger, E.

    1991-01-01

    The vacuum magnetic field outside the last closed magnetic surface of Helias configurations is investigated with respect to its field line diversion properties. In a Helias configuration with N periods N half-helix like edges run on the toroidally outward side of the plasma boundary and yield the possibility of separatrix formation due to the coincidence of helical edge and x-points between islands. With the choice N=5, and ι=1 at the plasma boundary, there are five magnetic islands outside the last closed magnetic surface. In the case considered, islands are lying in front of the helical edge at the beginning, in the middle and at the end of this edge, while in positions in between x-points are in front of the helical edge. (author) 3 refs., 5 figs

  13. TWRS authorization basis configuration control summary

    International Nuclear Information System (INIS)

    Mendoza, D.P.

    1997-01-01

    This document was developed to define the Authorization Basis management functional requirements for configuration control, to evaluate the management control systems currently in place, and identify any additional controls that may be required until the TWRS [Tank Waste Remediation System] Configuration Management system is fully in place

  14. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... The deformed configurations and rotational band structures in =50 Ge and Se nuclei are studied by deformed Hartree–Fock with quadrupole constraint and angular momentum projection. Apart from the `almost' spherical HF solution, a well-deformed configuration occurs at low excitation. A deformed ...

  15. Improving the quotation process with product configuration

    DEFF Research Database (Denmark)

    Hvam, Lars; Christensen, Simon Pape

    2006-01-01

    How can product configuration support the process of engineering highly complex industrial products? This article describes how an IT-based product configuration system was developed to support the process of mak-ing budget quotations. The article is based on a research project carried out...

  16. Configuration of Web services as parametric design

    NARCIS (Netherlands)

    Ten Teije, Annette; Van Harmelen, Frank; Wielinga, Bob

    2004-01-01

    The configuration of Web services is particularly hard given the heterogeneous, unreliable and open nature of the Web. Furthermore, such composite Web services are likely to be complex services, that will require adaptation for each specific use. Current approaches to Web service configuration are

  17. Upgrades to the ISIS moderator configuration

    International Nuclear Information System (INIS)

    Taylor, A.D.

    1989-01-01

    The current ISIS moderator configuration, was designed in 1980 to provide a flexible set of beams for a hypothetical instrument suite. The use of fluid moderators at three different temperatures offering six faces to the instruments, has proved to be effective. In this paper we discuss an upgrade of these moderators in the light of the current and projected instrument configuration. (author)

  18. Overview of Java application configuration frameworks

    OpenAIRE

    Denisov, Victor

    2013-01-01

    This paper reviews three major application configuration frameworks for Java-based applications: java.util.Properties, Apache Commons Configuration and Preferences API. Basic functionality of each framework is illustrated with code examples. Pros and cons of each framework are described in moderate detail. Suggestions are made about typical use cases for each framework.

  19. Synthesis and configurational analysis of phosphonate cavitands

    NARCIS (Netherlands)

    Jacopozzi, Paola; Dalcanale, Enrico; Spera, Silvia; Chrisstoffels, L.A.J.; Reinhoudt, David; Lippmann, Tino; Mann, Gerhard

    1998-01-01

    Synthesis, separation and configurational analysis of phosphonated and partially phosphonated cavitands derived from resorcinarenes are described. The configuration of all diastereomers has been elucidated by their 1H, 31P NMR spectra and 13C relaxation times. In all cases the course of the bridging

  20. Microsoft System Center Configuration Manager advanced deployment

    CERN Document Server

    Coupland, Martyn

    2014-01-01

    If you are an experienced Configuration Manager administrator looking to advance your career or get more from your current environment, then this book is ideal for you. Prior experience of deploying and managing a Configuration Manager site would be helpful in following the examples throughout this book.

  1. Generation of Astron-Spherator configuration

    International Nuclear Information System (INIS)

    Narihara, Kazumichi; Hasegawa, Mitsuru; Tomita, Yukihiro; Tsuzuki, Tetsuya; Sato, Kuninori; Mohri, Akihiro.

    1983-01-01

    It was experimentally demonstrated that Astron-Spherator configuration is formed by injecting a pulsed relativistic electron beam in a toroidal device SPAC-VI with external toroidal and vertical magnetic fields. A plasma is confined in the extended magnetic region produced by a slender core of current carrying energetic electrons. This configuration continued for 40 ms without fatal instabilities. (author)

  2. Exotic configurations for gauge theory strings

    International Nuclear Information System (INIS)

    Yajnik, U.A.

    1987-01-01

    This paper discusses a class of string configurations occuring in nonabelian gauge theories, which are such that a component of the charged scalar field responsible for the string has a nonvanishing expectation value in the core of the string. A systematic procedure is given for setting up the ansatz for such configurations. (orig.)

  3. A new approach to configurable primary data collection.

    Science.gov (United States)

    Stanek, J; Babkin, E; Zubov, M

    2016-09-01

    The formats, semantics and operational rules of data processing tasks in genomics (and health in general) are highly divergent and can rapidly change. In such an environment, the problem of consistent transformation and loading of heterogeneous input data to various target repositories becomes a critical success factor. The objective of the project was to design a new conceptual approach to configurable data transformation, de-identification, and submission of health and genomic data sets. Main motivation was to facilitate automated or human-driven data uploading, as well as consolidation of heterogeneous sources in large genomic or health projects. Modern methods of on-demand specialization of generic software components were applied. For specification of input-output data and required data collection activities, we propose a simple data model of flat tables as well as a domain-oriented graphical interface and portable representation of transformations in XML. Using such methods, the prototype of the Configurable Data Collection System (CDCS) was implemented in Java programming language with Swing graphical interfaces. The core logic of transformations was implemented as a library of reusable plugins. The solution is implemented as a software prototype for a configurable service-oriented system for semi-automatic data collection, transformation, sanitization and safe uploading to heterogeneous data repositories-CDCS. To address the dynamic nature of data schemas and data collection processes, the CDCS prototype facilitates interactive, user-driven configuration of the data collection process and extends basic functionality with a wide range of third-party plugins. Notably, our solution also allows for the reduction of manual data entry for data originally missing in the output data sets. First experiments and feedback from domain experts confirm the prototype is flexible, configurable and extensible; runs well on data owner's systems; and is not dependent on

  4. SRP [Salt Repository Project] configuration management plan

    International Nuclear Information System (INIS)

    1987-01-01

    This configuration management plan describes the organization, policies, and procedures that will be used on the Salt Repository Project (SRP) to implement the configuration management disciplines and controls. Configuration management is a part of baseline management. Baseline management is defined in the SRP Baseline Procedures Notebook and also includes cost and schedule baselines. Configuration management is a discipline applying technical and administrative direction and surveillance to identify and document the functional and physical characteristics of an item, to control changes to those characteristics, to record and report change processing and implementation status, and to audit the results. Configuration management is designed as a project management tool to determine and control baselines, and ensure and document all components of a project interface both physically and functionally. The purpose is to ensure that the product acquired satisfies the project's technical and operational requirements, and that the technical requirements are clearly defined and controlled throughout the development and acquisition process. 5 figs

  5. Configuration Management Plan for K Basins

    International Nuclear Information System (INIS)

    Weir, W.R.; Laney, T.

    1995-01-01

    This plan describes a configuration management program for K Basins that establishes the systems, processes, and responsibilities necessary for implementation. The K Basins configuration management plan provides the methodology to establish, upgrade, reconstitute, and maintain the technical consistency among the requirements, physical configuration, and documentation. The technical consistency afforded by this plan ensures accurate technical information necessary to achieve the mission objectives that provide for the safe, economic, and environmentally sound management of K Basins and the stored material. The configuration management program architecture presented in this plan is based on the functional model established in the DOE Standard, DOE-STD-1073-93, open-quotes Guide for Operational Configuration Management Programclose quotes

  6. Interactive Cost Configuration Over Decision Diagrams

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Hadzic, Tarik; Pisinger, David

    2010-01-01

    interaction online. In particular,binary decision diagrams (BDDs) have been successfully used as a compilation target for product and service configuration. In this paper we discuss how to extend BDD-based configuration to scenarios involving cost functions which express user preferences. We first show...... that an efficient, robust and easy to implement extension is possible if the cost function is additive, and feasible solutions are represented using multi-valued decision diagrams (MDDs). We also discuss the effect on MDD size if the cost function is non-additive or if it is encoded explicitly into MDD. We...... then discuss interactive configuration in the presence of multiple cost functions. We prove that even in its simplest form, multiple-cost configuration is NP-hard in the input MDD. However, for solving two-cost configuration we develop a pseudo-polynomial scheme and a fully polynomial approximation scheme...

  7. Evolution of the Configuration Database Design

    International Nuclear Information System (INIS)

    Salnikov, A.

    2006-01-01

    The BABAR experiment at SLAC successfully collects physics data since 1999. One of the major parts of its on-line system is the configuration database which provides other parts of the system with the configuration data necessary for data taking. Originally the configuration database was implemented in the Objectivity/DB ODBMS. Recently BABAR performed a successful migration of its event store from Objectivity/DB to ROOT and this prompted a complete phase-out of the Objectivity/DB in all other BABAR databases. It required the complete redesign of the configuration database to hide any implementation details and to support multiple storage technologies. In this paper we describe the process of the migration of the configuration database, its new design, implementation strategy and details

  8. Communicating knowledge: Making embedded configuration work

    DEFF Research Database (Denmark)

    Oddsson, Gudmundur Valur; Hvam, Lars

    2007-01-01

    A lot of systems are assembled from near-independent mechatronic subsystems that have to be configured to match each other. An example of such systems are e.g. home entertainment systems, where TV, DVD and Receiver are matched to form an overall system, and compilation of pumps and controllers...... to form fresh water supply systems. Sometimes an external knowledge system keeps track of how each subsystem has to be configured, but the actual configuration is often done manually. Installing and maintaining those kinds of systems can be a tedious task and often requires repetitive labour. The idea...... is to “split-up” the product knowledge and encapsulate it into each subsystem. Then, when the subsystems are assembled, the configuration of each subsystem can either be done automatically or with minimum input. The concept could be called: embedded configuration. This article will try to connect three aspects...

  9. Simulation of steam explosion in stratified melt-coolant configuration

    International Nuclear Information System (INIS)

    Leskovar, Matjaž; Centrih, Vasilij; Uršič, Mitja

    2016-01-01

    Highlights: • Strong steam explosions may develop spontaneously in stratified configurations. • Considerable melt-coolant premixed layer formed in subcooled water with hot melts. • Analysis with MC3D code provided insight into stratified steam explosion phenomenon. • Up to 25% of poured melt was mixed with water and available for steam explosion. • Better instrumented experiments needed to determine dominant mixing process. - Abstract: A steam explosion is an energetic fuel coolant interaction process, which may occur during a severe reactor accident when the molten core comes into contact with the coolant water. In nuclear reactor safety analyses steam explosions are primarily considered in melt jet-coolant pool configurations where sufficiently deep coolant pool conditions provide complete jet breakup and efficient premixture formation. Stratified melt-coolant configurations, i.e. a molten melt layer below a coolant layer, were up to now believed as being unable to generate strong explosive interactions. Based on the hypothesis that there are no interfacial instabilities in a stratified configuration it was assumed that the amount of melt in the premixture is insufficient to produce strong explosions. However, the recently performed experiments in the PULiMS and SES (KTH, Sweden) facilities with oxidic corium simulants revealed that strong steam explosions may develop spontaneously also in stratified melt-coolant configurations, where with high temperature melts and subcooled water conditions a considerable melt-coolant premixed layer is formed. In the article, the performed study of steam explosions in a stratified melt-coolant configuration in PULiMS like conditions is presented. The goal of this analytical work is to supplement the experimental activities within the PULiMS research program by addressing the key questions, especially regarding the explosivity of the formed premixed layer and the mechanisms responsible for the melt-water mixing. To

  10. Onset of pseudo-thermal equilibrium within configurations and super-configurations

    International Nuclear Information System (INIS)

    Busquet, Michel

    2006-01-01

    Level populations within a configuration and configuration populations within super-configuration or within one ion are shown to follow a Boltzmann law at some effective temperature different from the actual electron temperature (as it would be when Griem criterion is valid). Origin of this pseudo-thermal equilibrium is discussed and basis of a model are presented

  11. Onset of pseudo-thermal equilibrium within configurations and super-configurations

    Energy Technology Data Exchange (ETDEWEB)

    Busquet, Michel [ARTEP Inc., 2922 Excelsior Springs Court, Elicott City, MD 21042 (United States)]. E-mail: busquet@this.nrl.navy.mil

    2006-05-15

    Level populations within a configuration and configuration populations within super-configuration or within one ion are shown to follow a Boltzmann law at some effective temperature different from the actual electron temperature (as it would be when Griem criterion is valid). Origin of this pseudo-thermal equilibrium is discussed and basis of a model are presented.

  12. Improving motorcycle conspicuity through innovative headlight configurations.

    Science.gov (United States)

    Ranchet, Maud; Cavallo, Viola; Dang, Nguyen-Thong; Vienne, Fabrice

    2016-09-01

    Most motorcycle crashes involve another vehicle that violated the motorcycle's right-of-way at an intersection. Two kinds of perceptual failures of other road users are often the cause of such accidents: motorcycle-detection failures and motion-perception errors. The aim of this study is to investigate the effect of different headlight configurations on motorcycle detectability when the motorcycle is in visual competition with cars. Three innovative headlight configurations were tested: (1) standard yellow (central yellow headlight), (2) vertical white (one white light on the motorcyclist's helmet and two white lights on the fork in addition to the central white headlight), and (3) vertical yellow (same configuration as (2) with yellow lights instead of white). These three headlight configurations were evaluated in comparison to the standard configuration (central white headlight) in three environments containing visual distractors formed by car lights: (1) daytime running lights (DRLs), (2) low beams, or (3) DRLs and low beams. Video clips of computer-generated traffic situations were displayed briefly (250ms) to 57 drivers. The results revealed a beneficial effect of standard yellow configuration and the vertical yellow configuration on motorcycle detectability. However, this effect was modulated by the car-DRL environment. Findings and practical recommendations are discussed with regard to possible applications for motorcycles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. National Ignition Facility Configuration Management Plan

    International Nuclear Information System (INIS)

    Cabral, S G; Moore, T L

    2002-01-01

    This Configuration Management Plan (CMP) describes the technical and administrative management process for controlling the National Ignition Facility (NIF) Project configuration. The complexity of the NIF Project (i.e., participation by multiple national laboratories and subcontractors involved in the development, fabrication, installation, and testing of NIF hardware and software, as well as construction and testing of Project facilities) requires implementation of the comprehensive configuration management program defined in this plan. A logical schematic illustrating how the plan functions is provided in Figure 1. A summary of the process is provided in Section 4.0, Configuration Change Control. Detailed procedures that make up the overall process are referenced. This CMP is consistent with guidance for managing a project's configuration provided in Department of Energy (DOE) Order 430.1, Guide PMG 10, ''Project Execution and Engineering Management Planning''. Configuration management is a formal discipline comprised of the following four elements: (1) Identification--defines the functional and physical characteristics of a Project and uniquely identifies the defining requirements. This includes selection of components of the end product(s) subject to control and selection of the documents that define the project and components. (2) Change management--provides a systematic method for managing changes to the project and its physical and functional configuration to ensure that all changes are properly identified, assessed, reviewed, approved, implemented, tested, and documented. (3) Data management--ensures that necessary information on the project and its end product(s) is systematically recorded and disseminated for decision-making and other uses. Identifies, stores and controls, tracks status, retrieves, and distributes documents. (4) Assessments and validation--ensures that the planned configuration requirements match actual physical configurations and

  14. Configurations of Leadership Practices in Hospital Units

    DEFF Research Database (Denmark)

    Meier, Ninna

    2015-01-01

    configurations of leadership practices varied in four different clinical settings, thus contributing with contextual accounts of leadership as practice, and suggested “configurations of practice” as a way to carve out similarities and differences in leadership practices across settings....... and interviews with ten interdisciplinary clinical managers. Findings: – Comparing leadership as configurations of practices across four different clinical settings, the author shows how flexible and often shared leadership practices were embedded in and central to the core clinical work in all units studied...

  15. Atom localization with double-cascade configuration

    International Nuclear Information System (INIS)

    Gordeev, Maksim Yu; Rozhdestvensky, Yuri V; Efremova, Ekaterina A

    2016-01-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation. (paper)

  16. A configural dominant account of contextual cueing: Configural cues are stronger than colour cues.

    Science.gov (United States)

    Kunar, Melina A; John, Rebecca; Sweetman, Hollie

    2014-01-01

    Previous work has shown that reaction times to find a target in displays that have been repeated are faster than those for displays that have never been seen before. This learning effect, termed "contextual cueing" (CC), has been shown using contexts such as the configuration of the distractors in the display and the background colour. However, it is not clear how these two contexts interact to facilitate search. We investigated this here by comparing the strengths of these two cues when they appeared together. In Experiment 1, participants searched for a target that was cued by both colour and distractor configural cues, compared with when the target was only predicted by configural information. The results showed that the addition of a colour cue did not increase contextual cueing. In Experiment 2, participants searched for a target that was cued by both colour and distractor configuration compared with when the target was only cued by colour. The results showed that adding a predictive configural cue led to a stronger CC benefit. Experiments 3 and 4 tested the disruptive effects of removing either a learned colour cue or a learned configural cue and whether there was cue competition when colour and configural cues were presented together. Removing the configural cue was more disruptive to CC than removing colour, and configural learning was shown to overshadow the learning of colour cues. The data support a configural dominant account of CC, where configural cues act as the stronger cue in comparison to colour when they are presented together.

  17. Modelling of radial electric field profile for different divertor configurations

    International Nuclear Information System (INIS)

    Rozhansky, V; Kaveeva, E; Voskoboynikov, S; Counsell, G; Kirk, A; Meyer, H; Coster, D; Conway, G; Schirmer, J; Schneider, R

    2006-01-01

    The impact of divertor configuration on the structure of the radial electric field has been simulated by the B2SOLPS5.0 transport fluid code. It is shown that the change in the parallel flows in the scrape-off layer, which are transported through the separatrix due to turbulent viscosity and diffusivity, should result in variation of the radial electric field and toroidal rotation in the separatrix vicinity. The modelling predictions are compared with the measurements of the radial electric field for the low field side equatorial mid-plane of ASDEX Upgrade in lower, upper and double-null (DN) divertor configurations. The parallel (toroidal) flows in the scrape-off layer and mechanisms for their formation are analysed for different geometries. It is demonstrated that a spike in the electric field exists at the high field side equatorial mid-plane in the connected DN divertor configuration. Its origin is connected with different potential drops between the separatrix vicinity and divertor plates in the two disconnected scrape-off layers, while the separatrix should be at almost the same potential. The spike might be important for additional turbulent suppression

  18. External magnetic field configurations for EXTRAP

    International Nuclear Information System (INIS)

    Bonnevier, B.

    1982-08-01

    The strongly inhomogeneous magnetic field for stabilization of a pinch in an Extrap configuration can be created in various ways. Some possibilities both for the linear case and for the toroidal case are discussed. (author)

  19. Space shuttle configuration accounting functional design specification

    Science.gov (United States)

    1974-01-01

    An analysis is presented of the requirements for an on-line automated system which must be capable of tracking the status of requirements and engineering changes and of providing accurate and timely records. The functional design specification provides the definition, description, and character length of the required data elements and the interrelationship of data elements to adequately track, display, and report the status of active configuration changes. As changes to the space shuttle program levels II and III configuration are proposed, evaluated, and dispositioned, it is the function of the configuration management office to maintain records regarding changes to the baseline and to track and report the status of those changes. The configuration accounting system will consist of a combination of computers, computer terminals, software, and procedures, all of which are designed to store, retrieve, display, and process information required to track proposed and proved engineering changes to maintain baseline documentation of the space shuttle program levels II and III.

  20. Configuration Management for Wendelstein 7-X

    International Nuclear Information System (INIS)

    Brakel, R.; Eeten, P.v.; Hartmann, D.A.; Henkelmann, K.; Knauer, J.; Mueller, K.; Okkenga-Wolf, A.; Wenzel, U.

    2009-01-01

    A complex system like the large superconducting Wendelstein 7-X stellarator necessitates a dedicated organizational structure which assures permanent consistency between the requirements of its system specification and the performance attributes of all its components throughout its life time. This includes well-defined processes and centrally coordinated information structures. For this purposes the department Configuration Management (CM) has recently been established at W7-X. The detailed tasks of CM for W7-X are oriented along common CM standards and comprise configuration identification, change management, configuration status accounting and configuration verification. While the assembly of W7-X is proceeding some components are still under procurement or even under design. Thus design changes and non-conformances may have a direct impact on the assembly process. Highest priority has therefore been assigned to efficient control of change and non-conformance processes which might delay the assembly schedule.

  1. Molecular Electronic Terms and Molecular Orbital Configurations.

    Science.gov (United States)

    Mazo, R. M.

    1990-01-01

    Discussed are the molecular electronic terms which can arise from a given electronic configuration. Considered are simple cases, molecular states, direct products, closed shells, and open shells. Two examples are provided. (CW)

  2. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... Our study gives insight into possible deformed structures at spherical shell closure. ... Considerable experimental and theoretical efforts ... True deformation effects can be seen only by considering configuration mixing.

  3. Microsoft Windows 2000 Router Configuration Guide

    National Research Council Canada - National Science Library

    Richburg, Florence

    2001-01-01

    The purpose of this guide is to provide technical guidance to network administrators of small to medium size networks in the configuration and integration of Microsoft Windows 2000 Server Router features...

  4. Configuring the development space for conceptualization

    DEFF Research Database (Denmark)

    Brønnum, Louise; Clausen, Christian

    2013-01-01

    This paper addresses issues of conceptualization in the early stages of concept development noted as the Front End of Innovation [FEI]. We examine this particular development space as a socio technical space where a diversity of technological knowledge, user perspectives and organizational agendas...... meet and interact. Based on a case study from an industrial medical company, the paper addresses and analyses the configuration of the development space in a number of projects aiming to take up user oriented perspectives in their activities. It presents insights on how the FEI was orchestrated...... and staged and how different elements and objects contributed to the configuration of the space in order to make it perform in a certain way. The analysis points at the importance of the configuration processes and indicate how these configurations often may act as more or less hidden limitations on concept...

  5. Status Configurations, Military Service and Higher Education.

    Science.gov (United States)

    Wang, Lin; Elder, Glen H; Spence, Naomi J

    2012-12-01

    The U.S. Armed Forces offer educational and training benefits as incentives for service. This study investigates the influence of status configurations on military enlistment and their link to greater educational opportunity. Three statuses (socioeconomic status of origin, cognitive ability and academic performance) have particular relevance for life course options. We hypothesize that young men with inconsistent statuses are more likely to enlist than men with consistent status profiles, and that military service improves access to college for certain configurations. Analyses of the National Longitudinal Study of Adolescent Health (Add Health) show (1. that several status configurations markedly increased the likelihood of military enlistment and (2. within status configurations, recruits were generally more likely to enroll in higher education than nonveterans, with associate degrees being more likely.

  6. Optimal sensor configuration for complex systems

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    . The procedure for sensor configuration is based on the simultaneous perturbation stochastic approximation (SPSA) algorithm. SPSA avoids the need for detailed modeling of the sensor response by simply relying on the observed responses obtained by limited experimentation with test sensor configurations. We......The paper considers the problem of sensor configuration for complex systems with the aim of maximizing the useful information about certain quantities of interest. Our approach involves: 1) definition of an appropriate optimality criterion or performance measure; and 2) description of an efficient...... and practical algorithm for achieving the optimality objective. The criterion for optimal sensor configuration is based on maximizing the overall sensor response while minimizing the correlation among the sensor outputs, so as to minimize the redundant information being provided by the multiple sensors...

  7. Optimal sensor configuration for complex systems

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    configuration is based on maximizing the overall sensor response while minimizing the correlation among the sensor outputs. The procedure for sensor configuration is based on simultaneous perturbation stochastic approximation (SPSA). SPSA avoids the need for detailed modeling of the sensor response by simply......Considers the problem of sensor configuration for complex systems. Our approach involves definition of an appropriate optimality criterion or performance measure, and description of an efficient and practical algorithm for achieving the optimality objective. The criterion for optimal sensor...... relying on observed responses as obtained by limited experimentation with test sensor configurations. We illustrate the approach with the optimal placement of acoustic sensors for signal detection in structures. This includes both a computer simulation study for an aluminum plate, and real...

  8. Theorem on axially symmetric gravitational vacuum configurations

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, A; Le Denmat, G [Paris-6 Univ., 75 (France). Inst. Henri Poincare

    1977-01-24

    A theorem is proved which asserts the non-existence of axially symmetric gravitational vacuum configurations with non-stationary rotation only. The eventual consequences in black-hole physics are suggested.

  9. Status Configurations, Military Service and Higher Education

    Science.gov (United States)

    Wang, Lin; Elder, Glen H.; Spence, Naomi J.

    2012-01-01

    The U.S. Armed Forces offer educational and training benefits as incentives for service. This study investigates the influence of status configurations on military enlistment and their link to greater educational opportunity. Three statuses (socioeconomic status of origin, cognitive ability and academic performance) have particular relevance for life course options. We hypothesize that young men with inconsistent statuses are more likely to enlist than men with consistent status profiles, and that military service improves access to college for certain configurations. Analyses of the National Longitudinal Study of Adolescent Health (Add Health) show (1. that several status configurations markedly increased the likelihood of military enlistment and (2. within status configurations, recruits were generally more likely to enroll in higher education than nonveterans, with associate degrees being more likely. PMID:24511161

  10. Configurable Web Warehouses construction through BPM Systems

    Directory of Open Access Journals (Sweden)

    Andrea Delgado

    2016-08-01

    Full Text Available The process of building Data Warehouses (DW is well known with well defined stages but at the same time, mostly carried out manually by IT people in conjunction with business people. Web Warehouses (WW are DW whose data sources are taken from the web. We define a flexible WW, which can be configured accordingly to different domains, through the selection of the web sources and the definition of data processing characteristics. A Business Process Management (BPM System allows modeling and executing Business Processes (BPs providing support for the automation of processes. To support the process of building flexible WW we propose a two BPs level: a configuration process to support the selection of web sources and the definition of schemas and mappings, and a feeding process which takes the defined configuration and loads the data into the WW. In this paper we present a proof of concept of both processes, with focus on the configuration process and the defined data.

  11. Discharge breakdown in the EXTRAP configuration

    International Nuclear Information System (INIS)

    Drake, J.R.

    1982-02-01

    The breakdown of a discharge in a linear EXTRAP configuration has been studied experimentally. In this configuration the breakdown occurs along the zero B-field line, which is the axis of the linear octupole magnetic field, between the anode and cathode which constitute the ends of the linear device. Breakdown could be described by a modified Townsend criterion which included additional electron losses due to the presence of the B-field transverse to the discharge. (author)

  12. An intelligent sales assistant for configurable products

    OpenAIRE

    Molina, Martin

    2001-01-01

    Some of the recent proposals of web-based applications are oriented to provide advanced search services through virtual shops. Within this context, this paper proposes an advanced type of software application that simulates how a sales assistant dialogues with a consumer to dynamically configure a product according to particular needs. The paper presents the general knowl- edge model that uses artificial intelligence and knowledge-based techniques to simulate the configuration process. Finall...

  13. Control Configuration Selection for Multivariable Descriptor Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; Stoustrup, Jakob

    2012-01-01

    Control configuration selection is the procedure of choosing the appropriate input and output pairs for the design of SISO (or block) controllers. This step is an important prerequisite for a successful industrial control strategy. In industrial practices it is often the case that the system, whi...... is that it can be used to propose a richer sparse or block diagonal controller structure. The interaction measure is used for control configuration selection of the linearized CSTR model with descriptor from....

  14. Benzofuranoid and bicyclooctanoid neolignans:absolute configuration

    International Nuclear Information System (INIS)

    Alvarenga, M.A. de; Giesbrecht, A.M.; Gottlieb, O.R.; Yoshida, M.

    1977-01-01

    The naturally occuring benzofuranoid and bicyclo (3,2,1) octanoid neolignans have their relative configurations established by 1 H and 13 C NMR, inclusively with aid of the solvent shift technique. Interconversion of the benzofuranoid type compounds, as well as for a benzofuranoid to a bicyclooctanoid derivate, make ORD correlations, ultimately with (2S, 3S) - and (2R,3R)-2,3- dihydrobenzofurans, possible, and led to the absolute configurations of both series of neolignans [pt

  15. Observed benefits from product configuration systems

    DEFF Research Database (Denmark)

    Hvam, Lars; Haug, Anders; Mortensen, Niels Henrik

    2013-01-01

    This article presents a study of the benefits obtained from applying product configuration systems based on a case study in four industry companies. The impacts are described according to main objectives in literature for imple-menting product configuration systems: lead time in the specification...... affected by the use of product configu-ration systems e.g. increased sales, decrease in the number of SKU's, improved ability to introduce new products, and cost reductions.......This article presents a study of the benefits obtained from applying product configuration systems based on a case study in four industry companies. The impacts are described according to main objectives in literature for imple-menting product configuration systems: lead time in the specification...... processes, on-time delivery of the specifica-tions, and resource consumption for making specifications, quality of specifications, optimization of products and services, and other observations. The purpose of the study is partly to identify specific impacts observed from implementing product configuration...

  16. Dynamic airspace configuration by genetic algorithm

    Directory of Open Access Journals (Sweden)

    Marina Sergeeva

    2017-06-01

    Full Text Available With the continuous air traffic growth and limits of resources, there is a need for reducing the congestion of the airspace systems. Nowadays, several projects are launched, aimed at modernizing the global air transportation system and air traffic management. In recent years, special interest has been paid to the solution of the dynamic airspace configuration problem. Airspace sector configurations need to be dynamically adjusted to provide maximum efficiency and flexibility in response to changing weather and traffic conditions. The main objective of this work is to automatically adapt the airspace configurations according to the evolution of traffic. In order to reach this objective, the airspace is considered to be divided into predefined 3D airspace blocks which have to be grouped or ungrouped depending on the traffic situation. The airspace structure is represented as a graph and each airspace configuration is created using a graph partitioning technique. We optimize airspace configurations using a genetic algorithm. The developed algorithm generates a sequence of sector configurations for one day of operation with the minimized controller workload. The overall methodology is implemented and successfully tested with air traffic data taken for one day and for several different airspace control areas of Europe.

  17. Intellectual Model-Based Configuration Management Conception

    Directory of Open Access Journals (Sweden)

    Bartusevics Arturs

    2014-07-01

    Full Text Available Software configuration management is one of the most important disciplines within the software development project, which helps control the software evolution process and allows including into the end project only tested and validated changes. To achieve this, software management completes certain tasks. Concrete tools are used for technical implementation of tasks, such as version control systems, servers of continuous integration, compilers, etc. A correct configuration management process usually requires several tools, which mutually exchange information by generating various kinds of transfers. When it comes to introducing the configuration management process, often there are situations when tool installation is started, yet at that given moment there is no general picture of the total process. The article offers a model-based configuration management concept, which foresees the development of an abstract model for the configuration management process that later is transformed to lower abstraction level models and tools are indicated to support the technical process. A solution of this kind allows a more rational introduction and configuration of tools

  18. Formation of Service Ecosystems

    DEFF Research Database (Denmark)

    Jonas, Julia M.; Sörhammar, David; Satzger, Gerhard

    – i.e. the “birth phase” (Moore, 2009) of a service ecosystem. This paper, therefore, aims to explore how the somewhat “magic” processes of service ecosystem formation that are being taken for granted actually occur. Methodology/Approach: Building on a review of core elements in the definitions...... for Harvard students) or value proposition (share messages, photos, videos, etc. with friends). Processes of configuring actors, resources, and value propositions are influenced by the structural embeddedness of the service ecosystem (e.g., regional infrastructure, existing networks of actors, or resource...... availability) as well as guided by the actors’ own and shared institutions (e.g., rules, norms,and beliefs).We contextualize each starting point with illustrative cases and analyze the service ecosystem configuration process: “Axoon/Trumpf” (initiated by resources), “JOSEPHS – the service manufactory...

  19. Driving reconnection in sheared magnetic configurations with forced fluctuations

    Science.gov (United States)

    Pongkitiwanichakul, Peera; Makwana, Kirit D.; Ruffolo, David

    2018-02-01

    We investigate reconnection of magnetic field lines in sheared magnetic field configurations due to fluctuations driven by random forcing by means of numerical simulations. The simulations are performed with an incompressible, pseudo-spectral magnetohydrodynamics code in 2D where we take thick, resistively decaying, current-sheet like sheared magnetic configurations which do not reconnect spontaneously. We describe and test the forcing that is introduced in the momentum equation to drive fluctuations. It is found that the forcing does not change the rate of decay; however, it adds and removes energy faster in the presence of the magnetic shear structure compared to when it has decayed away. We observe that such a forcing can induce magnetic reconnection due to field line wandering leading to the formation of magnetic islands and O-points. These reconnecting field lines spread out as the current sheet decays with time. A semi-empirical formula is derived which reasonably explains the formation and spread of O-points. We find that reconnection spreads faster with stronger forcing and longer correlation time of forcing, while the wavenumber of forcing does not have a significant effect. When the field line wandering becomes large enough, the neighboring current sheets with opposite polarity start interacting, and then the magnetic field is rapidly annihilated. This work is useful to understand how forced fluctuations can drive reconnection in large scale current structures in space and astrophysical plasmas that are not susceptible to reconnection.

  20. Configuration affects parallel stent grafting results.

    Science.gov (United States)

    Tanious, Adam; Wooster, Mathew; Armstrong, Paul A; Zwiebel, Bruce; Grundy, Shane; Back, Martin R; Shames, Murray L

    2018-05-01

    A number of adjunctive "off-the-shelf" procedures have been described to treat complex aortic diseases. Our goal was to evaluate parallel stent graft configurations and to determine an optimal formula for these procedures. This is a retrospective review of all patients at a single medical center treated with parallel stent grafts from January 2010 to September 2015. Outcomes were evaluated on the basis of parallel graft orientation, type, and main body device. Primary end points included parallel stent graft compromise and overall endovascular aneurysm repair (EVAR) compromise. There were 78 patients treated with a total of 144 parallel stents for a variety of pathologic processes. There was a significant correlation between main body oversizing and snorkel compromise (P = .0195) and overall procedural complication (P = .0019) but not with endoleak rates. Patients were organized into the following oversizing groups for further analysis: 0% to 10%, 10% to 20%, and >20%. Those oversized into the 0% to 10% group had the highest rate of overall EVAR complication (73%; P = .0003). There were no significant correlations between any one particular configuration and overall procedural complication. There was also no significant correlation between total number of parallel stents employed and overall complication. Composite EVAR configuration had no significant correlation with individual snorkel compromise, endoleak, or overall EVAR or procedural complication. The configuration most prone to individual snorkel compromise and overall EVAR complication was a four-stent configuration with two stents in an antegrade position and two stents in a retrograde position (60% complication rate). The configuration most prone to endoleak was one or two stents in retrograde position (33% endoleak rate), followed by three stents in an all-antegrade position (25%). There was a significant correlation between individual stent configuration and stent compromise (P = .0385), with 31

  1. Configuring Airspace Sectors with Approximate Dynamic Programming

    Science.gov (United States)

    Bloem, Michael; Gupta, Pramod

    2010-01-01

    In response to changing traffic and staffing conditions, supervisors dynamically configure airspace sectors by assigning them to control positions. A finite horizon airspace sector configuration problem models this supervisor decision. The problem is to select an airspace configuration at each time step while considering a workload cost, a reconfiguration cost, and a constraint on the number of control positions at each time step. Three algorithms for this problem are proposed and evaluated: a myopic heuristic, an exact dynamic programming algorithm, and a rollouts approximate dynamic programming algorithm. On problem instances from current operations with only dozens of possible configurations, an exact dynamic programming solution gives the optimal cost value. The rollouts algorithm achieves costs within 2% of optimal for these instances, on average. For larger problem instances that are representative of future operations and have thousands of possible configurations, excessive computation time prohibits the use of exact dynamic programming. On such problem instances, the rollouts algorithm reduces the cost achieved by the heuristic by more than 15% on average with an acceptable computation time.

  2. 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.

  3. Configuration Fuzzing for Software Vulnerability Detection.

    Science.gov (United States)

    Dai, Huning; Murphy, Christian; Kaiser, Gail

    2010-02-15

    Many software security vulnerabilities only reveal themselves under certain conditions, i.e., particular configurations of the software together with its particular runtime environment. One approach to detecting these vulnerabilities is fuzz testing, which feeds a range of randomly modified inputs to a software application while monitoring it for failures. However, typical fuzz testing makes no guarantees regarding the syntactic and semantic validity of the input, or of how much of the input space will be explored. To address these problems, in this paper we present a new testing methodology called configuration fuzzing. Configuration fuzzing is a technique whereby the configuration of the running application is randomly modified at certain execution points, in order to check for vulnerabilities that only arise in certain conditions. As the application runs in the deployment environment, this testing technique continuously fuzzes the configuration and checks "security invariants" that, if violated, indicate a vulnerability; however, the fuzzing is performed in a duplicated copy of the original process, so that it does not affect the state of the running application. In addition to discussing the approach and describing a prototype framework for implementation, we also present the results of a case study to demonstrate the approach's efficiency.

  4. Evaluating the fermionic determinant of dynamical configurations

    International Nuclear Information System (INIS)

    Hasenfratz, Anna; Alexandru, Andrei

    2002-01-01

    We propose and study an improved method to calculate the fermionic determinant of dynamical configurations. The evaluation or at least stochastic estimation of the ratios of fermionic determinants is essential for a recently proposed updating method of smeared link dynamical fermions. This update creates a sequence of configurations by changing a subset of the gauge links by a pure gauge heat bath or over-relaxation step. The acceptance of the proposed configuration depends on the ratio of the fermionic determinants on the new and original configurations. We study this ratio as a function of the number of links that are changed in the heat bath update. We find that even when every link of a given direction and parity of a 10 fm 4 configuration is updated, the average of the determinant ratio is still close to one and with the improved stochastic estimator the proposed change is accepted with about 20% probability. This improvement suggests that the new updating technique can be efficient even on large lattices and could provide an updating method for dynamical overlap actions

  5. System of ispFlash configuration

    International Nuclear Information System (INIS)

    Bourrion, Olivier

    2003-01-01

    The aim of this module is to allow the use of FPGA components instead of EPLD components which for an equivalent or even inferior capacity are more expensive. For instance, the idea is to replace CPLD components having 512 macro-cells by one FPGA spartan II of Xilinx. However, due to the configuration's volatility, one configuration means is needed to put under voltage. A solution appears to be the using of a high capacity Flash memory coupled to a CPLD of small size to comply with the FPGA configuration protocol; also, one has to provide an in situ configuration means for this memory. Obviously, a product having an equivalent functionality already exists, since Xilinx and ALTERA supply PROMs of serial configuration. Unfortunately, they are expensive and a dealer is implied while the FLASH, the small CPLD and the FPGA spartan II are currently available. In conclusion, by using this assembly, which requires a small supplementary surface and a delay of upmost 240 ms (for the largest FPGA 1 Mbit), one obtains a solution cheaper and more performing than an EPLD of high capacity

  6. Prediction of Protein Configurational Entropy (Popcoen).

    Science.gov (United States)

    Goethe, Martin; Gleixner, Jan; Fita, Ignacio; Rubi, J Miguel

    2018-03-13

    A knowledge-based method for configurational entropy prediction of proteins is presented; this methodology is extremely fast, compared to previous approaches, because it does not involve any type of configurational sampling. Instead, the configurational entropy of a query fold is estimated by evaluating an artificial neural network, which was trained on molecular-dynamics simulations of ∼1000 proteins. The predicted entropy can be incorporated into a large class of protein software based on cost-function minimization/evaluation, in which configurational entropy is currently neglected for performance reasons. Software of this type is used for all major protein tasks such as structure predictions, proteins design, NMR and X-ray refinement, docking, and mutation effect predictions. Integrating the predicted entropy can yield a significant accuracy increase as we show exemplarily for native-state identification with the prominent protein software FoldX. The method has been termed Popcoen for Prediction of Protein Configurational Entropy. An implementation is freely available at http://fmc.ub.edu/popcoen/ .

  7. Stellar formation

    CERN Document Server

    Reddish, V C

    1978-01-01

    Stellar Formation brings together knowledge about the formation of stars. In seeking to determine the conditions necessary for star formation, this book examines questions such as how, where, and why stars form, and at what rate and with what properties. This text also considers whether the formation of a star is an accident or an integral part of the physical properties of matter. This book consists of 13 chapters divided into two sections and begins with an overview of theories that explain star formation as well as the state of knowledge of star formation in comparison to stellar structure

  8. A Configuration Model of Organizational Culture

    Directory of Open Access Journals (Sweden)

    Daniel Dauber

    2012-01-01

    Full Text Available The article proposes a configuration model of organizational culture, which explores dynamic relationships between organizational culture, strategy, structure, and operations of an organization (internal environment and maps interactions with the external environment (task and legitimization environment. A major feature of the configuration model constitutes its well-defined processes, which connect the elements of the model systematically to each other, such as single- and double-loop learning, operationalization of strategies, legitimization management, and so on. The model is grounded in a large review of literature in different research areas and builds on widely recognized models in the field of organization and culture theory. It constitutes a response to the call for new models, which are able to explain and facilitate the exploration of the empirical complexity that organizations face today. The configuration model of organizational culture is of particular interest to scholars who investigate into cultural phenomena and change over time.

  9. Fiber optic configurations for local area networks

    Science.gov (United States)

    Nassehi, M. M.; Tobagi, F. A.; Marhic, M. E.

    1985-01-01

    A number of fiber optic configurations for a new class of demand assignment multiple-access local area networks requiring a physical ordering among stations are proposed. In such networks, the data transmission and linear-ordering functions may be distinguished and be provided by separate data and control subnetworks. The configurations proposed for the data subnetwork are based on the linear, star, and tree topologies. To provide the linear-ordering function, the control subnetwork must always have a linear unidirectional bus structure. Due to the reciprocity and excess loss of optical couplers, the number of stations that can be accommodated on a linear fiber optic bus is severely limited. Two techniques are proposed to overcome this limitation. For each of the data and control subnetwork configurations, the maximum number of stations as a function of the power margin, for both reciprocal and nonreciprocal couplers, is computed.

  10. Configurational entropy in brane-world models

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R.A.C. [CCNH, Universidade Federal do ABC, Santo Andre, SP (Brazil); Rocha, Roldao da [CMCC, Universidade Federal do ABC, Santo Andre, SP (Brazil); International School for Advanced Studies (SISSA), Trieste (Italy)

    2015-11-15

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy. (orig.)

  11. Configurational entropy in brane-world models

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R. A. C., E-mail: fis04132@gmail.com [CCNH, Universidade Federal do ABC, 09210-580, Santo André, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [CMCC, Universidade Federal do ABC, 09210-580, Santo André, SP (Brazil); International School for Advanced Studies (SISSA), Via Bonomea 265, 34136, Trieste (Italy)

    2015-11-02

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy.

  12. Configurational entropy in brane-world models

    International Nuclear Information System (INIS)

    Correa, R. A. C.; Rocha, Roldão da

    2015-01-01

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy

  13. Modelling Configuration Knowledge in Heterogeneous Product Families

    DEFF Research Database (Denmark)

    Queva, Matthieu Stéphane Benoit; Männistö, Tomi; Ricci, Laurent

    2011-01-01

    Product configuration systems play an important role in the development of Mass Customisation. The configuration of complex product families may nowadays involve multiple design disciplines, e.g. hardware, software and services. In this paper, we present a conceptual approach for modelling...... the variability in such heterogeneous product families. Our approach is based on a framework that aims to cater for the different stakeholders involved in the modelling and management of the product family. The modelling approach is centred around the concepts of views, types and constraints and is illustrated...... by a motivation example. Furthermore, as a proof of concept, a prototype has been implemented for configuring a non-trivial heterogeneous product family....

  14. Dependability Analysis Methods For Configurable Software

    International Nuclear Information System (INIS)

    Dahll, Gustav; Pulkkinen, Urho

    1996-01-01

    Configurable software systems are systems which are built up by standard software components in the same way as a hardware system is built up by standard hardware components. Such systems are often used in the control of NPPs, also in safety related applications. A reliability analysis of such systems is therefore necessary. This report discusses what configurable software is, and what is particular with respect to reliability assessment of such software. Two very commonly used techniques in traditional reliability analysis, viz. failure mode, effect and criticality analysis (FMECA) and fault tree analysis are investigated. A real example is used to illustrate the discussed methods. Various aspects relevant to the assessment of the software reliability in such systems are discussed. Finally some models for quantitative software reliability assessment applicable on configurable software systems are described. (author)

  15. Modeling the planar configuration of extraordinary magnetoresistance

    International Nuclear Information System (INIS)

    El-Ahmar, S; Pozniak, A A

    2015-01-01

    Recently the planar version of the extraordinary magnetoresistance (EMR) magnetic field sensor has been constructed and verified in practice. Planar configuration of the EMR device gives many technological advantages, it is simpler than the classic and allows one to build the sensor using electric materials of the new type (such as graphene or topological insulators) much easier. In this work the planar configuration of the EMR sensor is investigated by performing computational simulations using the finite element method (FEM). The computational comparison of the planar and classic configurations of EMR is presented using three-dimensional models. Various variants of the geometry of EMR sensor components are pondered and compared in the planar and classic version. Size of the metal overlap is considered for sensor optimization as well as various semiconductor-metal contact resistance dependences of the EMR signal. Based on computational simulations, a method for optimal placement of electric terminals in a planar EMR device is proposed. (paper)

  16. Model-Driven Configuration of SELinux Policies

    Science.gov (United States)

    Agreiter, Berthold; Breu, Ruth

    The need for access control in computer systems is inherent. However, the complexity to configure such systems is constantly increasing which affects the overall security of a system negatively. We think that it is important to define security requirements on a non-technical level while taking the application domain into respect in order to have a clear and separated view on security configuration (i.e. unblurred by technical details). On the other hand, security functionality has to be tightly integrated with the system and its development process in order to provide comprehensive means of enforcement. In this paper, we propose a systematic approach based on model-driven security configuration to leverage existing operating system security mechanisms (SELinux) for realising access control. We use UML models and develop a UML profile to satisfy these needs. Our goal is to exploit a comprehensive protection mechanism while rendering its security policy manageable by a domain specialist.

  17. Applying Product Configuration Systems in Engineering Companies

    DEFF Research Database (Denmark)

    Ladeby, Klaes Rohde

    This Ph.D. thesis looks into the application of configuration systems in engineering companies, and how configuration systems can be used to support business processes in engineering companies. Often the motivation stated by researchers and practitioners is, that a configuration project...... and sustain competitive advantage” (Teece, Pisano, & Shuen, 1997, pp.509) This question has puzzled academics and preoccupied managers for the last century. Yet, it seems there is still no consensus regarding the meaning of strategy, and how strategy works. Type in the word “strategy” on Amazon.co.uk and 76......,133 books apply. Type it in on Google scholar and 8,580,000 homepages apply3. Obviously, strategy is an important subject. However, the subject also seems to be difficult to perceive. Although this thesis is not about strategy, or strategizing, I would like to pursue the definition of strategy one step...

  18. Dark Energy and Structure Formation

    International Nuclear Information System (INIS)

    Singh, Anupam

    2010-01-01

    We study the gravitational dynamics of dark energy configurations. We report on the time evolution of the dark energy field configurations as well as the time evolution of the energy density to demonstrate the gravitational collapse of dark energy field configurations. We live in a Universe which is dominated by Dark Energy. According to current estimates about 75% of the Energy Density is in the form of Dark Energy. Thus when we consider gravitational dynamics and Structure Formation we expect Dark Energy to play an important role. The most promising candidate for dark energy is the energy density of fields in curved space-time. It therefore become a pressing need to understand the gravitational dynamics of dark energy field configurations. We develop and describe the formalism to study the gravitational collapse of fields given any general potential for the fields. We apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting evolution equations which determine the time evolution of field configurations as well as the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our universe.

  19. Siroco, a configurable robot control system

    International Nuclear Information System (INIS)

    Tejedor, B.G.; Maraggi, G.J.B.

    1988-01-01

    The SIROCO (Configurable Robot Control System) is an electronic system designed to work in applications where mechanized remote control equipment and robots are necessary especially in Nuclear Power Plants. The structure of the system (hardware and software) determines the following user characteristics: a) Reduction in the time spent in NDT and in radiation doses absorbed, due to remote control operation; b) possibility for full automation in NDT, c) the system can simultaneously control up to six axes and can generate movements in remote areas; and d) possibility for equipment unification, due to SIROCO being a configurable system. (author)

  20. Mastering System Center 2012 Configuration Manager

    CERN Document Server

    Rachui, Steve; Martinez, Santos; Daalmans, Peter

    2012-01-01

    Expert coverage of Microsoft's highly anticipated network software deployment tool The latest version of System Center Configuration Manager (SCCM) is a dramatic update of its predecessor Configuration Manager 2007, and this book offers intermediate-to-advanced coverage of how the new SCCM boasts a simplified hierarchy, role-based security, a new console, flexible application deployment, and mobile management. You'll explore planning and installation, migrating from SCCM 2007, deploying software and operating systems, security, monitoring and troubleshooting, and automating and customizing SCC

  1. TWRS configuration management requirement source document

    International Nuclear Information System (INIS)

    Vann, J.M.

    1997-01-01

    The TWRS Configuration Management (CM) Requirement Source document prescribes CM as a basic product life-cycle function by which work and activities are conducted or accomplished. This document serves as the requirements basis for the TWRS CM program. The objective of the TWRS CM program is to establish consistency among requirements, physical/functional configuration, information, and documentation for TWRS and TWRS products, and to maintain this consistency throughout the life-cycle of TWRS and the product, particularly as changes are being made

  2. Design review of the INTOR mechanical configuration

    International Nuclear Information System (INIS)

    Brown, T.G.

    1981-01-01

    The INTOR conceptual design has been carried out by design teams working in the home countries with periodic workshop sessions in Vienna to review the ongoing work and to make decisions on the evolving design. The decisions taken at each workshop session were then incorporated into each national design activity, so that the four national design contributions would progressively converge toward a single design with increasingly greater detail. This paper defines the final INTOR configuration that has evolved during the conceptual design phase, defining the major system design alternatives that were considered and the rationale for selecting the final system configuration

  3. Automated firewall analytics design, configuration and optimization

    CERN Document Server

    Al-Shaer, Ehab

    2014-01-01

    This book provides a comprehensive and in-depth study of automated firewall policy analysis for designing, configuring and managing distributed firewalls in large-scale enterpriser networks. It presents methodologies, techniques and tools for researchers as well as professionals to understand the challenges and improve the state-of-the-art of managing firewalls systematically in both research and application domains. Chapters explore set-theory, managing firewall configuration globally and consistently, access control list with encryption, and authentication such as IPSec policies. The author

  4. Design configuration of GCFR core assemblies

    International Nuclear Information System (INIS)

    LaBar, M.P.; Lee, G.E.; Meyer, R.J.

    1980-05-01

    The current design configurations of the core assemblies for the gas-cooled fast reactor (GCFR) demonstration plant reactor core conceptual design are described. Primary emphasis is placed upon the design innovations that have been incorporated in the design of the core assemblies since the establishment of the initial design of an upflow GCFR core. A major feature of the design configurations is that they are prototypical of core assemblies for use in commercial plants; a larger number of the same assemblies would be used in a commercial plant

  5. Runtime accelerator configuration tools at Jefferson Laboratory

    International Nuclear Information System (INIS)

    Tiefenback, M.G.; Doolittle, L.; Benesch, J.F.

    1997-01-01

    RF and magnet system configuration and monitoring tools are being implemented at Jefferson Lab to improve system reliability and reduce operating costs. They are prototype components of the Momentum Management System being developed. The RF is of special interest because it affects the momentum and momentum spread of the beam, and because of the immediate financial benefit of managing the klystron DC supply power. The authors describe present and planned monitoring of accelerating system parameters, use of these data, RF system performance calculations, and procedures for magnet configuration for handling beam of any of five beam energies to any of three targets

  6. Configuration Management Issues at Research Reactors

    International Nuclear Information System (INIS)

    Morris, Charles R.

    2013-01-01

    Configuration Management (from IAEA TECDOC 1651): • The Main Functions of the configuration management process are to: • maintain design requirements of structures, systems and components; • track current as-built drawings, documents, and design basis library; • confirm design change packages demonstrate compliance to design basis in calculations, procurement, safety reviews, update of affected documents, and SSC data; • confirm work orders demonstrate compliance to mandated preventive maintenance; • surveillance, parts replacement and design change installation requirements; • demonstrate procurement of spare parts qualified to meet design basis for proper make, model and quality-level for the SSC location and form, fit and function

  7. Position paper - primary ventilation system configuration

    International Nuclear Information System (INIS)

    Dalpiaz, E.L.

    1994-06-01

    The purpose of this paper is to develop and document a position on the configuration of the primary ventilation system. This configuration will be used on the waste storage tanks currently being designed for the Multi-Function Waste Tank Facility. The primary ventilation system provides a single treatment train and exhaust fan for each waste storage tank. The ventilation systems from each of two tanks are grouped with an additional treatment train and exhaust fan that function as backup to either of the two systems

  8. Calculation of Configurational Entropy in Complex Landscapes

    Directory of Open Access Journals (Sweden)

    Samuel A Cushman

    2018-04-01

    Full Text Available Entropy and the second law of thermodynamics are fundamental concepts that underlie all natural processes and patterns. Recent research has shown how the entropy of a landscape mosaic can be calculated using the Boltzmann equation, with the entropy of a lattice mosaic equal to the logarithm of the number of ways a lattice with a given dimensionality and number of classes can be arranged to produce the same total amount of edge between cells of different classes. However, that work seemed to also suggest that the feasibility of applying this method to real landscapes was limited due to intractably large numbers of possible arrangements of raster cells in large landscapes. Here I extend that work by showing that: (1 the proportion of arrangements rather than the number with a given amount of edge length provides a means to calculate unbiased relative configurational entropy, obviating the need to compute all possible configurations of a landscape lattice; (2 the edge lengths of randomized landscape mosaics are normally distributed, following the central limit theorem; and (3 given this normal distribution it is possible to fit parametric probability density functions to estimate the expected proportion of randomized configurations that have any given edge length, enabling the calculation of configurational entropy on any landscape regardless of size or number of classes. I evaluate the boundary limits (4 for this normal approximation for small landscapes with a small proportion of a minority class and show it holds under all realistic landscape conditions. I further (5 demonstrate that this relationship holds for a sample of real landscapes that vary in size, patch richness, and evenness of area in each cover type, and (6 I show that the mean and standard deviation of the normally distributed edge lengths can be predicted nearly perfectly as a function of the size, patch richness and diversity of a landscape. Finally, (7 I show that the

  9. Control of divertor configuration in JT-60

    International Nuclear Information System (INIS)

    Yoshino, R.; Kukuchi, M.; Ninomiya, H.; Yoshida, H.; Tsuji, S.; Hosogane, N.; Seki, S.

    1985-01-01

    The control algorithm of JT-60 divertor configuration is presented. JT-60 has five types of poloidal magnetic field coil with each power supply in order to regulate the control objectives mentioned above. However, if one controls each objective by each coil current independently, there must inevitably occur large interaction between control objectives. Because the relation between control objectives and coil currents is complicated. This situation may be the same with a fusion reactor device. For making it possible to control each objective independently without causing large interaction, the authors adopt the noninteracting control algorithm. Hence, this report demonstrates the availability of this method to the control of JT-60 divertor configuration

  10. New superconducting coil configuration for energy storage

    International Nuclear Information System (INIS)

    Tokorabet, M.; Mailfert, A.; Colteu, A.

    1998-01-01

    Energy storage using superconducting coils involves the problem of electromagnetic field pollution outside the considered system. Different configurations are widely studied: the torus, the alone solenoid and multiple parallel solenoids enclosed in one container. A new configuration which minimizes the external pollution is studied in this paper. The theoretical system is composed of two spherical distributions of the current which are concentric. The analytical study uses solution of Laplace equations. Parametric study covers energy, flux density and geometrical data. The second study concerns the numerical approach of this design using coaxial solenoids. A comparison between this new system and the known systems is presented as a conclusion. (orig.)

  11. Redetermination and absolute configuration of atalaphylline

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-02-01

    Full Text Available The title acridone alkaloid [systematic name: 1,3,5-trihydroxy-2,4-bis(3-methylbut-2-enylacridin-9(10H-one], C23H25NO4, has previously been reported as crystallizing in the chiral orthorhombic space group P212121 [Chantrapromma et al. (2010. Acta Cryst. E66, o81–o82] but the absolute configuration could not be determined from data collected with Mo radiation. The absolute configuration has now been determined by refinement of the Flack parameter with data collected using Cu radiation. All features of the molecule and its crystal packing are similar to those previously described.

  12. Helical post stellarator. Part 1: Vacuum configuration

    International Nuclear Information System (INIS)

    Moroz, P.E.

    1997-08-01

    Results on a novel type of stellarator configuration, the Helical Post Stellarator (HPS), are presented. This configuration is different significantly from all previously known stellarators due to its unique geometrical characteristics and unique physical properties. Among those are: the magnetic field has only one toroidal period (M = 1), the plasma has an extremely low aspect ratio, A ∼ 1, and the variation of the magnetic field, B, along field lines features a helical ripple on the inside of the torus. Among the main advantages of a HPS for a fusion program are extremely compact, modular, and simple design compatible with significant rotational transform, large plasma volume, and improved particle transport characteristics

  13. Design issues for optimum solar cell configuration

    Science.gov (United States)

    Kumar, Atul; Thakur, Ajay D.

    2018-05-01

    A computer based simulation of solar cell structure is performed to study the optimization of pn junction configuration for photovoltaic action. The fundamental aspects of photovoltaic action viz, absorption, separation collection, and their dependence on material properties and deatails of device structures is discussed. Using SCAPS 1D we have simulated the ideal pn junction and shown the effect of band offset and carrier densities on solar cell performance. The optimum configuration can be achieved by optimizing transport of carriers in pn junction under effect of field dependent recombination (tunneling) and density dependent recombination (SRH, Auger) mechanisms.

  14. Galaxy formation

    International Nuclear Information System (INIS)

    Silk, J.; Di Cintio, A.; Dvorkin, I.

    2014-01-01

    Galaxy formation is at the forefront of observation and theory in cosmology. An improved understanding is essential for improving our knowledge both of the cosmological parameters, of the contents of the universe, and of our origins. In these lectures intended for graduate students, galaxy formation theory is reviewed and confronted with recent observational issues. In lecture 1, the following topics are presented: star formation considerations, including IMF, star formation efficiency and star formation rate, the origin of the galaxy luminosity function, and feedback in dwarf galaxies. In lecture 2, we describe formation of disks and massive spheroids, including the growth of supermassive black holes, negative feedback in spheroids, the AGN-star formation connection, star formation rates at high redshift and the baryon fraction in galaxies.

  15. Stereoselective total synthesis of Oxylipin from open chain gluco-configured building block.

    Science.gov (United States)

    Borkar, Santosh Ramdas; Aidhen, Indrapal Singh

    2017-04-18

    Total synthesis of naturally occurring Oxylipin has been achieved from open chain gluco-configured building block which is readily assembled from inexpensive and commercially available D-(+)-gluconolactone. Grignard reaction and Wittig olefination reactions are key steps for the requisite CC bond formation. Copyright © 2017. Published by Elsevier Ltd.

  16. The Broader Spectrum of Magnetic Configurations for Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Prager, S C [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Ryutov, D D [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2012-09-15

    Over the decades, a large array of magnetic configurations has been studied, producing a huge amount of fusion plasma science. As configurations are developed, information and techniques learned through one configuration influence the development of other configurations. In this way, configurations evolve unexpectedly in response to new information. Configurations that were at a pause can become unstuck by new discoveries, and configurations that appeared promising for fusion energy can become unattractive as new limits are uncovered. The plasma science of fusion energy is sufficiently complex that, as we approach ever closer to practical fusion power, the need for potential contributions of broad research of multiple magnetic configurations remains strong. (author)

  17. Selecting Actuator Configuration for a Benson Boiler

    DEFF Research Database (Denmark)

    Kragelund, Martin Nygaard; Leth, John-Josef; Wisniewski, Rafal

    2009-01-01

    with particular focus on a boiler in a power plant operated by DONG Energy - a Danish energy supplier. The problem has been reformulated using mathematic notions from economics. The selection of actuator configuration has been limited to the fuel system which in the considered plant consists of three different...

  18. Length scale for configurational entropy in microemulsions

    NARCIS (Netherlands)

    Reiss, H.; Kegel, W.K.; Groenewold, J.

    1996-01-01

    In this paper we study the length scale that must be used in evaluating the mixing entropy in a microemulsion. The central idea involves the choice of a length scale in configuration space that is consistent with the physical definition of entropy in phase space. We show that this scale may be

  19. Quality in Supply in Project Configured Networks

    DEFF Research Database (Denmark)

    Koch, Christian; Larsen, Casper Schultz

    2006-01-01

    The paper argues that in the AEC-industry the material and knowledge supply chains are increasingly intertwined and moreover characterised by configuration by project. In such a setting creating value for the customers and the enterprises becomes dependent of the ability to organise and coordinate...

  20. Spent Nuclear Fuel Project Configuration Management Plan

    International Nuclear Information System (INIS)

    Reilly, M.A.

    1995-01-01

    This document is a rewrite of the draft ''C'' that was agreed to ''in principle'' by SNF Project level 2 managers on EDT 609835, dated March 1995 (not released). The implementation process philosphy was changed in keeping with the ongoing reengineering of the WHC Controlled Manuals to achieve configuration management within the SNF Project

  1. Offshore Vendors' Software Development Team Configuration

    DEFF Research Database (Denmark)

    Chakraborty, Suranjan; Sarker, Saonee; Rai, Sudhanshu

    2011-01-01

    were compared on their inherent process-related and resource-related flexibilities. The thick-at-client configuration emerged as the one that offers superior flexibility (in all dimensions).However, additional analysis also revealed contingencies apart from flexibility that may influence...

  2. Sandia software guidelines, Volume 4: Configuration management

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-01

    This volume is one in a series of Sandia Software Guidelines for use in producing quality software within Sandia National Laboratories. This volume is based on the IEEE standard and guide for software configuration management. The basic concepts and detailed guidance on implementation of these concepts are discussed for several software project types. Example planning documents for both projects and organizations are included.

  3. Apple Configurator 2 (version 2.3)

    OpenAIRE

    Lara Lasner-Frater

    2018-01-01

    Apple Configurator 2 (AC2) is a free mass-deployment utility that allows you to update multiple iPads, iPhones, iPod Touch devices, and Apple TVs at the same time, including apps, website links, iBooks, and software updates.

  4. XVCL: XML-based Variant Configuration Language

    DEFF Research Database (Denmark)

    Jarzabek, Stan; Basset, Paul; Zhang, Hongyu

    2003-01-01

    XVCL (XML-based Variant Configuration Language) is a meta-programming technique and tool that provides effective reuse mechanisms. XVCL is an open source software developed at the National University of Singapore. Being a modern and versatile version of Bassett's frames, a technology that has...

  5. Status Configurations, Military Service and Higher Education

    Science.gov (United States)

    Wang, Lin; Elder, Glen H., Jr.; Spence, Naomi J.

    2012-01-01

    The U.S. Armed Forces offer educational and training benefits as incentives for service. This study investigates the influence of status configurations on military enlistment and their link to greater educational opportunity. Three statuses (socioeconomic status of origin, cognitive ability and academic performance) have particular relevance for…

  6. Configurable multi-perspective business process models

    NARCIS (Netherlands)

    La Rosa, M.; Dumas, M.; Hofstede, ter A.H.M.; Mendling, J.

    2011-01-01

    A configurable process model provides a consolidated view of a family of business processes. It promotes the reuse of proven practices by providing analysts with a generic modeling artifact from which to derive individual process models. Unfortunately, the scope of existing notations for

  7. Holistic processing of face configurations and components.

    Science.gov (United States)

    Hayward, William G; Crookes, Kate; Chu, Ming Hon; Favelle, Simone K; Rhodes, Gillian

    2016-10-01

    Although many researchers agree that faces are processed holistically, we know relatively little about what information holistic processing captures from a face. Most studies that assess the nature of holistic processing do so with changes to the face affecting many different aspects of face information (e.g., different identities). Does holistic processing affect every aspect of a face? We used the composite task, a common means of examining the strength of holistic processing, with participants making same-different judgments about configuration changes or component changes to 1 portion of a face. Configuration changes involved changes in spatial position of the eyes, whereas component changes involved lightening or darkening the eyebrows. Composites were either aligned or misaligned, and were presented either upright or inverted. Both configuration judgments and component judgments showed evidence of holistic processing, and in both cases it was strongest for upright face composites. These results suggest that holistic processing captures a broad range of information about the face, including both configuration-based and component-based information. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. Integrating configuration workflows with project management system

    International Nuclear Information System (INIS)

    Nilsen, Dimitri; Weber, Pavel

    2014-01-01

    The complexity of the heterogeneous computing resources, services and recurring infrastructure changes at the GridKa WLCG Tier-1 computing center require a structured approach to configuration management and optimization of interplay between functional components of the whole system. A set of tools deployed at GridKa, including Puppet, Redmine, Foreman, SVN and Icinga, provides the administrative environment giving the possibility to define and develop configuration workflows, reduce the administrative effort and improve sustainable operation of the whole computing center. In this presentation we discuss the developed configuration scenarios implemented at GridKa, which we use for host installation, service deployment, change management procedures, service retirement etc. The integration of Puppet with a project management tool like Redmine provides us with the opportunity to track problem issues, organize tasks and automate these workflows. The interaction between Puppet and Redmine results in automatic updates of the issues related to the executed workflow performed by different system components. The extensive configuration workflows require collaboration and interaction between different departments like network, security, production etc. at GridKa. Redmine plugins developed at GridKa and integrated in its administrative environment provide an effective way of collaboration within the GridKa team. We present the structural overview of the software components, their connections, communication protocols and show a few working examples of the workflows and their automation.

  9. Configuration mixing of mean-field states

    International Nuclear Information System (INIS)

    Bender, M; Heenen, P-H

    2005-01-01

    Starting from self-consistent mean-field models, we discuss how to include correlations from fluctuations in collective degrees of freedom through symmetry restoration and configuration mixing, which give access to ground-state correlations and collective excitations. As an example for the method, we discuss the spectroscopy of neutron-deficient Pb isotopes

  10. Self Configurable Intelligent Distributed Antenna System

    DEFF Research Database (Denmark)

    Kumar, Ambuj; Mihovska, Albena Dimitrova; Prasad, Ramjee

    2016-01-01

    with their respective base stations, spectrum pooling and management at antenna end is not efficient. The situation worsens in Heterogeneous and Dense-net conditions in an Area of Interest (AoI). In this paper, we propose a DAS based intelligent architecture referred to as Self Configurable Intelligent Distributed...

  11. Static Equilibrium Configurations of Charged Metallic Bodies ...

    African Journals Online (AJOL)

    In this paper we developed a simple numerical scheme to determine the static equilibrium configuration of charged metallic bodies by minimizing the potential energy function. The method developed has some advantages; it combines the general theory and the physical meanings nested in the mathematical model and this ...

  12. Pushing configuration-interaction to the limit

    DEFF Research Database (Denmark)

    Vogiatzis, Konstantinos D.; Ma, Dongxia; Olsen, Jeppe

    2017-01-01

    A new large-scale parallel multiconfigurational self-consistent field (MCSCF) implementation in the open-source NWChem computational chemistry code is presented. The generalized active space (GAS) approach is used to partition large configuration interaction (CI) vectors and generate a sufficient...

  13. Studies of a flexible heliac configuration

    International Nuclear Information System (INIS)

    Hender, T.C.; Cantrell, J.L.; Harris, J.H.

    1987-07-01

    This paper documents a detailed study of the Flexible Heliac configuration. The remarkable flexibility of this device - which allows variation of the rotational transform, shear, and magnetic well depth over a relatively wide range - is described. Engineering considerations of error fields, finite cross-section conductors, and plasma coil clearances are also discussed

  14. Sibling Gender Configuration and Family Processes

    NARCIS (Netherlands)

    van der Pol, Lotte D.; Mesman, Judi; Groeneveld, Marleen G.; Endendijk, Joyce J.; van Berkel, Sheila R.; Hallers-Haalboom, Elizabeth T.; Bakermans-Kranenburg, Marian J.

    2016-01-01

    The current study focuses on the effects of sibling gender configuration on family processes during early childhood. In a sample of 369 two-parent families with two children (youngest 12 months, oldest about 2 years older), both siblings’ noncompliant and oppositional behaviors and fathers’ and

  15. Private Cloud Configuration with MetaConfig

    DEFF Research Database (Denmark)

    Nielsen, Thomas; Iversen, Christian; Bonnet, Philippe

    2011-01-01

    With the advent of private clouds, the challenge of configuring a mix of physical and virtual machines is no longer reserved to a few system administrator gurus. How to assign virtual machines onto physical machines to leverage the available resources? How to maintain the virtual machine...

  16. Motion-insensitive rapid configuration relaxometry.

    Science.gov (United States)

    Nguyen, Damien; Bieri, Oliver

    2017-08-01

    Triple echo steady state (TESS) uses the lowest steady state configuration modes for rapid relaxometry. Due to its unbalanced gradient scheme, however, TESS is inherently motion-sensitive. The purpose of this work is to merge TESS with a balanced acquisition scheme for motion-insensitive rapid configuration relaxometry, termed MIRACLE. The lowest order steady state free precession (SSFP) configurations are retrieved by Fourier transformation of the frequency response of N frequency-shifted balanced SSFP (bSSFP) scans and subsequently processed for relaxometry, as proposed with TESS. Accuracy of MIRACLE is evaluated from simulations, phantom studies as well as in vivo brain and cartilage imaging at 3T. Simulations and phantom results revealed no conceptual flaw, and artifact-free configuration imaging was achieved in vivo. Overall, relaxometry results were accurate in phantoms and in good agreement for cartilage and for T2 in the brain, but apparent low T1 values were observed for brain white matter; reflecting asymmetries in the bSSFP profile. Rapid T1 and T2 mapping with MIRACLE offers analogous properties as TESS while successfully mitigating its motion-sensitivity. As a result of the Fourier transformation, relaxometry becomes sensitive to the voxel frequency distribution, which may contain useful physiologic information, such as structural brain integrity. © 2016 International Society for Magnetic Resonance in Medicine. Magn Reson Med 78:518-526, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  17. Formation of coronal cavities

    International Nuclear Information System (INIS)

    An, C.H.; Suess, S.T.; Tandberg-Hanssen, E.; Steinolfson, R.S.

    1986-01-01

    A theoretical study of the formation of a coronal cavity and its relation to a quiescent prominence is presented. It is argued that the formation of a cavity is initiated by the condensation of plasma which is trapped by the coronal magnetic field in a closed streamer and which then flows down to the chromosphere along the field lines due to lack of stable magnetic support against gravity. The existence of a coronal cavity depends on the coronal magnetic field strength; with low strength, the plasma density is not high enough for condensation to occur. Furthermore, we suggest that prominence and cavity material is supplied from the chromospheric level. Whether a coronal cavity and a prominence coexist depends on the magnetic field configuration; a prominence requires stable magnetic support

  18. Formal Verification Method for Configuration of Integrated Modular Avionics System Using MARTE

    Directory of Open Access Journals (Sweden)

    Lisong Wang

    2018-01-01

    Full Text Available The configuration information of Integrated Modular Avionics (IMA system includes almost all details of whole system architecture, which is used to configure the hardware interfaces, operating system, and interactions among applications to make an IMA system work correctly and reliably. It is very important to ensure the correctness and integrity of the configuration in the IMA system design phase. In this paper, we focus on modelling and verification of configuration information of IMA/ARINC653 system based on MARTE (Modelling and Analysis for Real-time and Embedded Systems. Firstly, we define semantic mapping from key concepts of configuration (such as modules, partitions, memory, process, and communications to components of MARTE element and propose a method for model transformation between XML-formatted configuration information and MARTE models. Then we present a formal verification framework for ARINC653 system configuration based on theorem proof techniques, including construction of corresponding REAL theorems according to the semantics of those key components of configuration information and formal verification of theorems for the properties of IMA, such as time constraints, spatial isolation, and health monitoring. After that, a special issue of schedulability analysis of ARINC653 system is studied. We design a hierarchical scheduling strategy with consideration of characters of the ARINC653 system, and a scheduling analyzer MAST-2 is used to implement hierarchical schedule analysis. Lastly, we design a prototype tool, called Configuration Checker for ARINC653 (CC653, and two case studies show that the methods proposed in this paper are feasible and efficient.

  19. Continuous Security and Configuration Monitoring of HPC Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Lomeli, H. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bertsch, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fox, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-08

    Continuous security and configuration monitoring of information systems has been a time consuming and laborious task for system administrators at the High Performance Computing (HPC) center. Prior to this project, system administrators had to manually check the settings of thousands of nodes, which required a significant number of hours rendering the old process ineffective and inefficient. This paper explains the application of Splunk Enterprise, a software agent, and a reporting tool in the development of a user application interface to track and report on critical system updates and security compliance status of HPC Clusters. In conjunction with other configuration management systems, the reporting tool is to provide continuous situational awareness to system administrators of the compliance state of information systems. Our approach consisted of the development, testing, and deployment of an agent to collect any arbitrary information across a massively distributed computing center, and organize that information into a human-readable format. Using Splunk Enterprise, this raw data was then gathered into a central repository and indexed for search, analysis, and correlation. Following acquisition and accumulation, the reporting tool generated and presented actionable information by filtering the data according to command line parameters passed at run time. Preliminary data showed results for over six thousand nodes. Further research and expansion of this tool could lead to the development of a series of agents to gather and report critical system parameters. However, in order to make use of the flexibility and resourcefulness of the reporting tool the agent must conform to specifications set forth in this paper. This project has simplified the way system administrators gather, analyze, and report on the configuration and security state of HPC clusters, maintaining ongoing situational awareness. Rather than querying each cluster independently, compliance checking

  20. Snowflake divertor configuration studies for NSTX-Upgrade

    International Nuclear Information System (INIS)

    Soukhanovskii, V.A.

    2011-01-01

    Snowflake divertor experiments in NSTX provide basis for PMI development toward NSTX-Upgrade. Snowflake configuration formation was followed by radiative detachment. Significant reduction of steady-state divertor heat flux observed in snowflake divertor. Impulsive heat loads due to Type I ELMs are partially mitigated in snowflake divertor. Magnetic control of snowflake divertor configuration is being developed. Plasma material interface development is critical for NSTX-U success. Four divertor coils should enable flexibility in boundary shaping and control in NSTX-U. Snowflake divertor experiments in NSTX provide good basis for PMI development in NSTX-Upgrade. FY 2009-2010 snowflake divertor experiments in NSTX: (1) Helped understand control of magnetic properties; (2) Core H-mode confinement unchanged; (3) Core and edge carbon concentration reduced; and (4) Divertor heat flux significantly reduced - (a) Steady-state reduction due to geometry and radiative detachment, (b) Encouraging results for transient heat flux handling, (c) Combined with impurity-seeded radiative divertor. Outlook for snowflake divertor in NSTX-Upgrade: (1) 2D fluid modeling of snowflake divertor properties scaling - (a) Edge and divertor transport, radiation, detachment threshold, (b) Compatibility with cryo-pump and lithium conditioning; (2) Magnetic control development; and (3) PFC development - PFC alignment and PFC material choice.